Keywords
Pre and post chemo-radiotherapy
MRI
How to Cite
Abstract
Rectal cancer is associated with a high risk of metastases and local recurrence; local recurrence rates after surgical treatment being up to 32%. An accurate local staging at the time of initial diagnosis is therefore very important. Magnetic Resonance Imaging (MRI) is already established as an accurate tool for the preoperative staging of rectal cancer and has resulted in marked improvements in staging accuracy.
Material and Methods: This study used MRI in comparing the morphologic features of rectal cancer before and after 8 weeks of chemo-radiation treatment (CRT) and to correlate the post treatment MRI appearances with the histological findings in resected tumors. 45 patients with histo-pathologically proven rectal adenocarcinoma received standardized 8 weeks chemo-radiation therapy and subjected to MRI before and after treatment for clinical staging. A correlation between pathological response and MRI findings was done.
Results: The MRI diagnostic accuracy to diagnose T2 is 74.2% with relatively low specificity (64.7%). The diagnostic accuracy of MRI in evaluation of stage T3 and T4, the MRI sensitivity was 96.2% however of low specificity 26.3%. The diagnostic accuracy was 66.7%. Additionally, in evaluation of T2 stage, the sensitivity of MRI was very low 27.3% and specificity relatively high 94.7%. Diagnostic accuracy was 70%.
Post RCT, based on downstaging after CRT, the sensitivity of MRI to show no tumor was very low 0% with diagnostic accuracy 88.9%. However, to evaluate stage T2, the sensitivity was 84.6% with low specificity 66.7% and the diagnostic accuracy was 74.2%.
Conclusion: MRI had an accuracy average of 81.6% in T stage and 68.9% in N stage in re-staging rectal tumors after CRT. Over-staging results of majority of the inaccuracy. The statistical agreement between post-CRT MRI and the pathologic staging involving T and N stages was not satisfactory. In view of the above, Post CRT, restaging rectal cancer remains a challenge.
References
Samee A, Selvasekar CR. Current trends in staging rectal cancer. World J Gastroenterol 2011; 17:828-34.
Dewhurst C, Rosen MP, Blake MA, et al. ACR Appropriateness Criteria pretreatment staging of colorectal cancer. J Am Coll Radiol 2012; 9:775-81.
Dewhurst CE, Mortele KJ. Magnetic resonance imaging of rectal cancer. Radiol Clin North Am 2013; 51:121-31.
Mercury study group. Diagnostic accuracy of preoperative magnetic resonance imaging n predicting curative resection of rectal cancer: prospective observational study. BMJ 2006; 33:779
Bipat S, Glas AS, Slors FJ, Zwinderman AH, Bossuyt PM, Stoker J. Rectal cancer: local staging and assessment of lymph node involvement with end luminal US, CT, and MR imaging—a meta-analysis. Radiology 2004; 232:773–783.
Sauer R, Becker H, Hohenberger W, et al. Preoperative versus postoperative chemo radiotherapy for rectal cancer. N Engl J Med 2004; 351:1731–1740.
Kim DJ, Kim JH, Lim JS, et al. Restaging of rectal cancer with MR imaging after concurrent chemotherapy and radiation therapy. RadioGraphics 2010; 30:503–516
Patel UB, Taylor F, Blomqvist L, et al. Magnetic resonance imaging–detected tumor response for locally advanced rectal cancer predicts survival outcomes: MERCURY experience. J Clin Oncol 2011; 29:3753–3760.
O’Neill BD, Brown G, Heald RJ, Cunningham D, Tait DM. Non-operative treatment after neoadjuvant chemo radiotherapy for rectal cancer. Lancet Oncol 2007; 8:625–633.
Kevin R. Kalisz1, Michael D. Enzerra, Raj M. Paspulati : MRI Evaluation of the Response of Rectal Cancer to Neoadjuvant Chemoradiation Therapy, 2019, https://doi.org/10.1148/rg.2019180075
Sagar PM, Pemberton JH. Surgical management of locally recurrent rectal cancer. Br J Surg 1996;83: 293- 304.
Bokey EL, Ojerskog B, Chapuis PH, Dent OF, Newland RC, Sinclair G. Local recurrence after curative excision of the rectum for cancer without adjuvant therapy: role of total anatomical dissection. Br J Surg 1999; 86:1164-1170.
