Evaluation of prognostic factors and two radiation techniques in patients treated with surgery followed by radio(chemo) therapy or definitive radio(chemo) therapy for locally advanced head-and-neck cancer

Background and purpose: Conventional radiotherapy (RT) still is the standard technique for head-and-neck cancer in many centers worldwide, whereas other centers replaced this technique by 3-D conformal RT, which is associated with more appropriate dose distributions. Comparative studies regarding outcome and toxicity are lacking. This study compared both techniques for overall survival (OS), metastases-free survival (MFS), loco-regional control (LC), and toxicity in stage III/IV head-and-neck cancer. Patients and methods: Data of 345 patients irradiated for stage III/IV squamous cell head-and-neck cancer were retrospectively analyzed. Patients received conventional RT (group A, n = 166) or 3-D conformal RT (group B, n = 179). Both techniques were compared for outcomes and toxicity. Eleven further potential prognostic factors were investigated: age, gender, performance status, tumor site, grading, T-stage, N-stage, AJCC-stage, chemotherapy, surgery, pre-RT hemoglobin. Results: 3-year-OS was 62% in group A and 57% in group B (p = 0.15). 3-year-MFS was 67% and 76% (p = 0.46), 3-year-LC was 65% and 68%, respectively (p = 0.71). On multivariate analysis, gender (p = 0.005), performance status (p < 0.001), T-stage (p = 0.002), and N-stage (p < 0.001) were associated with OS. MFS was influenced by performance status (p < 0.001) and N-stage (p < 0.001), LC by gender (p = 0.021), T-stage (p < 0.001), and pre-RT hemoglobin level (>= 12 better than < 12 g/dl, p = 0.004). Grade 2-3 xerostomia was less frequent with 3-D conformal RT (43% vs. 58%, p = 0.06). Otherwise, toxicities were similar. Conclusions: Both RT techniques resulted in similar treatment outcomes. Because xerostomia was less with 3-D conformal RT, this technique appeared beneficial for patients, in whom one parotid gland can be spared. Outcome was associated with gender, performance status, tumor stage, and pre-RT hemoglobin.