SO SÁNH LIỀU LƯỢNG TRONG LẬP KẾ HOẠCH XẠ TRỊ UNG THƯ PHỔI KHÔNG TẾ BÀO NHỎ SỬ DỤNG KỸ THUẬT IMRT VÀ FIF TẠI BỆNH VIỆN UNG BƯỚU NGHỆ AN

Abstract

Objective: This study compares the treatment planning dosimetry between the field-in-field (FiF) technique and intensity-modulated radiation therapy (IMRT) for patients with non-small cell lung cancer (NSCLC) at Nghe An Oncology Hospital, using the MONACO 5.11.03 treatment planning system. Materials and Methods: A retrospective study was conducted on 51 patients with NSCLC who underwent radiotherapy at Nghe An Oncology Hospital from January 2023 to December 2024. Dosimetric parameters including Dmax, dose–volume metrics, mean dose to the planning target volume (PTV) and organs at risk (OARs), homogeneity index (HI), conformity index (CI), monitor units (MU), and number of radiation fields were analyzed from dose–volume histograms (DVHs) using the MONACO 5.11.03 treatment planning system for each IMRT and FiF plan. All IMRT plans passed quality assurance requirements using the MiniPhantom and MatriXX Evolution system (IBA Dosimetry, Germany). Results: Among the 51 patients with NSCLC, the IMRT demonstrated superior dose coverage compared to FiF, with a mean V60Gy to the PTV of 97.9% versus 96% (p < 0.001). The homogeneity index (HI) and conformity index (CI) for IMRT were 1.05 and 0.999, respectively, compared to 1.10 and 0.995 for FiF (p < 0.001). The FiF resulted in a lower spinal cord Dmax (2992.2 ± 1239.2 cGy vs. 3517.8 ± 895.7 cGy, p < 0.001). IMRT delivered significantly lower mean doses to the heart (883.8 vs. 1447.7 cGy), contralateral lung (646.4 vs. 882 cGy), and esophagus (1869.2 vs. 2233.8 cGy), with p-values < 0.01. However, IMRT required a higher number of monitor units (776.5 vs. 250.3). Conclusion: IMRT provides better dose homogeneity and higher coverage to the PTV while reducing the dose to the OARs compared to FiF. With FiF, the maximum dose to the spinal cord is lower and the irradiation time is shorter than with IMRT. Therefore, FiF is an alternative option in cases where spinal cord protection is prioritized or when the treatment position cannot be maintained for a long period.