2020 Student Abstracts

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A case study confirming the reliability of Gated N13 ammonia PET/CT over Tc-99m Sestamibi D-SPECT in diagnosing cardiovascular disease

Samar Z.El-Khatib

Nuclear Medicine Technology Department, Regis College,Weston, MA

 

Rest/Stress protocols with ECG and Tc-99m SestamibiD-SPECT imaging are commonly used for the diagnosis of coronary disease, sometimes confounded by arrhythmias such as atrial fibrillation, or balanced ischemia from multivessel disease (1). More precise nuclear diagnostic techniques with higher specificity will be needed to localize heart microvascular stenosis and calcifications (3). Studies indicated that PET is the gold standard for the evaluation of microvascular dysfunction (CMD) in non-ischemic cardiomyopathies (2) (4). Rest/Stress N13 ammonia with PET/CT tests demonstrated increased accuracy namely due to the rapid and wide distribution of N13 ammonia to organs and as being extracted from coronary capillaries into myocardial cells. Both techniques were applied in sequence to the same case reviewed in this abstract.

 

Methods: Journal articles on the comparative use of Tc-99m Sestamibi with D-SPECT and N13 ammonia PET/CT in CMD were reviewed. In addition, a case of a 76 year old male who underwent MP MIBI on a D-SPECT followed by an N13 ammonia PET/CT 45 days later was reviewed.

 

Results: ECG readings of the reviewed case indicated atrial fibrillation (AF). This was followed with an MP study by injecting 6.6 mCiTc-99m Sestamibi at rest. Forty-five minutes later,DSPECT images were taken as per the departmentprotocol. For the stress portion of the exam, the patient exercised for 3:25 minutes of a Standard Bruce protocol and was injected at 85% of the maximum age-predicted heart rate(MPHR) with 18.4 mCi of Tc-99m Sestamibi. The symptomatic response to exercise was non-ischemic, and the ECG indicated no significant ST-T changes. Another set of images were acquired at stress after recovery as per the department protocol. The LV and RV sizes were found to be normal as well. No regional perfusion defects or ischemia were noted (Figure 1). As symptoms persisted an N13 ammonia with PET/CT was conducted after 45 days. A rest/stress protocol was performed with the patient having a rest dose of 3.9 mCi N13 ammonia and a stress dose of 13.2 mCi N13 ammonia. The patient was stressed with a pharmacologic vasodilator of 0.4 mg Regadenoson (Lexiscan). Both testing modalities confirmed the absence of large vessel coronary disease or prior infarct.. However, the Gated N-13 ammonia PET/CT test detected 31% resting LV ejection Fraction (EF) while the minimal threshold is 50%, Global myocardial flow reserve(MFR) was also low (1.47 vs >2). Moreover, the PET/CT images revealed extensive multivessel coronary artery calcification after a calcium score with abnormal global stress MFR and abnormal global LV function (Figure 2). Overall, these imaging studies confirmed decreased LV function in the setting of microvascular disease, with an absence of large vessel disease.

 

Conclusion: The reviewed case had microvascular dysfunction due to calcification of coronary microvessels which was not detected by gated Tc-99m SestamibiD-SPECT. The N13 ammonia PET/CT technique was shown to be more specific in diagnosing hidden CMD defects and multivessel CAD. Further reviews will be needed to verify the feasibility of early use of N13 ammonia with PET/CT in order to save time and reduce costs.

 

Acknowledgements:

The author recognizes the contribution and support provided by the technologists at the Dept. of Nuclear Medicine at Brigham and Women’sHospital, Boston, MA.

Special thanks for LeonasNalivaikaMBA,CNMT(RS),ARRT(N)(BD),FSNMMITS

Program Director/Assistant Professor Nuclear MedicineRegis College,

Kyle Seaver, CNMT, RT(N), NMTCB(CT)Lead Nuclear Medicine Technologist,

And Karla SirianniSenior Clinical Exercise Physiologist, MS, RCEPNon-Invasive Cardiovascular Imaging.

 

Submitted by:

Samar Z. El-Khatib

References:

1- Ammann, Peter, M.D et al. Characteristics of patients with Abnormal Stress Technetium Tc99m Sestamibi SPECT Studies without Significant Coronary Artery Diameter Stenoses. Clin. Cardiol. 26,521-524 (2003).

 

2- Bravo, Paco E.,MD , et al. Role of PET to Evaluate Coronary Microvascular Dysfunction in Non-ischemic Cardiomyopathy. 455-464. V 22(4). ( 2017).

 

3- Di Carli, Marcelo E, MD , et al. Cardiac PET/CT for the Evaluation of Known or Suspected Coronary Artery Disease. RadioGraphics. 1239-1254, V 31(5). ( 2011).

 

4- Al- Mallah, Mouaz H., MD, MSC, FACC, et al. Assessment of Myocardial Perfusion and Function with PET and PET/CT. J NuclCardiol., 498-513. V17(3). (2010).

