Volumetric Modulated Arc Radiotherapy for Early Stage Non-Small-Cell Lung Carcinoma: Is It Better Than the Conventional Static Beam Intensity Modulated Radiotherapy?

This study compared the performance of volumetric modulated arc therapy (VMAT) techniques: single arc volumetric modulated arc therapy (SA-VMAT) and double arc volumetric modulated arc therapy (DA-VMAT) with the static beam conventional intensity modulated radiotherapy (C-IMRT) for non-small-cell lung carcinoma (NSCLC). Twelve stage I and II NSCLC patients were recruited and their planning CT with contoured planning target volume (PTV) and organs at risk (OARs) was used for planning. Using the same dose constraints and planning objectives, the C-IMRT, SA-VMAT, and DA-VMAT plans were optimized. C-IMRT consisted of 7 static beams, while SA-VMAT and DA-VMAT plans consisted of one and two full gantry rotations, respectively. No significant difference was found among the three techniques in target homogeneity and conformity. Mean lung dose in C-IMRT plan was significantly lower than that in DA-VMAT plan P=0.04. The ability of OAR sparing was similar among the three techniques, with no significant difference in V20, V10, or V5 of normal lungs, spinal cord, and heart. Less MUs were required in SA-VMAT and DA-VMAT. Besides, SA-VMAT required the shortest beam on time among the three techniques. In treatment of early stage NSCLC, no significant dosimetric superiority was shown by the VMAT techniques over C-IMRT and DA-VMAT over SA-VMAT.

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The Therapeutic Value of Volumetric-Modulated Arc Therapy In Advanced Non-Small Cell Lung Cancer Primary Tumors: A Multicenter Retrospective Analysis Based On Propensity Score Matching And Comparison With Intensity-Modulated Radiotherapy

10.21203/rs.3.rs-1071095/v1 ◽

2021 ◽

Author(s):

Jie Liu ◽

Tao Li ◽

Wang Xiaohu ◽

Shengfa Su ◽

Qingsong Li ◽

...

Keyword(s):

Lung Cancer ◽

Volumetric Modulated Arc Therapy ◽

Intensity Modulated Radiotherapy ◽

Small Cell ◽

Small Cell Lung ◽

Primary Tumors ◽

Intensity Modulated ◽

Dose Volume ◽

Significant Difference ◽

Arc Therapy

Abstract Objective:.To explore the feasibility of volumetric-modulated arc therapy (VMAT) instead of intensity-modulated radiotherapy (IMRT) for primary tumors of advanced non–small-cell lung cancer (A-NSCLC). Methods:.We used propensity score matching (PSM) and multicenter retrospective analysis to study the efficacy and toxicity of VMAT technology in radiotherapy for primary tumors of A-NSCLC.We used the chi-squared test to analyze the response rate(RR), local control (LC), acute radiation injury, and dose-volume parameters; the Kaplan–Meier and log-rank tests were used to determine local-regional progression-free survival (LRPFS) and overall survival (OS). Results: LRPFS was significantly prolonged in stage III patients treated with IMRT before PSM (P< .05) and cases of grade 1 or 2 acute radiation esophagitis (RE) or radiation pneumonia(RP) in the IMRT than the VMAT(P< .05), but cases of grade 3 or 4 RE and RP were not significantly different between the groups (P> .05). Before PSM, there was no significant difference in the LRPFS and OS rates of the whole study group and the RR, LC, and stage IV subgroups, respectively (P> .05). After PSM, there was no significant difference in the RR, LC, LRPFS, OS, RP, or RE of patients treated with VMAT and IMRT (P> .05), normal whole-lung (V5, V20, MLD), heart (V30, V40, MHD), and equal dose-volume parameters were significantly lower in the VMAT group (P< .05).Conclusion:.Radiation therapy of A-NSCLC primary tumors using VMAT can achieve a similar efficacy to that of IMRT but with significantly lower low-dose volume parameters of normal tissues and organs; this is true especially in stage N2 cases, where the reduction in radiation damage may be more favorable.

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