Biochemical Recurrence and Late Toxicity Following External Beam Radiotherapy Combined With Permanent Source Prostate Brachytherapy: Analysis of RTOG 0019
Previous clinical trials have demonstrated the benefits of higher doses of external beam radiation therapy for patients with prostate cancer. One strategy to deliver higher radiation doses to the prostate is to combine external beam radiation therapy with a seed implant (brachytherapy). There is a chance that the combination of external radiation and brachytherapy may cause higher rates of treatment-related toxicity.
This study found that the combination of the two types of radiation resulted in similar relapse rates, but caused a higher rate of side effects (rectal and urinary toxicities). The presenters only reported grade 3 and 4 toxicities, but grade 2 toxicities are not insignificant and should also be considered, as they can still impact negatively on quality of life. An ongoing study (RTOG 0232) is comparing brachytherapy alone to brachytherapy and external beam radiation, which will give us more information on the side effects related to the combination approach. Until then, it appears that combination therapy should not replace monotherapy as the standard of care for men with intermediate risk prostate cancer.