Search

Introduction: Currently, there is a lack of consensus on the fixed dosage of RAI to be administered for this purpose between the main guideline frameworks set forth by the American Thyroid Association (ATA), Society of Nuclear Medicine and Molecular Imaging (SNMMI), European Association of Nuclear Medicine (EANM) and the European Thyroid Association (ETA). In this retrospective study, we will investigate the effectiveness of using a standard dose of 15 mCi ±10% of RAI in the treatment of Graves'., Methods: A retrospective chart review was conducted for the period between 1 May 2014 and 2 September 2020, to identify patients diagnosed with hyperthyroidism due to Graves' disease. The patients were grouped based on outcome and assessed for the efficacy of the dosage of 15 mCi ±10% of RAI in a successful treatment., Results: Sixty-seven patients were identified that met the inclusion criteria between 1 May 2014 and 2 September 2020. Of the 67 RAI ablations; 60 patients became hypothyroid [60/67, (89.55%)], 2 euthyroid [2/67, (2.99%)] and 5 remained hyperthyroid [5/67, (7.46%)]., Conclusions: For the treatment of Graves' disease, the use of a standard low dose of 15 mCi ±10% has a high success rate without additional measurements or calculations beyond a standard planar image and 24-h uptake %. The adoption of a standard low dose of 15 mCi of I-131 across institutional guidelines would streamline dosage questions and eliminate the need to determine the weight of the thyroid for calculations in all RAI treatments for hyperthyroidism caused by Graves' disease., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To document the outcome of radioiodine therapy (RIT) in differentiated thyroid cancer (DTC) patients with recent contrasted computed tomography (CCT)., Methods: Eighteen patients with DTC and recent thyroidectomy who underwent RIT within 90 days after a CCT were included. Disease status following RIT and whether the expected response to RIT was achieved were documented. Disease status was classified into one of three categories based on the patient's thyroglobuline level, radioiodine scan (RIS), and other imaging modalities: no evidence of disease (NED), microscopic residual disease (MRD), or gross residual disease (GRD). Expected response to RIT was based on the overall interpretation of the referring physicians of follow up thyroglobuline values, RIS findings and clinical assessment as reflected in progress notes. Follow-up stimulated thyroglobuline and (or) RIS was performed on average 10.8 months after RIT (median 12 months). The last progress note reviewed was on average 33.3 months after RIT (median 31 months)., Results: There were 12 patients with NED, two with MRD and four with GRD. Expected response to RIT was achieved in 17 patients. In one patient, the effectiveness of RIT could not be determined., Conclusion: RIT in postthyroidectomy setting can be successfully performed within 90 days after CCT. Further research is needed to confirm our findings.

Objective: The objective of this study was to analyze the uptake of rubidium in malignant tumors., Participants and Methods: Sixteen malignant lesions were included. Two radiologists compared each lesion to four references (subcutaneous fat, lung, mediastinal blood pool, and liver) at rest and stress and scored as 1-4. Maximum standardized uptake value (SUV) in each lesion and four references, as well as ratios of lesion SUV to SUV of each of the references, were calculated at rest and stress. We assessed an agreement for scores of reader 1 versus reader 2 (inter-reader) at rest and stress, scores at rest versus stress (intrapatient) for reader 1 and reader 2, and lesion SUV and respective ratios at rest and stress using paired t-test and Bland-Altman analyses., Results: Fifteen (94%) out of 16 lesions had a score of 3 or 4 at rest or stress or both by at least one reviewer. We did not find evidence of inter-reader bias at rest or stress or intrapatient (rest vs. stress) bias for either reader. SUV ranged from 1.0 to 8.1 at rest and from 0.7 to 6.7 at stress. There was an excellent agreement between ratios of lesion SUV to lung SUV at rest versus stress. On the extreme, there was a poor agreement between ratios of lesion SUV to liver SUV at rest versus stress. Otherwise, the agreement was good for the majority of the results, and moderate for a few others., Conclusion: Malignant tumors can be readily depicted and quantified on rubidium PET/CT. Further research is needed.

Objective: The objective of this study was to collect preliminary data on the predictive value of pretherapy 18F-fluorodeoxyglucose positron emission tomography in primary renal cell carcinoma (RCC) patients undergoing neoadjuvant therapy with sorafenib., Methods: As part of a clinical trial to assess the safety and feasibility of using neoadjuvant sorafenib in patients with RCC, 26 patients [19 with clear cell RCC (ccRCC), seven with non-clear cell RCC (non-ccRCC)] underwent 18F-fluorodeoxyglucose positron emission tomography with concurrent computed tomography (CT) before commencing sorafenib therapy and 17 (13 ccRCC, four non-ccRCC) of them also at the end of sorafenib therapy. The maximal standard uptake value at baseline (SUV base) and its change from baseline after therapy (SUV diff and SUV rel) were recorded and correlated with therapy response, measured as percentage size change on CT, using Spearman's rank and Pearson's correlation coefficients., Results: SUV base and size change on CT showed a strong inverse correlation (Spearman's rank correlation coefficient=-0.72, P=0.0003; Pearson's correlation coefficient=-0.64, P=0.002) in ccRCC. There was no statistically significant correlation in non-ccRCC (Spearman's rank correlation coefficient=0.67, P=0.098; Pearson's correlation coefficient=0.46, P=0.32). In neither group was there a statistically significant correlation between change in SUV and size after commencement of treatment. All findings were limited by the small number of samples included in this analysis., Conclusion: Primary ccRCC tumors with lower SUV base are more likely to respond to neoadjuvant sorafenib, whereas this trend was not observed for non-ccRCC tumors.

