A Prospective Study of Magnetic Resonance Imaging Assessment of Post-radiation Changes Following Stereotactic Body Radiation Therapy for Non-small Cell Lung Cancer.

AIMS: Follow-up computed tomography scans after lung stereotactic body radiation therapy (SBRT) are difficult to interpret due to the presence of benign fibrosis, which can make the detection of local recurrence difficult. The objective of this study was to determine the feasibility of a novel thoracic magnetic resonance imaging (MRI) protocol incorporating diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) imaging for the assessment of the treated lung parenchyma after SBRT. MATERIALS AND METHODS: On a prospective trial, post-treatment MR images were acquired in 30 patients treated with SBRT (divided into three different cohorts according to the likelihood of local recurrence as per an expert panel). These images were assessed by an expert thoracic radiologist blind to clinical data, who indicated local recurrence in a dichotomous manner. Local recurrence was confirmed by biopsy or subsequent growth on follow-up computed tomography scans. RESULTS: Thirty patients underwent MRI as part of this study; 27/30 patients were analysable for local recurrence. MRI was conducted at a median of 27.3 months (range 6.5-71 months) from SBRT. No side-effects resulted from either MRI or contrast administration. At a median follow-up time of 45 months after treatment, three local recurrence episodes have occurred. MRI assessment diagnosed seven patients as having a local recurrence, which was later confirmed in three and did not miss any of the true local recurrences. When comparing apparent diffusion coefficient (ADC) values according to local recurrence, the mean ADC value for the local recurrence-free group was 1770 × 10-3 mm/s2 (range 1038-3105 × 10-3 mm/s2) versus 981 × 10-3 mm/s2 (range 926.6-1065 × 10-3 mm/s2) for the local recurrence group (P = 0.0014). CONCLUSIONS: A novel 3.0 T MRI protocol incorporating DWI and DCE was feasible and confirmed the suspicion of local recurrence in patients with highly suspicious computed tomography scans. This imaging tool could potentially aid in selecting patients for salvage treatment after local SBRT failure. Future work should be pursued to validate these findings.

Quantifying Health Utilities in Patients Undergoing Stereotactic Body Radiation Treatment for Liver Metastases for Use in Future Economic Evaluations.

AIM: Stereotactic body radiation therapy (SBRT) is increasingly used as an option for those with liver metastases. In order to facilitate future economic impact of health technologies, health utility scores may be used. The EuroQOL-5D-3L (EQ-5D) preference-based healthy utility instrument was used to evaluate the impact of treatment with SBRT on health utility scores. MATERIALS AND METHODS: Between August 2013 and October 2014, 31 patients treated with 3-5 fractions of SBRT for liver metastases were enrolled in this study. The EQ-5D instrument was administered at baseline, during and up to 6 months post-SBRT. RESULTS: Mean EQ-5D score at baseline was 0.857, which remained stable across the entire study time period. Transient increases in difficulties with mobility (9.7% reported at baseline to 16.1% on the last day of treatment) and usual activities (3.2% reported at baseline to 34.5% on day two) were found during the course of treatment; these returned to baseline levels subsequently. The mean visual analogue score at baseline was 65.8 and remained unchanged throughout treatment and follow-up. CONCLUSIONS: The stability of health utility scores and problems reported by patients undergoing treatment indicate that SBRT for liver metastases does not impart a significant adverse effect on quality of life. These results may be used for future economic evaluation of SBRT.