Clinical practice in stereotactic radiotherapy delivery at treatment unit: a practitioner survey and consensus-based...

Stereotactic radiation therapy (SRT) is on the rise around the world. We aimed to provide recommendations to streamline and assess medical practices in SRT delivery at treatment unit, while complying with legal obligations concerning safety.

We conducted an online closed practice survey for heads of radiotherapy departments both nationally in comprehensive cancer centers and university hospitals throughout France, and internationally. The aim was to obtain a better understanding of how the delivery of SRT at treatment unit was managed across different centers according to experience, and to the machines and repositioning techniques used. Radiation oncologists (ROs) were also asked to assess the difficulties of technical implementation in the department, and whether residents were involved in the validation and delivery of SRT. Differences among countries regarding legislation governing the validation of SRT sessions at treatment unit were also collected. A videoconference was then held to draw up proposals for regulatory changes based on the results obtained. Finally, recommendations were drawn up by the steering committee and approved by heads of radiotherapy departments in comprehensive cancer centers and university hospitals throughout France.

Thirty-five French centers and 15 centers from 14 foreign countries responded to the questionnaire. The most common stereotactic machines were Varian Truebeam STX® (45%) and Cyberknife® (39.2%). The departments had been performing SRT for more than 10 years in 60.5% of cases, and for less than 5 years in 10.1% of cases. A RO validated the SRT fractions at each session in 62.9% of French departments, while in countries outside France RO validation concerned the first fraction only for 35.3% or was performed only in the event of an issue for 23.5%. RO patient positioning validation of SRT fractions were considered as: time-consuming / task-interrupting (80%); having no added value with regards its systematic use (41.8%); and leading to a loss of machine time (33.1%). Most heads of departments would like to see an evolution towards systematic RO validation for the first session, then validation by a radiation therapist (RTT) for all subsequent sessions, leaving open the possibility of RO intervention when required in case of difficulty. We drew up a task delegation procedure to meet these requirements.

Comparing the French practice to international ones confirmed the need to develop and harmonize recommendations in terms of patient positioning validation at treatment unit. Regulatory changes incorporating a competence transfer to RTTs, particularly after the empowerment process, is key. However, these changes need to be adapted to the experience of each Center and to that of each RTT, as assessed with clearly established criteria and learning curve.