Diagnostic performance of magnetic resonance imaging and 3D endoanal ultrasound in detection, staging and assessment post treatment, in anal cancer

Abstract

// Alfonso Reginelli 1 , Vincenza Granata 2 , Roberta Fusco 2 , Francesco Granata 3 , Daniela Rega 4 , Luca Roberto 1 , Gianluca Pellino 5 , Antonio Rotondo 1 , Francesco Selvaggi 5 , Francesco Izzo 6 , Antonella Petrillo 2 , Roberto Grassi 1 1 Department of Internal and Experimental Medicine, Magrassi-Lanzara, Institute of Radiology, Second University of Naples, Naples, Italy 2 Department of Diagnostic Imaging, Radiant and Metabolic Therapy, “Istituto Nazionale Tumori Fondazione Giovanni Pascale – IRCCS”, Naples, Italy 3 Departement of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, Italy 4 Department of Colorectal Surgical Oncology, “Istituto Nazionale Tumori Fondazione Giovanni Pascale – IRCCS”, Naples, Italy 5 Department of Medical, Surgical, Neurological, Metabolic and Ageing Sciences, Second University of Naples, Naples, Italy 6 Department of Surgical Oncology, “Istituto Nazionale Tumori Fondazione Giovanni Pascale – IRCCS”, Naples, Italy Correspondence to: Roberta Fusco, email: r.fusco@istitutotumori.na.it Keywords: anal cancer, 3D endo anal ultrasound, magnetic resonance imaging, diagnostic performance, post-treatment imaging assessment Received: October 17, 2016     Accepted: December 27, 2016     Published: February 01, 2017 ABSTRACT We compared Magnetic Resonance Imaging (MRI) and 3D Endoanal Ultrasound (EAUS) imaging performance to confirm anal carcinoma and to monitor treatment response. 58 patients with anal cancer were retrospectively enrolled. All patients underwent clinical examination, anoscopic examination; EAUS and contrast-enhanced MRI study before and after treatment. Four radiologists evaluated the presence of lesions, using a 4-point confidence scale, features of the lesion and nodes on EAUS images, T1-weighted (T1-W), T2-weighted (T2-W) and diffusion-weighted images (DWI) signal intensity (SI), the apparent diffusion coefficient (ADC) map for nodes and lesion, as well as enhancement pattern during dynamic MRI were assessed. All lesions were detected by EAUS while MRI detected 93.1% of anal cancer. MRI showed a good correlation with EAUS, anoscopy and clinical examination. The residual tissue not showed significant difference in EAUS assessment and T2-W SI in pre and post treatment. We found significant difference in dynamic study, in SI of DWI, in ADC map and values among responder’s patients in pre and post treatment. The neoplastic nodes were hypoecoic on EAUS, with hyperintense signal on T2-W sequences and hypointense signal on T1-W. The neoplastic nodes showed SI on DWI sequences and ADC value similar to anal cancer. We found significant difference in nodes status in pre and post therapy on DWI data. 3D EAUS and MRI are accurate techniques in anal cancer staging, although EAUS is more accurate than MRI for T1 stage. MRI allows correct detection of neoplastic nodes and can properly stratify patients into responders or non responders.