Background: A correlation exists between applied dose to the prostate and local tumour control. External radiotherapy of the prostate implies administering curative doses near the upper limit of normal tissue tolerance. Brachytherapy with a high dose rate permits an escalation of dose within the prostate without increasing the risk of side effects to the surrounding rectum and bladder. This article presents a study of the first 100 patients in Norway with localized/locally advanced prostate cancer treated with high dose-rate brachytherapy combined with external radiotherapy.
Material and methods: Patients belonging to an intermediate or high risk group and patients in whom radiotherapy was expected to give rise to increased toxicity (irrespective of the clinical stage) were included. Several hollow steel needles were implanted through the perineum into the gland during general anaesthesia. A small Iridium source with a short irradiation length was introduced stepwise and temporarily into each steel needle, according to a meticulate dosing plan. All patients came to an outpatient control 3-5 months after the combined treatment.
Results and interpretation: Median follow-up was 8 months. Acute side effects were scarce and few complications from the rectum were seen. The observation time was too short to evaluate the relapse-free survival. High dose rate brachytherapy is indicated in patients with prostate cancer of an intermediate or high risk or if a radiation dose with a full external beam proposes a hazard to the patient. Combined radiotherapy (external beam and high dose rate brachytherapy) is considered to be a standard treatment at the Norwegian Radium Hospital.