SBRT Treatment Planning: Practical Considerations
Linda Hong1*, (1) Montefiore Medical Center, Bronx, NYWE-E-BRCD-1 Wednesday 2:00:00 PM - 2:55:00 PM Room: Ballroom CD
Stereotactic Body Radiation Therapy (SBRT) is being increasingly used in the radiation oncology community to treat tumors in extra-cranial sites such as spine, lung, liver, pancreas and prostate. There are well established RTOG protocols (e.g. RTOG 0631 for spine, RTOG 0813 and 0915 for lung and RTOG 0438 for liver) that specify detailed requirements for treatment planning of SBRT plans. SBRT plans have to meet strict criteria on maximum PTV dose, prescription isodose, prescription isodose surface coverage, high dose spillage and intermediate dose spillage in addition of the constraints of dose limiting organs at risk. This lecture aims to educate members on treatment planning issues for SBRT cases with concentration on strategies to create highly inhomogeneous dose distributions inside the PTV and steep dose gradients in the surrounding normal tissues.
1. What characteristics SBRT plans have and how they are different from conventional fractionated radiotherapy plans.
2. For IMRT/VMAT SBRT plans (such as spine SBRT plans that concave distributions around the cord are required), we will discuss strategies that can be employed to overcome many commercial treatment planning system’s IMRT algorithms’ intrinsic penalty for inhomogeneous plans. Additional issues related to VMAT will be also discussed.
3. For non-IMRT SBRT plans (such as many lung or liver cases where target motion is a concern), we will discuss techniques to control dose inhomogeneities and dose fall off.
4. We will also discuss policy and procedures on SBRT patient setup and verification issues to ensure safe delivery of SBRT treatments.