Endorectal ultrasound and magnetic resonance imaging for staging of early rectal cancers: how well does it work in practice?

Abstract

Background: Rectal tumor treatment strategies are individually tailored based on tumor stage, and yield different rates of posttreatment morbidity, mortality, and local recurrence. Therefore, the accuracy of pretreatment staging is highly important. Here we investigated the accuracy of staging by magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) in a clinical setting. Material and methods: A total of 500 patients were examined at the rectal cancer outpatient clinic at Haukeland University Hospital between October 2014 and January 2018. This study included only cases in which the resection specimen had a histopathological staging of adenoma or early rectal cancer (pT1-pT2). Patients with previous pelvic surgery or preoperative radiotherapy were excluded. The 145 analyzed patients were preoperatively examined via biopsy (n ¼ 132), digital rectal examination (n ¼ 77), rigid rectoscopy (n ¼ 127), ERUS (n ¼ 104), real-time elastography (n ¼ 96), and MRI (n ¼ 84). Results: ERUS distinguished between adenomas and early rectal cancer with 88% accuracy (95% CI: 0.68-0.96), while MRI achieved 75% accuracy (95% CI: 0.54-0.88). ERUS tended to overstage T1 tumors as T2-T3 (16/24). MRI overstaged most adenomas to T1-T2 tumors (18/22). Neither ERUS nor MRI distinguished between T1 and T2 tumors. Conclusions: In a clinical setting, ERUS differentiated between benign and malignant tumors with high accuracy. The present findings support previous reports that ERUS and MRI have low accuracy for T-staging of early rectal cancer. We recommend that MRI be routinely combined with ERUS for the clinical examination of rectal tumors, since MRI consistently overstaged adenomas as cancer. In adenomas, MRI had no additional benefit for preoperative staging.

Endorectal Ultrasound and Magnetic Resonance Imaging for Rectal Cancer Staging: A Modern Multimodality Approach

“…Endorectal ultrasonography (ERUS) is a reliable imaging method, able to evaluate rectal wall infiltration, especially for early tumors [4,[18][19][20][21]. However, the imaging distinction between rectal cancer having a mesorectal fat invasion and desmoplastic reaction remains difficult and could mislead patients' staging, causing important clinical implications [11,[22][23][24]. Despite the recent technical improvements, all imaging modalities are still at risk of staging failure, with an overstaging rate reported up to 30% [22][23][24].…”

“…However, the imaging distinction between rectal cancer having a mesorectal fat invasion and desmoplastic reaction remains difficult and could mislead patients' staging, causing important clinical implications [11,[22][23][24]. Despite the recent technical improvements, all imaging modalities are still at risk of staging failure, with an overstaging rate reported up to 30% [22][23][24]. Numerous studies have reported on MRI and ERUS diagnostic performance for rectal cancer staging, but there are considerable differences in methodologic analysis, results and accuracy measures among them, particularly for T3 staging [4,22,[24][25][26][27].…”

“…Despite the recent technical improvements, all imaging modalities are still at risk of staging failure, with an overstaging rate reported up to 30% [22][23][24]. Numerous studies have reported on MRI and ERUS diagnostic performance for rectal cancer staging, but there are considerable differences in methodologic analysis, results and accuracy measures among them, particularly for T3 staging [4,22,[24][25][26][27]. Moreover, none of the studies have been performed using three different imaging modalities in comparison and focused on a single stage of the disease.…”

Robotic transanal minimally invasive surgery – technical, oncological and patient outcomes from a single institution

“…Given the known limitations of each modality, the conflicting evidence in the literature and the potential impact on patient management, discussion in the multidisciplinary team and with the patient may help decide if both MRI and ERUS would be beneficial in lesions deemed T1/T2. With a benign appearance endoscopically or on biopsy it is better to clarify whether TAMIS is appropriate, and additionally whether ERUS should be favoured over MRI in the setting of a suspected adenoma [21,22]. It will be interesting to see how advancement of imaging techniques such as the inclusion of real-time elastography impact on this area.…”

Semiotics and the role of transrectal ultrasound in rectal cancer staging

“…Точность определения Т1-и Т2-стадии у МРТ и ТРУЗИ значительно не различалась и составила около 80 % у обоих исследований. Точность, чувствительность, специфичность, прогностическая ценность положительного и отрицательного ответов для ТРУЗИ в данном исследовании составили 84, 82, 87, 88 и 81 % соответственно [26].…”