Clinical Outcomes for Patients With Gleason Score 10 Prostate Adenocarcinoma: Results From a Multi-institutional Consortium Study

Radioactive Iodine-125 in Tumor Therapy: Advances and Future Directions

Radioactive iodine-125 (I-125) is the most widely used radioactive sealed source for interstitial permanent brachytherapy (BT). BT has the exceptional ability to deliver extremely high doses that external beam radiotherapy (EBRT) could never achieve within treated lesions, with the added benefit that doses drop off rapidly outside the target lesion by minimizing the exposure of uninvolved surrounding normal tissue. Spurred by multiple biological and technological advances, BT application has experienced substantial alteration over the past few decades. The procedure of I-125 radioactive seed implantation evolved from ultrasound guidance to computed tomography guidance. Compellingly, the creative introduction of 3D-printed individual templates, BT treatment planning systems, and artificial intelligence navigator systems remarkably increased the accuracy of I-125 BT and individualized I-125 ablative radiotherapy. Of note, utilizing I-125 to treat carcinoma in hollow cavity organs was enabled by the utility of self-expandable metal stents (SEMSs). Initially, I-125 BT was only used in the treatment of rare tumors. However, an increasing number of clinical trials upheld the efficacy and safety of I-125 BT in almost all tumors. Therefore, this study aims to summarize the recent advances of I-125 BT in cancer therapy, which cover experimental research to clinical investigations, including the development of novel techniques. This review also raises unanswered questions that may prompt future clinical trials and experimental work.

Outcomes with brachytherapy based dose escalation for gleason 8 versus 9-10 prostate cancer: An NCDB analysis

INTRODUCTION

The addition of brachytherapy (BT) in high risk prostate cancer is supported by Level 1 evidence. Whether all high risk patients benefit from BT to the same extent is unknown. The National Cancer Database (NCDB) was used to investigate overall survival (OS) differences between GS 8 and 9-10 treated with external beam radiation (EBRT) only or BT +/- EBRT.

MATERIALS AND METHODS

We included localized prostate adenocarcinoma definitively treated with radiation between 2004-2014. Patients were stratified into various radiation treatment groups: EBRT 7560 - 8640 cGy, EBRT 5940 - 7540 cGy, and BT +/- EBRT. All EBRT only and BT +/- EBRT patients received ADT. A multivariable Cox proportional hazard model was used to assess OS. Propensity score matching was used to account for differences between groups. Median survival was determined based on Kaplan-Meier survival curves.

RESULTS

30,698 patients were included. On multivariable analysis among GS 8 patients, BT was associated with improved OS compared to 7560 - 8640 cGy (HR-0.80 (95% CI 0.70-0.92, P = 0.002). In Gleason 9-10 BT did not result in improved OS compared to 7560 - 8640 cGy (HR- 0.91 (95% CI 0.79 - 1.05, P = 0.212). Results remained significant with propensity score matching and removing patients with medical comorbidities.

CONCLUSION

BT was associated with improved OS when compared to 7560 - 8640 cGy in GS 8, but not in Gleason 9-10 disease. This hypothesis generating study suggests there may be variable benefit with BT in high risk prostate cancer patients on OS. Future prospective studies are needed to investigate whether the benefit of BT is similar across all high risk prostate cancer patients.

Application of a Prognostic Stratification System for High-risk Prostate Cancer to Patients Treated With Radiotherapy: Implications for Treatment Optimization

OBJECTIVES

We applied an established prognostic model to high-risk prostate cancer (HRPC) patients treated with radiotherapy (RT) and evaluated the influence of clinical and treatment variables on treatment outcomes.

METHODS

In total, 1075 HRPC patients undergoing definitive radiotherapy (RT) between 1995 and 2010 were retrospectively reviewed. Median follow-up was 62.3 months. Patients received either dose-escalated external beam radiotherapy (n=628, EBRT) or combined-modality radiotherapy (n=447, pelvic RT and low-dose rate brachytherapy boost, CMRT). 82.9% received androgen-deprivation therapy (ADT). A prognostic model stratified patients into predefined groups (good, intermediate, and poor). Kaplan-Meier methods and Cox proportional hazards regressions assessed biochemical failure (BF), distant metastasis (DM), prostate cancer-specific mortality (PCSM) and overall mortality (OM). C-indices analyzed predictive value.

RESULTS

The model was prognostic; C-indices for BF, DM, PCSM and OM were: 0.62, 0.64, 0.61, and 0.57. On multivariate analysis, CMRT and longer ADT (≥24 mo) were associated with improved BF, DM, and PCSM. Gleason score (GS) 9-10 was the strongest predictor of PCSM. C-indices for BF, DM, PCSM, and OM using a 4-compartment model incorporating GS 9-10 were: 0.62, 0.65, 0.68, and 0.56. In poor-prognosis patients (GS 8-10+additional risk factors), CMRT+LTADT (>12 mo) had 10-year PCSM (3.7%±3.6%), comparing favorably to 25.8%±9.2% with EBRT+LTADT.

CONCLUSIONS

The model applies to high-risk RT patients; GS 9-10 remains a powerful predictor of PCSM. Comparing similar prognosis patients, CMRT is associated with improved disease-specific outcomes relative to EBRT. In poor-prognosis patients, CMRT+LTADT yields superior 10-year PCSM, potentially improving RT treatment personalization for those with HRPC.