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Redesigning Nuclear Medical Imaging: One Approach to Multi-Detectors

Lauren M. Pettigrew

MCPHS University, Boston, MA

Nuclear Medicine Technology Program

 

In the rapidly progressive field that is Medical Imaging and Therapeutics, the desire to enhance and personalize treatment is at an all-time high in attempt to evade expensive and invasive procedures. With the support of rapidly evolving medical technology it was only a matter of time before the traditional two-headed gamma cameras became outdated. The VERITON-CT, made by Spectrum Dynamics Medical, is considered by some to be cutting-edge technology for hybrid digital nuclear medicine scanners. With the revolutionary redesigning of the overall physicality of the machine, its function has the potential to drastically enhance and standardize results. This multi-purpose SPECT-CT scanner stands out in a multitude of ways comparatively in terms of design, structure and function.

 

Methods: As a student observer I wasgiven theability to study the veracity of implementing this new machine into clinical practice. The VERITON-CT was installed just 3 months prior to the start of fall student rotations and as a student observer was given the opportunity to comparatively study and research the theocraticals of this machine while also first-hand witnessing the clinical application of this new multi-detector camera in a high-volume clinical setting.

 

Results: The first and fore most the overall design and the appearance alone shows off the radical modifications made to the hardware of this machine. The most obvious and frequently mentioned visual change in design aspect “is the 12 swiveling high-resolution detectors covering an axial field-of view of 32 cm and assembled with a helicoidal CT in a hybrid system” (Imbert et al., 2019a, p. 1).  Spectrum Dynamics Medical calls this detector technology CZT (Cadmium Zinc Telluride) crystals that have a ring configuration with wide-angle square hole tungsten collimators. With latest researching proving “consecutive whole-body recordings of 18 min each were obtained in conventional planar mode and in 3D mode using the hybrid SPECT/CT system VERITON CZT-camera” (Saifeddine et al., 2019 p.1).Having 12 retractable detectors and auto-positioning laser systems is optimal for high resolution and high-quality images due to increased volumetric sensitivity. “The field-of-view length is 320 mm and can be focused for single-organ acquisitions or used for whole-torso scanning. The optimized collimator design results in higher volumetric sensitivity (0.0192%) than dual-head camera systems with conventional collimators (,0.01%). Additionally, with image resolution recovery, this system achieves high spatial resolution (4.3 mm) … The VERITON-CT system is configured with up to a 128-slice CT camera, allowing both calcium scoring and CT angiography studies” (Slomka et al., 2019 p1). “The quality of the brain perfusion images recorded with the high-sensitivity VERITON CZT-camera is dramatically higher than that provided by a conventional Anger camera and rather close to that observed for the 18F-FDG brain images from an analog PET, thereby providing a potential alternative to 18F-FDG PET for functional brain imaging” (Imbert et al., 2019b, p. 1).

 

Conclusion: After evaluating distance reducing detectors, laser positioning, and sensitivity enhancing CZT crystals it’s clear that the innovations being made by Spectrum Dynamics Medical are conducive to improving all aspects of conventional gamma cameras. From the physics and instrumentation of the physicality of the machinery effecting overall function and how proper monitoring and daily testing is still required to preserve uniformity of this new design all while maintaining the priority of minimizing patient radiation dose. The veracity of implementing this new machine into clinical practice seemingly concludes to prove as a beneficial improvement compared to conventional gamma cameras. 

 

Summited by:

Lauren M. Pettigrew

 

References:

Imbert L., Jurczak J., Perrin M., Karcher G., Pierre-Yves M. & Verger A. (2019b). Image quality of brain SPECT recorded with the whole-body VERITON CZT camera and a focal brain configuration of detectors, as compared with conventional SPECT and PET systems. The Journal of Nuclear Medicine, 60 (1) 1395.

 

Slomka P., Miller R., Lien-Hsin H., Germano1 G. &Bermanm D. (2019).  Solid-State Detector SPECT Myocardial Perfusion Imaging. The Journal of Nuclear Medicine, 60 (9).

 

Nuclear Myocardial Perfusion Imaging: The Need for Both Stress and Rest Tests

Michael Le Jr.

MCPHS University, Boston, MA

Nuclear Medicine Technology Program

 

Objectives: Coronary Artery Disease (CAD) is the number one cause of death in the United States, with an expectancy rate of 49% for men, and 32% women after the age of 40. (Vesely&Dilsizian, 2008) CAD is the narrowing or blocking of coronary arteries which can restrict blood flow to the heart muscle. Early detection of CAD to localize possible ischemia and/or myocardial infarction is the primary objective of cardiac testing. Myocardial perfusion is a nuclear medicine imaging procedure that uses radiotracers during rest and stress tests to detect the heart’s function and blood flow by assessing potential blockages inside the coronary arteries.Although much research has been done, literature that was found provided information about the need for myocardial perfusion, and how it can be helpful with diagnosing myocardial defects, but not the need for both stress and rest tests. There’s a dearth of literature that claims there was a need for both stress and rests, which is the reasoning behind this critical literature review. Two studies were reviewed, proving that both stress and rest tests are necessary.

