Feasibility of IMRT to cover pelvic nodes while escalating the dose to the prostate gland: dosimetric data on 35 consecutive patients.
Utilizing available dosimetric and acute toxicity data, we confirm the feasibility of intensity modulated radiotherapy (IMRT) to include treatment of the pelvic nodes (PN) while escalating the dose to the prostate. Data were obtained from 35 consecutive patients with prostate cancer with > or =15% risk of PN involvement. Patients received an initial boost to the prostate, delivering 16 Gy over 8 fractions using a 6-field conformal technique, followed by an 8-field coplanar inverse planning IMRT technique delivering an additional 60 Gy over 30 fractions to the prostate (76 Gy total) and 54 Gy over 30 fractions to the seminal vesicles (SV) and PN. Dose-volume histogram analysis was performed for planning target volumes and organs at risk. Acute toxicity (RTOG/EORTC scale) was prospectively and independently scored weekly for each patient. The maximum, mean, minimum dose, and D95 to each planning target volume is provided: prostate (82.2, 78.2, 72.6, 75.2 Gy), SV (79.0, 72.5, 56.9, 61.1 Gy), and PN (80.4, 59.7, 46.5, 53.3 Gy), respectively. The percent volume receiving a dose at or above "x" Gy (Vx) was recorded for V75, V70, V65, V60, and V50 as: bladder (14%, 24%, 32%, 39%, and 54%) and rectum (3%, 18%, 26%, 34%, and 51%), respectively. Acute toxicity was as follows: 54% grade 2+ GI (n = 19), 25% grade 2+ GU (n = 9). IMRT enables treatment of pelvic nodes while escalating dose to the prostate and is clinically feasible with acute toxicity within expected ranges.
Bayouth
John E
JE
Department of Radiation Oncology, University of Iowa Health Care, Iowa City, IA 52242, USA. john-bayouth@uiowa.edu
Pena
John
J
Culp
Laura
L
Brack
Collin
C
Sanguineti
Giuseppe
G
D000368:Aged; D024221:Antineoplastic Protocols; D002277:Carcinoma / Q000532:radiotherapy* / Q000556:secondary; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology / Q000528:radiation effects*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000473:pathology* / Q000528:radiation effects; D011467:Prostate / Q000473:pathology / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011836:Radiation Tolerance; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012007:Rectum / Q000528:radiation effects; D012669:Seminal Vesicles / Q000528:radiation effects