A Study of Radiation-induced Temporomandibular Joint Lesion (RIJL) in Patients with Nasopharyngeal Carcinoma
LI Feng, WEI Bao-qing (Jiangsu Tumor Hospital, Nanjing 210009, China)
[Purpose] To study the correlative factors of radiation-induced temporomandibular joint lesion (RTJL) in nasopharyngeal carcinoma (NPC). [Methods] The influences of gender, age, extent of primary lesion, radiation dose, cervical fibrosis on RTJL in 109 patients with NPC from Jan. 1998 to Dec. 2001 were analyzed. [Results] The prevalence of RTJL was 45.1%(49/109), with grade Ⅰ, 25 cases (51.0%); grade Ⅱ, 17 cases (34.7%); grade Ⅲ, 7 cases (14.3%) and grade Ⅳ, 0. The interval from the first day of radiotherapy to occurring RTJL was 27 months (4~64 months). Radiation dose for temporomandibular joint was 59.8Gy~79.9Gy. The prevalence of RTJL in patients with dose ≥65Gy and 65Gy was 56.7%(38/67) and 26.2%(11/42), respectively with significant difference(P0.01). And the prevalence of RTJL was 78.3% (36/46) and 20.6% (13/63) in patients with or without cervical fibrosis, with significant difference (P0.01). [Conclusion] Temporomandibular joint dose≥65Gy and cervical fibrosis might be the important factors of RTJL in NPC patients.