 

Methods: Study 1 examined 153 patients were evaluated for suspected coronary artery disease were examined with the use of nuclear medicine myocardial perfusion. 107 patients (70%) were identified to have defects. Tc99m-Tetrofosmin was used for both rest and stress tests. 62 of the patients were diagnosed with infarction, 16 patients had classified ischemia, and 29 patients were normal. (Fleischmann, 2003)Study 2 examined 179 patients with suspected coronary artery disease. 76 of the patients were diagnosed with fixed defects (infarction), and 103 patients had reversible defects (ischemia). (Elhendy et al., 2005)

Results: The total of both perfusion imaging studies shows that 138 patients out of 332 total (42%) were diagnosed with myocardial infarction. This proves that without both rest and stress studies approximately 42% of patients would not be able to be properly diagnosed. Stress tests provide defects that are not seen in resting conditions. When a patient with coronary disease is at rest, blood flow in a diseased coronary artery is not decreased until coronary stenosis exceeds 85-90% of the luminal diameter. Although patients with coronary artery disease have symptoms, their myocardial blood flow is mostly homogenous, even if they have severely narrowed coronary arteries. Stress on the heart, or in this case, exercise or pharmaceutical induced stress, will cause heterogeneous blood flow to the heart, confirming the possible presence of myocardial infarction/ischemia. Essentially without the complimenting stress and rest portion of the test, patients would not have been identified within these diagnostic categories. This information is a literature review of why the stress and rest portion of myocardial perfusion is necessary.

Conclusions: In patients with suspected CAD, it is important to perform both rest and stress tests to determine the effect of physical stress on the flow of blood through the coronary arteries and heart muscle compared to during rest. Myocardial perfusion has shown to be beneficial to the diagnosis of coronary artery disease but without both tests, it would be near impossible to differentiate between ischemia or myocardial infarction. Although many other researchers say oppose these ideas, this literature review validates that stress tests are necessary.

 

Submitted by: Michal Le

 References:

Elhendy, A., Hurrman, A., Schinkel, A., Bax, J., Van Domburg, R., Valkema, R., . . . Poldermans, D. (2005). Association of Ischemia on Stress99mTc-Tetrofosmin Myocardial Perfusion Imaging with All-Cause Mortality in Patients with Diabetes Mellitus (10th ed., Vol. 46). Journal of Nuclear Medicine.

Fleischmann, S. (2003). P2304 Gated 99mTc-tetrofosmin single-photon emission computed tomography for differentiation of myocardial scar from attenuation artifact. European Heart Journal,24(5), 444. doi:10.1016/s0195-668x(03)95298-5

Vesely, M. R., &Dilsizian, V. (2008). Nuclear Cardiac Stress Testing in the Era of Molecular Medicine. Journal of Nuclear Medicine, 49(3), 399–413. doi: 10.2967/jnumed.107.033530

 

Zaret, B. L., &Wackers, F. J. (1993). Nuclear Cardiology. The New England Journal of Medicine, 329.

 

Potential improvements in patient compliance in F-18 FDG PET/CT. Imaging with the incorporation of patient and interprofessional communication.

Nicole E. LaBrecque

MCPHS University, Boston, MA

Nuclear Medicine Technology Program

 

F-18 FDG-PET/CT imaging has started to become the powerhouse in the field of nuclear medicine. It is a useful imaging modality utilized in millions of oncology patients. In addition to its use in detection and localization of metastatic disease, F-18 FDG-PET/CT can be used for many different applications for a vast spectrum of patients. However, F-18 FDG-PET/CT protocols require specific patient preparation guidelines to adhere to that include diet and fasting regulations to obtain the highest quality images that lead to accurate interpretation. Thus, in what ways can nuclear medicine technologists and physicians better inform patients of preparation instructions for F-18 FDG-PET scans for the best possible imaging quality?

 

Methods: Various studies evaluate this common issue that arises in nuclear medicine practice. Study format varies from a case report to group comparison research, both with similar findings supporting literature reviews regarding F-18 FDG-PET/CT patient preparation protocols and image quality. All studies were published between the years 2013 and 2019.

 

Results: A case report of a 79-year-old male compared to scans performed on the same day. The initial scan was obtained after the patient had a light meal 1-hour prior. The second scan was obtained 5 hours later, with the patient fasting, and showed FDG uptake that was not present in the initial scan; the second scan further confirmed the presence of bladder cancer that was not detected in the initial scan. In addition to findings of variable FDG uptake utilized in cancer patients for metastatic disease localization, the same principles were seen with varying FDG uptake in cardiac sarcoidosis patients. A different study examined the effects of structured patient protocol on myocardial uptake in patients with cardiac sarcoidosis. The study was conducted by group comparison; group one received a simple meal suggested plan, whereas group two received structured diet instructions and a list of foods in which were approved and non-approved. In addition, group two received more in depth follow up from hospital staff. Group two showed to have significantly improved images with ideal amounts of myocardial uptake. Both studies expose how effective and important patient preparation is for accurate imaging techniques.

