USPIO – enhanced rectal cancer specimen MRI: how well does it correlate with node identification at histopathology?

Abstract

Introduction: Detection of lymph node (LN) metastasis is important for the optimal management of rectal cancer patients. Ultrasmall-particle superparamagnetic iron oxide (USPIO) contrast enhanced magnetic resonance imaging (MRI) has emerged as an effective method of assessing nodal involvement in various malignancies. We have investigated the correlation between nodes seen on specimen MRI and those found at histopathology and the optimum time interval between contrast injection and surgery in USPIO mesorectal lymphography.Method: Thirteen rectal cancer patients underwent MRI before and 24 h after intravenous infusion of USPIO contrast (SineremÒ, Advanced Magnetics Inc, Cambridge, MA, USA). Total Mesorectal Excision (TME) surgery was followed by fixed specimen MRI. Lymph nodes seen on specimen MRI and those found at pathology were compared for studies performed <5 days and ‡5 days prior to surgery.Results: Histopathological LNs found correlated well with those seen on specimen MRI (all patients, r = 0.73; P = 0.005, figure). Correlation was better for the <5 day group (r = 0.84; P = 0.01) than for the ‡5 day group (r = 0.54; P = 0.35).Discussion: USPIO specimen MRI is useful in mesorectal LN assessment. We demonstrate good correlation between specimen MRI and histopathology and show that fewer errors occur in assessment when the time interval between contrast injection and surgery is <5 days.Factors influencing lymph node retrieval in colorectal cancer and its effect on survival Introduction: NICE has set standards for lymph node (LN) harvest in surgery for colorectal cancer (CRC). We report the effect of the operating surgeon and reporting pathologist on lymph node yield and the role of LN yield on survival.

Phase II study of preoperative radiation plus concurrent daily tegafur-uracil (UFT) with leucovorin for locally advanced rectal cancer

“…Sensitivity and specificity were not good even at the first pretreatment examination: some tumors initially staged as T0 or T1 by EUS were found to be T3 on pathologic examination. Based on evidence from the literature and our own experience, the current practice in our institutions is to use magnetic resonance imaging for the evaluation of local and regional tumor extension, as it provides more precise and reliable results [ 38 , 39 ] (Rasheed et al , 2006; Muthusamy et al , 2007).…”

Radiation, chemotherapy and biological therapy in the curative treatment of locally advanced rectal cancer

“…Because of difficulty in distinguishing residual scar tissue from active tumour and an inability to identify accurately small mesorectal deposits of viable tumour, MRI scanning post‐CRT is an unreliable method of assessing response and resectability after CRT [64]. It is possible that in the future, additional modalities such as the use of diffusion MRI [152] and novel contrast agents such as iron oxide [153] and USPIO [154] may be of additional benefit. The magnitude of decrease in SUV on PET scanning has been shown to correlate with the degree of pathological response and downstaging following CRT [155,156], but at present the use of PET to predict response to CRT is experimental.…”