Inversion-recovery ultrashort-echo-time (IR-UTE) MRI-based detection of radiation dose heterogeneity in gynecologic cancer patients treated with HDR brachytherapy

• DOI: 10.1186/s13014-024-02499-2
• Publication Date: 2024-08-06T12:03:14Z
• Authors: Khadija Sheikh; Bruce L. Daniel; Michael Roumeliotis; Junghoon Lee; William T. Hrinivich; Thomas Benkert; Himanshu Bhat; Ravi T. Seethamraju; Akila N. Viswanathan; Ehud J. Schmidt
• Keywords: Genital Neoplasms, Female; Research; Radiotherapy Planning, Computer-Assisted; Brachytherapy; R895-920; Neoplasms. Tumors. Oncology. Including cancer and carcinogens; Radiotherapy Dosage; Middle Aged; Magnetic Resonance Imaging; Medical physics. Medical radiology. Nuclear medicine; 03 medical and health sciences; 0302 clinical medicine; Humans; Female; RC254-282; Aged

Abstract Purpose To evaluate the relationship between delivered radiation (RT) and post-RT inversion-recovery ultrashort-echo-time (IR-UTE) MRI signal-intensity (SI) in gynecologic cancer patients treated with high-dose-rate (HDR) brachytherapy (BT). Methods Seven underwent whole-pelvis RT (WPRT) followed by BT to high-risk clinical target volume (HR-CTV). MR images were acquired at three time-points; pre-RT, post-WPRT/pre-BT, 3–6 months post-BT. Diffuse-fibrosis (F Diffuse ) was imaged a non-contrast dual-echo IR (inversion time [TI] = 60 ms) UTE research application, image-subtraction of later echo, only retaining ultrashort-echo SI. Dense-fibrosis Dense imaging utilized single-echo Late-Gadolinium-Enhanced IR-UTE, ∼ 15 min post-Gadavist injection. Resulting F SI normalized corresponding gluteal-muscle Images deformably registered time-points based on normal tissue anatomy. The remnant tumor both segmented using multi-parametric MRI. Contours 50%, 100%, 150%, 200% isodose lines (IDLs) prescription BT-dose created. Mean within (i) each IDL contour (ii) calculated. Post-BT correlated prescribed BT-dose. determine IR-UTE SI, differences post-BT across IDLs determined paired t-tests Bonferroni correction. Results higher regions dose for 6/7 patients, mean ± SD values 357 103% 331 97% ( p .03) 100% 50% IDL, respectively. responsive 380 122% 356 135% 150% Within tumor, an increase n 5, r .89, .04). inversely 7, -.83, .02) IDL. Conclusions suggest that is sensitive measure response heterogeneous radiation-dose. Future studies will validate whether are accurate biomarkers fibrotic response.