 

Conclusion: Non-adherence to diet and fasting plans can alter FDG uptake, leading to poor image quality and misdiagnosis. Detailed and structured patient preparation plans must be provided to patients to ensure the best quality images. Findings from both studies further support the guidelines outlined in a literature review on F-18 FDG PET/CT patient preparation found in the Journal of Nuclear Medicine Technology. In order to provide the best possible care to future patients, it is essential to improve interprofessional communication, as well as thorough communication with the patient prior to appointments.

 

Summited by:

Nicole LaBrecque

References

Christopoulos, G., Jouni, H., Acharya, G. A., Blauwet, L. A., Kapa, S., Bois, J.,Chareonthaitawee, P.,            &Rodriguez-Porcel, M. G. (2019). Suppressingphysiologic 18-fluorodeoxyglucose uptake in            patients undergoingpositron emission tomography forcardiac sarcoidosis: The effect of a

structured patient preparation protocol.  Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology.https://doi.org/10.1007/s12350-019-01746-4

d’Amico, A., Przeorek, C., &Turska-d’Amico, M. (2013). Repetition of FDG PET study in the

same day after appropriate patient preparation revealed two new cancer localizations: a case report. Nuclear Medicine Review, 16(2), 88–90. https://doi.org/10.5603/NMR.2013.0041

Surasi, D. S., Bhambhvani, P., Baldwin, J. A., Almodovar, S. E., & O’Malley, J. P. (2014).

18F-FDG PET and PET/CT Patient Preparation: A Review of the Literature. Journal of Nuclear Medicine Technology, 42(1), 5-13. https://doi.org/10.2967/jnmt.113.132621

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The use of theranostics in nuclear medicine.

 Destiny J. Thompson

 Gateway Community College, New Haven, CT

Nuclear Medicine Program

 

Objectives: As cancer increases amongst the world population, the need for treatment directly increases. The introduction of theranostics creates a personalized treatment plan for individuals which is designed to target specific cancer cells at the molecular level. Technetium 99m Pertechnetate and Gallium 68 Dotatateare commonly used in theranostics in nuclear medicine for visualization of tumors. Theranostics is pivotal in treatment as it acts as a blueprint for calculating the proper radiopharmaceutical, dose, and risk factors.

 

Methods: A 34-year-old male underwent an I-131 post ablation thyroid whole body scan during treatment for papillary cell carcinoma post thyroidectomy. A capsule of 104.9 mCi of I-131 was administered orally. Five days later, the patient returned and images were taken revealing an area of increased uptake on the lower right leg. Whole-body, static spot, and SPECT images were taken to rule out contamination or artifact.

 

Results: SPECT/CT imaging confirmed that the area of increased uptake was in fact the bone marrow of the right tibia proximal diaphysis and was suspected to be osseous metastasis.Most often, thyroid cancer metastasizes to tissues proximal to the thyroid. Once cancer of the thyroid is detected and surgery has been performed, I-131 ablation therapy can be used to permanently damage any of the remaining thyroid tissue. However, since I-131 goes to the thyroid, tissues outside of the proximity are less affected by the dose. The further away the metastatic tumor, the lower the chances of a good outcome.

 

Conclusions: Theranostics creates a personalized treatment plan for individuals including those of thyroid cancer.It also helps patients avoid going through tough treatment options like chemo and invasive surgeries. Theranostics of I-131 thyroid ablation post thyroidectomy plays a substantial role in the prognoses of these patients. The five-year survival rate for thyroid cancer is nearly 98%, with most surviving longer.

 

Submitted by:

Destiny J. Thompson

 

A literature review of the theranostic pair Ga-68 DOTATATE and Lu-177 DOTATATE.

 Kaitlyn M. Gutmann

 MCPHS University, Boston, MA

Nuclear Medicine Technology Program

 

One of the newest forms of advanced therapy gaining popularity is theranostics, which is the combination of diagnostic imaging and therapeutic treatment. The Ga-68 DOTATATE and Lu-177 DOTATATE pair is quickly becoming a top combination in the field. Lutathera (Lu-177 DOTATATE) was FDA approved in 2018 for the treatment of advanced gastroenteropancreaticneuroendocrine tumors (GEP-NETs) accompanied by diagnostic imaging with Ga-68 DOTATATE. DOTATATE is a somatostatin analog that was chosen as the pharmaceutical component because GEP-NETs have an over-expression of somatostatin receptors.

 

Methods:Multiple journal articles were reviewed on the effectiveness of Lutathera in the treatment of neuroendocrine tumors. Additional articles were reviewed on the impact of imaging with Ga-68 DOTATATE in the management of treatment with Lutathera.

 

Results: Lutathera is administered intravenously over thirty to forty minutes as a dose of 200 mCi every 8 weeks for a total of 4 doses. Ga-68 DOTATATE detects GEP-NETs with a high level of accuracy when used in PET/CT and thus affects how the patient’s treatment is managed moving forward. These scans are performed after treatment 2 and treatment 4, as well as every 24 weeks for 3 years after treatment is completed.The NETTER-1 phase 3 clinical trial showed a 79% reduction in disease progression and death resulted from Lutathera when compared to the previous standard of treatment long-acting Octreotide. Imaging with Ga-68 DOTATATE captured these results better than imaging with the previous standard In-111 pentetreotide.

