Establishing the feasibility of the dosimetric compliance criteria of RTOG 1308: phase III randomized trial comparing overall survival after photon versus proton radiochemotherapy for inoperable stage II-IIIB NSCLC

Abstract

BackgroundTo establish the feasibility of the dosimetric compliance criteria of the RTOG 1308 trial through testing against Intensity Modulation Radiation Therapy (IMRT) and Passive Scattering Proton Therapy (PSPT) plans.MethodsTwenty-six lung IMRT and 26 proton PSPT plans were included in the study. Dose Volume Histograms (DVHs) for targets and normal structures were analyzed. The quality of IMRT plans was assessed using a knowledge-based engineering tool.ResultsMost of the RTOG 1308 dosimetric criteria were achieved. The deviation unacceptable rates were less than 10 % for most criteria; however, a deviation unacceptable rate of more than 20 % was computed for the planning target volume minimum dose compliance criterion. Dose parameters for the target volume were very close for the IMRT and PSPT plans. However, the PSPT plans led to lower dose values for normal structures. The dose parameters in which PSPT plans resulted in lower values than IMRT plans were: lung V5Gy (%) (34.4 in PSPT and 47.2 in IMRT); maximum spinal cord dose (31.7 Gy in PSPT and 43.5 Gy in IMRT); heart V5Gy (%) (19 in PSPT and 47 in IMRT); heart V30Gy (%) (11 in PSPT and 19 in IMRT); heart V45Gy (%) (7.8 in PSPT and 12.1 in IMRT); heart V50% (Gy) (7.1 in PSPT and 9.8 in IMRT) and mean heart dose (7.7 Gy in PSPT and 14.9 Gy in IMRT).ConclusionsThe revised RTOG 1308 dosimetric compliance criteria are feasible and achievable.

Validation and application of a fast Monte Carlo algorithm for assessing the clinical impact of approximations in analytical dose calculations for pencil beam scanning proton therapy

“…An in‐house and open‐source fast MC code, MCsquare, which is optimized and dedicated to pencil beam scanning (PBS) proton therapy simulations in voxelized geometries, such as a CT image, was employed. An open‐source collaboration, OpenReggui, has integrated both MCsquare‐based dose calculation and the planning tool MIROpt to make fast MC‐based post‐planning evaluation and planning available to community hospitals, and to provide an ideal tool for collaboration among institutions or potentially for centralized auditing IROC/NRG . MCsquare was previously benchmarked with Geant4 simulations and validated by measurements for simple homogeneous and heterogeneous phantom geometries …”

A Feasibility Study of the Dosimetric Compliance Criteria of the NRG-HN002 Head and Neck Clinical Trial Across Different Radiotherapy Treatment Planning Systems and Delivery Techniques: A Model for Optimizing Initial Trial Launch

“…The compliance criteria of clinical trials are often used as constraints for treatment planning and are always used for plan scoring upon final review [4]. Upon review at the Imaging and Radiation Oncology Core (IROC) RT QA center, treatment plans of patients enrolled in NRG-Oncology clinical trials are given scores of 1, 2 or 3.…”

“…A treatment plan is given a score of 1 if it exactly meets the criteria; given a score of 2 if it falls within the variation acceptable range, and given a score of 3 and rejected if it violates the variation acceptable range. The method used for designing compliance criteria should optimally examine a large number of treatment plans that are considered to be the result of significant effort on the part of experienced treatment planners [4]. Such a process should take place prior to the activation of the clinical trial.…”

“…Such a step represents an important improvement in the launch of a new clinical trial. In a previous study, the dosimetric compliance criteria of the RTOG 1308 clinical trial was investigated during the design stage of the trial [4], The investigation study analyzed 26 pairs (each pair consisted of IMRT and proton passive scattered therapy (PSPT) plan) of treatment plans submitted by two major institutions. The plans were developed using institutional protocols that have similar guidelines to RTOG 1308 and the doses were scaled to the prescription dose of RTOG 1308.…”

“…The plans were developed using institutional protocols that have similar guidelines to RTOG 1308 and the doses were scaled to the prescription dose of RTOG 1308. The study [4] helped in establishing feasible dosimetric criteria for RTOG 1308. This paper reports on assessing the dosimetric compliance criteria of clinical trials (applied to NRG HN002 trial) using a different approach.…”