ABSTRACT
INTRODUCTION: To report the toxicity and early efficacy of high-dose rate brachytherapy (HDR) as a boost to external beam radiation (EBRT) in the treatment of localised prostate cancer. METHODS: Between December 2002 and November 2007, 101 consecutive patients with intermediate or high risk prostate cancer were treated with EBRT plus an HDR boost. The HDR boost was initially delivered in three fractions of 6.5 Gy each via one implant; this was subsequently modified to a two-fraction technique with separate implants 2 weeks apart (8.5 Gy each). Most patients also received at least 3 months of androgen ablation. RESULTS: Our cohort included 65 intermediate risk and 36 high-risk patients. Sixty-seven patients received the three-fraction regime; 34 the two-fraction schedule. Median follow-up was 56 months, at which time 82% of patients were free from failure. The 4-year disease-free survival for intermediate and high-risk groups was 95% and 66%, respectively (overall 85%). Significant acute toxicities included clot retention (eight patients), one traumatic urethral injury, one case of retention requiring suprapubic catheter placement, one case of new onset atrial fibrillation and three cases of pulmonary emboli. At 4 years, the rate of late grade 2 genitourinary toxicity was 8%; two patients experienced grade 3 toxicity. No late grade 3 gastrointestinal toxicity was observed. Potency was preserved in 72% of those patients reporting normal pre-treatment sexual function. CONCLUSIONS: Our cohort experienced toxicity similar to previously published HDR boost series with very promising early efficacy results.
Subject(s)
Brachytherapy/methods , Prostatic Neoplasms/radiotherapy , Aged , Dose Fractionation, Radiation , Female , Humans , Male , Middle Aged , Prospective Studies , Prostate-Specific Antigen/blood , Quality of Life , Radiotherapy Dosage , Survival Rate , Treatment OutcomeABSTRACT
BACKGROUND AND PURPOSE: HDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9 Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. MATERIALS AND METHODS: Three fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5mm or more, indexer positions were adjusted prior to treatment delivery. RESULTS: Results are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254 min (range 81-367 min). Median catheter displacement was 7.5mm (range -2.9-23.9 mm), 67% of implants had displacement of 5mm or greater. Displacements were predominantly caudal. CONCLUSIONS: Catheter displacement can occur in the 1-3h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.
