Towards simulation-free MR-linac treatment: utilizing male pelvis PSMA-PET/CT and population-based electron density assignments.

. This study aimed to investigate the dosimetric impact of using population-based relative electron density (RED) overrides in lieu of simulation computerized tomography (CT) in a magnetic resonance linear accelerator (MRL) workflow for male pelvis patients. Additionally, the feasibility of using prostate specific membrane antigen positron emission tomography/CT (PSMA-PET/CT) scans to assess patients' eligibility for this proposed workflow was examined.

Conformance of a 3T radiotherapy MRI scanner to the QIBA Diffusion Profile.

Purpose: To assess the technical performance of the apparent diffusion coefficient (ADC) on a dedicated 3T radiotherapy scanner, using a standardized phantom and sequences. Investigations into factors that could impact the technical performance of ADC in the clinic were also completed, including changing the slice-encoded imaging direction and the reference sample ADC value.

Methods: ADC acquisitions were performed monthly on an isotropic diffusion phantom over 1 year.

Determining the longitudinal accuracy and reproducibility of T and T in a 3T MRI scanner.

Purpose: To determine baseline accuracy and reproducibility of T and T relaxation times over 12 months on a dedicated radiotherapy MRI scanner.

Methods: An International Society of Magnetic Resonance in Medicine/National Institute of Standards and Technology (ISMRM/NIST) System Phantom was scanned monthly on a 3T MRI scanner for 1 year. T was measured using inversion recovery (T -IR) and variable flip angle (T -VFA) sequences and T was measured using a multi-echo spin echo (T -SE) sequence.