Comparison of combinations of irradiation techniques and jaw conditions in intensity‐modulated radiotherapy for lung cancer

Abstract

Purpose: To assist in the selection of a suitable combination of an irradiation technique and jaw condition in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) for lung cancer treatment plans. Materials and methods: Thirty patients with lung cancer who underwent radiotherapy were enrolled retrospectively. They were categorized as having central lung cancer, peripheral lung cancer with mediastinal lymph node metastasis (peripheral E lung cancer), and peripheral lung cancer without mediastinal lymph node metastasis (peripheral N lung cancer). Four treatment plans were designed for each patient: fixed jaw and adaptive jaw IMRT technique (FJ-IMRT and JA-IMRT), and fixed jaw and jaw tracking VMAT technique (FJ-VMAT and JT-VMAT). The dose parameters of the four group plans were compared and analyzed. Results: Compared to FJ-IMRT, JA-IMRT significantly reduced the mean dose (D mean ) and volume percentage of 5 Gy (V 5Gy ) of the total lung in central and peripheral N lung cancer. Similarly, compared to FJ-VMAT, JT-VMAT provided better protection to most organs at risk (OARs), particularly for total lung and heart. In comparison with IMRT, VMAT significantly improved the conformity index (CI) of the planning target volume for the three lung cancer classifications, and it reduced the dose of almost all OARs except V 5Gy and D mean of the total lung. Moreover, the mean monitor units of the VMAT groups were far lower than the IMRT groups. Conclusion: Based on the dosimetric findings and considering clinical data published on lung and heart side effects, we propose recommendations on the preferred treatment technique based on tumor location and pulmonary function. For central lung cancer with normal pulmonary function, we advise JT-VMAT techniques. Conversely, for central lung cancer with poor pulmonary function, we recommend JA-IMRT techniques. We advocate JA-IMRT for peripheral E lung cancer. For peripheral N lung cancer, JT-VMAT techniques are strongly recommended.

Plan quality and treatment efficiency assurance of two VMAT optimization for cervical cancer radiotherapy

“…Researchers found that appropriate field fixed jaw setting showed superiority in OARs sparing. 6 , 25 , 26 , 27 In our studies, SPO‐FJ (fixed jaw) plans were significantly better than SPO‐NFJ (no fixed jaw) plans both in target coverage and OARs sparing, no matter what the width of PCTV is. However, for FMO plans, there was no significant difference between FMO‐FJ plans and FMO‐NFJ plans.…”

“… 1 , 2 The VMAT technique has become clinically and commercially available in all kinds of treatment planning system (TPS) and linear accelerators. However, there are many differences in machines 3 and optimization algorithms, 4 for example, the method of dose rate control, 5 and jaw tracking technique, 6 etc.…”

Radiation induced therapeutic effects in cancerous and tumor cells: A review

“…The JT-VMAT technique is strongly recommended. 60 Palliative pulmonary irradiation with increased total dose (including up to 30 Gy/10 fractions) improves survival regardless of performance status. 61 Thoracic radiation therapy has become more precise and has reduced risk of serious adverse events due to technical developments (IMRT, image-guided radiation therapy, stereotactic body radiation therapy.…”

Single isocenter versus dual isocenter treatment using flattening filter‐free and jaw‐tracking volumetrically modulated arc therapy for boot‐shaped lung cancer: Evaluation of dosimetric and feasibility

“…Recently, several reports have examined various VMAT techniques for treating lung cancer, analyzing their impact on normal lung dose and confirming their feasibility. 14 , 15 , 16 One of those studies investigated the benefit of the fixed jaw and jaw tracking VMAT technique, one study evaluated the benefit of the flattened filter‐free photon beam, and one study added a non‐coplanar arc to reduce dose to organs at risk (OAR). Nevertheless, to our knowledge, nearly none of the studies investigated the dosimetric effect of dual‐isocenter jaw‐tracking VMAT in lung cancer with a large longitudinal tumor target.…”

“…Meanwhile, radiotherapy technology has continued to evolve. Recently, several reports have examined various VMAT techniques for treating lung cancer, analyzing their impact on normal lung dose and confirming their feasibility 14–16 . One of those studies investigated the benefit of the fixed jaw and jaw tracking VMAT technique, one study evaluated the benefit of the flattened filter‐free photon beam, and one study added a non‐coplanar arc to reduce dose to organs at risk (OAR).…”