食管肿瘤在强调放射治疗中靶区位移的研究及其对放射剂量学的影响

Objective To study the displacement of tumor target areas in intensity-modulated radiotherapy(IMRT) for esophageal cancer and its impact on radiotherapy dosimetry. Methods The clinical data of 60 patients with esophageal cancer who received radiotherapy in our hospital from November 2024 to August 2025 were analyzed. All patients were divided into two groups according to whether they received volumetric intensity-modulated radiotherapy(VMAT) or conformal intensity-modulated radiotherapy(IMRT). Both groups measured the displacement of the target volume's geometric center along the X, Y, and Z axes following radiotherapy. They then compared dose changes to the tumor target volume and organs at risk under identical displacement conditions during three-dimensional conformal radiotherapy and intensitymodulated radiotherapy. Results Under the same displacement, when comparing the differences between the target area after displacement and before displacement, compared with the differences of the gross tumor target area(GTV D95%), clinical target area(CTV D95%), and planned target area(PTV D95%) of VMAT, the dose change difference of IMRT was higher, and the differences between groups showed statistically significant differences(P<0.05). Under the IMRT and VMAT plans, there was still a deviation between the dose of organs at risk(OARs) after target displacement and the initial plan. Moreover, the deviations before and after IMRT in the left lung(V20), right lung(V20), and heart(V30) were even greater, and the differences were statistically significant(P<0.05). Conclusion During the treatment of esophageal cancer with VMAT and IMRT, due to the displacement of the target area, it will lead to changes in the tumor target area(GTV, CTV, PTV) and OARs dose of the patient. The deviation of IMRT technology is even greater. Therefore, it is even more necessary to formulate standardized quality control to improve the radiotherapy effect and reduce adverse reactions.