Hello,
My clinic is new to using BrainLab Dynamic so we are trying to establish our tolerances for treatments of patients. Could anyone provide us with recommendations for X-ray and surface tolerances that you have found to work for treatments? Any and all body part tolerances would be appreciated. Breath-Hold and non Lung/Breast, Prostate, Brain, etc. SBRT tolerances as well and Conventional treatment tolerances would be appreciated as well.
Thank you in advance!
Comments
Dear Colleague,
At UCLA we formed a task group to address patient setup, indexing, image guidance and tolerance levels for patient positioning. This task group addressed many aspects of the IGRT used at our institution; one of them is the Exactrac tolerances.
We do not use Exactrac Dynamic just yet, so these are for the last generation Exactrac; however, some of the tolerances may be applicable.
Disclaimer: The data below cannot be used for clinical decision making. The table may include outdated information.
The table below lists the recommended Exactrac imaging tolerances for different treatment sites and treatment types (e.g. fractionated, SBRT or SRS). The table also lists the alignment structures (e.g. bone, tumor). Translation limits are meant as the limit above which positioning should be corrected. For example, a 2 mm limit means that if the image guidance system indicates > 2mm of positioning offset the couch shifts should be made before treatment proceeds. If the indicated positioning offset is 2 mm or less treatment may proceed without further table corrections. “Per Beam/Arc” means that initial and verification images should be acquired before each treatment beam/arc is delivered.
The frequency column suggests the frequency with which the image guidance should be employed during the course of treatment. In some cases we recommend two types of imaging for a given treatment, but with different frequencies each IGRT method. For example, we recommend TN patients be setup Per Beam using Exactrac, but also a CBCT prior to the treatment for independent verification of the Exactrac calibration.
Disclaimer: The data below cannot be used for clinical decision making. The table includes outdated information.
Dear Colleague,
At UZ Brussel, we primarily use the ETD surface in combination with stereoscopic X-rays for CNS (brain/spine) indications. For both, we apply inter-arc and intra-arc verifications. The combinations are also apply for breast DIBH.
For all brain treatments including SRS, we apply tolerances of 0.5 mm and 0.5 degrees for stereoscopic X-rays. Surface tolerances are set at 1 mm and 1 degree, as we prioritize X-ray-based repositioning.
For spine treatments, our tolerances are 1 mm and 1 degree for X-rays and 2 mm and 2 degrees for surface verification, again prioritizing X-ray-based corrections. We do not favor monoscopic imaging. After initial positioning with stereoscopic X-rays, we perform a CBCT scan for 3D volumetric verification.
For left-sided DIBH, our tolerances are set at 2 mm and 2 degrees for X-rays and 5 mm and 2 degrees for surface verification.
For all other cases, including right breast, conventional lung, SBRT, prostate, and palliative treatments, we follow a surface-only workflow. The goal is to track potential motion without applying a beam hold, using tolerances of 5 mm and 2 degrees.
Our ETD DIBH workflow for lung treatments is currently under investigation as a research topic, and we need more time before providing feedback.
Please don’t hesitate to reach out if you have any questions.
Kind regards,
Thierry