Comparison of 2D conventional, 3D conformal, and intensity-modulated treatment planning techniques for patients with prostate cancer with regard to target-dose homogeneity and dose to critical, uninvolved structures.
The purpose of this study was to compare 2-dimensional (2D), 3-dimensional (3D) and intensity-modulated radiation therapy (IMRT) techniques for external-beam radiation treatment for prostate cancer. Dose homogeneity within the target volume and doses to critical, uninvolved anatomic structures were evaluated. Computed tomography (CT) scans of 3 patients with localized prostate cancer (T2NOM0) were acquired and transferred to the treatment planning systems. The target volume and uninvolved structures were contoured on axial CT slices throughout the volume of interest. A comparison of the 3 treatment techniques was performed using isodose distributions, dose statistics, and dose-volume histograms. Dose homogeneity was found to be most uniform with the 2D technique; however, the 2D technique delivers unnecessary radiation doses to the rectum and bladder. The dose conformity observed with IMRT is increased compared with that observed with the 3D technique, as is the sparing of critical uninvolved structures; however, dose homogeneity appears to be worse with IMRT than with the 3D technique. Overall, of the 3 techniques, IMRT offers the most conformity in delivery of tumoricidal doses to the prostate while sparing dose to critical, uninvolved structures. Association of Medical Dosimetrists.
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Department of Medical Physics, University of Texas Southwestern Moncrief Cancer Center, Fort Worth, USA.
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Darby
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Song
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Starkschall
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D005270:Femur Head / Q000528:radiation effects; D006801:Humans; D008297:Male; D011467:Prostate / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011881:Radiotherapy, Computer-Assisted; D020266:Radiotherapy, Conformal; D012007:Rectum / Q000528:radiation effects; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000528:radiation effects