 

Conclusion:Upon review of all the articles, it is evident that this theranostic pair has outstanding outcomes. Ultimately, this form of targeted medicine is making breakthroughs in the treatment of poorly prognosed cancers giving patients a longer and greater chance of survival with a significant reduction in treatment side effects.

 

Submitted by:

Kaitlyn M. Gutmann

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Lutathera therapy on gastroenteropancreatic neuroendocrine tumors

 Tyler Bradley

 Gateway Community College, New Haven, CT

Nuclear Medicine Technology Program

 

Objective: On January 26,2018, the FDA approved Lutetium 177 Dotatate a radiolabeled somatostatin analog, for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GET- NETs). GET-NETs are neoplasms that arise from cells of the endocrine and nervous systems. Peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analog Lu-177 Dotatate has emerged as a promising treatment option in patients with non-resectable and chemotherapy-refractory GET-NETs.

 

Methods: From September 2012 through January 2016, a total of 229 patients underwent randomization at 41 sites. 221 of the 229 patients who underwent randomization received at least one dose of trial treatment. 200 mCi of Lutathera was administered on four separate occasions with 8-week intervals between administrations. An amino acid infusion was given on the starting day, 30 minutes prior to the administration of Lutathera and continuing for 4 hours after for renal protection.

 

Results:23 events of disease progression or death had occurred in the 177Lu-Dotatate group and 68 such events had occurred in the control group. The estimated rate of progression-free survival at month 20 was 65.2%. Studies also showed patients treated with Lutetium 177 Dotatate lived substantially longer without their cancer progressing than patients who received other forms of treatment. Side effects from the therapy were rare, but including low levels of blood cells, kidney damage, liver damage, abnormal levels of hormones in the body, and infertility.

 

Conclusion:Lu-177 Dotatate therapy shows promising results in the management of GET-NETs compared to previous therapies with high dose octreotide. Lu-177 Dotatate is a safe and effective therapy option for patients with progressive NETs who showinitial response to a prior PRRT cycle.

 

Submitted by:

Tyler Bradley

 

Multisite experience of the safety, detection rate and diagnostic performance of fluciclovine (18F) positron emission tomography/computerized tomography imaging in the staging of biochemically recurrent prostate cancer.

 Joseph Merid

 Gateway Community College, New Haven, CT

Nuclear Medicine Technology Program

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Objectives: Recurrence of prostate cancer is common among men previously diagnosed and treated for prostate cancer. Imaging or screening of treated prostate cancer patients is critical to preemptive treatment of recurrent cancer. The study uses data from four different clinical locations to examine the safety and performance/detection rate of Positron Emission Tomography/ Computerized Tomography (PET/CT) using fluciclovine (18F) as a diagnostic agent.

 

Methods: 596 patients (median age 67, 371 Norwegian, 186 white) across 4 clinical locations between 11-28-07 and 8-28-14 were administered with fluciclovine (18F).  PET/CT images were used to detect recurrent cancer in the prostate bed and pelvic lymph node regions. The resulting detection rates were stratified by prostate-specific antigen concentration baseline values. Also,performance assessment was based on the results’ comparison with the standard of histological reference using 143 prior scans.

 

Results: PET/CT using fluciclovine (18F) had an overall detection rate of 67.7% across all four sites, with 57.5% of detections in the prostate region and 42.4% of detections in the pelvic lymph node region. Patients across all demographics showed high toleration for the detection agent in initial and repeat administrations. PET/CT using fluciclovine (18F) was effective in detection at all four PSA concentration quartiles (<.79, .8-2.03, 2.04-6, and >6 ng/mL).

 

Conclusions: PET/CT is effective in the detection of prostate cancer recurrence with a low risk of side effects and high patient toleration. It can detect recurrence through a large range of prostate specific antigen concentrations.

 

Submitted by:

Joseph Merid

 

Nuclear medicines role ingenetherapyusingviral vectors.

 Juliet Cabezas

 Gateway Community College, New Haven, CT

Nuclear Medicine Technology Program

 

Objective: Gene therapy can manipulate the expression of genes in human cells. Itaims to treat genetic disorders by repairing damaged genes ordestroying damaged cells. Clinical trials on animals have shown diseases at a pre-symptomatic stage. It has been successfulin treating cancer, cystic fibrosis, heart diseaseand AIDS. This is accomplished by using certain viruses as vectors since they can deliver the new gene by infecting the targetcell. This method of therapy will allow physicians to treat a genetic disorder directly from the cell instead of using drugs or surgery.Nuclear medicine will be able to image and monitor the success of gene therapy.

 

Methods: The In-vivo gene therapy method used a prodrug activating protocolsuch as the Herpes Simplex Virus 1 – Thymidine Kinase (HSVl-tk). It includes an intratumoral injection containing a viral vector such as the retroviral vector which canfuse into the genome of multiplying cells. Adenoviral vectors will infect and express the transgene in both multiplying and non-multiplyingcells. A peak of gene expression after gene transfer will occur 1-3 days post injection.

