Analysis of toxicity in patients with high risk prostate cancer treated with intensity-modulated pelvic radiation therapy and simultaneous integrated dose escalation to prostate area.
OBJECTIVE
To report the treatment-related morbidity in patients with prostate cancer treated with an optimized pelvic intensity-modulated radiation therapy (IMRT) and simultaneous integrated dose escalation to prostate/prostate bed.


METHODS
Between November 2003 and May 2006, 55 patients with localized prostate cancer and >15% risk of lymph node involvement were treated with pelvic IMRT and simultaneous dose escalation to prostate area. Twenty-four patients received a radical radiation therapy program, and the remaining thirty-one patients received a postoperative irradiation as adjuvant treatment or after biochemical or macroscopic local/regional relapse. After a customized immobilization all patients underwent contrast-enhanced CT. On the CT slices CTV1 and CTV2 were delineated. CTV(1) included the prostate and seminal vesicles or prostate bed. CTV(2) consisted of CTV(1) plus pelvic nodes. CTV(1) and CTV(2) were then expanded by 0.5 and 1cm, respectively, to generate the planning target volumes. IMRT treatment plans were generated using commercial inverse planning software. Total doses of 66-80 Gy and 50-59 Gy in 33-40 fractions were prescribed to the prostate area and pelvis, respectively. The worst acute and late rectal, intestinal and GU toxicities during and after treatment were scored according to the EORTC/RTOG scales.


RESULTS
The IMRT dose distribution provided excellent PTV coverage and satisfying sparing of all the organs at risk, with no patient experiencing >grade 2 acute or late toxicities. Patients without acute grade 2 intestinal, rectal, and GU toxicity were 91%, 71%, and 63%, respectively. After a median follow-up of 19 months (interquartile range of 9 to 28 months), late grade 2 toxicity was detected only for rectum, with an actuarial 2-year rate of freedom from G2 rectal bleeding of 92%. (CI 95% 0.83-0.99.)


CONCLUSIONS
Pelvic IMRT and simultaneous dose escalation to prostate area is a well-tolerated technique in patients with prostate cancer requiring treatment of pelvic lymph nodes, and seems to be associated with a lower frequency and severity of side effects when compared with conventional techniques reported in other series.
Arcangeli
Stefano
S
Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome, Italy. arcangeli@ifo.it
Saracino
Biancamaria
B
Petrongari
Maria Grazia
MG
Gomellini
Sara
S
Marzi
Simona
S
Landoni
Valeria
V
Gallucci
Michele
M
Sperduti
Isabella
I
Arcangeli
Giorgio
G
D000368:Aged; D000369:Aged, 80 and over; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000528:radiation effects*; D011467:Prostate / Q000528:radiation effects*; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*