1. A Comparison of Isotoxic Dose-escalated Radiotherapy in Lung Cancer with Moderate Deep Inspiration Breath Hold, Mid-ventilation and Internal Target Volume Techniques
- Author
-
D. McQuaid, Sarah L. Gulliford, H. Bainbridge, Simeon Nill, Uwe Oelfke, Merina Ahmed, Fiona McDonald, Alex Dunlop, I. Locke, and R. Gunapala
- Subjects
Lung Neoplasms ,Lung ,business.industry ,Radiotherapy Planning, Computer-Assisted ,medicine.medical_treatment ,Planning target volume ,Radiotherapy Dosage ,medicine.disease ,Breath Holding ,Radiation therapy ,medicine.anatomical_structure ,Oncology ,Carcinoma, Non-Small-Cell Lung ,Breathing ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Lung volumes ,business ,Lung cancer ,Complication ,Nuclear medicine ,Deep inspiration breath-hold - Abstract
Aims With interest in normal tissue sparing and dose-escalated radiotherapy in the treatment of inoperable locally advanced non-small cell lung cancer, this study investigated the impact of motion-managed moderate deep inspiration breath hold (mDIBH) on normal tissue sparing and dose-escalation potential and compared this to planning with a four-dimensional motion-encompassing internal target volume or motion-compensating mid-ventilation approach. Materials and methods Twenty-one patients underwent four-dimensional and mDIBH planning computed tomography scans. Internal and mid-ventilation target volumes were generated on the four-dimensional scan, with mDIBH target volumes generated on the mDIBH scan. Isotoxic target dose-escalation guidelines were used to generate six plans per patient: three with a target dose cap and three without. Target dose-escalation potential, normal tissue complication probability and differences in pre-specified dose-volume metrics were evaluated for the three motion-management techniques. Results The mean total lung volume was significantly greater with mDIBH compared with four-dimensional scans. Lung dose (mean and V21 Gy) and mean heart dose were significantly reduced with mDIBH in comparison with four-dimensional-based approaches, and this translated to a significant reduction in heart and lung normal tissue complication probability with mDIBH. In 20/21 patients, the trial target prescription dose cap of 79.2 Gy was achievable with all motion-management techniques. Conclusion mDIBH aids lung and heart dose sparing in isotoxic dose-escalated radiotherapy compared with four-dimensional planning techniques. Given concerns about lung and cardiac toxicity, particularly in an era of consolidation immunotherapy, reduced normal tissue doses may be advantageous for treatment tolerance and outcome.
- Published
- 2022
- Full Text
- View/download PDF