The Impact of Posttreatment Imaging in Peptide Receptor Radionuclide Therapy.

Posttreatment imaging of γ-emissions after peptide receptor radionuclide therapy (PRRT) can be used to perform quantitative dosimetry as well as assessment response using qualitative measures. We aimed to assess the impact of qualitative posttreatment imaging on the management of patients undergoing PRRT. Methods: In this retrospective study, we evaluated 100 patients with advanced well-differentiated neuroendocrine tumors undergoing PRRT, who had posttreatment SPECT/CT imaging at 24 h. First, we evaluated the qualitative assessment of response at each cycle. Then using a chart review, we determined the impact on management from the posttreatment imaging. The changes in management were categorized as major or minor, and the cycles at which these changes occurred were noted. Additionally, tumor grade was also evaluated. Results: Of the 100 sequential patients reviewed, most (80% after cycle 2, 79% after cycle 3, and 73% after cycle 4) showed qualitatively stable disease during PRRT. Management changes were observed in 27% (n = 27) of patients; 78% of those (n = 21) were major, and 30% (n = 9) were minor. Most treatment changes occurred after cycle 2 (33% major, 67% minor) and cycle 3 (62% major, 33% minor). Higher tumor grade correlated with increased rate of changes in management (P = 0.006). Conclusion: In this retrospective study, qualitative analysis of posttreatment SPECT/CT imaging informed changes in management in 27% of patients. Patients with higher-grade tumors had a higher rate of change in management, and most of the management changes occurred after cycles 2 and 3. Incorporating posttreatment imaging into standard PRRT workflows could potentially enhance patient management.

Intraarterial Peptide Receptor Radionuclide Therapy Using 90Y-DOTATOC for Hepatic Metastases of Neuroendocrine Tumors.

Given the high frequency of liver metastases in neuroendocrine tumor patients, we aimed to determine whether hepatic intraarterial administration of 90Y-DOTATOC peptide receptor radionuclide therapy (PRRT) would increase treatment efficacy while reducing systemic toxicity compared with systemic toxicity from intravenous administration as previously reported in the literature. Methods: PRRT-naïve adult neuroendocrine tumor patients with liver-dominant metastases were enrolled in a prospective single-center, open-label pilot study. The patients underwent baseline PET/CT using intravenous 68Ga-DOTATOC. Then, 3.5 ± 0.2 GBq (94.7 ± 5.4 mCi) of 90Y-DOTATOC were administered into the proper hepatic artery over 30 min. The first 5 patients also received intraarterial 68Ga-DOTATOC and underwent PET/CT. All patients were followed for response (RECIST, version 1.1) (primary aim 2, safety) and toxicity (Common Terminology Criteria for Adverse Events, version 4.0) (primary aim 1, efficacy) for at least 6 mo, with optional follow-up for up to 1 y. In the subset of 5 patients who underwent both intravenous and intraarterial 68Ga-DOTATOC PET/CT, tumor SUVmax was compared between intravenous and intraarterial administration for hepatic tumors, intrahepatic tumors, and uninvolved background organs (secondary aim, intravenous vs. intraarterial uptake). Results: The study was terminated after a planned analysis of the first 10 patients because of lack of efficacy. The best response was stable disease in 90% (9/10 patients) and progressive disease in 10% (1/10 patients) at 3 mo, and stable disease in 8 of 10 patients and progressive disease in 2 of 10 patients at 6 mo. One additional patient developed progressive disease after the 6-mo follow-up period but within the optional 1-y follow-up period. No partial response or complete response was observed. The 2 patients with the highest liver tumor burden died within 6 mo of treatment, with treatment considered a possible contributor. Patients who received intraarterial administration failed to demonstrate higher uptake by hepatic metastases than patients who received intravenous administration, with a median intraarterial-to-intravenous SUVmax ratio of 0.81 (range, 0.36-2.09) on a lesion level. Conclusion: Our study found that administration of PRRT via the proper hepatic artery did not reproduce the increase in hepatic tumor uptake that was previously reported. In addition, the single treatment using 90Y-DOTATOC did not induce tumor shrinkage, indicating that more treatment cycles may be required. Possible safety concerns in patients with a high liver tumor burden should inform patient selection for future studies.

NANETS/SNMMI Procedure Standard for Somatostatin Receptor-Based Peptide Receptor Radionuclide Therapy with 177Lu-DOTATATE.

With the recent approval of 177Lu-DOTATATE for use in gastroenteropancreatic neuroendocrine tumors, access to peptide receptor radionuclide therapy is increasing. Representatives from the North American Neuroendocrine Tumor Society and the Society of Nuclear Medicine and Molecular Imaging collaborated to develop a practical consensus guideline for the administration of 177Lu-DOTATATE. In this paper, we discuss patient screening, maintenance somatostatin analog therapy requirements, treatment location and room preparation, drug administration, and patient release as well as strategies for radiation safety, toxicity monitoring, management of potential complications, and follow-up. Controversies regarding the role of radiation dosimetry are discussed as well. This document is designed to provide practical guidance on how to safely treat patients with this therapy.

Medullary Thyroid Cancer: It is a pain in the neck?

BACKGROUND: Medullary thyroid cancer (MTC) commonly presents with lymph node (LN) metastases, and has a worse prognosis than papillary thyroid cancer (PTC). Tumor size and LN involvement have been shown to affect stage of disease; however, to our knowledge, ours is the first study that attempts to correlate anterior neck pain on presentation with the extent of disease. METHODS: We performed a retrospective review of patients with MTC who underwent an operation from February 1998 through December 2008. We compared the symptom of anterior neck pain with the pathologic extent of disease. Our control group comprised patients who underwent an operation for PTC. Analysis was performed using the Fisher's exact test and the Mann-Whitney test. RESULTS: Of the 109 patients with MTC, 50 (46%) met our inclusion criteria. Of the 50 patients with MTC, 11 presented with neck pain, compared to 3 of the 50 patients with PTC (p = 0.041). Of those 11 patients, 9 (82%) had LN involvement on final pathology, as compared with 14 (36%) of the 39 without neck pain (p = 0.014). Of patients with neck pain, 18% were diagnosed at stage I to II and 82% at stage III to IV, compared to 64% at stage I to II and 36% at stage III to IV (p = 0.014). CONCLUSIONS: Our study demonstrates that more patients with MTC present with anterior neck pain than do patients with PTC and that patients with MTC and neck pain have an increased risk of LN metastases. The results of this study suggest that MTC patients, who present with concomitant neck pain, should undergo a total thyroidectomy, prophylactic bilateral central neck dissection, and ipsilateral lateral neck dissection.

Are additional localization studies and referral indicated for patients with primary hyperparathyroidism who have negative sestamibi scan results?

HYPOTHESIS: Additional imaging studies are useful to select patients who are candidates for minimally invasive parathyroidectomy, and referral is not indicated when results from a preoperative sestamibi scan are negative. DESIGN, SETTING, AND PATIENTS: Prospective analysis of 492 operations for primary hyperparathyroidism from May 2005 to May 2007 at a tertiary care center. MAIN OUTCOME MEASURES: Accuracy of imaging studies, pathologic findings, and biochemical cure. RESULTS: Among the patients, 96% were cured. Of the sestamibi scan results, 91% were positive and 82% were true-positive. Ultrasonography results were positive in 51% of patients with negative sestamibi scan results, and 43% were true-positive. Patients with positive sestamibi scan results compared with those with negative sestamibi scan results had a higher rate of single-gland disease (87% vs 63%, respectively) and lower rates of double adenoma (6% vs 22%, respectively) and asymmetric hyperplasia (7% vs 15%, respectively) (P<.001). In patients with positive sestamibi scan results compared with those with negative sestamibi scan results, there was no significant difference in the rate of ectopic parathyroid glands (18% vs 12%, respectively) but there was a significant difference in cure rate (97% vs 89%, respectively) (P=.008). CONCLUSIONS: Additional imaging with neck ultrasonography is helpful for selecting minimally invasive parathyroidectomy in most patients with primary hyperparathyroidism who have negative sestamibi scan results. Referral for parathyroidectomy may be considered in patients with negative sestamibi scan results because these results are associated with multigland disease and lower cure rates.

Results of rosiglitazone therapy in patients with thyroglobulin-positive and radioiodine-negative advanced differentiated thyroid cancer.

