Immunology is making a big impact in the Radiation Oncology world as a combination therapy. With the different tumor mechanisms, these multi-modality approaches may offer curative outcomes in preclinical studies. The SARRP can be used to target specific areas to cause an immune response that immunological agents may react to.
These preclinical immunotherapy plus radiation treatments offer compelling evidence to further these types of studies
Using an orthotopic GBM model, Anti-PD-1 was studied alone and in combination with stereotactic radiotherapy. A 3mm x 3mm nozzle was used to surround the tumor based on CBCT guidance. There were four arms in this study: Control, Anti-PD-1 only, Radiation only, Radiation plus Anti-PD-1. The radiation was given in one fraction of 10Gy 10 days after implantation of GBM. The SARRP was able to identify on CBCT and target only the brain of the mouse allowing for high dose escalation. Anti-PD-1 was given on day 10, 12, and 14 after implantation. Survival with immunotherapy alone was 27 days, radiotherapy alone was 28 days and combination therapy was 53 days.
Interestingly enough, the mice with no visible tumor were re-challenged on day 90 by the addition of a flank tumor. None of the mice showed visible tumor after 3 weeks as compared to the control which did show tumor in the same timeline.
SARRP was featured in the 2014 ASTRO Annual Meeting - Plenary Session http://www.softconference.com/astro/SessionDetail.asp?SID=367995. The session was titled: Radiotherapy combined with anti-PD-1 Checkpoint Blockade Immunotherapy: A Promising Future Direction. Andrew Sharabi, M.D./Ph.D. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins
To understand more about which Xstrahl system can be utilised for Immunology studies contact our technical team here.