Imaging in Colorectal Cancer: Progress and Challenges for the Clinicians

Abstract

The use of imaging in colorectal cancer (CRC) has significantly evolved over the last twenty years, establishing important roles in surveillance, diagnosis, staging, treatment selection and follow up. The range of modalities has broadened with the development of novel tracer and contrast agents, and the fusion of technologies such as positron emission tomography (PET) and computed tomography (CT). Traditionally, the most widely used modality for assessing treatment response in metastasised colon and rectal tumours is CT, combined with use of the RECIST guidelines. However, a growing body of evidence suggests that tumour size does not always adequately correlate with clinical outcomes. Magnetic resonance imaging (MRI) is a more versatile technique and dynamic contrast-enhanced (DCE)-MRI and diffusion-weighted (DW)-MRI may be used to evaluate biological and functional effects of treatment. Integrated fluorodeoxyglucose (FDG)-PET/CT combines metabolic and anatomical imaging to improve sensitivity and specificity of tumour detection, and a number of studies have demonstrated improved diagnostic accuracy of this modality in a variety of tumour types, including CRC. These developments have enabled the progression of treatment strategies in rectal cancer and improved the detection of hepatic metastatic disease, yet are not without their limitations. These include technical, economical and logistical challenges, along with a lack of robust evidence for standardisation and formal guidance. In order to successfully apply these novel imaging techniques and utilise their benefit to provide truly personalised cancer care, advances need to be clinically realised in a routine and robust manner.

Development of Halofluorochromic Polymer Nanoassemblies for the Potential Detection of Liver Metastatic Colorectal Cancer Tumors Using Experimental and Computational Approaches

“…Although magnetic resonance imaging (MRI), positron emission tomography (PET), computerized tomography (CT), and other advanced imaging techniques are available, intraoperative imaging using fluorescent dyes is the most cost-effective and direct way to visualize tumors and cancer cells (4, 5). During intraoperative fluorescence imaging, clinicians visualize fluorescent dyes accumulating in solid tumors and determine the accurate size and shape of the tumor for resection from the healthy organ.…”

Guanylate cyclase C as a target for prevention, detection, and therapy in colorectal cancer

“…Positron emission tomography has become a mainstay for staging CRC and monitoring treatment response [101]. This method capitalizes on the increased metabolic demand, and therefore increased glycolysis, by cancer cells.…”

“…However, glucose requirements by other tissues decreases specificity; false positives (due to inflammation, surgery, diverticulitis, etc.) lead to unnecessary follow-up colonoscopy or inappropriate staging [101]. Alternative imaging modalities using molecular targets, rather than metabolic patterns, may address these issues [102].…”

Pencitraan dan Terapi Transcathether Arterial Chemoinfusion pada Unresectable Adenocarcinoma Colorectal

“…28,29 Penilaian evaluasi respon pengobatan KKR berdasarkan pada kriteria Response Evaluation Criteria in Solid Tumours (RECIST) yang didasarkan pada pengurangan ukuran tumor yang diukur dengan modalitas pencitraan anatomi seperti CT atau MRI (Tabel 1). 30,31 Dynamic Contrast Enhanced CT (DCE-CT) menjadi teknik yang valid untuk menilai angiogenesis tumor dan memonitor pengendalian penyakit setelah terapi lokal-regional. 30 Dynamic contrast-enhanced MRI (DCE-MRI) dan DWI berguna untuk evaluasi respon setelah kemoterapi dimana menunjukan efek biologis dan fungsional pengobatan, sebagai tanda awal respon terapi karena apoptosis sel, anti-angiogenesis dapat terdeteksi sebelum perubahan ukuran tumor mulai 2 minggu paska terapi.…”

“…30,31 Dynamic Contrast Enhanced CT (DCE-CT) menjadi teknik yang valid untuk menilai angiogenesis tumor dan memonitor pengendalian penyakit setelah terapi lokal-regional. 30 Dynamic contrast-enhanced MRI (DCE-MRI) dan DWI berguna untuk evaluasi respon setelah kemoterapi dimana menunjukan efek biologis dan fungsional pengobatan, sebagai tanda awal respon terapi karena apoptosis sel, anti-angiogenesis dapat terdeteksi sebelum perubahan ukuran tumor mulai 2 minggu paska terapi. 4,[28][29][30] PET-CT menjadi modalitas yang berharga untuk menilai respon terapi paska kemoradioterapi neo-adjuvant, dengan respon metabolik yang dini pada FDG PET memungkinkan terjadi perubahan pada manajemen terapi.…”