Conventional conformal radiotherapy vs intracavitary brachytherapy for the adjuvant postoperative treatment of cervical cancer: a comparative dosimetric study.
OBJECTIVE
The aim of this pilot study is to evaluate the feasibility of 3D-conformal radiotherapy (3D-CRT) in the adjuvant postoperative radiotherapy of the vaginal cuff and upper third of present vaginal tissue.


METHODS
The representative patient (FIGO IB; PH: squamous cell carcinoma) was referred for adjuvant post-hysterectomy radiotherapy. A whole pelvis irradiation with concomitant high-dose-rate intracavitary brachytherapy (HDR-ICBT) was applied. HDR-ICBT total dose of 24 Gy in four fractions/one fraction per week was delivered to the vaginal cuff using two Fletcher-Suit ovoids. The feasibility of change from HDR-ICBT to CRT was evaluated by generating of three different plans using 10 MV photon beams shaped by multileaf collimator.


CONCLUSIONS
The referent volume received HDR-ICBT prescribed dose. The maximum ICBT percentage dose to the rectum and urinary bladder was 101% and 106% respectively. In all 3D-CRT plans almost 100% of planning target volume (PTV) was covered by 95% therapy isodose surface. From 12 - 13% of the rectum and 1-3% urinary bladder volume were covered by 100% isodose surface, with the highest maximum dose of 104% and 101%, respectively. Comparison of the PTV dose coverage and the maximum dose to the rectum and urinary bladder for HDR-ICBT and 3D-CRT plans showed no major difference. CONCLUSION; 3D-CRT could be considered as adequate replacement for ICBT in the adjuvant postoperative treatment of the vaginal cuff and upper thi-rd of present vaginal tissue. Time-dose-fractionation pattern for HDR-ICBT may be safely applied for 3D-CRT.
Milosević
N T
NT
Institute for Biophysics, Medical School, Belgrade, Serbia.
Dabić-Stanković
K M
KM
Stanković
J B
JB
Mileusnić
D S
DS
D001918:Brachytherapy; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006801:Humans; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy* / Q000601:surgery