A forward planned treatment planning technique for non small cell lung cancer stereotactic ablative body radiotherapy. Based on a Systematic Review of Literature.

Purpose & Method: A systematic literature review of six computerised databases was undertaken in order to review and summarise a forward planned lung Stereotactic Ablative Body Radiotherapy (SABR) treatment planning (TP) technique as a starting point for clinical implementation in the author's department based on current empirical research. The data was abstracted and content analysed to synthesize the findings based upon a SIGN quality checklist tool. Findings: A Four Dimensional Computer Tomography (4DCT) scan should be performed upon which the Internal Target Volume (ITV) and Organs at Risk (OAR) are drawn [1, 2]. A Set-up margin (SM) of 5mm is applied to account for inter-fraction motion. The field arrangement consists of a combination of 7 to 13 coplanar and non-coplanar beams all evenly spaced. Beam modifiers are used to assist in the homogeneity of the beam, although a 20% planning target volume (PTV) dose homogeneity is acceptable. The recommended fractionations by the UK SABR consortium are 54 Gy in 3#s (standard), 55–60 Gy in 5#s (conservative) and the 50-60 Gy in 8-10#s (very conservative). Conformity indices (CI) for both the target volume (TV) and OAR will be used to assess the planned distribution.) [3] Conclusion: An overview of a clinically acceptable forward planned lung SABR TP technique based on current literature as a starting point, with a view to inverse planning with support from the UK SABR Consortium mentoring scheme. [1, 2]