Overcoming Immune Resistance With Radiation Therapy in Prostate Cancer.

Prostate cancer is the second most common cancer in men and represents a significant healthcare burden worldwide. Therapeutic options in the metastatic castration-resistant setting remain limited, despite advances in androgen deprivation therapy, precision medicine and targeted therapies. In this review, we summarize the role of immunotherapy in prostate cancer and offer perspectives on opportunities for future development, based on current knowledge of the immunosuppressive tumor microenvironment. Furthermore, we discuss the potential for synergistic therapeutic strategies with modern radiotherapy, through modulation of the tumor microenvironment. Emerging clinical and pre-clinical data suggest that radiation can convert immune desert tumors into an inflamed immunological hub, potentially sensitive to immunotherapy.

A new method to visualize and to spare the ureters during SBRT for oligo metastatic patients.

This article describes a ureter-sparing procedure used to treat lymph node metastases with SBRT. We delivered 35 Gy in 5 fractions of 7 Gy to patients with lesions located less than 7 mm from the ureters using a urography CT scan for planification. Two dosimetry plans were created, one using a CT scan urography-based contour and the other using the native phase. PTV coverage were not statistically different but this technique was able to significantly reduce median delivered Dmax to the ureters. These preliminary results demonstrate the feasibility of locating the ureters in a planning CT scan to protect them.

Efficacy and tolerance of high-dose-rate brachytherapy boost after external radiotherapy in the treatment of squamous cell carcinoma of the anal canal.

PURPOSE: The aim of this study was to evaluate the efficacy and toxicity of high-dose-rate brachytherapy (HDR-BT) boost in anal squamous cell carcinoma (ASCC). MATERIAL AND METHODS: This was a monocentric retrospective study involving patients treated by external irradiation (± chemotherapy), with HDR-BT boost, for a localized ASCC. Clinical evaluation was performed every six months. Oncological results were analyzed with: local relapse-free survival (LRFS), colostomy-free survival (CFS), metastatic-free survival (MFS), disease-free survival (DFS), and overall survival (OS). Acute and late toxicities were collected (CTCV4.0) and LENT/SOMA score was performed. RESULTS: From May 2005 to January 2018, 46 patients (pts) were analyzed. The median follow-up was 61 months (10-145 months), the median age was 65 years (34-84 years), with a sex ratio M/F = 0.24. The TNM classification was as follows: T1 - 13 pts (21.7%), T2 - 34 pts (73.9%), T3 - 2 pts (4.3%), N+ - 6 pts (13.1%). External beam radiotherapy (EBRT) delivered a median dose of 45 Gy (36-50.4 Gy) in 25 fractions, and HDR-BT 12 Gy (10-18 Gy) in 3 fractions. The median overall treatment time (OTT) was 58 days (41-101 days), with a median EBRT/brachytherapy interval of 17 days (4-60 days). Oncological findings showed 5-year rates of LRFS 81.2%, MFS 88.7%, DFS 70%, and OS 90%. All abdominoperineal amputations were performed in case of local relapse (4 pts, 8.7%), leading to a 5-year CFS of 79.5%. Acute urinary toxicities were frequent (G1 41.3%, G2 4.3%). The acute digestive toxicities were: G1 71.7%, G2 6.5%, and G3 2.2%. The late urinary toxicities were: G1 4.3%, G2 2.2%, and G3 2.2%. Late digestive toxicities were: G1 56.5%, G2 8.7%, G3 2.2%, and G4 2.2%. CONCLUSIONS: In ASCC management, HDR-BT boost appears to be a treatment with a long-term acceptable toxicity profile, shorter than EBRT boost, with a reduction of side effects.