Feasibility and safety of shortened hypofractionated high dose palliative lung radiotherapy – A retrospective planning study

ObjectiveAssess the safety and feasibility of shortened hypo-fractionated high dose palliative lung radiotherapy in a retrospective planning study.MethodsFifteen palliative lung radiotherapy patients previously treated with the standard 36 Gy in 12 fractions (12F) schedule were non-randomly selected to achieve a representative distribution of tumour sizes, volumes, locations and staging. Plans were produced using 30 Gy in 5 fractions (5F) and 30 Gy in 6 fractions (6F) using a 6MV FFF co-planar VMAT technique. These plans were optimised to meet dose constraints for both PTVs and OARs where established OAR constraints were expressed as BED. The potential safety of the delivery of these plans was assessed using these BEDs and also with reductions of 10% and 20% to account for effects of chemotherapy or surgery.ResultsFor all 5F and 6F plans the mandatory constraints using the full BED were met, as with all 6F plans with 10% BED reductions, but reduced to 6 patients using 5F. Three of 15 5F and 6 of 15 6F plans met the 20% BED reductions.ConclusionIt is potentially safe and feasible to deliver high dose palliative radiotherapy using the 5F or 6F regimes described, when carefully planned to comparable OAR BEDs as for 12F standard. It appears that the toxicity from either of these regimes should be within acceptable limits provided that the dose constraints described can be adhered to. A Phase II study would be required to fully assess the safety and feasibility. The outcomes from such a study could potentially reduce the number of patient hospital visits for radiotherapy, thus benefiting the patient and the clinical service by optimising resource utilisation.Advances in KnowledgeShortened hypo-fractionated high dose palliative lung radiotherapy is technically feasible provided OAR constraints are respected.