Intensity-modulated radiation therapy in advanced head and neck patients treated with intensive chemoradiotherapy: preliminary experience and future directions

We review our recent experience with intensity-modulated radiation therapy (IMRT) and conventional three-dimensional radiation therapy (C3DRT) in advanced head and neck cancer. Sixty-nine patients with Stage IV head and neck cancer (and stage III base of tongue and hypopharynx) enrolled in a Phase II study of definitive chemoradiation; 20 received all or part of their radiation with IMRT. Image-guided set-up, using video subtraction techniques, was used in all patients. Six weekly doses of induction carboplatin (AUC=2) and paclitaxel (135 mg/m2) were followed by alternating weekly chemoradiation to 75 Gy with 1.5 Gy BID fractions, concurrent with paclitaxel (100 mg/m2/week), 5-fluorouracil (600 mg/m2/d) and hydroxyurea (500 mg PO BID). Two consecutive cohorts enrolled, differing in radiation scheme: 75 Gy to gross disease in both, 60 or 54 Gy to first echelon lymphatics and 45 or 39 Gy to second echelon lymphatics. With a median follow-up of 47 months, 3-year overall survival is 68.5% and 3-year locoregional control is 94.0%, with no significant differences between those treated with C3DRT versus IMRT, nor between the two radiation dosing schemes. Actuarial overall survival without tracheostomy or laryngectomy, or without a gastrostomy tube was also similar. Acute mucositis, dermatitis and pain were similar with C3DRT and IMRT. Preliminary data suggests IMRT is well tolerated, and does not compromise locoregional control, indicating that IMRT adequately covers the clinical volume at risk. Building on the present clinical experience, future directions include more directed efforts at reducing toxicity, with better planning software and planning techniques.