Consequential late radiation damage in the sldn in msopharyngeal carcinoma

Abstract

Objective To evaluate the relationship between early and late radiation damage in skin.Methods 335 patients with nasopharyngeal earcinoma treated with radical radiotherapy were evaluated. 240patients had lymph nodes in the neck at initial diagnosis. The median doses were 70 Gy (55-86 Gy) to thenasopharyngeal region by external beam radiotherapy. The median doses were 64 Gy (46-72 Gy) to the neck with lymph node metastases, 55 Gy (21-67 Gy) to the node-negative neck. 71 patients were treated with facial-neckfields, while 264 patients were treated with pre-auricular fields. Chemotherapy was given in 48 patients. According to the 1995 SOMA scales late radiation damage in the skin was evaluated. Results The median time from the radiotherapy to follow up was 14 years (range, 5-38 years). 63 patients have grade 0 late radiation reactions in the neck skin, the grade 1,2,3,4 late radiation reactions in the neck skin were 43.9% (147patients),20.9%(70 patients), 13.7% (46 patients)and 2.7% (9 patients), respectively.44 patients had moist desquamation in the medical records. The grade 1,2,3,4 late radiation reactions in the neck skin were 41% ,23%, 30% and 5%, respectively in patients with moist desquamation, while in patients without moist desquamation, the corresponding rates were 44.3%, 20.6%, 11.3% and 2.4%, respectively. The difference were significant between these two groups by chi-square analysis(χ2=17.42, P=0.002). Furthermore, whether patients had positive lymph node in the neck or not, the size of facial-neck fields and higher doses to the neck had more severe late radiation reaction in the neck skin, while age, gender and chemotherapy failed to show any effects on the development of late radiation reactions in the neck skin. Conclusion The severe early radiation damage in the skin possibly increases the late radiation damage in the neck skin. Key words: Nasopharyngeal carcinoma; Radiotherapy; Radiation-injury; Skin