Illustration of SpaceOAR Hydrogel

Clinical Summary

A Multi-Institutional Phase 2 Trial of High-Dose SAbR for Prostate Cancer Using Rectal Spacer


By: Folkert MC, Zelefsky MJ, Hannan R, et al.

High-dose stereotactic ablative radiotherapy (SAbR) for prostate cancer (PCa) offers the radiobiologic potency of the most intensified radiation therapy regimens, but was associated with >90% rates of ulceration of the anterior rectal wall on endoscopic assessment that infrequently progressed to severe rectal toxicity in prior prospective series. A multi-institutional Phase II prospective trial was conducted to assess whether placement of a peri-rectal hydrogel spacer would reduce acute periprostatic rectal ulcer events following high dose (> 40 Gy) SAbR.

45Gy/5 Fractions

  Acute Late
  Grade 1 Grade 2 Grade 3 Grade 1 Grade 2 Grade 3
Genitourinary (Any) 28 (65.1%) 20 (46.5%)  1 (2.3%) 27 (64.3%)  1 4 (33.3%) 1 (2.4%)
Irritative 19 (44.2%) 16 (37.2%) 1 (2.3%) 18 (42.9%) 12 (28.6%) 0 (0.0%)
Obstructive 18 (41.9%) 5 (11.6%) 0 (0.0%)  14 (33.3%) 6 (14.3%) 1 (2.4%)
Gastrointestinal 25 (58.1%) 10 (23.3%) 0 (0.0%) 14 (33.3%) 6 (14.3%) 0 (0.0%)
Reproductive 14 (32.6%) 6 (14.0%) 0 (0.0%) 6 (14.3%) 6 (14.3%) 0 (0.0%)
“This is the first prospective study to evaluate the efficacy of a temporary hydrogel spacer for patients undergoing high-dose SAbR (45 Gy in 5 fractions) for LR and IR PCa. Hydrogel spacer placement prior to high-dose SAbR treatment for LR and IR PCa increases the distance between anterior rectal wall and prostate. This increased space for dose falloff and reduction in incidental dose to the rectal wall is associated with a significant reduction in the incidence of rectal ulcer events to only 14.3% compared to prior studies, facilitating the safe delivery of high-dose SAbR. This is expected to reduce long-term rectal toxicity; there have been no (0%) high-grade (Grade ≥ 3) GI events noted on study to date.”


Link to full article >





Limitations of this report include:
 
  • The SpaceOAR Hydrogel pivotal study did not use SBRT so the results may not be comparable.
  • This study was not randomized and definitive claims about the benefits of a spacer cannot be made.
  • These results may not be achieved with other SBRT protocols.
  • Weaknesses of the study are primarily in terms of secondary endpoints, as the patient cohort was small with a median follow-up of 48 months to date.
  • While it is early to interpret biochemical control results, and this Phase 2 trial is not powered or structured for rigorous comparison across other prospective trials, they are promising with a 4-year FFBF of 93.8% despite over half the treated patients considered unfavorable IR, and no patients receiving concurrentor adjuvant ADT.


Frequently Asked Questions

We've got the answers.

FAQ

Get SpaceOAR Hydrogel

Become a certified applier.

CONNECT WITH A REP

Sign Up

Get exclusive updates and clincial data.

JOIN NOW

Disclaimers

SBRT was not the method used in the SpaceOAR Hydrogel single-blind Phase III trial performed to evaluate dosimetric and clinical effects of SpaceOAR Hydrogel. IG-IMRT delivered at 79.2 Gy in 1.8-Gy fractions was the method used.

Results from case studies are not necessarily predictive of results in other cases. Results in other cases may vary.

The content of this article/publication is under the sole responsibility of its author/publisher and does not represent the opinion of BSC.

Caution: U.S. Federal law restricts this device to sale by or on the order of a physician.

CAUTION: The law restricts these devices to sale by or on the order of a physician. Indications, contraindications, warnings and instructions for use can be found in the product labeling supplied with each device. Information for use only in countries with applicable health authority registrations. This material not intended for use in France.

Products shown for INFORMATION purposes only and may not be approved or for sale in certain countries. Please check availability with your local sales representative or customer service.

All images are the property of Boston Scientific. All trademarks are the property of their respective owners.

Top