Fentanyl Pectin Nasal Citrate (FPNC) to Control Breakthrough Pain (BP) and Improve Dysphagia in Head-and-Neck Cancer Patients Receiving Radiation Therapy (RT)

Abstract

applicator was constructed by attaching brachytherapy catheters at 1 cm intervals to a 5 mm thick bolus. Two treatment plans were generated for brachytherapy: one for Iridum-192 HDR and the other which assumed treatment with 50 kVp EBT using the same applicator. A third plan was generated for a 2 full arc 6 MV photon VMAT (also with a 5 mm thick bolus). The target and organs at risk (OARs) were contoured on a simulation CT scan. The prescription was 36 Gy in 8 fractions for a 9 cm 12 cm 1 cm target. The plans were optimized to a standard target coverage (V100% > 98%) and to minimize dose to OARs using Nucletron Oncentra MasterPlan (HDR), Varian BrachyVision (EBT) and Eclipse (VMAT). We compared mean target dose, dose heterogeneity, and doses to OARs. Results: The target V100% and D90% were 98% and 104% (HDR), 100% and 119% (EBT), and 98% and 102% (VMAT). The mean (and range from minimum to 1cc maximum) target doses were HDR 119% (86-157%), EBT 164% (86-271%), and VMAT 104% (96-108%). The Table summarizes mean dose to OARs. Conclusions: EBT provided the least dose to closest OAR (brain) due to rapid dose fall-off of low-energy X-rays, but it resulted in higher mean target doses and more heterogeneity than HDR and VMAT. HDR and VMAT provided similar V100% and D90% target doses. As expected, VMAT provided most dose uniformity. All methods resulted in acceptable normal tissue doses, but they were lower for EBT and VMAT than HDR specifically for this lesion located on the top of the skull. Comparative dosimetry facilitates treatment modality selection for extensive superficial lesions with complex surfaces, irregular contours, and close proximity to OARs. Author Disclosure: S. Park: None. M. Kamrava: None. O. Kayode: None. S.P. Lee: None. M.L. Steinberg: None. D.J. Demanes: None.