PT - JOURNAL ARTICLE AU - LINDBLOM, EMELY KJELLSSON AU - DASU, ALEXANDRU AU - TOMA-DASU, IULIANA TI - Hypoxia Induced by Vascular Damage at High Doses Could Compromise the Outcome of Radiotherapy AID - 10.21873/anticanres.13350 DP - 2019 May 01 TA - Anticancer Research PG - 2337--2340 VI - 39 IP - 5 4099 - http://ar.iiarjournals.org/content/39/5/2337.short 4100 - http://ar.iiarjournals.org/content/39/5/2337.full SO - Anticancer Res2019 May 01; 39 AB - Background/Aim: This study investigated the impact of temporary vascular collapse on tumour control probability (TCP) in stereotactic body radiotherapy (SBRT), taking into account different radiosensitivities of chronically and acutely hypoxic cells. Materials and Methods: Three-dimensional tumours with heterogeneous oxygenation were simulated assuming different fractions of collapsed vessels at every treatment fraction. The modelled tumours contained a chronically hypoxic subvolume of 30-60% of the tumour diameter, and a hypoxic fraction ≤5 mm Hg of 30-50%. The rest of the tumours were well-oxygenated at the start of the simulated treatment. Results: For all simulated cases, the largest reduction in TCP from 97% to 2% was found in a tumour with a small chronically hypoxic core treated with 60 Gy in eight fractions and assuming a treatment-induced vascular collapse of 35% in the well-oxygenated region. Conclusion: The timing of SBRT fractions should be considered together with the tumour oxygenation to avoid loss of TCP in SBRT.