[Permanent iodine 125 implant brachytherapy in localized prostate cancer: results of the first 4 years of experience]. / La curiethérapie par implants permanents d'iode 125 dans le cancer localise de prostate: résultats des 4 premières années d'experience.

OBJECTIVE: This study reports the preliminary national results of permanent Iodine 125 implant brachytherapy for the treatment of localized prostate cancer with a follow-up of 4 years. MATERIAL AND METHODS: The authors analyse a series of 260 patients treated consecutively according to the same technique (single-centre, with estimated dosimetry and the use of fixed implants) in terms of morbidity, recorded prospectively, and in terms of cancer control. In the group of 260 patients with stage T1-T2 prostate cancer 68.4% belonged to the low-risk group (PSA < 10 and Gleason score < 7), 28.4% belonged to the intermediate-risk group (PSA > 10 or Gleason score > 6) and 3% belonged to the high-risk group (PSA > 10 and Gleason score > 6). The mean follow-up was 29.5 months (range: 8-56 months). Adverse effects were dominated by obstructive and/or irritating voiding disorders in the majority of cases, with progressive improvement in 98% of cases. Acute urinary retention required drainage in 10.7% of cases. An endoscopic disobstruction operation was performed after at least 6 months in 2.3% of cases. Anorectitis was reported in 21.91% of cases: stage I in 20.3% and stage II in 1.5%, treated medically in every case. In the year following implantation, 34.2% of patients complained of erectile dysfunction that was successfully treated medically. Analysis of the dosimetric data after implantation demonstrated a learning curve in which optimal coverage of the therapeutic target by the dose of irradiation prescribed was obtained between the first 20 and 30 patients. This systematic, patient-by-patient analysis allowed optimization of the implantation technique, especially by ensuring better coverage of the base and anterior part of the prostate. RESULTS: The 3-year laboratory recurrence-free survival was 93.8% for all patients and 97. 7% for the good prognosis group. Fifteen of the 16 recurrences occurred during the first 18 months of the experience. The results of this study are concordant with those of North American teams at the same stage of experience. In this programme, optimization of the technique and patient selection criteria achieved excellent results in terms of morbidity and cancer control. The authors propose elective brachytherapy to the group of patients with a poor prognosis, a prostate volume less than 50 ml and with no obvious urinary functional disorders. An analysis is underway to confirm these results with a longer follow-up.

Predictive factors of acute urinary morbidity after iodine-125 brachytherapy for localised prostate cancer: a phase 2 study.

PURPOSE: To analyse predictive factors of acute urinary morbidity after transperineal permanent prostate brachytherapy. METHODS AND MATERIALS: Sixty patients treated in a phase 2 study with iodine-125 brachytherapy (9/1998 to 2/2000) for localised prostate adenocarcinoma were analysed after at least 1-year follow-up. Prescribed dose was 144 Gy and all patients had a pre-planning and a post-implant dosimetry. Urinary morbidity was evaluated prospectively using the Radiation Therapy Oncology Group (RTOG) scale. We examined the relationship between pre-implant ultrasound prostate volume, post-implant CT-scan prostate volume, neoadjuvant hormonotherapy, total number of needles and seeds, post-implant dosimetry variables, first 30 vs. last 30 treated patients and post-implant urinary morbidity. RESULTS: All patients experienced some degree of urinary distress symptoms after treatment. Symptoms were generally mild grade 1 in 56% and grade 2 in 10% lasting less than 6 months. Eight patients (13%) required bladder catheter for acute urinary obstruction. At 1-year follow-up, nine patients (15%) complained from persistent dysuria requiring in three cases endoscopic prostate resection. The percentage of urethra volume receiving 216 Gy (cut-off 40%) and the pre-implant prostate volume (cut-off 31 ml) were the only statistically significant predictor of grade 2-3 or persistent urinary morbidity on multivariate analysis. CONCLUSION: Our short-term data suggest that both pre-implant prostate volume value and post-implant V.U. 150 value might be predictors for urinary morbidity after prostate brachytherapy.