Re-treatment with radium-223: first experience from an international, open-label, phase I/II study in patients with castration-resistant prostate cancer and bone metastases.

BACKGROUND: Six radium-223 injections at 4-week intervals is indicated for patients with castration-resistant prostate cancer and symptomatic bone metastases. However, patients usually develop disease progression after initial treatment. This prospective phase I/II study assessed re-treatment safety and efficacy of up to six additional radium-223 injections. PATIENTS AND METHODS: Patients had castration-resistant prostate cancer and bone metastases and six initial radium-223 injections with no on-treatment bone progression; all had subsequent radiologic or clinical progression. Concomitant agents were allowed at investigator discretion, excluding chemotherapy and initiation of new abiraterone or enzalutamide. The primary endpoint was safety; additional exploratory endpoints included time to radiographic bone progression, time to total alkaline phosphatase and prostate-specific antigen progression, radiographic progression-free survival, overall survival, time to first symptomatic skeletal event (SSE), SSE-free survival, and time to pain progression. RESULTS: Among 44 patients, 29 (66%) received all six re-treatment injections. Median time from end of initial radium-223 treatment was 6 months. Forty-one (93%) reported ≥1 treatment-emergent adverse event. No grade 4-5 hematologic treatment-emergent adverse events occurred. Only one (2%) patient had radiographic bone progression; eight (18%) had radiographic soft tissue tumor progression (three lymph node and five visceral metastases). Median times to total alkaline phosphatase and prostate-specific antigen progression were not reached and 2.2 months, respectively. Median radiographic progression-free survival was 9.9 months (12.8-month maximum follow-up). Five (11%) patients died and eight (18%) experienced first SSEs. Median overall survival, time to first SSE, and SSE-free survival were not reached. Five (14%) of 36 evaluable patients (baseline worst pain score ≤7) had pain progression. After 2 years of follow-up, 28 (64%) patients died, and the median overall survival was 24.4 months. CONCLUSIONS: Re-treatment with a second course of six radium-223 injections after disease progression is well tolerated, with minimal hematologic toxicity and low radiographic bone progression rates in this small study with limited follow-up. Favorable safety and early effects on disease progression indicate that radium-223 re-treatment is feasible and warrants further evaluation in larger prospective trials.

The value of gallium imaging after therapy for Hodgkin's disease.

BACKGROUND: Although it is used widely, the value of gallium imaging in managing Hodgkin's disease remains unclear. METHODS: A retrospective review of gallium imaging and treatment outcome in 60 patients with Hodgkin's disease treated between January 1990 and July 1995 was conducted. The minimum follow-up was 1 year. RESULTS: Based on gallium imaging, 46 patients were in complete remission (CR) after initial treatment, 10 were in partial remission (PR), and 4 had persistent or progressive disease (NR). Ten of 29 patients (34%) with gallium CR after chemotherapy subsequently recurred, compared with no recurrences in 17 patients receiving initial radiotherapy or combined chemoradiation. Eight of ten patients received further therapy after gallium PR, and nine patients remained disease free at last follow-up. Survival did not differ in patients achieving a gallium CR or PR. CONCLUSIONS: Gallium-67 imaging may help confirm the presence of active Hodgkin's disease, but was unreliable in defining disease remission after chemotherapy in this study population. Patients with a gallium PR may still have a good prognosis after additional therapy.