Effect of radiation techniques in treatment of oropharynx cancer.

Abstract

To compare the toxicity and outcomes of three radiotherapy techniques-three-dimensional conformal (3D-RT), accelerated fractionation with concomitant boost (AFxCB), and intensity modulated radiotherapy (IMRT)-in the combined modality treatment of stage III-IV squamous cell carcinoma (SCC) of the oropharynx. Retrospective review. Between 1998 and 2007, a total of 87 patients were treated; 23 were treated with 3D-RT, 32 with AFxCB, and 32 with IMRT. Systemic therapy consisted of platinum-based chemotherapy in 81 and anti-epidermal growth factor receptor (anti-EGFR)-targeted therapy in 6 cases. Median radiotherapy doses were 70Gy with 3D-RT, 72Gy with AFxCB, and 69.3Gy with IMRT. Locoregional control, survival outcomes, and feeding tube (PEG) dependence were compared using log-rank method. The incidence of acute mucositis and skin reaction, and grade > or = 2 xerostomia at 6, 12, and 18 months after radiotherapy was compared using Fisher's exact test. Median follow-up was 24 months (range 3 to 103 months) for living patients. Two-year overall survival (OS), disease-free survival (DFS), and locoregional control (LRC) were 77.3%, 69.5%, and 86.4%, respectively. There was a trend toward improvement in LRC in patients treated with IMRT. Acute grade > or = 3 skin and mucosal toxicity were significantly lower with IMRT compared to AFxCB (P < .001). Grade > or = 2 xerostomia was significantly reduced with IMRT compared to AFxCB and 3D-RT (P < .001). There was no difference in the actuarial rate of PEG dependence (P = .96). Compared to AFxCB and 3D-RT, IMRT confers an improvement in toxicity and appears to have similar efficacy in patients with SCC of the oropharynx.