Benson AB, Bekaii-Saab T, Chan E et al. Rectal cancer. J Natl Compr Canc Netw 2012; 10:1528-1564.
Martin ST, Heneghan HM, Winter DC. Systematic review and meta-analysis of outcomes following pathological complete response to neoadjuvant chemoradiotherapy for rectal cancer. Br J Surg 2012; 99:918-928.
Kuo LJ, Chen MC, Tsou MH et al. Interpretation of magnetic resonance imaging for locally advanced rectal carcinoma after preoperative chemoradiation therapy. Dis Colon Rectum 2005;48: 23-28.
Kim CJ, Yeatman TJ, Coppola D et al. Local excision of T2 and T3 rectal cancers after downstaging chemoradiation. Ann Surg 2001; 234:352-359.
Habr-Gama A, Perez RO. Non-operative management of rectal cancer after neoadjuvant chemoradiation. Br J Surg 2009; 96:125-127.
Iafrate F, Laghi A, Paolantonio P et al. Preoperative Staging of Rectal Cancer with MR Imaging: Correlation with Surgical and Histopathologic Findings. Radiographics 2006; 26:701-714.
Vliegen RF, Beets GL, Lammering G et al. Mesorectal Fascia Invasion after Neoadjuvant Chemotherapy and Radiation Therapy for Locally Advanced Rectal Cancer: Accuracy of MR Imaging for Prediction. Radiology 2008; 246:454-462.
Vliegen RF, Beets GL, von Meyenfeldt MF et al. Rectal cancer: MR imaging in local staging--is gadolinium-based contrast material helpful? Radiology 2005; 234:179-188.
Chen CC, Lee RC, Lin JK, Wang LW, Yang SH. How accurate is magnetic resonance imaging in restaging rectal cancer in patients receiving preoperative combined chemo radiotherapy? Dis Colon Rectum 2005; 48:722-728.
Allen SD, Pandhani AR, Dzik-Jurasz AS, GlynneJones R. Rectal carcinoma: MRI with histologic correlation before and after chemoradiation therapy. Am J Roentgenol 2007; 188: 442-451.
Van der Paardt MP, Zagers MB, Beets-Tan RGH, Stoker J, Bipat S. Patients Who Undergo Preoperative Chemoradiotherapy for Locally Advanced Rectal Cancer Restaged by Using Diagnostic MR Imaging: A Systematic Review and Meta-Analysis. Radiology 2013; 269:101-112.
Shufang Zhan, Xingxing Wang, Xuefeng Huang, Hongbo Zhu. Magnetic resonance imaging in restaging rectal cancer after neoadjuvant chemoradiotherapy. JBUON 2015; 20(1): 62-67.
Pomerri F, Pucciarelli S, Maretto I et al. Prospective assessment of imaging after preoperative chemoradiotherapy for rectal cancer. Surgery 2011; 149:56-64.
Cho YB, Chun HK, Kim MJ et al. Accuracy of MRI and 18 F-FDG PET/CT for Restaging After Preoperative Concurrent Chemo radiotherapy for Rectal Cancer. World J Surg 2009; 33:2688-2694.
Brown G, Richards CJ, Bourne MW et al. Morphologic predictors of lymph node status in rectal cancer with use of high-spatial-resolution MR imaging with histopathologic comparison. Radiology 2003; 227:371- 377.
Barbaro B, Fiorucci C, Tebala C et al. Locally advanced rectal cancer: MR imaging in prediction of response after preoperative chemotherapy and radiation therapy. Radiology 2009; 252:71-80.
Park JS, Jang YJ, Choi GS et al. Accuracy of preoperative MRI in predicting pathology stage in rectal cancers: node-for-node matched histopathology validation of MRI features. Dis Colon Rectum 2014; 57:32-38.
Kim JH, Beets GL, Kim MJ, Kessels AG, Beets-Tan RG. High-resolution MR imaging for nodal staging in rectal cancer: are there any criteria in addition to the size? Eur J Radiol 2004; 52:78-83.
Nougaret S, Reinhold C, Mikhael HW, Rouanet P, Bibeau F, Brown G. The Use of MR Imaging in Treatment Planning for Patients with Rectal Carcinoma: Have You Checked the “DISTANCE”? Radiology 2013; 268:330-344.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.