Hypofractionated adjuvant radiotherapy with helical tomotherapy after radical prostatectomy: planning data and toxicity results of a Phase I-II study.
OBJECTIVE
To report on planning and toxicity findings of hypofractionated adjuvant radiotherapy with helical Tomotherapy (HTT) after radical prostatectomy (RP) for prostate carcinoma (pCa).


METHODS
Fifty consecutive patients submitted to RP for pT2R1/pT3a/pT3b-pN0 pCa were enrolled in a Phase I-II trial to receive 58Gy/20 fractions (5/week) on tumoral bed. Endpoint was to verify a risk of toxicity and biochemical failure not exceeding that observed in our Institutional 3DCRT, conventionally fractionated series (153 patients). Toxicities were graded according the RTOG scoring system.


RESULTS
Excellent coverage of PTV and high homogeneity of dose distribution were always achieved. Median follow-up was 25 months. Acute G2-3 RTOG genitourinary (GU) and acute G2 intestinal toxicities were similar (12% vs 15.6% and 4% vs 7%, respectively), while acute G2 proctitis was 0% vs 9% in HTT and 3DCRT group, respectively. Similarly, late Grade 2 gastrointestinal sequelae were 0% vs 8.5%. The incidence of late urethral stricture, 8% and 9% in HTT and 3DCRT group, respectively, is comparable to that of RP-only series.


CONCLUSIONS
Acute toxicity and early late toxicity outcomes of a moderately hypofractionated regimen with HTT post-RP are excellent. A longer follow-up is needed to fully assess the validity of this approach.
Cozzarini
Cesare
C
Department of Radiotherapy, and Scientifc Institute H San Raffaele, Milan, Italy. cozzarini.cesare@hsr.it
Fiorino
Claudio
C
Di Muzio
Nadia
N
Valdagni
Riccardo
R
Salonia
Andrea
A
Alongi
Filippo
F
Broggi
Sara
S
Guazzoni
Giorgio
G
Montorsi
Francesco
F
Rigatti
Patrizio
P
Calandrino
Riccardo
R
Fazio
Ferruccio
F
D000704:Analysis of Variance; D016009:Chi-Square Distribution; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D015641:Radiography, Interventional; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects / Q000379:methods*; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome