TY - JOUR
T1 - Helical tomotherapy vs. Intensity-modulated proton therapy for whole pelvis irradiation in high-risk prostate cancer patients
T2 - Dosimetric, normal tissue complication probability, and generalized equivalent uniform dose analysis
AU - Widesott, Lamberto
AU - Pierelli, Alessio
AU - Fiorino, Claudio
AU - Lomax, Antony J.
AU - Amichetti, Maurizio
AU - Cozzarini, Cesare
AU - Soukup, Martin
AU - Schneider, Ralf
AU - Hug, Eugen
AU - Di Muzio, Nadia
AU - Calandrino, Riccardo
AU - Schwarz, Marco
PY - 2011/8/1
Y1 - 2011/8/1
N2 - Purpose: To compare intensity-modulated proton therapy (IMPT) and helical tomotherapy (HT) treatment plans for high-risk prostate cancer (HRPCa) patients. Methods and Materials: The plans of 8 patients with HRPCa treated with HT were compared with IMPT plans with two quasilateral fields set up (-100°; 100°) and optimized with the Hyperion treatment planning system. Both techniques were optimized to simultaneously deliver 74.2 Gy/Gy relative biologic effectiveness (RBE) in 28 fractions on planning target volumes (PTVs)3-4 (P + proximal seminal vesicles), 65.5 Gy/Gy(RBE) on PTV2 (distal seminal vesicles and rectum/prostate overlapping), and 51.8 Gy/Gy(RBE) to PTV1 (pelvic lymph nodes). Normal tissue calculation probability (NTCP) calculations were performed for the rectum, and generalized equivalent uniform dose (gEUD) was estimated for the bowel cavity, penile bulb and bladder. Results: A slightly better PTV coverage and homogeneity of target dose distribution with IMPT was found: the percentage of PTV volume receiving ≥95% of the prescribed dose (V 95%) was on average >97% in HT and >99% in IMPT. The conformity indexes were significantly lower for protons than for photons, and there was a statistically significant reduction of the IMPT dosimetric parameters, up to 50 Gy/Gy(RBE) for the rectum and bowel and 60 Gy/Gy(RBE) for the bladder. The NTCP values for the rectum were higher in HT for all the sets of parameters, but the gain was small and in only a few cases statistically significant. Conclusions: Comparable PTV coverage was observed. Based on NTCP calculation, IMPT is expected to allow a small reduction in rectal toxicity, and a significant dosimetric gain with IMPT, both in medium-dose and in low-dose range in all OARs, was observed.
AB - Purpose: To compare intensity-modulated proton therapy (IMPT) and helical tomotherapy (HT) treatment plans for high-risk prostate cancer (HRPCa) patients. Methods and Materials: The plans of 8 patients with HRPCa treated with HT were compared with IMPT plans with two quasilateral fields set up (-100°; 100°) and optimized with the Hyperion treatment planning system. Both techniques were optimized to simultaneously deliver 74.2 Gy/Gy relative biologic effectiveness (RBE) in 28 fractions on planning target volumes (PTVs)3-4 (P + proximal seminal vesicles), 65.5 Gy/Gy(RBE) on PTV2 (distal seminal vesicles and rectum/prostate overlapping), and 51.8 Gy/Gy(RBE) to PTV1 (pelvic lymph nodes). Normal tissue calculation probability (NTCP) calculations were performed for the rectum, and generalized equivalent uniform dose (gEUD) was estimated for the bowel cavity, penile bulb and bladder. Results: A slightly better PTV coverage and homogeneity of target dose distribution with IMPT was found: the percentage of PTV volume receiving ≥95% of the prescribed dose (V 95%) was on average >97% in HT and >99% in IMPT. The conformity indexes were significantly lower for protons than for photons, and there was a statistically significant reduction of the IMPT dosimetric parameters, up to 50 Gy/Gy(RBE) for the rectum and bowel and 60 Gy/Gy(RBE) for the bladder. The NTCP values for the rectum were higher in HT for all the sets of parameters, but the gain was small and in only a few cases statistically significant. Conclusions: Comparable PTV coverage was observed. Based on NTCP calculation, IMPT is expected to allow a small reduction in rectal toxicity, and a significant dosimetric gain with IMPT, both in medium-dose and in low-dose range in all OARs, was observed.
KW - Intensity-modulated proton therapy
KW - Normal tissue complication probability
KW - Pelvic lymph nodes
KW - Prostate
KW - Tomotherapy
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U2 - 10.1016/j.ijrobp.2010.10.005
DO - 10.1016/j.ijrobp.2010.10.005
M3 - Article
C2 - 21167651
AN - SCOPUS:79960088753
VL - 80
SP - 1589
EP - 1600
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
SN - 0360-3016
IS - 5
ER -