Efficacy and Safety of 177Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer Patients.

PURPOSE: The aim of this study was to evaluate the efficacy and safety of Lu-PSMA-617 radioligand therapy in metastatic castration-resistant prostate cancer (mCRPC). METHODS: In this prospective, single-arm, single-institutional study, 90 mCRPC patients with progressive disease (PD) on second-line hormonal therapy and/or docetaxel chemotherapy were recruited for the study. All patients underwent diagnostic Ga-PSMA-HBED-CC PET/CT, prior to inclusion for therapy. Included patients underwent Lu-PSMA-617 therapy at 8- to 12-weekly intervals. The primary end point was to assess the overall survival. The secondary and cosecondary end points included biochemical response assessment as per the Prostate Cancer Working Group 3 criteria, progression-free survival, radiological and molecular response criteria, clinical response, safety profile, and disease control rates. All the outcome parameters were evaluated in 90 patients except for the radiographic and molecular response, which was evaluated in 69 patients. RESULTS: The median age of patients was 66.5 years (range, 30-88 years). The median activity administered per cycle was 3.7 to 8 GBq ranging from 1 to 7 cycles, and patients were followed up over a median duration of 28 months. At 2- to 3-month interval after the first therapy and the end of the assessment, greater than 50% decline in prostate-specific antigen was observed in 32.2% and 45.5%, respectively. Univariate analysis did not reveal any variables such as prior therapies, laboratory parameters, concomitant hormonal therapy, and SUV patient parameters associated with prostate-specific antigen decline. Radiographic response by diagnostic CT revealed partial remission in 23% (16/69), stable disease in 54% (37/69), and PD in 23% (16/69) of patients. Molecular tumor response by PET Response Criteria in Solid Tumor 1 criteria revealed 19 (27.5%) of 69 patients with partial remission, 30 (43.5%) of 69 with stable disease, and 20 (29%) of 69 with PD. The disease control rates according to the radiographic and molecular response were 77% and 71%, respectively. The median overall survival and median progression-free survivals were 14 and 11.8 months, respectively. Toxicities related to radioligand therapy were low and transient with no serious adverse effects. CONCLUSIONS: Lu-PSMA-617 radionuclide therapy is a safe and effective approach to the treatment of mCRPC patients.

Cocktail Therapy of 177Lu-PSMA-617 and 177Lu-EDTMP in Patients With mCRPC: A Proof-of-Principle Application.

Prostate cancer is the second most common primary tumor affecting men worldwide. Among them, 10-20% develop castration resistant prostate cancer (CRPC). Ga-PSMA-PET/CT is an important theranostic agent for the evaluation of CRPC to assess the feasibility of treatment with Lu-PSMA-617 which is a novel therapeutic agent. Interestingly, in certain cases, we have observed non-PSMA-avid lesions despite raised sPSA levels. In this regard, we present a case of cocktail therapy applied using Lu-PSMA-617 and Lu-EDTMP therapy in a 38-year-old male CRPC patient with both soft tissue and extensive skeletal metastases.

Intermediate-risk differentiated thyroid carcinoma patients who were surgically ablated do not need adjuvant radioiodine therapy: long-term outcome study.

OBJECTIVE: The mute question is whether patients with DTC of intermediate risk of recurrence, second most common presentation, who were surgically ablated in the first place, ever needed adjuvant RAI therapy? This study exclusively evaluated the long-term outcome in intermediate-risk patients with DTC. DESIGN: Two-arm retrospective cohort study conducted between years 1991 and 2012. SETTING: Institutional practice. PATIENTS: Intermediate-risk DTC patients, with pathologically proven T1/2 N1 M0, T3 with/without N1 M0 disease, with a minimum follow-up of 12 months, were included. Of 254 patients who fulfilled the inclusion/exclusion criteria, 125 patients were surgically ablated (Gr-I) and 129 patients had significant remnant and/nodal disease (Gr-II). No radioiodine in Gr-I and adjuvant RAI therapy was administered in Gr-II patients. MEASUREMENTS: Baseline characteristics were compared and overall survival, event-free survival, disease-free survival/overall remission rates and recurrence rates were calculated for both the groups. RESULTS: All baseline patient characteristics were comparable except 24-h RAIU between two groups. Depending on adjuvant radioiodine therapy outcome, Gr-II patients were subclassified as Gr-IIa (ablated) and Gr-IIb (not ablated). With a median follow-up duration of 10·3 years (range: 1-21 years), 12/125 (9·6%) patients had disease recurrence and 10 (8%) showed persistent disease in Gr-I. In Gr-IIa, 6/102 (5·9%) patients recurred but only one of them was successfully ablated with (131) I, and 5 (4·9%) had persistent disease. However, in Gr-IIb, 27 patients who failed first-dose adjuvant RAI therapy, 8/27 (29·6%) showed persistent disease (P = 0·000). Overall survival was 100%; however, disease-free survival rates were 92% and 90%, in Gr-I and Gr-II, respectively. CONCLUSION: Intermediate-risk surgically ablated patients do not need adjuvant RAI therapy and patients who failed to achieve ablation with first dose of (131) I may be dynamically risk stratified as high-risk category and managed aggressively.