BACKGROUND: Rosiglitazone is a peroxisome proliferator-activated receptor (PPAR) gamma agonist that has shown promise as both an antiproliferative and redifferentiating agent for the treatment of thyroid cancer in preclinical studies. We investigated the efficacy and side effects of rosiglitazone therapy in patients with differentiated thyroid cancer of follicular cell origin that fails to take up radioiodine or is unresectable. METHODS: Twenty patients with differentiated thyroid cancer were enrolled in an open-label, phase II trial of oral rosiglitazone treatment (4 mg daily for 1 week, then 8 mg daily for 7 weeks). RESULTS: Five of 20 patients had a positive radioiodine scan after rosiglitazone treatment. Four patients had radioiodine uptake in the neck and one patient had uptake in the pelvis. Unstimulated thyroglobulin levels after rosiglitazone treatment increased in five patients, remained stable in 12 patients, and decreased in three patients. Seven patients had progressive disease on follow-up cross-sectional imaging; six patients in the size and number of lung metastasis and two patients in the size of the neck tumors. Overall, five patients had a partial response (decreased thyroglobulin or positive radioiodine uptake), three patients had stable disease (no change in thyroglobulin and radioiodine uptake status), and 12 patients had disease progression (increased thyroglobulin). By RECIST criteria, no patient had a complete or partial response to rosiglitazone treatment at 3 months follow-up. The mean follow-up time after protocol treatment was 12 months (median 12 months). CONCLUSIONS: Our findings suggest that rosiglitazone therapy may induce radioiodine uptake and reduce serum thyroglobulin levels in some patients with differentiated thyroid cancer but this did not result in clinically significant response on long-term follow-up. Moreover, no patients had response to rosiglitazone therapy by anatomic imaging studies.

Waiting for change: symptom resolution after adrenalectomy for Cushing's syndrome.

BACKGROUND: The debilitating symptoms and physical changes from Cushing's syndrome may resolve after treatment, but the time course to resolution is not well established. METHODS: Between February 1995 and May 2007, 60 patients underwent adrenalectomy for Cushing's syndrome. Pre-operative and operative variables were collected from a prospective database. Long-term follow-up was obtained via patient survey. RESULTS: Unilateral adrenalectomy was performed in 53% and a bilateral adrenalectomy in 47% of patients. Median time to diagnosis was 24 months (range, 1-384). Three percent had intra-operative complications, and 28% developed post-operative complications. Steroids were required post-operatively for a median of 30 months after unilateral adrenalectomy (range, 0-96). At a median follow-up of 3.7 years (range, 0-13.3), 85% of patients are still alive. The majority of the physical changes resolved after adrenalectomy. The time to symptom resolution varied from a few weeks to up to 4 years. Most of the physical changes resolved by a mean of 7-9 months after surgery. Quality of life improved in 78% of patients, with 68% improving dramatically (P < .001). CONCLUSION: Adrenalectomy can provide excellent palliation of the symptoms of cortisol excess and can dramatically improve patient quality of life, but both patients and physicians must know that these changes may take years.

A phase II trial of rosiglitazone in patients with thyroglobulin-positive and radioiodine-negative differentiated thyroid cancer.

BACKGROUND: Rosiglitazone is a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist that has been shown to induce differentiation, cell cycle arrest, and apoptosis in a variety of human cancers including thyroid cancer. METHODS: Ten patients with differentiated thyroid cancer were enrolled in an open-label, phase II trial of oral rosiglitazone treatment (4 mg daily for 1 week, then 8 mg daily for 7 weeks). The levels of PPARgamma receptor mRNA and protein expression were determined in the patient's neoplasm. RESULTS: Of 10 patients, 4 had positive radioiodine scans after rosiglitazone therapy with uptake in the neck in 3 patients and in the pelvis in 1 patient. After treatment, the serum thyroglobulin level decreased in 2 patients, increased in 5 patients, and was stable in 3 patients. No patient developed clinically important toxicity associated with rosiglitazone treatment. We found no relationship in the level of PPARgamma mRNA and protein expression in patients who had radioiodine uptake compared with those who did not. CONCLUSIONS: Our findings suggest that rosiglitazone treatment may induce radioiodine uptake in some patients with thyroglobulin-positive and radioiodine-negative differentiated thyroid cancer. We found no relationship between the expression level of the PPARgamma mRNA and protein in the neoplasm and radioiodine uptake status after rosiglitazone therapy, questioning the potential pathway of effect.