Open AccessA complete 4 DCT ‐ventilation functional avoidance virtual trial: Developing strategies for prospective clinical trials
Author(s) -
Waxweiler Timothy,
Schubert Leah,
Diot Quentin,
Faught Austin,
Stuhr Kelly,
Castillo Richard,
Castillo Edward,
Guerrero Thomas,
Rusthoven Chad,
Gaspar Laurie,
Kavanagh Brian,
Miften Moyed,
Vinogradskiy Yevgeniy
Publication year - 2017
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1002/acm2.12086
Subject(s) - clinical trial , medicine , lung cancer , ventilation (architecture) , radiation therapy , functional imaging , medical physics , radiology , nuclear medicine , mechanical engineering , engineering
Abstract Introduction 4 DCT ‐ventilation is an exciting new imaging modality that uses 4 DCT data to calculate lung‐function maps. Because 4 DCT s are acquired as standard of care for lung cancer patients undergoing radiotherapy, 4 DCT ‐ventiltation provides functional information at no extra dosimetric or monetary cost to the patient. The development of clinical trials is underway to use 4 DCT ‐ventilation imaging to spare functional lung in patients undergoing radiotherapy. The purpose of this work was to perform a virtual trial using retrospective data to develop the practical aspects of a 4 DCT ‐ventilation functional avoidance clinical trial. Methods The study included 96 stage III lung cancer patients. A 4 DCT ‐ventilation map was calculated using the patient's 4 DCT ‐imaging, deformable registration, and a density‐change‐based algorithm. Clinical trial inclusion assessment used quantitative and qualitative metrics based on the patient's spatial ventilation profile. Clinical and functional plans were generated for 25 patients. The functional plan aimed to reduce dose to functional lung while meeting standard target and critical structure constraints. Standard and dose‐function metrics were compared between the clinical and functional plans. Results Our data showed that 69% and 59% of stage III patients have regional variability in function based on qualitative and quantitative metrics, respectively. Functional planning demonstrated an average reduction of 2.8 Gy (maximum 8.2 Gy) in the mean dose to functional lung. Conclusions Our work demonstrated that 60–70% of stage III patients would be eligible for functional planning and that a typical functional lung mean dose reduction of 2.8 Gy can be expected relative to standard clinical plans. These findings provide salient data for the development of functional clinical trials.