Advances in the use of motion management and image guidance in radiation therapy treatment for lung cancer

Abstract

The development of advanced radiation technologies, including intensity-modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT) and proton therapy, has resulted in increasingly conformal radiation treatments. Recent evidence for the importance of minimizing dose to normal critical structures including the heart and lungs has led to incorporation of these advanced treatment modalities into radiation therapy (RT) for non-small cell lung cancer (NSCLC). While such technologies have allowed for improved dose delivery, implementation requires improved target accuracy with treatments, placing increasing importance on evaluating tumor motion at the time of planning and verifying tumor position at the time of treatment. In this review article, we describe issues and updates related both to motion management and image guidance in the treatment of NSCLC.

Keywords: Radiation; carcinoma, non-small cell lung cancer (NSCLC); image guidance; motion management; proton therapy.

Figure 1

Coronal CT images of a patient with newly diagnosed LA-NSCLC planned for concurrent chemoradiotherapy. (A) CT simulation with delineation of ITV (orange), CTV (red), and PTV (green); (B) CBCT performed at the time of first treatment with overlaid target volumes from simulation with interval lung collapse and associated shifting of the target volumes.

Figure 2

Coronal (A,B) and sagittal (C,D) CT images of a patient planned for pencil beam scanning proton therapy for newly diagnosed LA-NSCLC. (A,C) CT simulation with delineation of GTV (thin red line) and radiation isodose lines (red: 100%, blue: 95%, purple: 90%, light blue: 75%, brown: 50%); (B,D) weekly quality assurance CT scan demonstrating consolidation and under-coverage of the superior aspect of initial target volume (arrow). For reference the original ITV location is outlined (thin pink line).