title: Dosimetric parameters correlate with duodenal histopathologic damage after stereotactic body radiotherapy for pancreatic cancer: Secondary analysis of a prospective clinical trial.
abstract: Prospectively assess relationships between dosimetric parameters and histopathologic/clinical duodenal toxicities in patients on a phase I trial for pancreatic cancer.
  
  
  
  Forty-six borderline resectable/unresectable patients were enrolled on a prospective trial testing neoadjuvant gemcitabine/5-fluorouracil followed by SBRT (5 daily fractions of 5-8Gy) and concurrent nelfinavir. Post-SBRT surgery was performed in 13 resectable patients, which constituted the patient population herein. Pathologic duodenal damage was assessed using predetermined criteria: 1, no/minimal; 2, moderate; and 3, marked damage. Clinical toxicities were assessed per the Clinical Terminology Criteria for Adverse Events (CTCAE). Duodenal dosimetric parameters included V5-V40 and mean/maximum doses. Spearman correlation and linear regression evaluated associations between dosimetric parameters and clinical/pathologic duodenal toxicity.
  
  
  
  The median duodenal mean and maximum doses were 20 and 37Gy. Median duodenal V5-V40 were 64, 62, 52, 39, 27, 14, 5 and 0cc, respectively. The median duodenal damage score was 2 (four 1, eight 2, and one 3). Higher duodenal damage scores correlated with higher duodenal mean doses (r=0.75, p=0.003), V35 (r=0.61, p=0.03), V30 (r=0.67, p=0.01), V25 (r=0.68, p=0.01), V20 (r=0.56, p=0.05), and the planning target volume (PTV) mean (r=0.59, p=0.03) and maximum (r=0.61, p=0.03) doses. Clinical toxicities did not correlate with dosimetric parameters or duodenal pathologic damage.
  
  
  
  Duodenal histologic damage correlates with mean duodenal dose, V20-V35, and PTV mean/maximum doses.
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Vivek
authors.initials: V
authors.lastname: Verma
authors.affiliation: Department of Pathology, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Audrey J
authors.initials: AJ
authors.lastname: Lazenby
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Abhijeet R
authors.initials: AR
authors.lastname: Bhirud
authors.affiliation: Department of Surgery, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Quan P
authors.initials: QP
authors.lastname: Ly
authors.affiliation: Department of Surgery, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Chandrakanth
authors.initials: C
authors.lastname: Are
authors.affiliation: Department of Surgery, Stony Brook University School of Medicine Stony Brook, USA.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Sasson
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, USA. Electronic address: clin@unmc.edu.
authors.forename: Chi
authors.initials: C
authors.lastname: Lin
mesh_terms: D000368:Aged; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004386:Duodenum / Q000473:pathology / Q000528:radiation effects*; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D000093542:Gemcitabine
chemical_list: D003841:Deoxycytidine; D005472:Fluorouracil; D000093542:Gemcitabine
keywords: Duodenum; Pancreatic cancer; Stereotactic body radiotherapy; Toxicity