Room: Celestin D-E
Introducing new treatment modalities to a clinic can be a challenge. There are financial, organizational, technical, philosophical, and patient-population considerations to consider, to just name a handful of what goes into a new program. In this session we will hear about two newer treatment modalities and how clinics have successfully brought them into successful routine use. The first half will be spent on stereotactic radiosurgery approaches for multiple and recurrent brain metastases. The second half will be spent on VMAT approaches to total body irradiation.
Brain metastases (BMs) are diagnosed in up to 40% of cancer patients. Current data estimate ~200,000 new patients develop BMs annually and the onset is predominantly multiple BMs (mBMs). Moreover, with the advance of systemic therapy, a growing number of treated patients live long to experience recurrent BMs (rBMs). Historically, mBMs and rBMs patients were primarily treated with whole brain radiotherapy (WBRT) which is linked to the neurocognitive function decline. With technological advances, stereotactic radiosurgery (SRS) has emerged as a new standard of care with superior capability to limit toxicity and preserve neurocognitive function compared to conventional WBRT.
SRS in general is a complex, time-consuming and labor-intensive clinical procedure. The complexity is compounded in cases of multiple brain metasteses (mBMs) and further in recurrent brain metasteses (rBMs). Many clinically important questions are raised and urgently needed to be addressed: How many BMs are too many, in other words, in which scenarios we should choose SRS over WBRT? How to conduct safe initial SRS and repeat SRS for mBMs and rBMs? How to ensure an optimal SRS to preserve patients’ neurocognitive function? Last but not least, how to streamline treatment and follow-up workflow?
Different institutions implement mBMs SRS on different treatment platforms and tackle its complexity with diverse strategies. In this education session, two physicists will share their mBMs SRS clinical experience on three mainstream radiotherapy platforms, Gamma Knife, CyberKnife, and LINAC.
Total body irradiation (TBI) is essential for myeloablative conditioning regimens in patients undergoing allogeneic hematopoietic stem cell transplantation (HCT). In this setting, the TBI total dose varies from 10-16 Gy, with 1.2 to 1.35 Gy per fraction given 3 times per day, or in 1.5 to 2 Gy fractions twice a day (BID). This high dose of radiation can lead to both acute and late toxicity, such as radiation-induced interstitial pneumonitis, with incidence of idiopathic pneumonia syndrome (IPS) of 7% to 35%. The traditional approach to treat TBI is at extended distance (~ 4 m from the source) with either the patient standing or lying down, which requires some kind of lung shielding in order to keep the mean lung dose below 10 Gy, and has shown to reduce the incidence of pneumonitis. Moreover, differences in separation along the patient's length result in dose heterogeneity that can exceed 20%.
At a handful of institutions, high dose TBI treatment has moved from the traditional extended distance approach to VMAT-TBI, in some cases as part of clinical trial, in an effort to improve dose uniformity and organ sparing. However, the planning and delivery at standard distance using VMAT introduces new challenges. This session aims to show commissioning processes and workflow to incorporate VMAT-TBI in the clinic, from CT-simulation to treatment delivery. In addition, we emphasize the use of checklists as a tool to highlight the most critical steps for physics independent checks and treatment delivery for enhancing quality and patient safety.
1. The attendees will be introduced to the available mBMs SRS clinical workflows on different platforms
2. The attendees will understand how to safely, optimally and efficiently introduce mBMs SRS strategies to their clinic
3. Attendees will be conversant with the commissioning steps involved in VMAT TBI program
4. Attendees will know with how automation could help in the treatment planning process