BACKGROUND: Stereotactic body radiotherapy (SBRT) can emulate high dose rate brachytherapy (HDR-BRT) dose fractionation.
We report our preliminary results using SBRT in monotherapy or pre-external-beam radiotherapy (EBRT) boost in patients with localized prostate cancer (LpC). The primary end point was the evaluation of both acute and late toxicities; secondary end point was the observation of prostate-specific antigen (PSA) nadir.
PATIENTS AND METHODS: Patients with LpC having prostate volume ≤ 90 cm3 were enrolled in the present study. Patients were treated with SBRT alone or in combined modality (SBRT + EBRT). SBRT was performed using a CyberKnife System (Accuray Incorporated, Sunnyvale, California) and fiducial tracking system.
RESULTS: From February 2008 to July 2013, 21 patients for monotherapy (38 Gy/4 fractions) and 5 for combined modality (9.5 Gy/2 fractions plus 46 Gy/23 fractions EBRT) were enrolled. Androgen deprivation therapy (ADT) was administered in 16 of the 26 patients. The median pretreatment PSA was 9.4 (range, 4.5-14.3) ng/mL. All patients completed the planned therapy. Acute Grade 1 toxicity was observed in 18 patients, genitourinary (GU) in 12 / 26 patients, and gastrointestinal (GI) in 6 / 26 patients. Acute Grade 2 GU toxicity was reported in 1 / 26 patients, and Grade 2 GI toxicity was observed in 2 / 26 patients. The median PSA nadir was 0.15 (range, 0.02 = 1.4) ng/mL. Late toxicities were observed in 5 / 26 patients: Grade 1 GU (3 of 26), Grade 2 GU (1 of 26), and Grade 1 GI (1 of 26). Median follow-up was 21.5 (range, 8-65) months.
CONCLUSIONS: Our preliminary results of SBRT "simulating" HDR for LpC confirm a minimal toxicity and an optimal PSA response. The PSA nadirs appear comparable with HDR-BRT.
Written by:
Pontoriero A, Iatì G, Mondello S, Midili F, Siragusa C, Brogna A, Ielo I, Anastasi G, Magno C, Pergolizzi S, De Renzis C. Are you the author?
Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy; A.O.U. "G. Martino", Operative Unit of Radiation Oncology, Messina, Italy; Department of Neuroscience Messina, University of Messina, Messina, Italy; Department of General Surgery, Oncology and Pathology, University of Messina, Messina, Italy.
Reference: Technol Cancer Res Treat. 2015 Jan 13. pii: 1533034614566994.
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PubMed Abstract
PMID: 25586517