 

Results: The effect of gene therapy and result of the prodrug activating protocolhas been evaluated by measuring changes in tumor size. This was done by imagingpatient with diagnostic doses of Iodine 124 Fialuridine(FIAU) with a gamma or PET camera. Fialuridine is a nucleoside analogthat functions as a therapy for hepatitis B virus. The whole-body radiation exposure from therapeutic doses is 3700 Megabecquerels (100 millicuries) which is within satisfactory limits based on the results of diagnostic imaging animal studies of HSV-tk expression in rats.

 

Conclusion: Viral vectors can be optimized to allow for tissue-specific targeting, site-specific integration, and efficient long-term effect of multiplying and non-multiplying cells. Perfecting gene therapy can be a way to inactivate viruses and genetic diseases implemented at birth. It is important to keep our expectations of gene therapy realistic because progress of new genetic markers may make genetic imaging in nuclear medicine a clinical possibility in the near future.

 

Submitted by:

Juliet L. Cabezas

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SPECT/CT whole body bone scan protocol. Confidently diagnosing breast and prostate cancer patients with metastatic bone lesions.

Alexia Romano

Lifespan School of Medical Imaging, Providence, RI

School of Nuclear Medicine Technology

 

Whole body bone scintigraphy is a useful and relatively inexpensive exam used in the diagnosis of osseous metastases, especially in patients with breast and prostate cancer. Although bone scans can identify abnormalities in the entire skeleton, the specificity can be limited. Traditionally bone scans consist of planar imaging with a SPECT of the region of interest if indicated. However, SPECT/CT may be utilized with whole body skeletal imaging to increase sensitivity, specificity, and accuracy, thus decreasing the number of equivocal findings, additional imaging, and the patient’s time to be confidently diagnosed.Research suggests that a whole-body bone scan with SPECT/CT protocol may be a more efficient way to differentiate and specifically identify areas of bone metastases in patients with breast and prostate cancer.

 

Methods: Journal articles were reviewed,and a literature review was conducted on retrospective studies regarding whole-body bone scintigraphy with SPECT/CT. The studies collectively consisted of 689 patients with known cancer who had either whole-body planar bone imaging, SPECT and/or SPECT/CT of localized areas or whole-body SPECT/CT(head to femurs) for staging, restaging, or suspected osseous metastases. Of these patients, 467 had been diagnosed with breast or prostate cancer and the mean age was 66 years old. In one of the studies, additional imaging reports from other modalities were used to confirm results. Images wereanalyzed by a nuclear medicine physician or radiologist and compared and/or rated in terms of correct localization, sensitivity, specificity, and overall accuracy.

 

Results: All cases showed an improvement in sensitivity, localization, and accuracy with SPECT/CT. In retrospective study with 212 patients with a history of various cancers, although primarily; prostate (70 patients) and breast (50 patients), showed a higher sensitivity with whole-body SPECT/CT at 100% versus 90.5% with targeted SPECT/CT. In an additional study, correct localization of bone lesions was found in 62% of whole-body bone scans and 76% of SPECT exams. However, SPECT/CT exams had a correct localization of 98%. The specificity for planar imaging, SPECT, and SPECT/CT was 78%, 71% and 91%. An additional retrospective study of 26 cases of women with breast cancer who had SPECT/CT in addition to planar imaging had; 94% sensitivity, 97% specificity, and 91% accuracy.

 

Conclusion: According to data, SPECT/CT is highly sensitive, specific, and accurate for diagnosing bone metastases in breast and prostate cancer patients. Due to these cancers being more likely than other types to metastasize to the bone, a specific protocol using SPECT/CT for whole-body imaging may improve clinical management of the patient and decrease the number of cases with equivocal findings and additional imaging.

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An investigation of the potential role of 18FDG PET/CT in the detection of invasive fungal infections.

C. Gadwah

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INTRODUCTION-Invasive fungal infections (IFI) have been a growing concern with haematologic malignant and immunocompromised patients. IFI cause diagnostic and therapeutic challenges for patients with metastatic neoplasms and can be life threatening if antifungal treatment is delayed or prolonged. Clinically, Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are the common radiologic procedures used to diagnose IFI.18FDG PET/CT imaging has been considered a useful tool in IFI diagnostics, however there are limited studies to support this. The objective of this paper is to determine the value of 18FDG PET/CT in the diagnosis of IFI and tocompare imaging results with conventional CT.

 

METHODS- Several journal articles were examined for background information and a literature review was conducted on retrospective and prospective case studies. The studies involved 79 immunocompromised patients with known or probable IFI; who received 18FDG PET/CT and conventional CT imaging prior to and/or following IFI diagnosis, and as a follow up during antifungal therapy. The prospective studies took place for 1-2 years depending on the effectiveness of treatment. The retrospective study patients were selected between a 10-year period using a keyword data base from Radiology Information System (RIS), standard work-up information and confirmed IFI diagnosis according to EORTC/MSG criteria. Images were evaluated qualitatively and quantitatively with the use of SUV by a trained nuclear medicine radiologist. 18FDG PET/CT and CT imaging were compared with chi-squared or Fisher exact test.

