Koper Peter C, Jansen Peter, van Putten Wim, van Os Marjolein, Wijnmaalen Arend J, Lebesque Joos V, Levendag Peter C
Erasmus MC/Daniel den Hoed Cancer Center, Groene Hilledijk 301, 3075 EA Rotterdam, The Netherlands.
Radiother Oncol. 2004 Oct;73(1):1-9. doi: 10.1016/j.radonc.2004.07.020.
The late morbidity of a randomized study was analyzed after a follow up of 2 years. The difference in intestinal morbidity was analyzed as a function of the treatment arm and dose volume parameters. The correlation with acute toxicity and (pre-existing) bowel complaints was investigated.
266 T1-4N0M0 prostate cancer patients were randomized for conventional (open fields) and 3D conformal radiotherapy using beams eye view blocked fields with the same dose (66 Gy) and gross target volume-planning target volume margin (15 mm). Apart from the RTOG toxicity scoring system a patient self-assessment questionnaire was used to obtain detailed information on morbidity.
At 2 years there is only a trend for less rectal toxicity (grade >/=1) in favor of the conformal radiotherapy (grade 1, 47 versus 40% and grade 2, 10 versus 7% for conventional and conformal radiotherapy, respectively (P=0.1). A significant relation was found between late rectal toxicity (grade >/=1) and the volume of the anus and rectum exposed to >/=90% tumor dose (TD). A highly significant relationship is observed between acute rectum and anal toxicity and late rectal toxicity. The patient self-assessment questionnaire analysis revealed that patients are most bothered by compliance related symptoms like urgency, soiling and fecal loss. In a multivariate analysis, all other variables loose significance, when anal volume exposed to >/=90% TD and pre-treatment defaecation frequency are accounted for. Late anal toxicity is low and related only to acute anal toxicity. Late bladder toxicity is related solely to pre-treatment frequency and overall urological symptoms. The incidence of grade 2 toxicity increases with a factor 2.5-4 when (stool or urine) frequency is unfavorable at the start of treatment.
Conformal radiotherapy at the dose level of 66 Gy does not significantly decrease the incidence of rectal, anal and bladder toxicity compared to conventional radiotherapy. There is a significant relationship between acute and late toxicity and the anal volume exposed to 90% TD. Intestinal (and urological) symptoms at start have a major impact on late toxicity.
在一项随机研究随访2年后，分析其晚期发病率。将肠道发病率差异作为治疗组和剂量体积参数的函数进行分析。研究其与急性毒性和（既往存在的）肠道症状的相关性。
266例T1 - 4N0M0前列腺癌患者被随机分为接受传统（开放野）放疗和三维适形放疗两组，采用束流视场阻挡野，剂量相同（66 Gy），大体肿瘤体积 - 计划靶体积边界相同（15 mm）。除了放射肿瘤学组（RTOG）毒性评分系统外，还使用了患者自我评估问卷来获取关于发病率的详细信息。
2年后，适形放疗组直肠毒性（≥1级）略低，但仅呈趋势性差异（传统放疗组1级为47%，2级为10%；适形放疗组1级为40%，2级为7%，P = 0.1）。发现晚期直肠毒性（≥1级）与接受≥90%肿瘤剂量（TD）的肛门和直肠体积之间存在显著关系。急性直肠和肛门毒性与晚期直肠毒性之间存在高度显著的关系。患者自我评估问卷分析显示，患者最困扰的是与顺应性相关的症状，如尿急、便污和粪便失禁。在多变量分析中，当考虑接受≥90% TD的肛门体积和治疗前排便频率时，所有其他变量均失去显著性。晚期肛门毒性较低，仅与急性肛门毒性有关。晚期膀胱毒性仅与治疗前频率和总体泌尿系统症状有关。当治疗开始时（大便或小便）频率不利时，2级毒性的发生率增加2.5 - 4倍。
与传统放疗相比，66 Gy剂量水平的适形放疗并未显著降低直肠、肛门和膀胱毒性的发生率。急性和晚期毒性与接受90% TD的肛门体积之间存在显著关系。治疗开始时的肠道（和泌尿系统）症状对晚期毒性有重大影响。
