What Is the BioProtect Balloon Spacer?
The BioProtect Balloon Spacer is a next generation, biodegradable device designed to enhance the safety and precision of prostate cancer radiation therapy. Unlike traditional gel spacers, BioProtect uses a balloon-based, non-gel design to create consistent, full separation between the prostate and rectum.
At Ackerman Cancer Center, a recognized center of excellence for BioProtect, this technology is integrated into an advanced approach focused on delivering safer and more precise radiation therapy, producing better outcomes for our patients.
Why Spacing Matters in Prostate Cancer Treatment
In prostate cancer treatment, the rectum lies directly behind the prostate, making it vulnerable to radiation exposure, even with highly advanced Proton Therapy.
Creating space between these structures helps to minimize rectal radiation dose, reduce gastrointestinal side effects, improve treatment accuracy, and support long term quality of life.
BioProtect provides reliable, whole gland spacing, which is critical for maximizing the precision of Proton Therapy.
Ackerman Cancer Center: A Leader in BioProtect and Proton Therapy
Ackerman Cancer Center is not simply offering BioProtect, it is leading its clinical integration.
As a center of excellence, Ackerman Cancer Center provides extensive expertise in Proton Therapy for prostate cancer, advanced imaging and treatment planning, early adoption of innovative technologies like BioProtect, and a strong focus on both outcomes and patient quality of life.
This combination positions Ackerman among a select group of centers delivering highly advanced prostate cancer care.
Key Benefits of the BioProtect Balloon Spacer
BioProtect is engineered for precision and reproducibility, delivering consistent spacing from the base to the apex of the prostate. This supports accurate Proton Therapy planning and optimized dose delivery. Clinical evidence suggests that spacing of at least 14 mm across the gland is associated with lower rectal radiation exposure.
The device also provides reliable coverage at the prostate apex, an area that can be difficult to protect with other spacer technologies. BioProtect has demonstrated consistent apical spacing, full gland coverage, and improved anatomical symmetry.
Another advantage is its stability and visibility. BioProtect is placed under transrectal ultrasound guidance and is clearly visible on CT, MRI, and ultrasound imaging. The spacing remains stable throughout the full course of Proton Therapy, helping maintain treatment accuracy.
Clinical and dosimetry studies show that BioProtect significantly reduces radiation exposure to the rectum across multiple treatment approaches. This reduction is especially important when looking at side effects and quality of life outcomes after treatment.
Preservation of Quality of Life
Maintaining quality of life is a critical priority in prostate cancer treatment. BioProtect has been associated with improved bowel function, reduced urinary side effects, and preservation of sexual function.
Long term data show that patients receiving BioProtect experienced better maintenance of bowel, urinary, and sexual quality of life compared with control groups. It is also the only spacer to demonstrate statistically significant preservation of sexual quality of life in long term follow up.
Designed for Modern Proton Therapy
Advancements in prostate cancer treatment require consistent and reproducible anatomy to fully leverage precision technologies. BioProtect supports high dose Proton Therapy regimens, efficient workflows, and reduced variability in daily treatment positioning.
What to Expect During BioProtect Placement
BioProtect placement is a minimally invasive procedure performed prior to treatment. It is completed under imaging guidance, on-site at Ackerman Cancer Center, by a board-certified radiation oncologist. The spacer remains in place during treatment and is gradually absorbed by the body over time.
Clinical Evidence Supporting BioProtect
BioProtect has been evaluated in a multicenter, prospective randomized trial involving 222 men with prostate cancer. Results showed that 97.9 percent of patients achieved significant rectal dose reduction. The average separation between the prostate and rectum was about 19 mm at placement, and 98.5 percent of patients demonstrated full resorption at six months.1
Long term follow up extending to 48 months demonstrated durable preservation of bowel and urinary function, along with sustained improvements in sexual quality of life.2
Comparative studies against gel spacers show greater rectal dose reduction, more consistent spacing across the prostate, and superior coverage at the apex.3
- Song, Daniel et al. “Prospective, Randomized Controlled Pivotal Trial of Biodegradable Balloon Rectal Spacer for Prostate Radiation Therapy.” International journal of radiation oncology, biology, physics vol. 120,5 (2024): 1410-1420. doi:10.1016/j.ijrobp.2024.07.2145
- Song, Daniel et al. “Long-term toxicity and patient-reported quality of life after prostate IMRT with or without biodegradable balloon rectal spacer: analysis of a pivotal randomized trial.” Abstract presented at: American Society for Radiation Oncology (ASTRO) 67th Annual Meeting; 2025; San Francisco, CA.
- Kos, Michael et al. “Multicenter, dual fractionation scheme, single core lab comparison of rectal volume dose reduction following injection of two biodegradable perirectal spacers.” Journal of applied clinical medical physics vol. 24,10 (2023): e14086. doi:10.1002/acm2.14086
Why BioProtect Matters at a Center of Excellence
At Ackerman Cancer Center, technologies are selected based on measurable clinical benefit. BioProtect enhances the precision of Proton Therapy, improves patient safety, and supports better long-term outcomes.
This reflects Ackerman’s commitment to delivering best in class prostate cancer care through innovation, expertise, and a focus on the patient experience.
Is BioProtect Right for You?
BioProtect may be recommended for patients undergoing Proton Therapy for prostate cancer, particularly when rectal protection is a priority or when high dose treatment approaches are being used.
A consultation with the radiation oncology team at Ackerman Cancer Center can determine whether this approach is appropriate for your individual treatment plan.



