Are there any potential benefits to irradiating the partial breast with an MR-linac over conventional linac?

The group at WashU has done a great job publishing on this topic (Price et al., PMID 34624406).

At this time, I don't think we can say there is a clear benefit to MR linac over conventional CBCT when it comes to cancer control or toxicity, though there may be dosimetric benefits (that could translate into toxicity differences) MR-linac may allow for smaller target volumes.