Chen S W, Liang J A, Yang S N, Liu R T, Lin F J
Department of Radiation Therapy and Oncology, Shin Kong Memorial Hospital, Taipai, Taiwan.
Int J Radiat Oncol Biol Phys. 2000 Jul 1;47(4):955-61. doi: 10.1016/s0360-3016(00)00559-9.
This study aimed to correlate patient, treatment, and dosimetric factors with the risk of late rectal sequelae in patients with uterine cervical cancer treated with external beam radiation therapy (EBRT) and high dose rate intracavitary brachytherapy (HDRICB).
From September 1992 to December 1995, a total of 128 patients with uterine cervical cancer, who were treated and survived more than 12 months, were evaluated. After EBRT with 40-44 Gy/20-22 Fr/4-5 weeks to the whole pelvis, the dose was boosted up to 54-58 Gy with central shielding for patients with bilateral parametria of Stage IIb or greater. HDRICB consisted of three to four insertions at doses of 5-7.2 Gy (to Point A) at intervals of 1 week. Patient and treatment factors were analyzed using logistic regression analysis and the cumulative rectal biologic equivalent dose (CRBED) was calculated.
After 30-75 months of follow-up (median, 43 months), 38 patients (29.7%) had late rectal sequelae. Patients who had Stage IIb-IVa disease, cumulative rectal dose (external RT + total ICRU rectal dose) greeater than 65 Gy, or age greater than 70 years had a high risk of developing late rectal sequelae. When 110 Gy was used as the cut-off value, 19.6% (10 of 51) of patients whose CRBED was less than 110 Gy had rectal complications, while 36.4% (28/77) of patients whose CRBED was greater than 110 Gy developed rectal complications.
Risk factors of late rectal complications were advanced stage, age greater than 70 years, and cumulative rectal dose of greater than 65 Gy.
本研究旨在探讨子宫颈癌患者接受体外照射放疗（EBRT）和高剂量率腔内近距离放疗（HDRICB）后，患者因素、治疗因素和剂量因素与直肠晚期后遗症风险之间的相关性。
对1992年9月至1995年12月期间接受治疗且存活超过12个月的128例子宫颈癌患者进行评估。对全盆腔进行EBRT，剂量为40 - 44 Gy/20 - 22次分割/4 - 5周，对于IIb期及以上双侧宫旁组织受累的患者，采用中央屏蔽技术将剂量增至54 - 58 Gy。HDRICB包括每隔1周进行3 - 4次插植，剂量为5 - 7.2 Gy（至A点）。采用逻辑回归分析患者和治疗因素，并计算直肠累积生物等效剂量（CRBED）。
随访30 - 75个月（中位随访时间43个月）后，38例患者（29.7%）出现直肠晚期后遗症。患有IIb - IVa期疾病、直肠累积剂量（外照射放疗 + 总ICRU直肠剂量）大于65 Gy或年龄大于70岁的患者发生直肠晚期后遗症的风险较高。以110 Gy作为临界值时，CRBED小于110 Gy的患者中有19.6%（51例中的10例）出现直肠并发症，而CRBED大于110 Gy的患者中有36.4%（77例中的28例）出现直肠并发症。
直肠晚期并发症的危险因素为疾病晚期、年龄大于70岁以及直肠累积剂量大于65 Gy。
