Rectal cancer: MR imaging before neoadjuvant chemotherapy and radiation therapy for prediction of tumor-free circumferential resection margins and long-term survival.

To retrospectively evaluate the prognostic importance of involvement of the circumferential resection margin predicted by using magnetic resonance (MR) imaging before neoadjuvant treatment in patients with rectal cancer. The local institutional review board approved the retrospective analysis of the data and waived informed consent. Sixty-eight patients (52 men, 16 women; mean age +/- standard deviation, 58.9 years +/- 9.4) with cT3 NX M0 tumors were included. T2-weighted MR images were analyzed in consensus by two radiologists with respect to the shortest distance between the outermost parts of the tumor to the adjacent mesorectal fascia (as the potential circumferential resection margin in total mesorectal excision). Histopathologic and follow-up data were available for all patients (mean follow-up time, 54 months; range, 31-77 months). To compare local recurrence and survival rates, the population was divided into three groups categorized according to the minimum distance of the tumor to the mesorectal fascia (group 1, <or=1 mm; group 2, >1 to 5 mm; group 3, >5 mm). Univariate Cox and multivariate proportional hazard regression models were used to test the prognostic importance of clinical, histopathologic regression, and histopathologic tumor parameters. MR imaging led to accurate prediction of a histologically involved circumferential resection margin (sensitivity, 100%; specificity, 88%). The rates for local recurrence (group 1, 33%; group 2, 5%; group 3, 6%; P<.02) and 5-year overall survival (group 1, 39%; group 2, 70%; group 3, 90%; P<.001) differed significantly among the predefined groups. The distance to the mesorectal fascia was an independent prognostic parameter in multivariate analysis (P<.001), and histopathologic response to treatment provided no additional information. Prediction of the tumor-free circumferential resection margin assessed with MR imaging before initiation of neoadjuvant chemotherapy and radiation therapy proved to be a prognostic factor in rectal cancer.

Wieder HA ，Rosenberg R ，Lordick F ，Geinitz H ，Beer A ，Becker K ，Woertler K ，Dobritz M ，Siewert JR ，Rummeny EJ ，Stollfuss JC ... -  《RADIOLOGY》

Locally advanced rectal cancer: MR imaging for restaging after neoadjuvant radiation therapy with concomitant chemotherapy. Part I. Are we able to predict tumor confined to the rectal wall?

To retrospectively assess accuracy of magnetic resonance (MR) imaging after radiation therapy with concomitant chemotherapy for downsizing of the primary lesion to ypT0-2 tumor confined to rectal wall in locally advanced rectal cancer, with histopathologic findings as reference standard, and to evaluate additional value of volumetric analysis. The institutional review board approved the study and waived informed consent. Sixty-seven patients met criteria of the study. T2-weighted MR images obtained before and after radiation therapy with concomitant chemotherapy were assessed for tumor stage by expert abdominal radiologist, colorectal surgeon, and general radiologist. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated; tumor volume was measured (compared with Mann-Whitney U test). Findings were correlated with histopathologic findings. Sixty-seven patients (38 men, 29 women; mean age, 63 years) who underwent radiation therapy with concomitant chemotherapy and surgery (all but one) were evaluated. The PPV for prediction of tumor confined to rectal wall (ypT0-2) was 91% (10 of 11), 86% (six of seven), and 88% (seven of eight) for expert abdominal radiologist, surgeon, and general radiologist, respectively. In 24 patients, sensitivity was 42% (10), 25% (six), and 29% (seven). ypT0-2 tumors had significantly smaller volumes than did ypT3-4 tumors before radiation therapy with concomitant chemotherapy (55 vs 92 cm(3), P = .038). Volume reduction rates were significantly higher in ypT0-2 than in ypT3-4 tumors (89% vs 61%, P < .001). If volume before radiation therapy with concomitant chemotherapy was 50 cm(3) or smaller and volume reduction rate was 75% or higher, excised tumor was always confined to rectal wall (ypT0-2). By using these criteria, 43% (six of 14) of cases with overstaging could have been predicted to be ypT0-2 tumors correctly. Downsizing to ypT0-2 tumors can be accurately predicted by combining morphologic tumor staging predictions with results from volumetric analyses. MR images obtained after radiation therapy with concomitant chemotherapy might be helpful in more individualized treatment planning.

Dresen RC ，Beets GL ，Rutten HJ ，Engelen SM ，Lahaye MJ ，Vliegen RF ，de Bruïne AP ，Kessels AG ，Lammering G ，Beets-Tan RG ... -  《-》

Locally advanced rectal cancer: added value of diffusion-weighted MR imaging for predicting tumor clearance of the mesorectal fascia after neoadjuvant chemotherapy and radiation therapy.

Park MJ ，Kim SH ，Lee SJ ，Jang KM ，Rhim H ... -  《-》

The effect of circumferential tumor location in clinical outcomes of rectal cancer patients treated with total mesorectal excision.

Lee SH ，Hernandez de Anda E ，Finne CO ，Madoff RD ，Garcia-Aguilar J ... -  《DISEASES OF THE COLON & RECTUM》

Preoperative hyperfractionated chemoradiation for locally recurrent rectal cancer in patients previously irradiated to the pelvis: A multicentric phase II study.

Valentini V ，Morganti AG ，Gambacorta MA ，Mohiuddin M ，Doglietto GB ，Coco C ，De Paoli A ，Rossi C ，Di Russo A ，Valvo F ，Bolzicco G ，Dalla Palma M ，Study Group for Therapies of Rectal Malignancies (STORM) ... -  《INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS》