Michael Macfarlane | University of Western Ontario (original) (raw)
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Papers by Michael Macfarlane
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, Jan 31, 2016
Recently our group developed a unified intensity-modulated arc therapy (UIMAT) technique which al... more Recently our group developed a unified intensity-modulated arc therapy (UIMAT) technique which allows for the simultaneous inverse-optimization and the combined delivery of volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). The aim of this study was to evaluate the dosimetric benefits of UIMAT plans for radiation treatment of complex head-and-neck cancer cases. A retrospective treatment planning study was performed on 30 head-and-neck cases, 15 of which were treated clinically with VMAT while the other 15 were treated with step-and-shoot IMRT. These cases were re-planned using our UIMAT technique and the results were compared with the clinically delivered plans. Plans were assessed in terms of clinically relevant metrics describing target volume coverage, dose conformity, and the sparing of organs at risk. When compared to stand-alone VMAT or IMRT, UIMAT plans offered slightly better tumor volume coverage (Median D95: 98.1% vs. 97.5%, p=0.01) and s...
Practical radiation oncology, Jan 26, 2014
To evaluate the dosimetric potential of respiratory-gated volumetric modulated arc therapy (VMAT)... more To evaluate the dosimetric potential of respiratory-gated volumetric modulated arc therapy (VMAT) to reduce the dose to normal lung when treating early-stage non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT). Twenty patients with inoperable stage I/II NSCLC with motion greater than 5 mm were retrospectively planned with 4-dimensional computed tomography-based gated and nongated VMAT. Each plan was optimized using two 225° arcs with 10-MV flattening filter-free beams with maximum dose rate of 2400 MU/min. A host script was generated and used to optimize all 40 plans to minimize dosimetric bias. The main dosimetric parameters compared were percent volume of the lung receiving 20 Gy or more (V20Gy) and the absolute volume of lung minus the internal tumor volume receiving at least 50% of the prescription dose for normal lung (V50%). Other parameters considered were the maximum dose 2 cm from the planning target volume (D2cm), percent volume of the contra...
Medical physics, 2015
To study the feasibility of unified intensity-modulated arc therapy (UIMAT) which combines intens... more To study the feasibility of unified intensity-modulated arc therapy (UIMAT) which combines intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) optimization and delivery to produce superior radiation treatment plans, both in terms of dose distribution and efficiency of beam delivery when compared with either VMAT or IMRT alone. An inverse planning algorithm for UIMAT was prototyped within the pinnacle treatment planning system (Philips Healthcare). The IMRT and VMAT deliveries are unified within the same arc, with IMRT being delivered at specific gantry angles within the arc. Optimized gantry angles for the IMRT and VMAT phases are assigned automatically by the inverse optimization algorithm. Optimization of the IMRT and VMAT phases is done simultaneously using a direct aperture optimization algorithm. Five treatment plans each for prostate, head and neck, and lung were generated using a unified optimization technique and compared with clinical IMRT or...
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, Jan 31, 2016
Recently our group developed a unified intensity-modulated arc therapy (UIMAT) technique which al... more Recently our group developed a unified intensity-modulated arc therapy (UIMAT) technique which allows for the simultaneous inverse-optimization and the combined delivery of volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). The aim of this study was to evaluate the dosimetric benefits of UIMAT plans for radiation treatment of complex head-and-neck cancer cases. A retrospective treatment planning study was performed on 30 head-and-neck cases, 15 of which were treated clinically with VMAT while the other 15 were treated with step-and-shoot IMRT. These cases were re-planned using our UIMAT technique and the results were compared with the clinically delivered plans. Plans were assessed in terms of clinically relevant metrics describing target volume coverage, dose conformity, and the sparing of organs at risk. When compared to stand-alone VMAT or IMRT, UIMAT plans offered slightly better tumor volume coverage (Median D95: 98.1% vs. 97.5%, p=0.01) and s...
Practical radiation oncology, Jan 26, 2014
To evaluate the dosimetric potential of respiratory-gated volumetric modulated arc therapy (VMAT)... more To evaluate the dosimetric potential of respiratory-gated volumetric modulated arc therapy (VMAT) to reduce the dose to normal lung when treating early-stage non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT). Twenty patients with inoperable stage I/II NSCLC with motion greater than 5 mm were retrospectively planned with 4-dimensional computed tomography-based gated and nongated VMAT. Each plan was optimized using two 225° arcs with 10-MV flattening filter-free beams with maximum dose rate of 2400 MU/min. A host script was generated and used to optimize all 40 plans to minimize dosimetric bias. The main dosimetric parameters compared were percent volume of the lung receiving 20 Gy or more (V20Gy) and the absolute volume of lung minus the internal tumor volume receiving at least 50% of the prescription dose for normal lung (V50%). Other parameters considered were the maximum dose 2 cm from the planning target volume (D2cm), percent volume of the contra...
Medical physics, 2015
To study the feasibility of unified intensity-modulated arc therapy (UIMAT) which combines intens... more To study the feasibility of unified intensity-modulated arc therapy (UIMAT) which combines intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) optimization and delivery to produce superior radiation treatment plans, both in terms of dose distribution and efficiency of beam delivery when compared with either VMAT or IMRT alone. An inverse planning algorithm for UIMAT was prototyped within the pinnacle treatment planning system (Philips Healthcare). The IMRT and VMAT deliveries are unified within the same arc, with IMRT being delivered at specific gantry angles within the arc. Optimized gantry angles for the IMRT and VMAT phases are assigned automatically by the inverse optimization algorithm. Optimization of the IMRT and VMAT phases is done simultaneously using a direct aperture optimization algorithm. Five treatment plans each for prostate, head and neck, and lung were generated using a unified optimization technique and compared with clinical IMRT or...