- 作者：Brunella Barbaro ; M.D.&lowast ; ; bbarbaro@rm.unicatt.it ; Renata Vitale ; M.D.&lowast ; ; Vincenzo Valentini ; M.D.&lowast ; ; Sonia Illuminati ; M.D.&lowast ; ; Fabio M. Vecchio ; M.D.&dagger ; ; Gianluca Rizzo ; M.D.&Dagger ; ; Maria Antonietta Gambacorta ; M.D.&lowast ; ; Claudio Coco ; M.D.&Dagger ; ; Antonio Crucitti ; M.D.&Dagger ; ; Roberto Persiani ; M.D.&Dagger ; ; Luigi Sofo ; M.D.&Dagger ; ; Lorenzo Bonomo ; M.D.&lowast ;
- 关键词：Rectal cancer ; Chemoradiotherapy ; Diffusion-weighted magnetic resonance imaging
- 刊名：International Journal of Radiation Oncology*Biology*Physics
- 出版年：2012
- 期刊代码：136_03603016
- 类别：med
- 出版时间：1 June, 2012
- 卷：83
- 期：2
- 页码：594-599
- 文件大小：360 K
Purpose
To prospectively monitor the response in patients with locally advanced nonmucinous rectal cancer after chemoradiotherapy (CRT) using diffusion-weighted magnetic resonance imaging. The histopathologic finding was the reference standard.Methods and Materials
The institutional review board approved the present study. A total of 62 patients (43 men and 19 women; mean age, 64 years; range, 28-83) provided informed consent. T2- and diffusion-weighted magnetic resonance imaging scans (b value, 0 and 1,000 mm2/s) were acquired before, during (mean 12 days), and 6-8 weeks after CRT. We compared the median apparent diffusion coefficients (ADCs) between responders and nonresponders and examined the associations with the Mandard tumor regression grade (TRG). The postoperative nodal status (ypN) was evaluated. The Mann-Whitney/Wilcoxon two-sample test was used to evaluate the relationships among the pretherapy ADCs, extramural vascular invasion, early percentage of increases in ADCs, and preoperative ADCs.
Results
Low pretreatment ADCs (<1.0 脳 10鈭?mm2/s) were correlated with TRG 4 scores (p聽= .0011) and associated to extramural vascular invasion with ypN+ (85.7%positive predictive value for ypN+). During treatment, the mean percentage of increase in tumor ADC was significantly greater in the responders than in the nonresponders (p < .0001) and a >23%ADC increase had a 96.3%negative predictive value for TRG 4. In 9 of 16 complete responders, CRT-related tumor downsizing prevented ADC evaluations. The preoperative ADCs were significantly different (p = .0012) between the patients with and without downstaging (preoperative ADC 鈮?.4 脳 10鈭?mm2/s showed a positive and negative predictive value of 78.9%and 61.8%, respectively, for response assessment). The TRG 1 and TRG 2-4 groups were not significantly different.
Conclusion
Diffusion-weighted magnetic resonance imaging seems to be a promising tool for monitoring the response to CRT.