T-1 rho for Radiotherapy Treatment Response Monitoring in Rectal Cancer Patients: A Pilot Study

Autor: Kooreman, E.S., Tanaka, M., Beek, L.C. ter, Peters, F.P., Marijnen, C.A.M., Heide, U.A. van der, Houdt, P.J. van
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Journal of Clinical Medicine, 11(7). MDPI
Journal of Clinical Medicine; Volume 11; Issue 7; Pages: 1998
Popis: Quantitative MRI has the potential to produce imaging biomarkers for the prediction of early response to radiotherapy treatment. In this pilot study, a potential imaging biomarker, the T1ρ relaxation time, is assessed for this purpose. A T1ρ sequence was implemented on a 1.5 T MR-linac system, a system that combines an MRI with a linear accelerator for radiation treatment. An agar phantom with concentrations of 1–4% w/w was constructed for technical validation of the sequence. Phantom images were assessed in terms of short-term repeatability and signal-to-noise ratio. Twelve rectal cancer patients, who were treated with 5 × 5 Gy, were imaged on each treatment fraction. Individual changes in the T1ρ values of the gross tumor volume (GTV) showed an increase for most patients, although a paired t-test comparing values in the GTV from the first to the last treatment fraction showed no statistically significant difference. The phantom measurements showed excellent short-term repeatability (0.5–1.5 ms), and phantom T1ρ values corresponded to the literature values. T1ρ imaging was implemented successfully on the MR-linac, with a repeatability comparable to diagnostic systems, although clinical benefit in terms of treatment response monitoring remains to be demonstrated.
Databáze: OpenAIRE