Stereotactic Body Radiotherapy as Monotherapy or Post-External Beam Radiotherapy Boost for Prostate Cancer: Technique, Early Toxicity, and PSA Response

Journal Article · Sun Jan 01 04:00:00 EST 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2010.10.026· OSTI ID:22055938

Jabbari, Siavash ^[1]; Weinberg, Vivian K ^[2]; Kaprealian, Tania; Hsu, I-Chow; Lijun, Ma; Chuang, Cynthia; Descovich, Martina; Shiao, Stephen ^[1]; Shinohara, Katsuto ^[3]; Roach, Mack ^[1]

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1. Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States)
2. Biostatistics and Computational Biology Core, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California (United States)
3. Department of Urology, University of California San Francisco, San Francisco, California (United States)

Purpose: High dose rate (HDR) brachytherapy has been established as an excellent monotherapy or after external-beam radiotherapy (EBRT) boost treatment for prostate cancer (PCa). Recently, dosimetric studies have demonstrated the potential for achieving similar dosimetry with stereotactic body radiotherapy (SBRT) compared with HDR brachytherapy. Here, we report our technique, PSA nadir, and acute and late toxicity with SBRT as monotherapy and post-EBRT boost for PCa using HDR brachytherapy fractionation. Patients and Methods: To date, 38 patients have been treated with SBRT at University of California-San Francisco with a minimum follow-up of 12 months. Twenty of 38 patients were treated with SBRT monotherapy (9.5 Gy Multiplication-Sign 4 fractions), and 18 were treated with SBRT boost (9.5 Gy Multiplication-Sign 2 fractions) post-EBRT and androgen deprivation therapy. PSA nadir to date for 44 HDR brachytherapy boost patients with disease characteristics similar to the SBRT boost cohort was also analyzed as a descriptive comparison. Results: SBRT was well tolerated. With a median follow-up of 18.3 months (range, 12.6-43.5), 42% and 11% of patients had acute Grade 2 gastrourinary and gastrointestinal toxicity, respectively, with no Grade 3 or higher acute toxicity to date. Two patients experienced late Grade 3 GU toxicity. All patients are without evidence of biochemical or clinical progression to date, and favorably low PSA nadirs have been observed with a current median PSA nadir of 0.35 ng/mL (range, <0.01-2.1) for all patients (0.47 ng/mL, range, 0.2-2.1 for the monotherapy cohort; 0.10 ng/mL, range, 0.01-0.5 for the boost cohort). With a median follow-up of 48.6 months (range, 16.4-87.8), the comparable HDR brachytherapy boost cohort has achieved a median PSA nadir of 0.09 ng/mL (range, 0.0-3.3). Conclusions: Early results with SBRT monotherapy and post-EBRT boost for PCa demonstrate acceptable PSA response and minimal toxicity. PSA nadir with SBRT boost appears comparable to those achieved with HDR brachytherapy boost.

• OSTI ID: 22055938
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 1 Vol. 82; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ANDROGENS
BEAMS
BRACHYTHERAPY
DOSE RATES
DOSIMETRY
FRACTIONATION
NEOPLASMS
PATIENTS
PROSTATE
TOXICITY