Extra-cranial Stereotactic Radiation Therapy (ESRT) in the treatment of inoperable stage 1 & 2 non-small-cell lung cancer patients with highly mobile tumours: a literature review

Abstract

Objective: Extra-cranial Stereotactic Radiation Therapy (ESRT) techniques and equipment utilised in the treatment of Stage 1 or 2 inoperable non-small-cell lung cancer (NSCLC); accounting for Respiratory Induced Tumour Motion (RITM). Methods:A narrative review of current world literature.Results: Four main strategies are employed to address RITM: (1) tumour movement minimisation/immobilisation; (2) integration of respiratory movements into planning; (3) respiratory-gating techniques; and (iv) tumour-tracking techniques.Discussion: Analysis of data gathered suggests that due to inherent difficulties with respiratory function, combined with co-morbidities and the level of dose escalation facilitated by ESRT: techniques that do not require patient ability to comply are more likely to be effective with a wider range of patients. Similarly, treatment planning must incorporate accurate four-dimensional (4D) data to ensure target coverage, although setup and verification should be controlled to smaller margins for error. Conclusion:The disparate nature of reporting methods restricts statistical comparison. However, this paper suggests that the ESRT technique using abdominal compression (AC), free-breathing respiratorygating (FBRG), 4D computed tomography (4DCT) planning, combined with daily on board kV cone beam computed tomography (CBCT) imaging for setup and target verification, is a possible candidate for further treatment regime assessments in large multi-centre trials.

In this issue

“…In the next paper 4 , Tooke and Roe, from the University of the West of England, Bristol, undertake a literature review to examine the role of extra-cranial stereotactic radiation therapy in the treatment of inoperable stage 1 and 2 non small cell lung cancer patients with highly mobile tumours: accounting for respiratory induced tumour motion. The authors conclude that the data suggests using extra cranial stereotactic radiotherapy using the abdominal compression free-breathing respiratory gating and 4D computed tomography planning, combined with daily on board kV cone beam computed tomography imaging for setup and target verification, is a possible candidate for further treatment regime assessment in large multi-centre trials.…”