Top Line: Genomically adjusted radiation dose (GARD) characterizes the sensitivity of a specific patient/tumor to a given radiation dose.
The Study: We’ve seen multiple prior studies associating GARD with recurrence risk and survival outcomes across a broad range of tumor types. This study sought to determine if GARD was associated with locoregional failure in patients with nasopharyngeal carcinoma. It included 92 patients with stage III to IVB NPC treated on a randomized phase 3 trial with concurrent chemoradiation +/- neoadjuvant chemotherapy. In multivariable analysis, GARD was significantly associated with freedom from locoregional failure. Using a minimum GARD threshold that was strongly associated with freedom from locoregional failure, the authors were able to identify three groups based on their radiosensitivity. The first and largest (64.1%) group reached the GARD threshold for optimal locoregional control at a physical dose below current standard prescription doses (<66Gy). In other words, these patients may have been cured with doses well below those commonly used for NPC. Another 21.7% of patients met the GARD threshold with standard prescription doses (66-74Gy). The final 14.1% would have required a physical dose >74Gy to achieve optimal locoregional control. While these findings help explain why NPC has high cure rates with current radiation regimens, further personalization could potentially improve treatment outcomes and reduce toxicity.
TBL: GARD can be used to categorize the radiosensitivity of NPC tumors, and it could potentially help personalize treatment intensity for patients receiving definitive chemoradiation. | Chiang, Radiother Oncol 2024
The Study: We’ve seen multiple prior studies associating GARD with recurrence risk and survival outcomes across a broad range of tumor types. This study sought to determine if GARD was associated with locoregional failure in patients with nasopharyngeal carcinoma. It included 92 patients with stage III to IVB NPC treated on a randomized phase 3 trial with concurrent chemoradiation +/- neoadjuvant chemotherapy. In multivariable analysis, GARD was significantly associated with freedom from locoregional failure. Using a minimum GARD threshold that was strongly associated with freedom from locoregional failure, the authors were able to identify three groups based on their radiosensitivity. The first and largest (64.1%) group reached the GARD threshold for optimal locoregional control at a physical dose below current standard prescription doses (<66Gy). In other words, these patients may have been cured with doses well below those commonly used for NPC. Another 21.7% of patients met the GARD threshold with standard prescription doses (66-74Gy). The final 14.1% would have required a physical dose >74Gy to achieve optimal locoregional control. While these findings help explain why NPC has high cure rates with current radiation regimens, further personalization could potentially improve treatment outcomes and reduce toxicity.
TBL: GARD can be used to categorize the radiosensitivity of NPC tumors, and it could potentially help personalize treatment intensity for patients receiving definitive chemoradiation. | Chiang, Radiother Oncol 2024