Late gastrointestinal tissue effects after hypofractionated radiation therapy of the pancreas

Background To consolidate literature reports of serious late gastrointestinal toxicities after hypofractionated radiation treatment of pancreatic cancer and attempt to derive normal tissue complication probability (NTCP) parameters using the Lyman-Kutcher-Burman model. Methods Published reports of late grade 3 or greater gastrointestinal toxicity after hypofractionated treatment of pancreatic cancer were reviewed. The biologically equivalent dose in 1.8 Gy fractions was calculated using the EQD model. NTCP parameters were calculated using the LKB model assuming 1–5 % of the normal tissue volume was exposed to the prescription dose with α/β ratios of 3 or 4. Results A total of 16 human studies were examined encompassing a total of 1160 patients. Toxicities consisted of ulcers, hemorrhages, obstructions, strictures, and perforations. Non-hemorrhagic and non-perforated ulcers occurred at a rate of 9.1 % and were the most commonly reported toxicity. Derived NTCP parameter ranges were as follows: n = 0.38–0.63, m = 0.48–0.49, and TD50 = 35–95 Gy. Regression analysis showed that among various study characteristics, dose was the only significant predictor of toxicity. Conclusions Published gastrointestinal toxicity reports after hypofractionated radiotherapy for pancreatic cancer were compiled. Median dose was predictive of late grade ≥ 3 gastrointestinal toxicity. Preliminary NTCP parameters were derived for multiple volume constraints

Does facial soft tissue protect against zygomatic fractures?: results of a finite element analysis

Introduction: Zygomatic fractures form a major entity in craniomaxillofacial traumatology. Few studies have dealt with biomechanical basics and none with the role of the facial soft tissues. Therefore this study should investigate, whether facial soft tissue plays a protecting role in lateral midfacial trauma

Late gastrointestinal tissue effects after hypofractionated radiation therapy of the pancreas

Background: To consolidate literature reports of serious late gastrointestinal toxicities after hypofractionatedradiation treatment of pancreatic cancer and attempt to derive normal tissue complication probability (NTCP)parameters using the Lyman-Kutcher-Burman model.Methods: Published reports of late grade 3 or greater gastrointestinal toxicity after hypofractionated treatment ofpancreatic cancer were reviewed. The biologically equivalent dose in 1.8 Gy fractions was calculated using the EQDmodel. NTCP parameters were calculated using the LKB model assuming 1--5 % of the normal tissue volume wasexposed to the prescription dose with a/β ratios of 3 or 4.Results: A total of 16 human studies were examined encompassing a total of 1160 patients. Toxicities consisted ofulcers, hemorrhages, obstructions, strictures, and perforations. Non-hemorrhagic and non-perforated ulcers occurredat a rate of 9.1 % and were the most commonly reported toxicity. Derived NTCP parameter ranges were as follows:n = 0.38--0.63, m = 0.48--0.49, and TD50 = 35--95 Gy. Regression analysis showed that among various studycharacteristics, dose was the only significant predictor of toxicity.Conclusions: Published gastrointestinal toxicity reports after hypofractionated radiotherapy for pancreatic cancerwere compiled. Median dose was predictive of late grade ≥ 3 gastrointestinal toxicity. Preliminary NTCP parameterswere derived for multiple volume constraints