Long-Term Results of a Randomized Trial Comparing Iridium Implant Plus External-Beam Radiation Therapy with External-Beam Radiation Therapy Alone in Node-Negative Locally Advanced Cancer of the Prostate

• Published in: International journal of radiation oncology, biology, physics Vol. 99; no. 1; pp. 90 - 93
• Main Authors: Dayes, I.S, Parpia, S, Gilbert, J, Julian, J.A, Davis, I.R, Levine, M.N, Sathya, J
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2017
• Subjects: BRACHYTHERAPY; Brachytherapy - methods; Cause of Death; EXTERNAL BEAM RADIATION THERAPY; Follow-Up Studies; GY RANGE; Hematology, Oncology and Palliative Medicine; Humans; IRIDIUM; Iridium Radioisotopes - therapeutic use; Male; NEOPLASMS; Neoplasms, Second Primary - mortality; PATIENTS; PROSTATE; Prostate-Specific Antigen - blood; Prostatic Neoplasms - blood; Prostatic Neoplasms - mortality; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; RADIATION SOURCE IMPLANTS; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; SURGERY; Survival Analysis; Time Factors; Treatment Outcome; radiotherapy; prostate cancer; brachytherapy; randomized trial; survival
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2017.05.013

Abstract Purpose To determine the impact on long-term survival from the addition of brachytherapy to external beam radiation therapy (EBRT) in patients with prostate cancer. Materials and Methods Between 1992 and 1997, 104 men with cT2-3, surgically staged node-negative prostate cancer were randomized to receive either EBRT (40Gy/20 fractions) with iridium implant (35Gy/48 h) or EBRT alone (66Gy/33 fractions) to the prostate. Based on T- stage, Gleason score and PSA (Prostate-Specific Antigen), 60% of patients had high-risk disease. Substantial improvements in biochemical control at 8 years have previously been reported. Additional follow up was collected on deaths and metastases. Results Median follow-up was 14 years. Five patients were lost to follow up. All other patients have been followed a minimum of 13 years. There have been 75 deaths, including 21 from prostate cancer and 25 from second cancers. No patients developing a second cancer have died from prostate cancer. There was no difference in overall survival between the two treatment groups, 34 (67%) deaths in the Implant arm and 41 (77%) in the EBRT arm, hazard ratio (HR) = 1.00, 95% confidence interval (CI) = (0.63, 1.59). Similarly, there was no difference in prostate cancer-specific deaths, 9 (18%) patients in the Implant arm compared to 12 (23%) in the EBRT arm, HR= 0.79, 95% CI = (0.34, 1.87). There was no statistically significant difference in the number of patients developing metastatic disease, 10 (20%) in the Implant arm to 15 (28%) in the EBRT arm, HR= 0.70, 95% CI = (0.32, 1.57). Improvements in biochemical control were maintained, HR = 0.53, 95% CI = (0.31, 0.88). Conclusions Despite a dramatic reduction of biochemical recurrence rates, the addition of iridium implant to EBRT did not translate into improved overall survival or prostate cancer-specific survival.