Functional perfusion image guided radiation treatment planning for locally advanced lung cancer

Abstract

Background and purpose: Functional avoidance radiation therapy (RT) aims at sparing functional lung regions. The purpose of this simulation study was to evaluate the feasibility of functional lung avoidance methodology in RT of lung cancer and to characterize the achievable dosimetry of single photon emission computed tomography (SPECT) guided treatment planning. Materials and methods: Fifteen consecutive lung cancer patients were included and planned for definitive RT of 60-66 Gy in 2-Gy fractions. Two plans were optimized: a standard CT-plan, and functional SPECT-plan. The objective was to reduce dose to the highly functional lung subvolumes without compromising tumour coverage, and respecting dose to other organs at risk. For each patient a 3D-conformal, intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy plans were created for standard and functional avoidance. Standard versus functional dose-volume parameters for functional lung (FL) subvolumes, organs at risk and tumour coverage were compared. Results: The largest dose reduction was achieved with IMRT plans. Functional plans resulted in dose reduction from 9.0 Gy to 6.7 Gy (mean reduction of 2.3 Gy or 26%) to the highest functional subvolume FL80% (95%CI 1.1; 3.5). Dose to FL40% was reduced from 13.3 Gy to 11.6 Gy with functional planning. Dose reduction to FL40% was 1.7 Gy (95%CI 0.9; 2.6). Functional volume of lung receiving over 20 Gy improved by 5% (standard 22%, functional 17%). Dose to organs at risk and tumour coverage were not significantly different between plans. Conclusions: SPECT/CT-guided planning resulted in improved dose-volumetric outcomes for functional lung. This methodology may lead to potential reduction in radiation-induced lung toxicity.

Personal innovative approach in radiation therapy of lung cancer- functional lung avoidance SPECT-guided (ASPECT) radiation therapy: a study protocol for phase II randomised double-blind clinical trial

“…Dose reduction to FL, achieved by functional avoidance plans for Centre 1 and Centre 2 were comparable. As shown in Supplementary Table S1, dose reduction to FL was comparable to the previously published results [ 8 , 12 ].…”

“…Total functional lung (FL) (all voxels with SPECT signal in the lungs excluding gross tumour volume (GTV)) is contoured. In addition, contours of functional lung are created from the SPECT signal using a threshold of 20–80% of maximum perfusion count (FLx, x = 20, 40, 60, 80%) for each patient individually, as described previously [ 9 , 12 ]. These contours are transferred from the SPECT/CT to the planning CT using rigid registration and cropped to the delineated total lung volume.…”

Cancer Chemoprevention Using Nanotechnology-Based Approaches

“…The average age of cohort diagnosed with lung cancer is 50-75 years with majority of patients being 65 years or older. The existing treatment modalities (surgery, chemotherapy, or radiation therapy) have succeeded in elongating life expectancy but in most cases, the disease is incurable leading to high fatality (American Cancer Society, 2019b; Farr et al, 2019;Mieras et al, 2019). Chemoprevention has been explored for management of lung cancer using natural or synthetic compounds to inhibit progression or suppress, reverse tumor growth.…”

Imaging science and development in modern high-precision radiotherapy

“…Several recent studies have investigated the role of multimodal functional imaging to stratify patient groups and individualize RT dose prescriptions and treatment planning / application strategies according to imaging information [69][70][71][72] great prognostic potential in different tumor entities [73,74] opening new possibilities for target volume definition [75]. Furthermore, the value of functional MRI, such as diffusion weighted imaging (DWI) [76][77][78] and perfusion imaging using dynamic contrast enhanced (DCE) MRI [79,80] for outcome prognosis of functional image guided RT planning has been investigated. Further studies have analyzed the combined information from multi-modal PET and MRI [75,81] for biologically adapted, personalized RT [82].…”