Urethral sparing and image-guided matching using a radio-opaque catheter in stereotactic body radiotherapy to the prostate with intraprostatic boosts
Kevin Martell, Shane Clay, Sara Fedoruk, Jason Hancock, Leon Malan, Andrea Mcormond, Lliana Jordan, Naami Mcaddy and Hong-Wei Liu
Purpose: A variety of on treatment matching techniques are used in prostate stereotactic body radiotherapy (SBRT). This study aimed to review the real world clinical outcomes when a radio opaque foley catheter is used for image matching and urethral sparing.
Materials and methods: A retrospective review of 42 sequential patients treated with prostate SBRT with intraprostatic boosts and radio opaque catheters inserted for urethral sparing and image matching was conducted. Patients received 40 Gy in 5 fractions to the prostate and catheter-based cone beam computed tomography image matching at the time of treatment. Dosimetric and acute urinary toxicity outcomes were then reviewed.
Results: Forty-two patients were offered therapy. Thirty-six (86%) patients received radical treatment for primary prostate cancer and 6 (14%) received SBRT as salvage therapy for recurrent disease after primary therapy. Two (5%) and 13 (36%) patients declined catheter insertion at simulation at the time of treatment, respectively. In 2 (5%) patients, catheterization at treatment was not possible due to false passage creation.
Median boost clinical target volume minimum dose in gray to hottest 98% of tissue (D98%) was greater than prostate D98% [4132 (4063–4240) cGy vs 3936 (3904–3960) cGy; p < 0.001]. The median maximum dose to prostatic urethra was 4000 (3982–4046) cGy. Baseline and 3 month American Urological Association scores were similar: [6 (4–13) vs 8 (4–12); p = 0.919].
Conclusion: In conclusion, the adoption of dose-escalated, urethral spared, radio-opaque catheter-based image-guided prostate SBRT is feasible and allows for safe dose escalation. There was little acute toxicity and a high degree of compliance amongst patients and the healthcare team.
Keywords: prostate cancer, urethral sparing, toxicity, image guidance, SBRT, dose escalation
Full Text (IP)
Purchase Article (PDF)