[2-axial conformational irradiation for whole-pelvis irradiation of cervical cancer: improvement and evaluation with DVH].
Whole-pelvis irradiation with the two-axial conformation technique has been performed in cervical cancer since 1976. In 1990 this technique was improved by obtaining target areas from serial CT images instead of axial transverse tomograms. The aim of this study was to show the advantage of the new two-axial conformation technique compared with the old type of conformation technique, and also with conventional techniques using DVH of normal tissues. The uniformity of dose within the high dose-region and fit to the target areas observed in the new type were better than those in the old type. This improved result was most remarkable in rectal DVH. The new two-axial conformation technique was also compared with the two-opposed technique and box technique. With the new type, cumulative irradiated volume in rectum of more than 40 Gy was reduced to 37% of that with the two-opposed technique. In bladder and intestine, the smallest volume irradiated to more than 40 Gy was observed using the new two-axial conformation technique. With these results, we conclude that the new two-axial conformation technique for whole-pelvis irradiation is suitable to conform the high dose region with the target region in the pelvis, and at the same time to protect the surrounding normal tissues.
Kato
E
E
Department of Radiation Therapy, Aichi Cancer Center.
Morita
K
K
D005260:Female; D006801:Humans; D010388:Pelvis; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*