Speaker: Max Peters, RT, Radiation Oncologist, Radiotherapiegroep Arnhem, Netherlands
Max Peters, RT: Hello everyone. My name is Max Peters. I'm a radiation oncologist and epidemiologist from the Netherlands. I work at the Radiotherapy Group, serving a large area in the east of the Netherlands. and we have been treating patients with brachytherapy for many years. Now, one of the things we know from the literature is that an HDR brachytherapy boost can lead to increased biochemical disease-free survival in intermediate to high-risk prostate cancer patients but at the cost of increased toxicity. We prospectively followed and analyzed patients treated with an HDR brachytherapy boost at our center from 2010 to 2020. Patients received external beam radiotherapy with or without elective pelvic lymph node radiation, followed by a single fraction HDR boost of 10 Gy to the entire prostate. This was combined with androgen deprivation therapy up to two years. We prospectively evaluated biochemical disease-free survival, overall survival toxicity according to the common terminology criteria for adverse events version three and quality of life. The cohort consisted almost exclusively of high-risk patients. A total of 274 patients were analyzed. Median follow-up was 95 months.
We found that achieving a PSA nadir below 0.1 nanograms per milliliter was the strongest predictor for both biochemical disease- free survival and overall survival. And this led to a 88% biochemical disease-free survival at eight years for patients achieving such a low PSA nadir, which is a very good result. We also found a clinically small but significant increase in IPSS scores during follow-up, as well as minor bowel symptoms. And a total of 4.4% and 0.7% of patients at late CTC grade three genital urinary and gastrointestinal toxicity, respectively. You can see in the poster or you can look at the poster for more details. Thank you for your attention.
