Purpose: Evaluation of the added value of radiotherapy guided by the cutaneous
surface in the positioning and monitoring of the radiotherapy
Patients and Methods: This study included 21 consecutive patients treated with an
accelerator dedicated to "True Beam®" stereotactic radiotherapy whose sessions were
monitored by an Optical Surface Monitoring System: "OSMS®". Excluded from our
study were treatments controlled exclusively by radiological imaging (IGRT).
Positioning variabilities were compared between conventional imaging and skin
surface infrared (OSMS) monitoring. Conventional imaging was in the form of
standard radiography (KV) performed during the treatment session or three-
dimensional by a series of Cone Beam computerized tomography (CBCT) scanned
images made at the beginning and end of The total time of the session and
the positioning variability’s in the 3 planes were
14
Results: The results of our study show that the cutaneous surface monitoring allowed
to obtain a faster alignment of the patient with an improvement in the overall time of
the session with a mean at 32% [14.5-49.27%], likewise a sub-millimeter positioning
quality for all locations with a median longitudinal distance of 0.02 cm [0-0.66], 01
cm verticality [0-0.32] and laterality 0.02 cm [0-0.77] This benefit is significantly
greater for cerebral and Head and neck’s localizations
21
Conclusion: Optical Surface Monitoring System (OSMS®) is a non-invasive and non-
irradiating means that allows reliable and fast
EP-1671: Accuracy evaluation of the Optical Surface Monitoring System on EDGE linear accelerator for patient positioning
