Pellizzon Antonio Cassio Assis, Salvajoli Joao Victor, Maia Maria Aparecida Conte, Ferrigno Robson, Novaes Paulo Eduardo Ribeiro Dos Santos, Fogarolli Ricardo Cesar, Pellizzon Ricardo Jose Assis
Radiation Oncology Department, Hospital A.C. Camargo, Faculdade de Medicina de Catanduva, Sao Paulo. Brazil.
J Urol. 2004 Mar;171(3):1105-8. doi: 10.1097/01.ju.0000113260.07979.d3.
Late urinary retention (UR) is a known complication that may occur when using high dose rate brachytherapy (HDR-B) to boost external beam radiation therapy (EBRT) when treating prostate cancer. However, the dosimetric, treatment and clinical factors associated with this complication are not well-known.
From March 1997 to March 2000 a total of 108 patients with local or locally advanced prostate adenocarcinoma were treated with EBRT (45 Gy) and HDR-B as a boost, when 16 to 20 Gy was given in 4 fractions twice daily. Median patient age was 68 years and median followup was 44 months (range 36 to 72). Each implant was performed using 8 to 18 needles with a median active length of 3 cm. Planning ultrasound target volume ranged from 23 to 65 cc.
Biological effective doses for the urethral region ranged from 107 to 138 Gy3 (median 113). Crude and 5-year actuarial UR-free survival were 95.4% and 86.2%, respectively. Predictive factors for UR on univariate analysis were age more than 65 years (p = 0.0416), planning ultrasound target volume greater than 35 cc and active length of needles more than 3.5 cm (p = 0.0158). On multivariate analysis by Cox regression age was the only predictive factor (p = 0.027).
HDR-B appears to offer a safe, reproducible and effective method of boosting conventional EBRT in patients with locally advanced prostate cancer. Results with this technology reveal late urinary morbidity rates paralleling those achieved with other forms of treatment, but further long-term followup is still needed to warrant a definitive conclusion.
晚期尿潴留（UR）是已知的一种并发症，在使用高剂量率近距离放射治疗（HDR - B）辅助外照射放疗（EBRT）治疗前列腺癌时可能会出现。然而，与该并发症相关的剂量学、治疗及临床因素尚不明确。
1997年3月至2000年3月，共有108例局部或局部晚期前列腺腺癌患者接受了EBRT（45 Gy）及作为辅助的HDR - B治疗，分4次给予16至20 Gy，每日2次。患者中位年龄为68岁，中位随访时间为44个月（范围36至72个月）。每次植入使用8至18根针，中位有效长度为3 cm。计划超声靶体积范围为23至65 cc。
尿道区域的生物等效剂量范围为107至138 Gy3（中位值为(113)）。粗略和5年精算无尿潴留生存率分别为95.4%和86.2%。单因素分析中尿潴留的预测因素为年龄大于65岁（(p = 0.0416)）、计划超声靶体积大于35 cc以及针的有效长度大于3.5 cm（(p = 0.0158)）。多因素Cox回归分析显示年龄是唯一的预测因素（(p = 0.027)）。
HDR - B似乎为局部晚期前列腺癌患者辅助传统EBRT提供了一种安全、可重复且有效的方法。该技术的结果显示晚期泌尿疾病发病率与其他治疗方式相当，但仍需要进一步的长期随访以得出确切结论。
