Pre-operative sentinel lymph node localization in breast cancer with superparamagnetic iron oxide MRI: the SentiMAG Multicentre Trial imaging subprotocol.

OBJECTIVE: Sentinel lymph node biopsy (SLNB) with a superparamagnetic iron oxide (SPIO) tracer was shown to be non-inferior to the standard combined technique in the SentiMAG Multicentre Trial. The MRI subprotocol of this trial aimed to develop a magnetic alternative for pre-operative lymphoscintigraphy (LS). We evaluated the feasibility of using MRI following the administration of magnetic tracer for pre-operative localization of sentinel lymph nodes (SLNs) and its potential for non-invasive identification of lymph node (LN) metastases. METHODS: Patients with breast cancer scheduled to undergo SLNB were recruited for pre-operative LS, single photon emission CT (SPECT)-CT and SPIO MRI. T1 weighted turbo spin echo and T2 weighted gradient echo sequences were used before and after interstitial injection of magnetic tracer into the breast. SLNs on MRI were defined as LNs with signal drop and direct lymphatic drainage from the injection site. LNs showing inhomogeneous SPIO uptake were classified as metastatic. During surgery, a handheld magnetometer was used for SLNB. Blue or radioactive nodes were also excised. The number of SLNs and MR assessment of metastatic involvement were compared with surgical and histological outcomes. RESULTS: 11 patients were recruited. SPIO MRI successfully identified SLNs in 10 of 11 patients vs 11 of 11 patients with LS/SPECT-CT. One patient had metastatic involvement of four LNs, and this was identified in one node on pre-operative MRI. CONCLUSION: SPIO MRI is a feasible technique for pre-operative localization of SLNs and, in combination with intraoperative use of a handheld magnetometer, provides an entirely radioisotope-free technique for SLNB. Further research is needed for the evaluation of MRI characterization of LN involvement using subcutaneous injection of magnetic tracer. ADVANCES IN KNOWLEDGE: This study is the first to demonstrate that an interstitially administered magnetic tracer can be used both for pre-operative imaging and intraoperative SLNB, with equal performance to imaging and localization with radioisotopes.

Targeted lymph node biopsy in mediastinoscopy using 3D FDG-PET/CT movies: a feasibility study.

In non-small-cell lung cancer, positive lymph nodes with increased fluorodeoxyglucose (FDG) uptake may be missed by mediastinoscopy. Lack of pathological confirmation may lead to radical, but unnecessary lung surgery. To minimize these false-negative results, the feasibility and potential value of three-dimensional (3D) FDG-PET/computed tomography (CT) movies were investigated to improve targeted lymph node biopsy during mediastinoscopies. PET/CT images were rendered in 3D volumes with multiplanar reconstructions and maximum intensity projections and reviewed in 3D 'fly-through' and 'fly-around' movies. These movies were developed and optimized by the Departments of Surgery and Nuclear Medicine. Twenty-two consecutive patients with non-small-cell lung cancer were included, of whom eight were FDG-PET positive for mediastinal lymph nodes. 3D FDG-PET/CT movies were presented to surgeons before mediastinoscopy. Surgical consequences were investigated, including sensitivity and the negative predictive value of mediastinoscopy. Results were compared with those of a retrospective study in which 3D techniques were not used. During mediastinoscopies, the 3D-PET/CT movies were found to be helpful in the surgical localization of FDG-positive lymph nodes. It led to more confidence in the surgical approach. The sensitivity and negative predictive value were 86 and 94%, respectively. Although not statistically significant, these results were higher compared with those of the retrospective study (75 and 92%, respectively). 3D FDG-PET/CT guidance during mediastinoscopy is feasible. The movies seem to lead to targeted biopsy of lymph nodes. They may reduce false-negative mediastinoscopies and improve staging of lung cancer. 3D FDG-PET/CT can be seen as a promising tool for further implementation of image-guided surgery.

Cardiac imaging in a symptomatic patient with multiple coronary artery-left ventricular microfistulae.

We present the case of a 44-year-old woman with acute coronary syndrome and multiple coronary artery-left ventricular microfistulae at angiography. To evaluate the clinical significance of this observation and to obtain further insights into this rare disease, the patient was further examined with echocardiography and both magnetic resonance imaging and single-photon emission computed tomography, which showed considerable abnormalities.