In an innovative pair of papers published in Radiotherapy and Oncology from the laboratories of Drs. Jian-Yue Jin and Feng-Ming (Spring) Kong of the Georgia Regents University (GRU) Cancer Center, a new model using biomarkers to predict radiation dose-response is proposed, and a new radiotherapy technique is described.
Along with GRU colleagues Drs. Jie Chen, Ramses Sadek, and Hong Zhang and University of Michigan collaborators Drs. Randall Ten Haken and Theodore Lawrence, Drs. Jin and Kong have developed a model for radiotherapy dosing that takes into account individual genetic variations of the patient. This is the first study to make such a correlation between radiosensitivity and biomarkers (i.e., single nucleotide polymorphisms (SNPs) in DNA repair genes). As such, it provides a means to predict the radiation dose-response of a given patient, offering a new, personalized approach to radiotherapy.
Retrospectively studying overall survival, radiation dose, and SNP genotype of 92 non-small cell lung cancer patients, researchers were able to derive a dose-response parameter (D50), which when modeled, generated an individualized dose prescription that could improve 2-year survival from ~50% to 85% in radio-sensitive individuals and from ~3% to 75% in radio-resistant patients. Validation of this approach may lead to improved outcomes.[Jin JY, Wang W, Ten Haken RK, Chen J, Bi N, Sadek R, Zhang H, Lawrence TS, Kong FS. Use a survival model to correlate single-nucleotide polymorphisms of DNA repair genes with radiation dose-response in patients with non-small cell lung cancer. Radiother Oncol. 2015 Aug 4. pii: S0167-8140(15)00378-3. doi: 10.1016/j.radonc.2015.07.024. [Epub ahead of print]]
In another collaborative effort between GRU and Henry Ford Hospital in Michigan, Drs. Jin and Kong along with GRU colleagues Drs. Joseph Kaminski and John Vender developed a radiotherapy technique that blends characteristics of 3D conformal radiotherapy (3DCRT) and spatially fractionated radiotherapy (SFRT) to achieve high-dose radiation to large tumors while minimizing radiation exposure to surrounding normal tissue. This technique relies on “channeling direction” beams instead of a physical grid. The treatment is not time-intensive and can be used by centers offering intensity-modulated radiation therapy (IMRT). The authors anticipate future clinical trials will verify the use of this technique as an effective strategy to safely target large tumors.[Jin JY, Zhao B, Kaminski JM, Wen N, Huang Y, Vender J, Chetty IJ, Kong FS. A MLC-based inversely optimized 3D spatially fractionated grid radiotherapy technique. Radiother Oncol. 2015 Aug 12. pii: S0167-8140(15)00408-9. doi: 10.1016/j.radonc.2015.07.047. [Epub ahead of print]]]