title: Individually optimized stereotactic radiotherapy for pancreatic head tumors: A planning feasibility study.
abstract: OBJECTIVE
  Aim of this study was to perform a planning feasibility analysis of a 3-level dose prescription using an IMRT-SIB technique.
  
  
  BACKGROUND
  Radiation therapy of locally advanced pancreatic cancer should administer a minimum dose to the duodenum and a very high dose to the vascular infiltration areas to improve the possibility of a radical resection.
  
  
  METHODS
  Fifteen patients with pancreatic head adenocarcinoma and vascular involvement were included. The duodenal PTV (PTVd) was defined as the GTV overlapping the duodenal PRV. Vascular CTV (CTVv) was defined as the surface of contact or infiltration between the tumor and vessel plus a 5 mm margin. Vascular PTV (PTVv) was considered as the CTVv plus an anisotropic margin. The tumor PTV (PTVt) was defined as the GTV plus a margin including the PTVv and excluding the PTVd. The following doses were prescribed: 30 Gy (6 Gy/fraction) to PTVd, 37.5 Gy (7.5 Gy/fraction) to PTVt, and 45 Gy (9 Gy/fraction) to PTVv, respectively. Treatment was planned with an IMRT technique.
  
  
  RESULTS
  The primary end-point (PTVvDmean> 90%) was achieved in all patients. PTVvD98%> 90% was achieved in 6 patients (40%). OARs constraints were achieved in all patients.
  
  
  CONCLUSIONS
  Although the PTVvD95%> 95% objective was achieved only in 40% of patients, the study showed that in 100% of patients it was possible to administer a strongly differentiated mean/median dose. Prospective trials based on clinical application of this strategy seem to be justified in selected patients without overlap between PTVd and PTVv.
authors.affiliation: Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine - DIMES, University of Bologna, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Milly
authors.initials: M
authors.lastname: Buwenge
authors.affiliation: Medical Physic Unit, Fondazione "Giovanni Paolo II", Catholic University of Sacred Heart, Campobasso, Italy.
authors.forename: Savino
authors.initials: S
authors.lastname: Cilla
authors.affiliation: Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine - DIMES, University of Bologna, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Guido
authors.affiliation: Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine - DIMES, University of Bologna, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Giaccherini
authors.affiliation: Radiotherapy Unit, Fondazione "Giovanni Paolo II", Catholic University of Sacred Heart, Campobasso, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Macchia
authors.affiliation: Radiotherapy Unit, Fondazione "Giovanni Paolo II", Catholic University of Sacred Heart, Campobasso, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Deodato
authors.affiliation: Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine - DIMES, University of Bologna, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Cammelli
authors.affiliation: Radiation Oncology Department, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cellini
authors.affiliation: Radiation Oncology Department, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Gian C
authors.initials: GC
authors.lastname: Mattiucci
authors.affiliation: Radiation Oncology Department, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Valentini
authors.affiliation: EBG MedAustron, Wiener Neustadt, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Stock
authors.affiliation: Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine - DIMES, University of Bologna, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Alessio G
authors.initials: AG
authors.lastname: Morganti
keywords: IMRT; Pancreatic neoplasms; Simultaneous integrated boost; Stereotactic body radiotherapy