Clinical value of three-dimensional conformal radiation therapy for postoperation cervix cancer

Objective： To observe the clinical value of three dimensional conformal radiation therapy （3D-CRT） followed by radical surgery and discuss the best radiation technique for cervical cancer patients after radical hysterectomy. Methods： From February 2003 to June 2006, 115 stage Ⅰ-Ⅲa uterus cervix cancer patients received postoperation radiotherapy in our department after radical surgery. They were randomly divided into two groups. There were 81 patients in 3D-CRT group and 74 patients in traditional radiation group. According to FIGO, there were 45 in stage Ⅰ, 77 in stage Ⅰa, 31 in stage Ⅱb, 2 in stage Ⅲa. Pathological examination confirmed that 148 cases had squamous carcinoma and 7 cases had adenocarcinoma. The target volume included supravaginal portion, the cervical stump, paracervical tissue, common iliac lymph nodes, intemal and extemal lilac lymph nodes, obturator and sacral lymph nodes. For 3D-CRT group we designed four-field or two-fields rotating irradiation in the left-right and the anterior-posterior direction. For traditional radiation group we designed two-field, anterior-posterior, at opposed lateral directions. The radiation dose ranged from 48-50 Gy. Stage lib patients with a cervical stump recurrence received postoperative boost radiation by 8-10 Gy. Results： There were no significant difference in 0.5-year, 1-year, 1.5-year, 2-year local control rate between 3D-CRT group and traditional radiation group （P 〉 0.05）. The occurrence of early and late complications was significant lower in 3D-CRT group than that in traditional radiation group （P 〈 0.05）. There was significant difference in gastrointestinal reaction and urinary system reaction between the two groups （P 〈 0.05）. In postoperation radiotherapy 3D-CRT was superior compared with traditional two-field radiation at opposed lateral direction. Conclusion： 3D-CRT is superior compared with traditional radiation. Four-field rotating irradiation in 3D-CRT has advantages of dose focusing, even dose distribution and cause less side effects and complications. The side-field and cervical stump-targeted boost irradiation are apparent advantages of 3D-CRT.

Fractionated radioimmunotherapy using low doses of iodine 131 labeled anti-CEA monoclonal antibody after tumor volume reduction

OBJECTIVE: To assess the efficacy of fractionated administration of radiolabeled monoclonal antibody in the treatment of metastases after tumor volume reduction surgery, various experimental therapies were studied comparatively. METHODS: A total of 200 inbred mice received tumor implantation from a murine adenocarcinoma cell line. The mice were randomly grouped to give saline, Arc-a, 131I-C50 in single or fractionated doses, cold C50, or non-specific 131I-IgG with or without surgical removal of the implanted tumor xenograft. RESULTS: In comparison to controls, animals receiving Arc-a and radioactive agents had longer survival, smaller tumor, better clinical condition, and less metastases foci. The best therapeutic response was noted after fractionated doses of 131I-C50, which showed better results in every aspect than those treated with other modalities. The favorable outcome was even more pronounced after tumor volume reduction. CONCLUSIONS: Fractionated dosing may improve the deposition of radiolabeled monoclonal antibody (McAb) and provide the best therapeutic effect on implanted tumor and metastases. Thus fractionated radioimmunotherapy (RIT) after tumor volume reduction might be a practical method with promising therapeutic results.