Re-staging and follow-up of rectal cancer patients with MR imaging when “Watch-and-Wait” is an option: a practical guide

Abstract

In the past nearly 20 years, organ-sparing when no apparent viable tumour is present after neoadjuvant therapy has taken an increasingly relevant role in the therapeutic management of locally-advanced rectal cancer patients. The decision to include a patient or not in a “Watch-and-Wait” program relies mainly on endoscopic assessment by skilled surgeons, and MR imaging by experienced radiologists. Strict surveillance using the same modalities is required, given the chance of a local regrowth is of approximately 25–30%, almost always surgically salvageable if caught early. Local regrowths occur at the endoluminal aspect of the primary tumour bed in almost 90% of patients, but the rest are deep within it or outside the rectal wall, in which case detection relies solely on MR Imaging. In this educational review, we provide a practical guide for radiologists who are, or intend to be, involved in the re-staging and follow-up of rectal cancer patients in institutions with an established “Watch-and-Wait” program. First, we discuss patient preparation and MR imaging acquisition technique. Second, we focus on the re-staging MR imaging examination and review the imaging findings that allow us to assess response. Third, we focus on follow-up assessments of patients who defer surgery and confer about the early signs that may indicate a sustained/non-sustained complete response, a rectal/extra-rectal regrowth, and the particular prognosis of the “near-complete” responders. Finally, we discuss our proposed report template.

Resultados oncológicos del manejo neoadyuvante con quimiorradioterapia seguido de cirugía en cáncer de recto localmente avanzado: en el Instituto Oncológico Nacional de Panamá

“…La necrosis, edema e inflamación peritumoral conllevan a dificultades en la re estadificación por imágenes de los pacientes con LARC. La RMP ha demostrado tasas de precisión global de 49% y 63.8% para la categoría T y N respectivamente sin embargo existe controversia en la herramienta ideal [15]. La mayoría de los pacientes reestadificados fueron sometido a una tomografía computada tóraxabdomenpelvis.…”

How We Treat Localized Rectal Cancer—An Institutional Paradigm for Total Neoadjuvant Therapy

“…Scans are performed on either 1.5 Tesla Philips Ingenia or 3 Tesla Philips Achieva Scanners (Philips Healthcare ® , Best, The Netherlands). We routinely use spasmolytics such as butylscopolamin or glucagon to reduce artefacts from peristalsis, but discourage the routine use of rectal fillings due to possible misinterpretation of the distance between the tumor and the mesorectal fascia with the risk of overstaging [ 25 , 30 ].…”

T2 relaxation time for the early prediction of treatment response to chemoradiation in locally advanced rectal cancer

“…The outcomes of CRT are a crucial endpoint in LARC management, with 14-36% achieving a pathological complete response (pCR) [2,3]. A wait-and-watch policy [4,5] has been proposed for these patients because it may have similar disease-free survival and overall survival benefit to surgery. However, a small proportion of patients fail to benefit from CRT [6] and develop toxicity and tumor progression during treatment.…”