This presentation will provide a detailed overview of a Medical Dosimetrist’s role in MR-guided adaptive SABR patient pathway. Medical Dosimetrists are intricately involved from the patient’s simulation to the real time plan adaption process, in addition to the usual contouring and dosimetry duties. 

For complex cases, a Medical Dosimetrist is required to provide detailed simulation instructions to Radiation Therapists, and these include tumor(s) location coordinates; scan length requirements; setup requests; whether breath-hold is required, tracking instructions and gating parameters; as well as an assessment whether a single or multiple iso centers are required. This requires a completion of an Adaptive Handover Form (AHF) and a simulation session using radiology images saved in MIM Software. For highly complex cases a Medical Dosimetrist must be present during simulation.  

Contouring on MR images is slightly different compared to CT images due to difference in contrast. There is currently no MIM auto-contouring workflow for Thoracic and Abdominal MR images. Therefore, there is more extensive manual contouring required. In post-surgical cases (e.g. post Whipple’s cases) contouring can be very complex, detailed knowledge of anatomy and image fusion is essential. 

A Medical Dosimetrist is expected to create a clinically acceptable, robust, and adaptable plan. This involves a creation of rules/formulae for a quick and accurate creation of target margins and optimization structures; anticipate anatomical changes on plan adaption and set up plan objectives accordingly. Provide detailed plan adaption instructions on the AHF and these include, contouring instructions, and optimization instructions.      Real Time Plan Adaption includes teamwork; attention to detail; efficiency; analytical and critical/clinical thinking skills are a must for a Medical Dosimetrist to safely execute on the day re-optimizations; quality assurance task

Learner Outcomes:

1.    Outline the daily responsibilities of a Medical Dosimetrist in Adaptive SABR patient pathway
2.    Provide examples of the differences between MR guided adaptive role and conventional planning Medical Dosimetrist role
3.    Summarize the roles of a Medical Dosimetrist in Adaptive RT

CE Credit = 1.0