 

RESULTS:18FDG PET/CT showed equal or greater success in localizing IFI compared with CT. All patient cases with 18FDG PET/CT IFI findings matched the same areas detected by CT. Of 45 patients in the retrospective study, 18FDG PET/CT was able to detect occult infection and dissemination to another tissue in 40% and 38% of IFI patients, respectively. 40 out of the 45 patients who received both18FDG PET/CT and CT, 35% and 5% (p < .001)of dissemination sites were detected, respectively. 10 patients of a prospective study with chronic candidiasis, CT missed dissemination lesions in 6 of those patients. Two additional cases within the same study, CT detected 14 liver lesions vs 18FDG detecting 16 and FDG uptake occurred in two left lobe lesions missed by CT.  Follow-up during antifungal therapy, resulted in no recurrence of IFI, or CT showed IFI lesions still remaining; while 18FDG PET/CT showed decreased or no uptake in the same region. This suggests inactive residual IFI, antifungal therapy effectiveness and treatment can be either lowered or terminated. 18FDG PET/CT SUV values of IFI lesions ranged from .93-4.85.

 

CONCLUSION: 18FDG-IFI associated uptake was identified in areas that were previously seen or missed with conventional CT imaging, effectively demonstrating increased sensitivity for IFI compared to CT, and can be a contributing factor in diagnosing IFI in immunocompromised patients. 18FDG has an affinity for IFI; observing normalization of this isotope during antifungal therapy makes 18FDG PET/CT beneficial for monitoring treatment response in patients. Consequently, pulmonary malignant lesions have SUVmax of 2.5; in these studies, IFI can have a similar SUV having a range of .93-4.85. With 18FDG PET/CT lack in specificity, this is a complication for determining IFI from neoplasms.

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A case study evaluating the performance of F18-FDG vs F18-FET in the assessment of primary brain tumors.

 Gaetano Rizzo

 Lifespan School of Medical Imaging

 

In Positron Emission Tomography (PET), diagnosing and grading tumors in cancer patients is the primary objective. For that reason, it is very important to have a radiopharmaceutical that has a high sensitivity and specificity rate.  F18 fluoro-ethyl-l-tyrosine (FET) and 18F-fluoro-deoxy-glucose (FDG) have been used in PET imaging to asses and help diagnose patients with brain tumors.  As known, F18 FDG is taken up by cells that have a glucose metabolism due to FDG being attached to glucose.  Increased glucose metabolism is indicated where there is increased FDG uptake.  The brain is constantly working therefore there is normal FDG uptake which can make imaging the brain for tumors difficult. However, F18 FET uses radiolabeled amino acids that can cross the BBB and go straight to the brain tumor.  FET is not retained in normal brain tissue which makes it easier to delineate where brain tumors are.  This literature review observed and compared the performance of FDG vs FET.

 

Methods: Several journal articles were reviewed on The National Center for Biotechnology Information (NCBI) and the Journal of Nuclear Medicine (JNM).  A F18 FET PET/CT scan was performed on the patient followed later on by a standard F18 FDG PET/CT scan.  Once the two scans were completed, their sensitivity and accuracyto detect primary brain tumors were compared.

 

Results: The PMT’sshowed increased F18 FET uptake as 86% with little uptake in surrounding brain tissue.  On the other hand, F18 FDG had 35% uptake, making diagnosing PMT’svery difficult due to a lot of uptake in the gray matter.  In another study, PMT recurrence was detected in 20 out of 25 patients that were scanned with F18 FET.  While with F18 FDG, recurrence was only detected in 5 out of 25 patients. 

 

Conclusion:  F18 FET was more proficient than F18 FDG when it came to detecting and diagnosing PMT’s.  Diffused activity throughout the brain with F18 FDG inhibited it from clearly detecting the lesions, therefore F18 FET lead to a superior performance in detecting lesions.  Due to the growing field of PET, FET could soon be approved and used commercially nationally. 

 

A Comparative study between [18F]- FDG and [18F]-fluoro-ethyl-L-tyrosine PET-CT in diagnosing recurrent brain tumours and grading of tumours using FET preoperatively. Journal of Nuclear Medicine(2018, May).

 

Performance of 18F-FET versus 18F-FDG-PET for the diagnosis and grading of brain tumors: systematic review and meta-analysis.The National Center for Biotechnology Information (2016, March).

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Progression Free Survival: Peptide Receptor Radionuclide Therapy vs Systemic Therapy and Prevalence of Adverse Reactions from both therapies.  Which is the better choice?

Leigh-Ann DiGregorio

Rhode Island College/Lifespan School of Medical Imaging

Providence, RI

 

Objective:On January 26, 2018, the FDA approved Lutetium 177 (177Lu) for the treatment of inoperable or metastasizedsomatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs). 177Lu is one of the most commonly used radionuclides for peptide receptor radionuclide therapy (PRRT). Itis a β-emitter and has a high range and energy, but also emits γ-rays, which is ideal for imaging/monitoring tumorresponse.  Approval was based on data from NETTER-1 (NCT01578239), a randomized, multinational phase III trial [1].  The goal of this phase III trial was to evaluate the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor positive midgut neuroendocrine tumors [2].

