Imaging for suspected colorectal cancer in frail and elderly patients.

Medicine faces many challenges, among which that of thegrowing number of old and often frail patients needs to beparticularly addressed. In our hospital, that serves one ofthe oldest population on earth (about 10 % of the inhabit-ants of Genoa are over 80 years old) problems related todiagnosing and treating pathologies in this type of patientsare part of our daily practice. Many old patients enter ourhospital for gastrointestinal symptoms possibly related tocolorectal cancer, often via the emergency room.In these patients (in which it is frequently difficult toobtain a good clinical history), there is the need to make adiagnosis, preferably noninvasively, to plan appropriatetreatment.In colorectal cancer, computed tomography (CT) offersdifferent modalities that allow to diagnose and stage cor-rectly the disease. The most commonly used are two thatrequire good bowel preparation:• CT colonography requires distention of the colon withgas (room air or, preferably, carbon dioxide), usuallywithout iodinated contrast media intravenously butoften with orally administered iodinated contrast media(and/or barium) before the examination to properly‘‘tag’’ residual feces and liquids in the colon [1, 2]. It ispossible to add intravenous contrast media to CTcolonography before the examination in patients withhigh pretest likelihood of positive findings (coloncancer or significant extra-colic findings) [3]. Intrave-nous contrast media can also be added when requiredduring the CT colonography itself after the first (usuallysupine) acquisition; but this requires the presence theimmediate evaluation of the radiologist during the CTexamination, which can be difficult in a real clinicalsetting (because of the high workflow in the CT suite)and since often colorectal cancer is depicted only afterextensive review of the CT images. In CT colonogra-phy performed after tagging, intravenous contrastmedia may, in our experience, make more difficultthe assessment/depiction of enhancing bowel walllesions located in segments with superimposablehyperdensity of the adjacent bowel content. In ouropinion, CT colonography should be mainly reservedfor old outpatients in good condition, in whomsignificant colon pathology must be ruled out and thereis a low pretest likelihood of significant findings.Hospitalized old and frail patients may have problemsin completing the full CT colonography preparation andeven in undergoing the CT scan itself with the tworequired positions of the patient (supine and prone).• Water enema CT is performed after distension of thecolon with water and, always, with intravenous iodin-ated contrast media [4]. This technique can be modifiedto obtain distention of the small bowel with oraladministration of a negative contrast medium such as apolyethylene glycol electrolyte solution [5]. Waterenema CT is mainly used in our hospital in those oldand frail patients with a high pretest likelihood of coloncancer, based on clinical suspicion. The use of iodin-ated contrast media intravenously allows to easily andcompletely assess the whole abdomen, particularly theliver (with at least portal and venous phases todifferentiate simple liver cysts from colorectal cancermetastases) [6, 7]. The chest can also be fully evaluatedduring water enema CT mainly for metastases fromcolorectal cancer (providing an important baseline CTstudy for follow-up) and also for cardiovascular