立体定向放射治疗胸部肿瘤初步结果

3-D conformal radiotherapy for malignant thoracic tumors

目的:探讨立体定向放射治疗在胸部肿瘤治疗中的应用。方法:自1999年9月～2002年8月,对36例经病理证实的胸部肿瘤进行了立体定向放射治疗。其中原发性肺癌22例,转移性肺癌12例,纵隔肿瘤2例。其中鳞癌16例,腺癌15例,小细胞癌2例,胚胎性癌1例,胸腺瘤1例,软组织肉瘤1例。原发性肿瘤放疗先采用普通外照射50 Gy/25次/5周,结束后即行立体定向放射治疗,对于不规则形病灶使用多叶光栅,球形病灶采用圆形限光筒。5～6个共面或非共面野,每次4 Gy,每周照射3次,共4～5次。转移性肿瘤单纯立体定向放射治疗,1～4个拉弧照射,每次4 Gy,每周3次,共7～10次。立体定向放疗时肿瘤体积为1.85 cm3至104.61 cm3(中位体积24.96 cm3)。结果:治疗结束后2个月拍摄胸部CT片进行疗效评价。可评价疗效的34例中,CR 13例,PR 14例,NC 5例,PD 2例。中位随访时间为24个月。一年和二年生存率分别为74.1％和38.4％。毒副反应主要为放射性肺损伤。其中急性放射性肺炎1级17例,2级10例,3级1例,5级2例(该2例肿瘤体积均超过60 cm3且为非共面照射)。晚期放射性肺纤维化1级20例,2级8例。结论:立体定向放射治疗作为普通外照射的补充在胸部肿瘤的治疗中近期疗效较好,远期疗效有待进一步观察。但要注意照射技术,照射体积不宜过大,适当调整非共面照射角度,?

Purpose: To evaluate the efficacy and the side effects of 3 D-conformal radiotherapy for malignant thoracic tumor. Methods: Between September 1999 and August 2002, 36 patients with malignant thoracic tumor were treated with 3D-conformal radiotherapy. Twenty-two patients had primary lung cancer, 12 patients had metastatic lung cancer, and 2 patients had malignant mediastinal tumor. All 36 patients were pathologically confirmed. Squamous cell carcinoma 16 cases, adenocarcinoma 15 cases, small cell carcinoma 2 cases, embryonal carcinoma 1 case, malignant thymoma 1 case and sarcoma 1 case. For the primary tumor, conventional radiotherapy was first used to 50Gy/25F/5W, followed by 3D-conformal radiotherapy 16-20Gy(4Gy per fraction, 3 fractions per week) with MLC or cone from 5 ~6 non coplanar or coplanar static ports. For metastatic tumor, using arc therapy to only 28-40Gy(4Gy per fraction, 3 fractions per week, 7-10 fractions) with cone from 1 ~ 4 arcs. Tumor volumes from 1. 85 cm3 to 104. 61 cm3 with a median of 24. 96 cm3 in 3D-CRT. Results: To evaluate the effects, thoracic CT scan was taken two months after completion of 3D-conformal radiotherapy. In 34 evaluated patients, 13 cases obtained CR, 14 PR, 5 NC, and 2PD. The overall 1 and 2-year survival rates were 74. 1% and 38.4%. Toxicity consisted of grade 1 acute radiation pneumonitis in 17 patients, grade 2 in 10 patients, grade 3 in 1 patients, and 2 patients dead of radiation pneumonitis ( with non coplanar technique), late complication was radiation pulmonary fibrosis, grade 1 in 20 cases, grade 2 in 8 cases. Conclusions: 3D-conformal radiotherapy as complement of conventional external beam radiotherapy for malignant thoracic tumor can obtain better short-term effects, although the survival is yet to be investigated. But attention must be given to the irradiation technique, the irradiation volume should not be too large and beams angles appropriately adjusted to avoid excessive irradiated volume in normal lung.