Sayali Pangarkar1,2, Kunal Mistry1,2, Amit Choudhari1,2, Vasundhara Smriti1,2, Ankita Ahuja1,2, Aparna Katdare1,2, Reena Engineer2,3, Vikas Ostwal2,4, Mukta Ramadwar2,5, Avanish Saklani2,6, Akshay D Baheti7,8. 1. Department of Radio-Diagnosis, Tata Memorial Centre, Mumbai, India. 2. Homi Bhabha National Institute, Mumbai, India. 3. Department of Radiation Oncology, Tata Memorial Centre, Mumbai, India. 4. Department of Medical Oncology, Tata Memorial Centre, Mumbai, India. 5. Department of Pathology, Tata Memorial Centre, Mumbai, India. 6. Department of Surgical Oncology, Tata Memorial Centre, Mumbai, India. 7. Department of Radio-Diagnosis, Tata Memorial Centre, Mumbai, India. akshaybaheti@gmail.com. 8. Homi Bhabha National Institute, Mumbai, India. akshaybaheti@gmail.com.
Abstract
AIM: Assessing metastatic mesorectal nodal involvement is a challenge in rectal cancer, especially in the post chemoradiation setting. We aim to assess the accuracy of MRI for nodal restaging and the validity of SAR criteria (≥ 5 mm size being metastatic). MATERIALS AND METHODS: This was an IRB-approved retrospective study of 166 patients with locally advanced rectal cancers, operated after neoadjuvant treatment. Two dedicated oncoradiologists reviewed the 166 post-chemoradiation presurgical MRIs in consensus. Nodal size and morphology (shape, margins, and signal intensity) were noted. The most accurate cut-off for size for predicting positive pN status was determined using the Youden index. RESULTS: MRI understaged 30/166 (18%) and overstaged 40/166 (24%) patients using the SAR criteria. The most accurate cut-off for node size was 5.5 mm, with a sensitivity of 75%, specificity of 60.2%, PPV of 40.7%, NPV of 86.9% (95% CI:78-92.5%), accuracy of 64.2%, and area under the curve (AUC) 0.657 (95% CI-0.524-0.79). Morphological characteristics were not significant to determine involvement, with positive nodes including 42% of round and 31% of oval nodes, 40% of heterogeneous and 45% of homogeneous nodes, and 31% irregularly marginated and 46% nodes with regular margins being positive on pathology. MRI was accurate in predicting pathology for mucinous nodes in 9/29 (31%) cases. Seven cases which were yN2 on MRI and yN0 on pathology demonstrated mucinous changes on MRI and had acellular mucin on histopathology. CONCLUSIONS: MRI has good negative predictive value, poor positive predictive value and moderate accuracy in nodal restaging. The cut-off of 5.5 mm demonstrated in our study is close to the SAR cut-off of 5 mm in the post-treatment setting. MRI accuracy is lower in patients with mucinous nodes.
AIM: Assessing metastatic mesorectal nodal involvement is a challenge in rectal cancer, especially in the post chemoradiation setting. We aim to assess the accuracy of MRI for nodal restaging and the validity of SAR criteria (≥ 5 mm size being metastatic). MATERIALS AND METHODS: This was an IRB-approved retrospective study of 166 patients with locally advanced rectal cancers, operated after neoadjuvant treatment. Two dedicated oncoradiologists reviewed the 166 post-chemoradiation presurgical MRIs in consensus. Nodal size and morphology (shape, margins, and signal intensity) were noted. The most accurate cut-off for size for predicting positive pN status was determined using the Youden index. RESULTS: MRI understaged 30/166 (18%) and overstaged 40/166 (24%) patients using the SAR criteria. The most accurate cut-off for node size was 5.5 mm, with a sensitivity of 75%, specificity of 60.2%, PPV of 40.7%, NPV of 86.9% (95% CI:78-92.5%), accuracy of 64.2%, and area under the curve (AUC) 0.657 (95% CI-0.524-0.79). Morphological characteristics were not significant to determine involvement, with positive nodes including 42% of round and 31% of oval nodes, 40% of heterogeneous and 45% of homogeneous nodes, and 31% irregularly marginated and 46% nodes with regular margins being positive on pathology. MRI was accurate in predicting pathology for mucinous nodes in 9/29 (31%) cases. Seven cases which were yN2 on MRI and yN0 on pathology demonstrated mucinous changes on MRI and had acellular mucin on histopathology. CONCLUSIONS: MRI has good negative predictive value, poor positive predictive value and moderate accuracy in nodal restaging. The cut-off of 5.5 mm demonstrated in our study is close to the SAR cut-off of 5 mm in the post-treatment setting. MRI accuracy is lower in patients with mucinous nodes.
Authors: Regina G H Beets-Tan; Doenja M J Lambregts; Monique Maas; Shandra Bipat; Brunella Barbaro; Filipe Caseiro-Alves; Luís Curvo-Semedo; Helen M Fenlon; Marc J Gollub; Sofia Gourtsoyianni; Steve Halligan; Christine Hoeffel; Seung Ho Kim; Andrea Laghi; Andrea Maier; Søren R Rafaelsen; Jaap Stoker; Stuart A Taylor; Michael R Torkzad; Lennart Blomqvist Journal: Eur Radiol Date: 2013-06-07 Impact factor: 5.315
Authors: Max J Lahaye; Geerard L Beets; Sanne M E Engelen; Alfons G H Kessels; Adriaan P de Bruïne; Herry W S Kwee; Jos M A van Engelshoven; Cornelis J H van de Velde; Regina G H Beets-Tan Journal: Radiology Date: 2009-04-29 Impact factor: 11.105
Authors: Luc A Heijnen; Monique Maas; Regina G Beets-Tan; Myrthe Berkhof; Doenja M Lambregts; Patty J Nelemans; Robert Riedl; Geerard L Beets Journal: Int J Colorectal Dis Date: 2016-04-07 Impact factor: 2.571