EVALUATION OF THE DEEP INSPIRATION BREATH-HOLD TECHNIQUE TO IMPROVE DOSIMETRIC OUTCOMES IN RADIOTHERAPY FOR STAGE III NON-SMALL CELL LUNG CANCER.

BACKGROUND

Radiotherapy is a key treatment for stage III non-small cell lung cancer (NSCLC), but tumor proximity to critical structures-such as the heart, esophagus, and spinal cord and respiratory motion complicates dose delivery. The Deep Inspiration Breath Hold (DIBH) technique actively controls respiratory motion, potentially improving treatment precision.

METHODS

This retrospective study included 56 patients with stage III NSCLC. Each underwent two CT scans: one during free breathing (FB) and one using DIBH. Dosimetric parameters for organs at risk (OARs) were compared between FB (with a 6 mm internal target volume margin) and DIBH plans using paired Student's t-tests.

RESULTS

DIBH increased total lung volume by 28% and reduced heart volume by 12.5%. Lung dose metrics improved significantly with DIBH, including V5, V20, and mean lung dose (all P < 0.001). Heart dose parameters (V10, V40, mean dose) also decreased. DIBH significantly reduced both maximum and mean doses to the esophagus and maximum dose to the spinal cord.

CONCLUSIONS

In stage III NSCLC, DIBH significantly lowers radiation exposure to OARs and enhances dose delivery accuracy. By expanding lung volume, it may reduce the risk of radiation-induced pneumonitis.