摘要目的 分析Ⅱ～Ⅲ期直肠癌患者螺旋断层放疗(HT)与5野调强放疗(5-IMRT)发生急性不良反应的差异.方法 回顾性分析84例Ⅱ～Ⅲ期直肠癌放疗患者的临床资料,19例接受术前放疗,65例接受术后放疗,其中HT治疗43例,5-IMRT治疗41例.两种照射方式的肿瘤靶区(GTV)及临床靶区(CTV)勾画原则一致,计划靶区(PTV) 5-IMRT外扩1.0 cm,HT外扩0.5 cm.PTV剂量45.0 ～ 50.4 Gy(1.8 Gy/次),45例患者给予同步补量照射,肿瘤或瘤床总剂量55.0 ～ 60.0 Gy(2.1～ 2.3 Gy/次).HT治疗患者每次治疗前在PTV范围内进行CT扫描,据骨性标识和软组织与定位CT图像进行配准并校位.全部患者放疗第1天开始同步口服卡培他滨每天1600 mg/m2,至放疗结束.结果 HT组与5-IMRT组比较,≥2级急性膀胱炎发生率分别为7.0％(3例)、2.4％(1例)(P=0.616),≥3级急性腹泻发生率分别为4.7％(2例)、12.2％(5例)(P=0.259).≥2级白细胞减少发生率分别为48.8％(21例)、19.5％(8例)(P=0.005);≥1级贫血发生率分别为34.9％(15例)、14.6％(6例)(P=0.032);≥1级血小板减少发生率分别为23.3％(10例)、14.6％(6例)(P=0.314).结论 Ⅱ～Ⅲ期直肠癌同步卡培他滨放化疗,采用HT放疗血液学不良反应发生率高于5-IMRT,急性腹泻和膀胱炎发生率两组相似.

abstractsObjective To compare acute toxicity for stage Ⅱ-Ⅲ patients with rectal cancer irradiated with helical tomotherapy (HT) and conventional five-field intensity-modulated radiotherapy (5-IMRT).Methods The data of 84 stage Ⅱ-Ⅲ patients with rectal adenocarcinoma treated with concurrent chemoradiotherapy (CRT) were retrospectively analyzed.19 patients underwent postoperative CRT,and 65 patients underwent preoperative CRT.43 patients received radiotherapy with HT and 41 patients with 5-IMRT.The delineation on clinical target volume (CTV) and gross tumor target (GTV) was similar for two groups.The CTV to plan tumor volume (PTV) margins were 1.0 cm for patients with 5-1MRT and 0.5 cm for patients with HT.For all patients,a dose of 45.0-50.4 Gy,in daily fractions of 1.8 Gy,was delivered to PTV.For 45 patients with high risk factors,simultaneous integrated boost (SIB) was given to the tumor or tumor bed of a total dose of 55.0-60.0 Gy,in daily fractions of 2.1-2.3 Gy.Before treatment,the patients treated with HT underwent scanning by the tomotherapy-integrated megavoltage computed tomography (MVCT) scan modality and were positioned by co-registration of these images to the original kilovoltage planning CT image set.Concurrent capecitabine every day 1 600 mg/m2,twice daily on every day in the week.Results The rates of grade ≥ 2 acute cystitis were 7.0 ％ (3 cases) in HT group and 2.4 ％ (1 case) in 5-IMRT group (P =0.616),and ≥3 grade acute diarrhea were 4.7 ％ (2 cases) and 12.2 ％ (5 cases),respectively (P =0.259).≥2 grade leukopenia were 48.8 ％ (21 cases) and 19.5 ％ (8 cases),respectively (P =0.005),≥1 grade anemia were 34.9 ％ (15 cases) and 14.6 ％ (6 cases),respectively (P =0.032),and ≥1 grade thrombocytopenia were 23.3 ％ (10 cases) and 14.6 ％ (6 cases),respectively (P =0.314).Conclusions There is no significant difference in acute diarrhea and cystitis for patients treated with HT and 5-IMRT.Leukopenia and anemia in patients treated with HT are worse than those in patients with 5-IMRT,and thrombocytopenia is similar in the two groups.