Department of Radiation Oncology, Sivas Numune Hospital, Sivas, Turkey , dr.cerencicibiyik@gmail.com
Abstract: (19 Views)
Background:To investigate the effect of radiation dose to thoracic vertebrae (TV) on the development of hematologic toxicity in esophageal cancer patients treated with intensity-modulated radiotherapy. Materials and Methods: We identified 28 patients with esophageal cancer treated with chemoradiotherapy between 2014-2021.Vertebral volumes receiving 5-50 Gy (TV5-50) and the mean vertebral and thoracic blood pool dose were collected from the dose-volume-histogram. Complete blood cell counts were analyzed and hematologic toxicities were graded according to the Common Terminology Criteria for Adverse Events version5.0 (CTCAE v5.0). Results: TV50 was negatively linearly associated with mean lymphocyte nadir by percentage. TV20 was negatively linearly associated with mean platelet nadir by cc. Planning Target Volume (PTV) length was negatively linearly associated with mean hemoglobin nadir. The optimal threshold dose values for avoiding grade ≥4 lymphopenia was TV40 of <22.3%, TV50 of <9.09%, mean thoracic blood pool dose of < 16.9 Gy, PTV volume of <652 cc and PTV length of <16.7 cm. The optimal threshold dose values for avoiding grade ≥3 leukopenia were TV10 of <47.6%, TV20 of <39.7%, TV30 of< 34.69%,and mean vertebral dose of <17.7Gy. Conclusion: This study demonstrated a statistically significant negative correlation between vertebral doses and hematologic parameters. The optimal threshold dose values for avoiding grade ≥3 leukopenia were TV10 of <47.6% and mean vertebral dose of <17.7Gy.