Technological quality requirements for stereotactic radiotherapy

Abstract

This review details and discusses the technological quality requirements to ensure the desired quality for stereotactic radiotherapy using photon external beam radiotherapy as defined by the DEGRO Working Group Radiosurgery and Stereotactic Radiotherapy and the DGMP Working Group for Physics and Technology in Stereotactic Radiotherapy. The covered aspects of this review are 1) imaging for target volume definition, 2) patient positioning and target volume localization, 3) motion management, 4) collimation of the irradiation and beam directions, 5) dose calculation, 6) treatment unit accuracy, and 7) dedicated quality assurance measures. For each part, an expert review for current state-of-the-art techniques and their particular technological quality requirement to reach the necessary accuracy for stereotactic radiotherapy divided into intracranial stereotactic radiosurgery in one single fraction (SRS), intracranial fractionated stereotactic radiotherapy (FSRT), and extracranial stereotactic body radiotherapy (SBRT) is presented. All recommendations and suggestions for all mentioned aspects of stereotactic radiotherapy are formulated and related uncertainties and potential sources of error discussed. Additionally, further research and development needs in terms of insufficient data and unsolved problems for stereotactic radiotherapy are identified, which will serve as The authors D. Schmitt and O. Blanck contributed equally to the manuscript.

Definition and quality requirements for stereotactic radiotherapy: consensus statement from the DEGRO/DGMP Working Group Stereotactic Radiotherapy and Radiosurgery

“…These are to be interpreted as minimal requirements which must be fulfilled to achieve best clinical outcome and treatment quality for stereotactic radiotherapy. For further details on the technological requirements we refer to the expert review of the DGMP working group for physics and technology in stereotactic radiotherapy [9].…”

“…In 2018, a statement about the definition and general quality requirements for stereotactic radiotherapy was established and published by the DEGRO society. This consensus statement was amended to the current version in collaboration with the German Society for Medical Physics (DGMP) working group for physics and technology in stereotactic radiotherapy, taking into consideration the results of an expert review on technological quality requirements for stereotactic radiotherapy [9].…”

Feasibility of Optical Surface-Guidance for Position Verification and Monitoring of Stereotactic Body Radiotherapy in Deep-Inspiration Breath-Hold

“…For gated treatments an individual part of the respiratory cycle, usually the end-exhale phase, is chosen as a treatment window and further mitigates respiratory motion (4,9). Tracking of targets with the beam is another method to manage respiratory motion, but requires real-time imaging during the treatment delivery (4,10). The most reduction of respiratory movement, however, is achieved by breath-hold techniques that primarily target deep inspiration, which is tolerated longer than the end-exhale breath-hold phase and also carries less residual motion than gating of free breathing (4,11).…”

Magnetic resonance imaging for brain stereotactic radiotherapy

“…For stereotactic radiotherapy very high and specific technological quality requirements are needed to assure highly precise treatment delivery. These requirements have been comprehensively formulated and defined in the accompanying DEGRO/DGMP editorial and the DGMP review in the present issue [7,8]. Optimal MR imaging is a crucial element for high overall accuracy in stereotactic radiotherapy and ultimately a necessity for treatment success but is frequently overshadowed by the technological requirements that are more closely related to treatment delivery.…”