Intensity modulated radiation therapy for 122 patients with untreated nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To analyse the preliminary clinical results of intensity modulated radiation therapy (IMRT) for 122 untreated nasopharyngeal carcinoma (NPC)pafients.Methods 122 NPC pa- tients received IMRT alone from Feb.2001 to Jun.2004,with 31 females and 91 males,and a median age of 45 years(range 25-66).According to the Fuzhou Stage Classification,there were StageⅠ11 patients, StageⅡ34,StageⅢ62,and StageⅣa 15.IMRT was carried out using an inverse planning system (COR- VUS 5.0,Peacock plan) developed by the NOMOS Corp.The treatment was given with the Multi-leaf Inten- sity Modulating Collimator (MIMIC) using a slice-by-slice arc rotation approach.The prescription dose was 68 Gy/30f to the nasopharynx gross tumor volume (GTV_(nx)),60-66 Gy/30f to positive neck lymph nodes (GTV_(nd)),60 Gy/30f to the first clinical target volume (CTV_1) and 54 Gy/30f to the second clinical target volume (CTV_2).Kaplan-Meier method was used to calculate the overall survival rate (OS),distant metas- tasis-free survival rates (DMFS),and local-regional control rates from the last date of therapy.Log-rank test was used to detect the difference between groups.Results The median follow-up time was 20 months ( range 6 to46 months).The 1-,2-,and 3-year OS was 95.2%,91.4%,85.1%,DMFS was 91.9%, 88.6%,85.6%,and the local-regional control rates was 96.5%,93.2%,93.2%,respectively.Statistics of the local control rate was insignificant either for advanced T(T3+T4) stage or early T(T1+T2) stage diseases(P=0.148).The 2-year regional control rate was insignificant either for patients with N(+) or N (-),but the 2-year DMFS was significant both for patients with N(+) and N(-)lesions(P=0.004).For 17 patients who failed,there were two with residual disease and one with recurrence at the primary site (17.6%),three patients in the neck (17.6%),twelve patients (70.6%) in distant metastases.Conclu- sions Intensity modulated radiation therapy does provide excellent local-regional control for untreated NPC, especially in patients with advanced T stage or N(+) lesion.Distant metastasis is the main cause of failure. N (+) is significantly correlated with distant metastasis.