Spontaneous remission of rectal ulcer associated with SpaceOAR® hydrogel insertion in radiotherapy for prostate cancer

Major Complications and Adverse Events Related to Use of SpaceOAR Hydrogel for Prostate Cancer Radiotherapy

OBJECTIVE

To determine the prevalence and severity of SpaceOAR-related adverse events using the Manufacturer and User Facility Device Experience (MAUDE) database.

METHODS

We analyzed SpaceOAR-related adverse event reports in the Manufacturer and User Facility Device Experience (MAUDE) database from January 2015 to May 2023. For each report, the event type, associated device and patient problems, event description, event timing, and event severity stratified by the Common Terminology Criteria for Adverse Events version 5.0 (CTCAE) grading system were recorded.

RESULTS

From 2015 to 2022, 206,619 SpaceOAR devices were sold. From January 2015 to May 2023, we identified 981 reports describing 990 SpaceOAR-related adverse events. Malfunctions were the most common event type (N = 626), followed by patient injuries (N = 350) with few reported deaths (N = 5). Device positioning problems were the most frequent device issue (N = 686). Pain was the most reported patient problem (N = 216). Abscesses and fistulas related to the device were each reported in 91 events. A noteworthy portion of relevant adverse events occurred before the initiation of radiation (N = 35, 22.4%), suggesting the device, rather than the radiation, was responsible. In total, 470 (50.2%) and 344 (36.7%) of the adverse events were CTCAE grade 1 and 2, respectively. There were 123 (13.1%) events that were CTCAE grade ≥3.

CONCLUSION

We identified multiple reports of SpaceOAR-related adverse events, many of which are more serious than have been reported in clinical trials. While SpaceOAR use is common, suggesting these events are rare, these data highlight the need for continued postmarket surveillance.

Cost-effectiveness analysis of hydrogel spacer for rectal toxicity reduction in prostate external beam radiotherapy

INTRODUCTION

Contemporary methods of external beam radiotherapy for prostate cancer have reduced toxicity rates through beam modulation and image guidance, however, rectal injury has not been eliminated completely in this population. For patients at greatest risk of developing rectal toxicities, hydrogel spacers are a viable option for risk reduction. Translation of clinical trial results into routine clinical practice relies on an understanding of the economic implications. This study completed a cost-effectiveness analysis of hydrogel spacers in the Australian healthcare setting.

METHOD

Simulation of possible health states following treatment was performed using a Markov model. Model outcomes included the incremental cost-effectiveness ratio and the net monetary benefit (NMB) at three published willingness-to-pay thresholds derived from literature. Probabilistic sensitivity analyses were provided on these results. A baseline cohort without hydrogel spacer use was compared to treat all and selective use cohorts. Cost variation scenarios were also investigated to assess the impact of hydrogel spacer cost on outcomes.

RESULTS

Using hydrogel spacers in a selective cohort was more likely to be cost-effective than giving to all patients (NMB -$43 versus -$997, respectively); however, the incremental cost-effectiveness ratio was not below the $28 000 willingness-to-pay threshold for a healthcare provider perspective. These outcomes were influenced by large parameter uncertainty. Cost variation strategies are worth investigating further as a method to achieve willingness-to-pay threshold targets.

CONCLUSION

The influence of parameter uncertainty currently limits the cost-effectiveness of this intervention in the Australian public health setting. However, a cost variation solution has been demonstrated to improve cost-effectiveness estimates for selected patients and should be examined further.