Significant reduction of acute toxicity following pelvic irradiation with helical tomotherapy in patients with localized prostate cancer.
OBJECTIVE
To assess and quantify the possible benefit deriving from IMRT with Helical Tomotherapy (HTT) delivery to the pelvic nodal area in patients with prostate cancer in terms of reduction of acute and late toxicities.


METHODS
Thirty-five patients candidate to radical or postoperative RT on whole pelvis (WPRT) were treated with HTT, while receiving a concomitant boost to the prostate or the prostatic bed (median 74.2 and 72 Gy, respectively) within a moderately hypofractionated (28-33 fractions; median HTT duration 44 days) regimen. Median and mean doses to whole pelvis were 52 and 54 Gy, respectively. One of the major goals of planning optimisation was to minimize the dose received by the intestinal cavity (IC) outside the nodal PTV.


RESULTS
HTT resulted to be very efficient in sparing the IC even at dose levels below 30-35 Gy and guaranteed a significant sparing of bladder and rectum even at intermediate-low doses (V20-V40). No acute Grade 3 RTOG toxicity was recorded. Eighteen G1 and two G2 GU acute toxicities, 13 G1 upper GI acute toxicities, 8 G1 and 1 G2 acute proctitis were observed; no patient experienced G2 upper GI toxicity. After a median FU of 11.5 months (>10 in 18 patients) one case of late G3 GU toxicity was reported in one post-prostatectomy treated patient; no G2 late rectal bleeding or other GI toxicity was recorded.


CONCLUSIONS
WPRT with HTT resulted in a very low incidence of acute Grade 2 and in the disappearance of acute Grade 3 toxicities.
Cozzarini
Cesare
C
Department of Radiotherapy, Scientific Institute H San Raffaele, 20132 Milan, Italy. cozzarini.cesare@hsr.it
Fiorino
Claudio
C
Di Muzio
Nadia
N
Alongi
Filippo
F
Broggi
Sara
S
Cattaneo
Mauro
M
Montorsi
Francesco
F
Rigatti
Patrizio
P
Calandrino
Riccardo
R
Fazio
Ferruccio
F
D006801:Humans; D008297:Male; D010388:Pelvis / Q000528:radiation effects*; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects* / Q000379:methods*; D012007:Rectum / Q000187:drug effects; D001743:Urinary Bladder / Q000528:radiation effects