Prognostic analysis of intensity modulated radiotherapy for locally recurrent nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To report the clinical outcome and prognostic factors for locally recurrent nasopharyngeal carcinoma(NPC)treated with intensity modulated radiotherapy(IMRT).Methods From January 2001 to August 2004,the data of 132 such NPC patients were analyzed retrospectively;104 male and 28 female with a median of 44.5 years(range 21-73 years).Ninety-eight patients(74.2%)were confirmed by biopsy as having NPC:9 with WHO TypeⅡand 89 WHO TypeⅢ.The other 34 patients were only diagnosed by MRI scan because of the extension/invasion was in the base of skull and/or cavernous sinus.Median interval time were 24 months(range 6-184 months).According to the 1992 Chinese Fuzhou Staging System:stageⅠ3.8 %,Ⅱ10.6 %,Ⅲ22.0% andⅣa 63.6%;T1 5.3%,T2 10.6%,T3 22.7% and T4 55.3%.Twenty-two patients had recurrence in the neck lymph nodes.IMRT was given with the sequential tomotherapy system(NOMOS Peacock systems)of 6 MV X-rays.Prescription dose was 60-70 Gy in GTV,with the fractional dose of 1.94-2.8 Gy.Sixty patients were also supplemented with two to six courses of cisplatin-based chemotherapy.Results The median volume of GTV was 39.5 cm~3(range 0.8-158.9 cm~3).The D95,V95,mean dose and fractionation dose of GTV was 66.9 Gy,98.3%,69.8 Gy and 2.32 Gy,respectively.The median follow-up time was 12 months(range,2-47 months).The 1-,2-and 3-year local progression-free rate was 96.4%,88.4% and 85.3%,respectively.The overall 1-,2-and 3-year survival rate was 6.5.9%,49.6% and 41.6%,respectively.Eleven patients developed distant metastases.Forty-seven patients were observed to devdop mucosa necrosis and/or massive hemorrhage in the nasopharynx.On univariate and multivariate analysis,fractional dose and vohane of GTV were significant prognostic factors for overall survival(P=0.016,0.009).Conclusions The local control and survival rate can be improved for patients with locally recurrent nasopharygeal carcinoma after treatment of intensity modulated radiotherapy.The fractional dose and volume of GTV are independent prognostic factors for the overall survival. The main death reasons are mucosa necrosis and/or massive hemorrhage in the nasopharynx.