Consolidating duodenal and small bowel toxicity data via isoeffective dose calculations based on compiled clinical data. Pract Radiat Oncol 2014;4(2):e125-e131
Date
06/04/2014Pubmed ID
24890358DOI
10.1016/j.prro.2013.05.003Scopus ID
2-s2.0-84896700388 (requires institutional sign-in at Scopus site) 10 CitationsAbstract
PURPOSE: To consolidate duodenum and small bowel toxicity data from clinical studies with different dose fractionation schedules using the modified linear quadratic (MLQ) model. A methodology of adjusting the dose-volume (D,v) parameters to different levels of normal tissue complication probability (NTCP) was presented.
METHODS AND MATERIALS: A set of NTCP model parameters for duodenum toxicity were estimated by the χ(2) fitting method using literature-based tolerance dose and generalized equivalent uniform dose (gEUD) data. These model parameters were then used to convert (D,v) data into the isoeffective dose in 2 Gy per fraction, (D(MLQED2),v) and convert these parameters to an isoeffective dose at another NTCP (D(MLQED2'),v).
RESULTS: The literature search yielded 5 reports useful in making estimates of duodenum and small bowel toxicity. The NTCP model parameters were found to be TD50(1)(model) = 60.9 ± 7.9 Gy, m = 0.21 ± 0.05, and δ = 0.09 ± 0.03 Gy(-1). Isoeffective dose calculations and toxicity rates associated with hypofractionated radiation therapy reports were found to be consistent with clinical data having different fractionation schedules. Values of (D(MLQED2'),v) between different NTCP levels remain consistent over a range of 5%-20%.
CONCLUSIONS: MLQ-based isoeffective calculations of dose-response data corresponding to grade ≥2 duodenum toxicity were found to be consistent with one another within the calculation uncertainty. The (D(MLQED2),v) data could be used to determine duodenum and small bowel dose-volume constraints for new dose escalation strategies.
Author List
Prior P, Tai A, Erickson B, Allen Li XAuthors
Beth A. Erickson MD Professor in the Radiation Oncology department at Medical College of WisconsinPhillip Prior PhD Assistant Professor in the Radiation Oncology department at Medical College of Wisconsin
An Tai PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Dose-Response Relationship, RadiationDuodenum
Humans
Intestine, Small
Linear Models
Radiation Injuries
Radiotherapy Planning, Computer-Assisted