Clinical Researches On Fractionated Stereotactic Radiotherapy For Residual Nasopharyngeal Carcinoma

Part I:Fractionated stereotactic radiotherapy for136patients with locally residual nasopharyngeal carcinomaObjective To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) in patients with residual nasopharyngeal carcinoma (NPC).Methods From January2000to December2009,136NPC patients with residual lesions after primary radiotherapy (RT) were treated by FSRT. The patients aged between13and77years with a median of43.0years,104of them were males and32were females. The stages (2002UICC) before primary RT were:Ⅰ1(0.8%),Ⅱa6(4.4%), Ⅱb24(17.6%),Ⅲ70(51.5%),Ⅳa24(17.6%),Ⅳb (8.1%). In primary RT,85patients received conventional RT,51patients received IMRT and75out of the136patients received concurrent chemoradiotherapy. The total dose of primary RT was68.0-78.0Gy (median,70.0Gy). The median time from the primary RT to FSRT was24.5days (range,2-147). Residual tumor volumes ranged from0.60to77.13cm3(median,13.45cm3). The total FSRT doses were8.0-32.0Gy (median,19.5Gy) with2.0-10.0Gy per fraction.Results The actuarial CR rate was72.1%and PR rate was23.5%. Five-year local failure-free survival (LFFS), freedom from distant metastasis (FFDM), overall survival (OS), and disease free survival (DFS) rates for all patients were92.5%,77.0%,76.2%, and73.6%, respectively. No statistical significant differences were found in LFFS, DFS and OS in comparison of stage Ⅰ/Ⅱ and stage Ⅲ/Ⅳ disease. Nineteen patients exhibited late toxicities including massive nasopharyngeal hemorrhage (3.7%), cranial nerve injuries (5.9%) and temporal lobe necrosis (4.4%). T stage at diagnosis was an significant prognostic factor for OS and DFS. Age is another prognostic factor for OS.Conclusion FSRT after external beam radiotherapy provides excellent local control for patients with residual NPC. The incidence of severe late toxicity was found to be acceptable with FSRT. Improved fractionation regimens of FSRT can avoid long-term complications. Part Ⅱ:Fractionated stereotactic radiotherapy with carotid sheath protection technique for local residual nasopharyngeal carcinoma after primary radiotherapyObjective Local failure of nasopharyngeal carcinoma (NPC) after radiotherapy (RT) remains one of the major treatment failures. This study aimed to evaluate the clinical efficacy and complications of fractionated stereotactic radiotherapy (FSRT) with vagina carotica protection technique for local residual of NPC patients after the primary RT.Methods and Materials From August2006to August2010, FSRT with carotid sheath protection technique was applied to36patients in our department, the patients aged between13and76years with a median of41.3years,25of them were males and11were females. According to2002UICC Staging System, the stages before primary radiotherapy were:Ⅱa2,Ⅱb5,Ⅲ18,Ⅳa7, Ⅳb4. In the first course of radiotherapy,9patients received conventional RT,27patients received IMRT and20out of the36patients received concurrent chemoradiotherapy. The total dose in the first course of RT was69.96-76.90Gy (median,72.58Gy). The intervals between the primary RT and FSRT ranged from12to147days (median,39.8days). Target volumes ranged from1.46to32.98cm3(median,14.94cm3). The total FSRT doses were10.0-24.0Gy (median,16.5Gy) with2.0-5.0Gy per fraction. The most common regimen was15Gy in5fractions of3Gy, the irradiation dose to carotid sheath was less than2Gy per fraction.Results The median follow-up time was34months (range,12-59months). The3-year local control rate was100%; the3-year overall survival rate was94.4%; the3-year disease-free survival rate was77.8%. In this study, we had one case of cranial nerve injury, two cases of temporal lobe necrosis, and no nasopharyngeal massive hemorrhage was observed. Conclusions FSRT with carotid sheath protection technique is an effective and safe RT regimen for local residual of NPC with reduction of radiation-related neurovascular lesions.