PURPOSE: To model the local dose-effect relation for lung perfusion reduction in lung cancer patients treated with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS: Forty-two patients having upper-lobe peripheral tumours <5 cm treated with SBRT (3×18 Gy) underwent single-photon emission computed-tomography (SPECT) scans to measure the lung perfusion 2 weeks pre-SBRT, 4-months post-SBRT, and for 8 patients 15-months post-SBRT. The relation between the calculated relative local perfusion reduction and the normalised total dose (α/β=3 Gy) at 4-months post-SBRT was modeled by 3-parameter logistic model and 2-parameter linear-maximum model. RESULTS: The relation between local dose and perfusion reduction at 4-months post-SBRT showed a maximum effect of 42.6% at doses >100 Gy and was best described by the logistic model with parameters (95% CI): M=42.6% (40.7-44.6), D50=28.7 Gy (26.3-31.1) and k=2.2 (1.8-2.5). A significant increase of this maximum effect to 65.2% was found at 15-months post-SBRT. CONCLUSIONS: The relation between local dose and perfusion reduction in patients treated with SBRT can be modeled by a 3-parameter logistic model. This demonstrated relationship 4-months post-SBRT approaches a plateau for doses >100 Gy, where 90% of the maximum lung-perfusion reduction is observed at NTD=78 Gy. A further perfusion reduction compared to 4-months post-SBRT was observed fifteen months post-SBRT.
PURPOSE: To model the local dose-effect relation for lung perfusion reduction in lung cancerpatients treated with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS: Forty-two patients having upper-lobe peripheral tumours <5 cm treated with SBRT (3×18 Gy) underwent single-photon emission computed-tomography (SPECT) scans to measure the lung perfusion 2 weeks pre-SBRT, 4-months post-SBRT, and for 8 patients 15-months post-SBRT. The relation between the calculated relative local perfusion reduction and the normalised total dose (α/β=3 Gy) at 4-months post-SBRT was modeled by 3-parameter logistic model and 2-parameter linear-maximum model. RESULTS: The relation between local dose and perfusion reduction at 4-months post-SBRT showed a maximum effect of 42.6% at doses >100 Gy and was best described by the logistic model with parameters (95% CI): M=42.6% (40.7-44.6), D50=28.7 Gy (26.3-31.1) and k=2.2 (1.8-2.5). A significant increase of this maximum effect to 65.2% was found at 15-months post-SBRT. CONCLUSIONS: The relation between local dose and perfusion reduction in patients treated with SBRT can be modeled by a 3-parameter logistic model. This demonstrated relationship 4-months post-SBRT approaches a plateau for doses >100 Gy, where 90% of the maximum lung-perfusion reduction is observed at NTD=78 Gy. A further perfusion reduction compared to 4-months post-SBRT was observed fifteen months post-SBRT.
Authors: Mohamad B Dabjan; Carolyn Ms Buck; Isabel L Jackson; Zeljko Vujaskovic; Brian Marples; Julian D Down Journal: Lab Invest Date: 2016-08-01 Impact factor: 5.662
Authors: Hesheng Wang; Mary Feng; Andrew Jackson; Randall K Ten Haken; Theodore S Lawrence; Yue Cao Journal: Int J Radiat Oncol Biol Phys Date: 2015-10-09 Impact factor: 7.038
Authors: Daniel Rocky Owen; Phillip S Boonstra; Benjamin L Viglianti; James M Balter; Matthew J Schipper; William C Jackson; Issam El Naqa; Shruti Jolly; Randall K Ten Haken; Feng-Ming Spring Kong; Martha M Matuszak Journal: Int J Radiat Oncol Biol Phys Date: 2018-06-01 Impact factor: 7.038