The effect of anti-spasmodic administration on the accuracy of magnetic resonance imaging staging of rectal cancer.

Abstract

Magnetic resonance imaging is the primary method for local staging in rectal cancer patients. Administration of intravenous (IV) hyoscine butylbromide is thought to improve accuracy, but there are contraindications and potential adverse effects. The aim was to assess the efficacy of IV hyoscine butylbromide on the accuracy of MRI rectal cancer staging of T2 and T3 rectal cancers. A retrospective cohort study was carried out on patients prospectively recorded on the Cabrini Monash colorectal neoplasia database. A total of 74 patients (53 males, 21 females) MRI pelvis and rectums with antispasmodics were performed at multiple centres in the pre-operative setting between 2010 and 2016. Each patient underwent total mesorectal excision of rectal cancer. The excision specimens were assessed and given a pathological TNM stage, which was considered the reference standard. There was no statistically significant impact on the overall accuracy of MRI rectal cancer staging between patient groups who received IV hyoscine butylbromide and groups who did not receive IV hyoscine butylbromide. The accuracy of T2 and T3 staged rectal cancers was more likely to be correct (compared with T1 cancers) with the administration of IV hyoscine butylbromide. Still, there was no improvement in the accuracy of N-staging. Given the potential side effects and adverse outcomes of IV anti-spasmodic agents, department protocols may need to be re-assessed regarding the prescription of these medications for MRI rectal cancer staging.