The prognostic significance of tumor volume regression during radiotherapy and concurrent chemoradiotherapy for cervical cancer using MRI.
OBJECTIVE
The purpose of this study was to determine the prognostic significance of tumor volume regression rate during radiotherapy (RT) measured by three serial magnetic resonance imaging (MRIs) studies performed in patients treated with RT alone and compare the results with patients treated with concurrent chemoradiotherapy (CCRT).


METHODS
We evaluated 81 patients with uterine cervical cancer who underwent three serial MR examinations, i.e., at the start of RT, at 36-45 Gy of external RT and 1 month after the end of RT. Forty-three patients were treated with RT alone and 38 patients were treated with CCRT. Pre-RT tumor volume (V1), the tumor volume regression rate measured during the fourth week of RT and residual tumor volume at 1 month after the end of RT (V3) were determined for each patient. The cut-off value used for the three parameters studied was the one that made the largest outcome difference. These volume parameters were analyzed to determine a difference in the treatment outcome.


RESULTS
In the patients treated with CCRT, the mean value of the V1 was larger and the mean value of the V3 was smaller than in patients treated with RT alone. The mean value of the mid-RT regression rate was somewhat higher in patients treated with CCRT than in patients treated with RT alone; however, this difference was not statistically significant (79% vs. 69%). In both the RT alone and the CCRT group, the patients with a mid-RT regression >/=75% had 100% 5-year local control rates and a better disease free survival than the patients with mid-RT regression <75%. The patients with V3=0 cm(3) also had a better 5-year local control rate than the patients with a V3>0 cm(3), but statistical significance was found only in the patients treated with CCRT.


CONCLUSIONS
The mid-RT tumor volume regression rate, at 36-45 Gy of external RT, was a predictor of local control rate in both RT and CCRT patient groups. However, in the patients who were treated with CCRT, the local control rate difference was even larger by post-RT residual volume than by the mid-RT tumor regression rate. Further studies on appropriate evaluation timing for mid-RT response in patients receiving CCRT are needed.
Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwhan University School of Medicine, 135-710, Irwon-dong 50, Gangman-gu, Seoul, South Korea.
Heerim
H
Nam
Won
W
Park
Seung Jae
SJ
Huh
Duk Soo
DS
Bae
Byoung Gie
BG
Kim
Je Ho
JH
Lee
Jeong Won
JW
Lee
Do Hoon
DH
Lim
Youngyih
Y
Han
Hee Chul
HC
Park
Yong Chan
YC
Ahn
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D002945:Cisplatin / Q000008:administration & dosage; D019583:Dose Fractionation, Radiation; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*
D002945:Cisplatin; D005472:Fluorouracil