WCLC 2025 - Posters & ePosters-P2.08 .20 VMAT vs IMRT Technique in Locally Advanced Lung Cancer Radiotherapy Treatment -Pulmonary Toxicity and Dosimetric Evaluation

P2.08 .20 VMAT vs IMRT Technique in Locally Advanced Lung Cancer Radiotherapy Treatment -Pulmonary Toxicity and Dosimetric Evaluation

Back to course

Pdf Summary

This study by Assoc. Prof. Slavica Marić compares Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) in the treatment of locally advanced lung cancer (stage III). Both techniques are advanced radiotherapy methods aimed at delivering high radiation doses precisely to the tumor while sparing healthy lung tissue, reducing pulmonary toxicity.<br /><br />Seventy patients with locally advanced lung cancer were divided equally into two groups: Group A received IMRT, and Group B received VMAT, both with 4D CT simulation. The study focused on dosimetric parameters for lungs—specifically volume receiving 20 Gy (V20), mean lung dose (MLD), and volume receiving 5 Gy (V5)—and assessed acute and late pulmonary toxicities.<br /><br />Results showed that VMAT yielded significantly lower V20 and MLD values compared to IMRT (p=0.01), indicating a dosimetric advantage for VMAT in protecting lung tissue. However, no significant differences were observed in V5 values (p=0.155). Clinically, acute and late pulmonary toxicities were similar between the groups, with no statistically significant differences (acute p=0.867, late p=0.564). Most patients experienced mild to moderate side effects (grades 0-2), with only a few developing chronic pulmonary toxicity grade 3 (3 in IMRT group, 1 in VMAT group).<br /><br />The study concludes that while VMAT offers dosimetric benefits, these do not currently translate into clear clinical advantages over IMRT regarding pulmonary toxicity. VMAT may have practical benefits such as fewer monitor units and shorter treatment times. Further research is recommended to establish the optimal radiotherapy technique for treating locally advanced lung cancer. Overall, both IMRT and VMAT play a crucial role in reducing lung toxicity during radiotherapy in this patient population.

Asset Subtitle

Slavica Maric

Meta Tag

Speaker Slavica Maric

Topic Local-Regional Non-small Cell Lung Cancer

Keywords

Intensity Modulated Radiation Therapy

IMRT

Volumetric Modulated Arc Therapy

VMAT

locally advanced lung cancer

stage III lung cancer

pulmonary toxicity

dosimetric parameters

V20 and MLD

radiotherapy treatment comparison