I do the procedure, but I get nervous about stuff like this....
Aminsharifi A, Kotamarti S, Silver D, Schulman A
Major Complications and Adverse Events Related to the Injection of the SpaceOAR Hydrogel System Before Radiotherapy for Prostate Cancer: Review of the Manufacturer and User Facility Device Experience Database.
J Endourol 2019 Oct ;33(10) 868-871 PMID:31452385 PubMed - in process
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Purpose: SpaceOAR® is a Food and Drug Administration-approved hydrogel injection used to create space between the prostate and rectum during prostate radiotherapy. It has shown to significantly reduce the rectal radiation dose with lower rates of rectal toxicity. Despite a high safety performance in initial trials, SpaceOAR remains in early clinical use. Thus, we examined emerging safety reports as the system becomes more widely utilized. Methods: We reviewed the SpaceOAR manufacturer website for the safety profile and complications associated with the SpaceOAR hydrogel. We then compared this with reports submitted to the Manufacturer and User Facility Device Experience (MAUDE) database. Results: The manufacturer website reported risks including pain, needle penetration, and/or gel injection into a nearby organ or blood vessel, local inflammation, infection, urinary retention, and local rectal injury or symptoms. There were 22 unique reports discussing 25 patient cases in the MAUDE database from January 2015 to March 2019, with an increasing number of reports each year up through 2018. Unique major complications including acute pulmonary embolism, severe anaphylaxis, prostatic abscess and sepsis, purulent perineal drainage, rectal wall erosion, and rectourethral fistula were reported. Conclusion: Despite well-documented clinical benefits of the SpaceOAR System, there are a number of severe and debilitating complications recently reported in proximity to gel injection. This highlights the need for further study of device complications in light of its increasing clinical use.
This citation was also selected in the following Editor's Choice Editions: Radiation Oncology May 2020
Here is Lawton's commentary on it:
Toxicities related to radiation therapy for prostate cancer should be mitigated as much as possible, as they should be for all cancers that are treated with radiation therapy. The most common toxicities associated with radiation therapy and the treatment of prostate cancer are bowel and bladder related. Although uncommon, some of the toxicities can be severe. Thus, the development of the system described in this article to increase the distance between the prostate and the rectum seems very reasonable.
The spacer system developed here was tested in a randomized trial which showed a 25% relative reduction in rectal radiation dose and an associated decrease in Grades I-III clinical rectal toxicity and improved bowel quality of life at 15 months and three years. Yet even though there was an invasive procedure done to place the spacer, and a foreign body (the spacer system) was placed, no device related toxicities were reported, except local fullness/tenderness at the injection site.
The data presented here is a report from an FDA-maintained archive for anonymous reporting of device-related adverse events during procedures. This report shows 25 patients (2015-2019) who had adverse events ranging from venous injection with no sequelae (2 patients) to severe complications of rectal ulcers, perirectal fistulas, prostatic abscess, urosepsis and even death. This information is critical for the patient considering this procedure and the medical personnel placing the spacer. The risk of significant rectal toxicity in the era of image guided radiation therapy and intensity modulated radiation therapy is low with less than 1% Grade 4 toxicity and less than 5% Grade 3 toxicity. The risk of a severe injury with this spacer is also low, but not zero and must be discussed. To the credit of the manufacturer, their website reports possible adverse events ranging from pain to local rectal injury and fistula formation. It is imperative that we as radiation oncologists discuss these possible toxicities if we choose to recommend the spacer system.
