The effect of photon energy on intensity-modulated radiation therapy (IMRT) plans for prostate cancer
Radiation Oncology Journal
;
: 27-35, 2012.
Article
in English
| WPRIM
| ID: wpr-49997
ABSTRACT
PURPOSE:
To evaluate the effect of common three photon energies (6-MV, 10-MV, and 15-MV) on intensity-modulated radiation therapy (IMRT) plans to treat prostate cancer patients. MATERIALS ANDMETHODS:
Twenty patients with prostate cancer treated locally to 81.0 Gy were retrospectively studied. 6-MV, 10-MV, and 15-MV IMRT plans for each patient were generated using suitable planning objectives, dose constraints, and 8-field setting. The plans were analyzed in terms of dose-volume histogram for the target coverage, dose conformity, organs at risk (OAR) sparing, and normal tissue integral dose.RESULTS:
Regardless of the energies chosen at the plans, the target coverage, conformity, and homogeneity of the plans were similar. However, there was a significant dose increase in rectal wall and femoral heads for 6-MV compared to those for 10-MV and 15-MV. The V20 Gy of rectal wall with 6-MV, 10-MV, and 15-MV were 95.6%, 88.4%, and 89.4% while the mean dose to femoral heads were 31.7, 25.9, and 26.3 Gy, respectively. Integral doses to the normal tissues in higher energy (10-MV and 15-MV) plans were reduced by about 7%. Overall, integral doses in mid and low dose regions in 6-MV plans were increased by up to 13%.CONCLUSION:
In this study, 10-MV prostate IMRT plans showed better OAR sparing and less integral doses than the 6-MV. The biological and clinical significance of this finding remains to be determined afterward, considering neutron dose contribution.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Prostate
/
Prostatic Neoplasms
/
Retrospective Studies
/
Organs at Risk
/
Head
/
Neutrons
Type of study:
Etiology study
/
Observational study
/
Risk factors
Limits:
Humans
Language:
English
Journal:
Radiation Oncology Journal
Year:
2012
Type:
Article
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