title: Linac based SBRT for prostate cancer in 5 fractions with VMAT and flattening filter free beams: preliminary report of a phase II study.
abstract: BACKGROUND
  To evaluate the feasibility and early side effects of a short course hypo-fractionated SBRT programme with Volumetric Modulated Arc Therapy (VMAT) and Flattening Filter Free (FFF) beams.
  
  
  METHODS
  A prospective phase I-II study, started on February 2012. Inclusion criteria were: age ≤ 80 years, WHO-PS ≤ 2, PSA ≤ 20 ng/ml, histologically proven prostate adenocarcinoma, T1-T2 stage, no distant metastases, no previous surgery other than TURP, no malignant tumours in the previous 5 years, IPSS 0-7. The schedule was 35 Gy in 5 alternative days. SBRT was delivered with RapidArc VMAT, with 10MV FFF photons. Toxicity assessment was performed according to CTCAE v4.0 scale. EPIC questionnaires assessed Quality-of-Life. Neo-adjuvant/concomitant hormonal-therapy was prescribed according to risk classification. SpaceOAR™ gel was optionally implanted to increase the separation space between the prostate and the rectal wall.
  
  
  RESULTS
  Median follow-up was 11 months (range: 5-16); 40 patients were recruited in the protocol and treated. According to NCCN criteria, 26/40 patients were low-risk and 14/40 were intermediate risk. Median age was 70 years (56-80), median initial PSA was 6.25 ng/ml (0.50-13.43 ng/ml). Median Gleason score was 6 (6-7). All patients completed the treatment as programmed (median 11.8 days (9-22). Acute Toxicities were as follow: Rectum G0: 30/40 cases (75%); G1: 6/40 (15%); G2: 4/40 (10%). Genito-urinary: G0: 16/40 (40%); G1: 8/40 (20%); G2: 16/34 (40%). In two G2 urinary retention cases, intermittent catheter was needed. No acute G3 or greater toxicity was found. Median treatment time was 126 sec (120-136). SpaceOAR™ was implanted in 8 patients. PSA reduction from the pre-treatment value of the marker was documented in all patients.
  
  
  CONCLUSIONS
  Early findings suggest that SBRT with RapidArc and FFF beams for prostate cancer in 5 fractions is feasible and tolerated in acute setting. Longer follow-up is needed for assessment of late toxicity and outcome.
authors.forename: Filippo
authors.initials: F
authors.lastname: Alongi
authors.forename: Luca
authors.initials: L
authors.lastname: Cozzi
authors.forename: Stefano
authors.initials: S
authors.lastname: Arcangeli
authors.forename: Cristina
authors.initials: C
authors.lastname: Iftode
authors.forename: Tiziana
authors.initials: T
authors.lastname: Comito
authors.forename: Elisa
authors.initials: E
authors.lastname: Villa
authors.forename: Francesca
authors.initials: F
authors.lastname: Lobefalo
authors.forename: Pierina
authors.initials: P
authors.lastname: Navarria
authors.forename: Giacomo
authors.initials: G
authors.lastname: Reggiori
authors.forename: Pietro
authors.initials: P
authors.lastname: Mancosu
authors.forename: Elena
authors.initials: E
authors.lastname: Clerici
authors.forename: Antonella
authors.initials: A
authors.lastname: Fogliata
authors.forename: Stefano
authors.initials: S
authors.lastname: Tomatis
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Taverna
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Graziotti
authors.forename: Marta
authors.initials: M
authors.lastname: Scorsetti
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*