 

 

Methods:Several journal articles were reviewed pertaining to a randomized prospective study of 229 patients with progressive, well-differentiated, locally advanced/inoperable or metastatic somatostatin receptor-positive midgut carcinoid tumors.  Of the 229 patients, 116 patients received 177Ludotatate(200 mCi) every 8 weeks up to 4 administrations,along with a long-acting octreotide (30 mg by intramuscular injection every 4 weeks); 113 patients received a high-dose LAR (60 mg by intramuscular injection every 4 weeks)[3].The primary goal was for progression-free survival.  Secondary end points included the objective response rate, safety, and side-effects.

 

Results:The most common grade 3/4 adverse reactions occurring with a greater frequency (at least 4%) among patients receiving PRRT with long-acting octreotide compared to patients receiving high-dose octreotide alone included lymphopenia (44% vs 4% ), increased gamma- glutamyltransferase levels(20% vs 16%), vomiting (7% vs 2%), nausea (5% vs 2%), elevated aspartate aminotransferase levels (5% vs 0%), increased alanine aminotransferase levels (4% vs 0%), hyperglycemia and hypokalemia (both 4% vs 2%) [3]. A median follow-up of 24 months, myelodysplastic syndrome was reported in 2.7% of patients in the PRRT group; no patients receiving high-dose octreotide LAR developed myelodysplastic syndrome [3].

The 20monthPFS in the 177Luarm was 65.2% compared to 10.8% in the control LAR arm [5].  The response rate was significantly higher in the 177Lu group (18%) compared to the control group (3%, P<0.004) [4]. 

 

Conclusions: The phase III trial provided evidence for a clinically meaningful and statistically significant increase in PFSwith limited acute toxic effects among patients with advanced midgut neuroendocrine tumorsand a significantly higher response rate when treated with177Lu dotatate combined with LAR octreotide compared to patients who received the high-dose LAR octreotide [2].

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References:

1. FDA APPROVES LUTETIUM LU 177 DOTATATE FOR TREATMENT OF GEP NETS.https://www.esmo.org/oncology-news/FDA-Approves-Lutetium-Lu-177-Dotatate-for-Treatment-of-GEP-NETs. 2018.

 

1. Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors. https://www.ncbi.nlm.nih.gov/pubmed/28076709. N Engl J Med. 2017 Jan 12;376(2):125-135.

 

3.Lutetium Lu-177 Dotatate in Gastroenteropancreatic Neuroendocrine Tumors. Stenger, Matthew, et al. https://www.ascopost.com/issues/march-10-2018/lutetium-lu-177-dotatate-in-gastroenteropancreatic-neuroendocrine tumors/?utm_source=TrendMD&utm_medium=cpc&utm_campaign=Gastrointestinal_Cancer_TrendMD_0. The ASCO Post. March 10, 2018.

 

1. Strosberg J, El-Haddad G, Wolin E, et al: Phase 3 trial of 177Lu-dotatate for midgut neuroendocrine tumors. N Engl J Med 376:125-135, 2017.

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A literary review of 123I and 131I pre-therapy whole body scan concordance with 131I thyroid ablation post-therapy whole body scan.

Molly Lumnah

 

Before a patient undergoes 131I thyroid ablation therapy,for thyroid cancer, they go for a pre-therapy whole body scan. This wholebody scan has the ability to show doctors if the cancer has spread either into the lymph nodes or to other parts of the body. 131I was the gold standard for imaging of these pre-therapy whole bodyscans before 123I was approved for use.The longer half-life allowed for imaging to be done at 48 to 72 hours allowing for better target to background clearance.123I is now the gold standard as it has a shorter half-life reducing the radiation exposure to patient, and it has a lower energy of 159keV, which is similar to that of 99mTc energy of 140keV, making it easily imaged with a gamma camera. The aim of this project is to determine whether a pre-therapy diagnostic scan with 123I or 131I is more concordant with the results of a post-therapy whole-body scan (remnant thyroid tissue, lymph node involvement, or distant metastatic disease) for thyroid cancer. 

 

Methods: Various journals were reviewedrelating to 123Iand 131Ipre-therapy imaging and its concordance to 131Ipost-therapy whole body imaging. The research in the journals were conducted by reviewing patient images of those that underwent either an 123Ior 131Ipre-therapy whole body scan and an131Ipost-therapy whole body scan. Then the images were analyzed to see how many of images resembled each other when identifying remnant thyroid tissue, lymph node involvement or distant metastatic disease (pre-therapy against post-therapy).

 

Results: Twelve patients, who had received a total thyroidectomy, were imaged pre-therapy using both 123Iand 131Ithen again post 131Itherapy. Of the twelve, nine showed remnant thyroid tissue. Six of the nine showed metastatic spread. In five studies of four patients 131Idetected metastases. Out of five studies, four had 123Imiss metastases that 131Ihad shown.

 

Conclusion:123Iis comparable to 131Ifor imaging residual thyroid. Although 123Iseems to be less concordant than 131Ifor identifying metastatic spread for thyroid cancer in pre-therapy whole body imaging when comparing with the post-therapy 131Iwhole body scan.