Can bronchoscopically implanted anchored electromagnetic transponders be used to monitor tumor position and lung inflation during deep inspiration breath‐hold lung radiotherapy?

• DOI: 10.1002/mp.15565
• Publication Date: 2022-02-22T14:23:27Z
• Authors: Wendy Harris; Ellen Yorke; Henry Li; Christian Czmiele...; Mohit Chawla; Robert P. Lee; Alexandra Hotca‐Cho; Dominique McKnight; Andreas Rimner; D. Michael Lovelock
• Keywords: Breath Holding; 03 medical and health sciences; Lung Neoplasms; 0302 clinical medicine; Radiotherapy Planning, Computer-Assisted; Humans; Prospective Studies; Lung; Retrospective Studies

To evaluate the efficacy of using bronchoscopically implanted anchored electromagnetic transponders (EMTs) as surrogates for 1) tumor position and 2) repeatability lung inflation during deep-inspiration breath-hold (DIBH) radiotherapy.Forty-one patients treated with either hypofractionated (HF) or conventional (CF) radiotherapy on an IRB-approved prospective protocol coached DIBH were evaluated this study. Three EMTs into small airways near within tumor. treatment was gated by tracking EMT positions. Breath-hold cone-beam-CTs (CBCTs) acquired prior to every HF weekly CF patients. Retrospectively, rigid registrations between each CBCT planning CT performed match spine, 3) Absolute differences in registration spine analyzed determine surrogacy inflation. Differences position. The stability analyzing difference inter-EMT displacements recorded at from that plan patients, well geometric residual (GR) time treatment.A total 219 CBCTs analyzed. average centroid among all 0.45±0.42 cm, 0.29±0.28 0.18±0.15 cm superior-inferior (SI), anterior-posterior (AP) lateral directions, respectively. Only 59% had < 0.5 compared indicating is not reproducible simulation treatment. 0.13±0.13 0.14±0.13 0.12±0.12 SI, AP Ninety-five percent resulted a change registration, positions correspond treatments. Six out seven ≤0.26 GR ≤0.22 are stable throughout treatment.Bronchoscopically good reliable maintaining when tracked treatment, long size shape stable. Large many treatments suggest achieved often reproduced.