Target Volume Delineation In Locally Advanced Squamous Cell Carcinoma Of The Head And Neck (Scchn) Using Fdg-Pet/Ct Images Post-Induction Chemotherapy (Ic).

e17519Background: Current guidelines define that pre-IC target volumes must be used for radiotherapy (RT) planning. This prospective, phase II trial assessed the results of pts with SCCHN treatment with IC following by chemoradiotherapy (CRT), using post-IC PET/CT images for RT planning. Methods: Two PET/CT were performed: one prior IC, and one 2 weeks after 3 cycles of IC: docetaxel 75mg/m2, cisplatin 75mg/m2 and 5-FU 750 mg/m2 day 1-5. The gross tumor (GTVt) and nodal (GTVn) volumes on the post-IC PET/CT scans were contoured. The CTVt and CTVn were obtained by GTVt and GTVn plus 5 mm respectively. The elective CTV included CTVt, CTVn and bilateral elective lymphnodes. The margin of 3 mm was added to each CTV to create the PTVs. For PTVt and PTVn the prescribed doses were 70 Gy and 60 respectively, for PTVel – 50 Gy. CRT consisted of a chemotherapy with cisplatin (40 mg/m2 weekly) and RT (2 Gy once daily, 5 days a week). The primary end points was PFS. Secondary end points were OS and treatment safety. A...