Transperineal Injection of Cross-linked Hyaluronan Gel Into Anterior Perirectal Fat to Reduce Rectal Toxicity From High Dose Rate Brachytherapy and/or Intensity-Modulated Radiation Therapy for Prostate Cancer

The main risk associated with transperineal injection of cross-linked hyaluronan gel into the anterior perirectal fat is infection. Prophylactic antibiotics will be given, resulting in a <5% risk. Another possible risk (<5%) is an allergic reaction such as itching. Patients who are allergic to avian products will be excluded from the study. Tenderness and pain at the injection site are possible. Bleeding, bruising, redness, or discoloration or the formation of a bump (granuloma) or scar (keloid) at the injection site is also possible. Embolization of cross-linked hyaluronan gel through the blood is a potential, rare complication if the gel is injected into a blood vessel rather than into fat. Prada et al. did not see any side effects related to the injection or the material itself in 27 patients based on a mean follow-up of 13 months (range: 9-22 months). Patients did not complain of pain, tenesmus, rectal pressure, or a sensation of rectal filling. Risks beyond 22 months are not well defined. Potential benefits of cross-linked hyaluronan gel include fewer rectal complications due to radiotherapy for early-stage prostate cancer.