Background: The role of rubidium-82 (Rb) in recognizing extracardiac diseases is minimally investigated. The aim of this study was to evaluate the frequency and incremental added value of extracardiac findings on Rb cardiac positron emission tomography/computed tomography (PET/CT) studies., Method: The study included all consecutive patients who were referred from July 2008 to June 2010 for Rb cardiac PET/CT to our institution. A blinded reader reviewed the images retrospectively to assess abnormal extracardiac PET findings., Results: Images of 406 patients (142 men; 264 women) with a mean age±standard deviation of 59.72±12.93 years (range: 18-91 years) were reviewed. Incidental extracardiac abnormalities were found in 67 of 406 patients (16.5%). Among them, eight patients had malignant etiologies (1.9%)., Conclusion: Incidental extracardiac findings were present in a significant portion of patients undergoing Rb cardiac PET/CT studies. Although most of the extracardiac findings on Rb cardiac PET/CT studies represented clinically known pathologies, these incidental findings on routine Rb cardiac PET/CT scans may have a significant clinical impact on a small number of patients, and offer the referring physician the chance to obtain additional clinically relevant information.

Objective: To evaluate the expression of glucose transporters (Gluts) 1 and 3 in Hodgkin and nonHodgkin lymphoma and to assess the association between their expression and the tumor intensity on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)., Methods: All 31 lymphoma patients in whom the histologic diagnosis was made and who had also undergone a prechemotherapy PET scan at our institution between June 2001 and December 2005 were included in this retrospective study. The percentage of tumor cells in the various lymphoma subtypes was estimated by comparison of hematoxylin and eosin stain with a lineage-associated immunohistochemical stain on the same block of tissue. Tissue specimens were stained with Glut1 and Glut3 antibodies. The percentages of Glut1+ and Glut3+ cells in the entire cell population (lymphoma cells and nonlymphomatous cells) and among the lymphoma cells were estimated. FDG PET images were reviewed and the tumor intensity was assessed by calculating the maximum standard uptake value (SUVmax). Correlation coefficients between SUVmax and the percentage of Glut1+ and Glut3+ cells in the entire cell population were calculated., Results: In all 31 cases, tumors were visible on FDG PET and positive for Glut1 and Glut3. The correlation between the percentage of Glut1+ cells and SUVmax was statistically significant across all 31 cases (r = 0.73, P<0.0001, 95% confidence interval: 0.50-0.86) and across the 25 cases of nonHodgkin lymphoma (r = 0.71, P<0.0001, 95% confidence interval: 0.44-0.87). There was no statistically significant correlation between the percentage of Glut3+ cells and SUVmax. More importantly, in 16 of 31 cases (52%), only nonlymphomatous, benign cells expressed Glut1 or Glut3., Conclusion: Intensity of lymphoma on FDG PET is likely associated with Glut1 expression. The nonlymphomatous, benign cells may play an important role in visualization of lymphoma on FDG PET.

Objective: To estimate the sensitivity of [F] fluorodeoxyglucose (FDG) positron emission tomography (PET) and to assess the expression of glucose transporter 1 (GLUT1) and proliferative index (PI) in bronchioloalveolar lung cancer (BAC)., Methods: Twenty-four patients with resected BAC underwent preoperative PET between October 1996 and February 2003. The surgical specimens were re-examined, and 18 patients who fulfilled the 1999 WHO definition for BAC were included in the study. The PET images were reviewed in order to determine the positive (PET+) and negative (PET-) tumours on PET. The pathology slides were stained with antibodies to GLUT1 and Proliferating cell nuclear antigen (PCNA) in order to determine GLUT1 expression and PI, respectively., Results: There were 13 cases of PET+ BAC (sensitivity, 72%; confidence interval, 52-93%); seven of them were GLUT1+ cases and six were GLUT1-. The stromal cell PI was significantly higher in GLUT1+ BAC compared to GLUT- BAC (50.9+/-17.1 vs. 33.2+/-14.2, P=0.0286), and higher in PET+ BAC compared to PET- BAC (45.5+/-15.3 vs. 29.6+/-19.6, P=0.0854)., Conclusion: After applying the 1999 WHO criteria, the sensitivity of PET for detecting BAC is still relatively low. Other glucose transporters such as GLUT3 likely play a role in FDG uptake in BAC. GLUT1+ or PET+ BAC tumours have a higher stromal cell PI when compared to GLUT1- BAC or PET- BAC tumours, respectively.

Objective: To measure the variability of cardiac uptake on serial whole-body F-FDG PET scans., Methods: Two hundred and eighteen whole-body PET scans were performed in 47 patients with different primary malignancies between October 1996 and April 2003 on a dedicated PET system. The number of scans per patient ranged between four and nine. Two experienced nuclear medicine physicians reviewed the scans retrospectively using the non-attenuation corrected images to assess the cardiac FDG uptake. Patients with cardiac uptake less or equal to lung uptake were assigned in the "low" uptake group, and those with cardiac uptake more than the lung uptake were assigned to the "high" uptake group. The reproducibility of cardiac uptake on serial whole-body PET scans and the effect of age, sex, weight, diabetes and primary diagnosis on cardiac uptake was evaluated., Results: There was very good reproducibility (intra-class correlation coefficient=0.77) of individual cardiac FDG uptake on serial whole-body PET scans. Diabetics (n=6) in comparison to non-diabetics were less likely to have high cardiac uptake (odds ratio (OR)=0.24, P<0.05). Patients with lymphoma (n=12) in comparison to patients with other primary diagnoses were more likely to have high cardiac uptake (OR=8.6, P<0.05). There was no association between cardiac uptake and age, sex or weight., Conclusion: Cardiac FDG uptake on whole-body PET does not appear to change significantly over time. It is likely that uptake is determined by individual characteristics; these likely include diabetes and primary diagnosis of lymphoma.