title: Image-guided stereotactic body radiation therapy for clinically localized prostate cancer: preliminary clinical results.
abstract: Stereotactic body radiotherapy (SBRT) is a new treatment modality for prostate cancer. The current study evaluates CyberKnife SBRT and reports toxicity and early Prostate-Specific Antigen (PSA) kinetics. From June 2006 to August 2009, 45 low-and intermediate-risk prostate cancer patients received Cyberknife SBRT of 35 Gy in five fractions with 95% minimum target coverage. Median follow-up was 20-months (range 6-42-months). Seventeen patients received androgen-deprivation therapy also. Acute complications were mild, short-lived and no greater than Grade 2 by RTOG scale. Late toxicities consisted of one patient (2.2%) experiencing Grade 2 rectal, one patient (2.2%) Grade 3 and four patients (8.8%) with Grade 1 urinary toxicity. PSA in all patients progressively declined from a mean 4.7 ng/ml baseline to 1.48 ng/ml at three months, to 0.68 ng/ml at 12 months and to 0, 35 ng/ml at 24 months. The 28 hormon-naive patients had the mean PSA value of 1.1 ng/ml at one year from a mean 6.65 ng/ml baseline. There was a significant PSA value reduction in 11 hormone therapy patients with low baseline PSA value (< or = 1 ng/ml) from 0.37 down 0.14 ng/ml (p value 0.0068) at one year. Moreover, 14 low risk patients gave better results of mean PSA value than 17 Intermediate risk patients 0.43 ng/ml vs. 0.93 ng/ml (p value 0.02) at one year. No patient had biochemical failure at last follow-up. Hypofractionated SBRT appears to have potential against prostate cancer. Low toxicity and encouraging biochemical control support its use in early-stage prostate cancer. Results encourage further follow-up and larger studies.
authors.affiliation: Division of Radiation Oncology, San Bortolo Hospital, Viale Rodolfi 37, 36100 Vicenza, Italy. giampaolo101@libero.it
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Bolzicco
authors.forename: Maria Silvia
authors.initials: MS
authors.lastname: Favretto
authors.forename: Enrico
authors.initials: E
authors.lastname: Scremin
authors.forename: Carmelo
authors.initials: C
authors.lastname: Tambone
authors.forename: Andrea
authors.initials: A
authors.lastname: Tasca
authors.forename: Rosabianca
authors.initials: R
authors.lastname: Guglielmi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000000981:diagnostic imaging / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: D017430:Prostate-Specific Antigen