Fractionated stereotactic radiotherapy:single-center stage II clinical study on the residual lesions of nasopharyngeal carcinoma

OBJECTIVE Nasopharyngeal carcinoma is still remaining after radiotherapy in patients with nasopharyngeal local,because of technical limitations and the protection of normal tissue.Conventional radiotherapy make the limited quantity,and curative effect is not significant.This study is to analyze the long-term effect and complications of fractionated stereotactic radiotherapy(FSRT)on residual lesions in nasopharynx cancer(NPC)patients,evaluating its value of clinical applications.METHODS Between July 1997 and October 2002,FSRT was performed in 54 patients with residual nasopharyngeal carcinoma after conventional fractionation.They all had comparatively complete follow-up data.The total administration dosage was 18-24 Gy in median single fractions of 6-8Gy.All patients were received follow-ups with a median follow-up time of 13.5years(ranging from 10.25 to 15.5years).The curative effect was evaluated according to the WHO standard.RESULTS FSRT was well tolerated in all patients.The complete remission rate(CR)was 63.0%,and partial remission rate was 37.0%.The 3,5,10,13,15-year overall survival(OS)rates were85.2%,77.8%,64.8%,60.7%,54.3%,respectively.The 3,5,10,13,15-year local recurrence-free survival(LRFS)rates were 98.1%,95.8%,86.3%,83.4%,83.4%,respectively.The 3,5,10,13,15-year progression-free survival(PFS)rates were 83.3%,75.9%,59.1%,55.1%,55.1%,respectively.The 3,5,10,13,15-year distant metastasis-free survival(DMFS)rates were 85.0%,81.0%,70.9%,70.9%,70.9% respectively.Twenty-three patients died during the study period.The Cox analysis showed that age,N stage were the prognostic factors for OS,LRFS,PFS,and DMFS.Clinical stage and the total administration dosage of FSRT were the prognostic factors for LRFS.The total administration dosage of FSRT were the prognostic factors for PFS.CONCLUSION FSRT has better clinical value for the treatment of residual lesions after conventional fractionation with high LRC,less damage,few complications and good long-term outcomes.