Purpose To assess the accumulated dose and the toxicity after reirradiation for tumors in the lung using non-rigid registration. Material and methods Twenty patients with a tumor in the lung were reirradiated with or after stereotactic radiotherapy. The summed dose distribution was calculated using non-rigid registration. All doses were recalculated to an equivalent dose of 2 Gy per fraction (EQD2). The median follow-up time was 12 months (range 2-52). Results The median Dmax of the lung in the summed plans was 363 Gy3 (range 123-590). The median accumulated V20 of the lungs was 15.2%. Seven patients had in the heart and the trachea an accumulated dose ≥70 Gy3, with a median Dmax of the heart of 115 Gy 3 and 89 Gy3 for the trachea. Eight patients had in the esophagus an accumulated dose ≥70 Gy3, with a median accumulated dose of 85 Gy3. No grade 3-5 toxicity was observed. Conclusion Reirradiation of the lung with or after stereotactic radiotherapy is feasible to a median Dmax of 363 Gy3 to the lung, as low toxicity was observed.

Dose accumulation, Lung cancer, Reirradiation, Toxicity
dx.doi.org/10.1016/j.radonc.2013.03.015, hdl.handle.net/1765/64906
Radiotherapy & Oncology
Erasmus MC: University Medical Center Rotterdam

Meijneke, T.R, Petit, S.F, Wentzler, D, Hoogeman, M.S, & Nuyttens, J.J.M.E. (2013). Reirradiation and stereotactic radiotherapy for tumors in the lung: Dose summation and toxicity. Radiotherapy & Oncology, 107(3), 423–427. doi:10.1016/j.radonc.2013.03.015