RESEARCH FOR IMPROVEMENT OF LOCAL CONTROL AND LATE EFFECT IN THE TREATMENT OF ORAL CANCER BY HYPERFRACTIONATED RADIOTHERAPY COMBINED WITH CHEMOTHE|RAFY

82例口腔鳞状细胞癌患者接受超分割放疗（HF）联合化疗，以提高放疗的疗效。T1 ~ T4的2年生存率分别为80.4%、65.5%、32.7%和5.8%。没有任何发现可以提高单独HP的生存率。然而，联合化疗似乎比HF单独治疗提高局部控制率。低分期者局部控制率高，从器官保护角度考虑，小体积颊癌应作为HF联合化疗的适应证。（1）单纯HF组采用1.2或1.4Gy分割，总剂量80 Gy以上可耐受，HF联合化疗组70- 74 Gy可耐受。2)较小的肿瘤是HF的良好候选者，有或没有化疗，但在较大的肿瘤中，HF的目标应该是为了根治性手术而降低分期。3)当地和区域控制影响生存。4)单纯HF的急性反应对患者来说是可耐受的，但联合治疗的急性反应通常需要1-2周的间隔。5)最常见的晚期并发症是下颌骨坏死。在治疗后约1.5至2年发现。尽可能将下颌骨排除在照射野之外可能是最重要的。这将通过计算机模拟系统来完成，该系统提供仔细的治疗计划。在放射治疗之前，应建议对可能是感染源的牙科疾病进行紧急治疗。放疗前、放疗中、放疗后均应加强口腔科护理，改善这一并发症是HF联合或不联合化疗治疗口腔癌的突破口。

Eighty two patients with previously untreated and biopsy-proven squamous cell carcinoma of the oral cavity were treated by hyperfractionated radiotherapy(HF) with chemotherapy to improve treatment results of radiotherapy. Two-year survival rates of T1 to 4 were 80.4%, 65.5%, 32.7%, and 5.8%, respectively. There was not any findings which improved survival rates by HP alone. However, combined chemotherapy seemed to improve local control rates than HF alone treatment. A higher local control rate was obtained in the patients with lower stages of tumors, and it was considered in the standpoint of organ preservation that a smaller size of buccal carcinoma should be an indication for HF combined with chemotherapy.The results showed followings ; l)The total dose of 80Gy or more was tolerable to patients in the HF alone using a fraction size of 1.2 or 1.4Gy, and 70-74Gy in the HF combined with chemotherapy. 2)Smaller tumors were good candidates for HF with or without chemotherapy, but in larger tumors the goal of HF should be down-staging for a curative operation. 3)Both local and regional controls influenced the survival. 4)Acute reactions in HF alone were torelable to patients, but those in the combined treatment often needed a split of 1-2 weeks. 5)The severest late complication was the mandibular bone necrosis. It was found about 1.5 to 2 years after the treatment. It might be most important to exclude the mandible from an irradiated field as much as possible. This would be accomplished with a computer-simulation system which provide careful treatment planning. Urgent treatment of dental diseases which might be a source of infection should be advisable before radiotherapy. Intensive dental care was necessary not only before radiotherapy but also during and after it. The improvement of this complication should be a breakthrough for further application of HF with and without chemotherapy to oral cancers.