USPIO‐enhanced magnetic resonance imaging for nodal staging in patients with head and neck cancer

Abstract

Purpose:To determine the accuracy of ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) for nodal staging in patients with head and neck cancer. Materials and Methods:Twenty patients with carcinomas of the upper aerodigestive tract were prospectively enrolled. MRI was performed before and 24 -36 hours after intravenous infusion of an USPIO agent, ferumoxtran-10 (Sinerem; Guerbet, France; and Combidex; Advanced Magnetics) at a dose of 2.6 mg Fe/kg using T2-weighted spin-echo and gradient-echo sequences. Surgery was performed the same day or the day after the ferumoxtran-10 -enhanced MR examination. Based on MRI, selected nodes were surgically removed and directly correlated with pathology using hematoxylin-eosin (H&E) and Perls stainings.Results: A total of 63 nodes were studied; 36 were nonmetastatic, 25 metastatic, and two inflammatory. Ferumoxtran-10 -enhanced MRI allowed diagnosis of 24 metastatic and 30 nonmetastatic nodes, yielding a sensitivity of 96%, a specificity of 78.9%, a positive predictive value of 75%, and a negative predictive value of 96.8%, compared to 64%, 78.9%, 66.6%, and 76.9%, respectively, for nonenhanced MRI. Accuracy of ferumoxtran-10 -enhanced MRI was 85.7%. The gradient-echo T2-weighted sequence was the most accurate to detect signal loss in nonmetastatic nodes.Conclusion: USPIO-enhanced MRI is useful for nodal staging of patients with head and neck cancers. CROSS-SECTIONAL IMAGING plays an important role in the study of patients with head and neck squamous cell carcinomas, allowing detection of lymph nodes (LN) missed by physical examination, or demonstrating invasion of structures such as the skull base or the carotid arteries (1,2). Using these imaging modalities, the criteria for diagnosing metastatic nodes is mainly dimensional. Measurements include the minimum transaxial diameter, the maximum transaxial diameter or a ratio between the maximum longitudinal and the maximum axial diameters (3-7). Other parameters, such as morphological criteria or the pattern of enhancement, are regarded as less important in this setting. Nodal metastases in the head and neck are frequently smaller than 10 mm, sometimes even under 5 mm in diameter, a fact that accounts for the unsatisfactory performance of the current imaging techniques (8,9).MRI can be improved when using contrast agents suited for intravenous MR lymphography, such as the new ultrasmall superparamagnetic iron oxide (USPIO) particles, which are taken up by cells of the reticuloendothelial system of nonmetastatic LN (10 -15). As it has been shown in previous studies, iron oxide deposition leads to a decrease in the signal intensity (SI) in nonmetastatic nodes due to the T2 shortening effects, whereas metastatic nodes, devoid of macrophages, will not undergo SI changes when using T2-weighted sequences (11). The clinical use of this contrast agent is still under evaluation on phase III clinical trials (15)(16)(17)(18)(19)(20). Reports show promising results, with sensitivity and specificity value...

A Review of Techniques for Sentinel Lymph Node Mapping with Special Reference to the Head and Neck Region

“…Malignant lymph nodes mainly consist of tumor cells these do not take up this contrast because of lacking reticuloendothelial system activity that can be detected by shorter T2 relaxation time. 59 As well as UPIO the gadolinium chelates have a small particle size which leads to poor retention in the lymphatic vessels and diffusion out of the vessels leads to such difficulties in interpretation as the background noise. 60 A meta-analysis of the investigation employed in different body regions has shown the sensitivity and specificity of 90% and 96%, respectively.…”

USPIO-enhanced MRI of highly invasive and highly metastasizing transplanted human squamous cell carcinoma: an experimental study

“…The mice were anaesthetized with ether and tumour cells were injected into the submucosa of the oral cavity (tongue, floor of oral cavity or buccal mucosa) via an intraoral approach at 1.0610 6 viable cells/0.025 ml in phosphate buffered saline per inoculum using a tuberculin syringe with a 26-gauge disposable needle. They were imaged using MRI approximately 3-4 weeks later when the size of the tumour was approximately 3 mm-8 mm in diameter.…”

“…USPIO-enhanced MRI can differentiate metastatic from normal lymph nodes in head and neck squamous cell carcinoma. 6 However, few studies have described the signal intensity characteristics of primary tumours. Varallyay et al 7 evaluated USPIO-enhanced MR images of intracranial squamous cell carcinoma in two patients and reported that they both showed iron uptake and signal intensity changes.…”

Possible pathological basis for false diagnoses of lymph nodes by USPIO‐enhanced MRI in rabbits

“…These differences in signal intensity between normal and metastatic nodes can be easily detected visually (3). Several clinical studies have demonstrated that USPIO-enhanced MR is a particularly promising technique that improves the sensitivity and specificity of metastatic lymph node detection in pelvic, head and neck, chest, and other malignancies (2,(4)(5)(6)(7)(8)(9)(10)(11)(12)(13).…”

“…Despite lots of promising results concerning USPIOenhanced MRI, there are still many important challenges to overcome, in which one problem is false-positive and false-negative results, affecting the accuracy of diagnosis (2,(4)(5)(6)(7)(8)(9)(10)(11)(12). Harisinghani et al (2) reported that there were metastasis nodes that went undetected, and the false diagnosis was not negligible.…”