Adaptive biological image-guided IMRT with anatomic and functional imaging in pharyngo-laryngeal tumors: Impact on target volume delineation and dose distribution using helical tomotherapy

摘要: BACKGROUND AND PURPOSE: Adaptive image-guided IMRT appears to be a promising approach for dose escalation in pharyngo-laryngeal tumors. In this framework, we assessed proof of concept study the impact anatomic and functional imaging modalities acquired prior during radiotherapy on target volume delineation distribution using helical tomotherapy. MATERIALS METHODS: Ten patients with squamous cell carcinoma were treated by concomitant chemo-radiation delivered 7 weeks. CT, T2-MRI, fat suppressed static dynamic FDG-PET each patient before start treatment radiotherapy, after mean prescribed doses 14, 25, 35 45 Gy. GTVs manually delineated CT MRI images while PET automatically segmented means gradient-based method. From these volumes, CTVs PTVs derived consistent guidelines. Simultaneous integrated boost planning was performed RESULTS: significantly decreased throughout course RT all (p<0.001). Clinically non-significant differences high correlations found between MRI, irrespective sequence used. By contrast, FDG-PET-based from pre- per-treatment smaller compared anatomical modalities, without any difference existing acquisition. These translated into parallel reductions both prophylactic therapeutic PTVs. Resulting adaptive reduced irradiated volumes 15-40% pre-treatment (V(90), V(95) V(100)), but did marginally OAR such as spinal cord parotid glands. CONCLUSIONS: has significant TVs Such an might thus considered strategies.