Long-term patient experience with online MR-guided radiotherapy: adaptive versus non-adaptive workflow

Area of Science:

• Radiation Oncology
• Medical Physics

Background:

• Magnetic resonance-linear accelerator (MR-Linac) systems offer advanced radiotherapy with real-time MR guidance and online adaptive planning.
• Online adaptation enhances dosimetric precision but prolongs treatment sessions, posing resource challenges.

Purpose of the Study:

• To evaluate patient-reported outcome measures (PROMs) and long-term toxicity in MR-guided radiotherapy.
• To assess the specific impact of online adaptive workflows on patient experience and outcomes.

Main Methods:

• A subgroup analysis of 231 patients treated with MRIdian Linac between January 2019 and May 2021.
• Utilized a custom questionnaire (PRO-Q) for patient experience and CTCAE v. 5.0 for toxicity assessment.
• Compared outcomes between non-adaptive (n=130) and adaptive (n=101) treatment groups.

Main Results:

• Adaptive treatment significantly increased session duration (71 min vs. 36 min) and patient-reported discomfort related to duration, immobility, and sensory perceptions.
• No significant differences in overall toxicity were observed between adaptive and non-adaptive groups.
• Patients receiving adaptive therapy showed a faster return to baseline status post-treatment (6-8 weeks vs. 6-12 months).

Conclusions:

• Online adaptive planning in MR-Linac radiotherapy increases treatment time and negatively affects short-term PROMs.
• The adaptive approach is safe, without compromising toxicity or oncologic outcomes.
• Further research with validated PROMs and cost-benefit analyses is needed to establish the clinical value of adaptive MR-guided radiotherapy.