ABSTRACT
Purpose: Magnetic resonance image (MRI)-guided radiation therapy with the 1.5 Tesla magnetic resonance linear accelerator (MR-Linac) is a rapidly evolving and emerging treatment. The MR-Linac literature mainly focused on clinical and technological factors in technology implementation, but it is relatively silent on health care system-related factors. Consequently, there is a lack of understanding of opportunities and barriers in implementing the MR-Linac from a health care system perspective. This study addresses this gap with a case study of the US health care system. Methods and Materials: An exploratory, qualitative research design was used. Data collection consisted of 23 semistructured interviews ranging from clinical experts at the radiation therapy and radiology department to insurance commissioners in 7 US hospitals. Analysis of opportunities and barriers was guided by the Nonadoption, Abandonment, Scale-up, Spread and Sustainability framework for new medical technologies in health care organizations. Results: Opportunities included high-precision MR-guidance during radiation therapy with potential continued technical advances and better patient outcomes. MR-Linac also offers opportunities for research, professional, and economic development. Barriers included the lack of empirical evidence of clinical effectiveness, technological complexity, and large staffing and structural investments. Furthermore, the presence of patients with disadvantaged socioeconomic background, and the lack of appropriate reimbursement as well as regulatory conditions can hinder technology implementation. Conclusions: Our study confirms the current literature on implementing the MR-Linac, but also reveals additional challenges for the US health care system. Alongside the well-known clinical and technical factors, also professional, socioeconomic, market, and governing influences affect technology implementation. These findings highlight new connections to facilitate technology uptake and provide a richer start to understanding its long-term effect.
ABSTRACT
PURPOSE: For the treatment of localized prostate cancer, focal therapy has the potential to cure with fewer side effects than traditional whole-gland treatments. We report an update on toxicity, quality of life (QoL), and tumor control in our magnetic resonance imaging (MRI)-guided ultrafocal high-dose-rate brachytherapy cohort. METHODS AND MATERIALS: Disease status was evaluated by systematic biopsies and 3T multiparametric MRI. The brachytherapy implant procedure under fused transrectal ultrasound/MRI guidance was followed by a 1.5 T MRI for contour adjustments and catheter position verification. A single dose of 19 Gy was delivered to the tumor with a margin of 5 mm. Genitourinary (GU) toxicity, gastrointestinal (GI) toxicity, and erectile dysfunction (ED) were graded with the Common Terminology Criteria for Adverse Events version 4.0. QoL was measured with RAND-36, European Organisation for Research and Treatment of Cancer QLQ-C30 and PR25. International Prostate Symptom Scores and International Index of Erectile Function scores were obtained. Prostate-specific antigen level was monitored, with biochemical recurrence defined as nadir + 2 ng/mL (Phoenix). RESULTS: Thirty patients with National Comprehensive Cancer Network low- (13%) to intermediate-risk (87%) prostate cancer were treated between May 2013 and April 2016. Median follow-up was 4 years. Median age was 71 years (interquartile range, 68-73) and median initial prostate-specific antigen level was 7.3 ng/mL (5.2-8.1). Maximum Gleason score was 4 + 3 = 7 (in 2 patients). All tumors were radiologic (MRI) stage T2. No grade >2 GU or >1 GI toxicity occurred. International Prostate Symptom Scores only deteriorated temporarily. Mild pretreatment ED deteriorated to moderate/severe ED in 50% of patients. Long-term clinically relevant QoL deterioration was seen in sexual activity and tiredness, whereas emotional and cognitive functioning improved. At 4 years, biochemical disease-free survival was 70% (95% confidence interval, 52%-93%), metastases-free survival was 93% (85%-100%), and overall survival was 100%. Of intraprostatic recurrences, 7 of 9 were out of field. CONCLUSIONS: Ultrafocal high-dose-rate brachytherapy conveys minimal GU or GI toxicity and has a marginal effect on QoL. An early decline in erectile function was seen. Tumor control outcomes are poor (biochemical disease-free survival of 70% [52%-93%] at 4 years), most likely as a result of poor patient selection.
