Assessing diabetic foot osteomyelitis remission with white blood cell SPECT/CT imaging.

AIMS: Diabetic foot osteomyelitis is an important risk factor of lower limb amputation. Antibiotic therapy is often effective in preventing surgery. However, the duration of antibiotic therapy is difficult to define in the absence of a marker to diagnose osteomyelitis remission at the end of the treatment. In this study, we assessed the diagnostic performance of white blood cell SPECT/CT imaging for evaluating osteomyelitis remission. PATIENTS AND METHODS: Twenty-nine out of 42 episodes of diabetic foot osteomyelitis seen between December 2009 and April 2012 had radiographs, a three-phase bone scintigraphy and a white blood cell SPECT/CT at the end of antibiotic therapy. They were treated with antibiotics alone and considered in clinical remission. White blood cell SPECT/CT results were considered positive when abnormal uptake in the osteomyelitis location was identified. Osteomyelitis remission was defined by the absence of an osteomyelitis relapse after 12 months' follow-up. RESULTS: A negative white blood cell SPECT/CT was seen for 22 episodes of osteomyelitis. All of them were in remission. A positive white blood cell SPECT/CT was observed for seven episodes. A relapse occurred in five episodes (71.5%) after a median duration of 4 months (2-7 months). Sensitivity, specificity, positive predictive value and predictive negative value in predicting osteomyelitis relapse after the discontinuation of antibiotic treatment were, respectively, for radiographs 80%, 33%, 20% and 89%; for three-phase bone scintigraphy 100%, 12.5%, 15.5% and 100%; and for the white blood cell SPECT/CT 100%, 91.5%, 71.5% and 100%. CONCLUSION: Negative uptake on white blood cell SPECT/CT is a good marker for diagnosis of diabetic foot osteomyelitis remission and might be very useful in guiding antibiotic therapy.

Whole-body MRI with diffusion-weighted sequences compared with 18 FDG PET-CT, CT and superficial lymph node ultrasonography in the staging of advanced cutaneous melanoma: a prospective study.

OBJECTIVES: The aim of our study was to compare the diagnostic performances of non-radiating whole-body magnetic resonance imaging (wbMRI), either volumetric, with Volumetric interpolated breath-hold examination (VIBE) or metabolic, with diffusion-weighted sequences (wbMRI), with classical irradiating techniques such as PET-CT, CT and with lymph node ultrasonography (US) for the staging of advanced melanoma. PATIENTS AND METHODS: Thirty-seven melanoma AJCC stage IV patients were prospectively included. All images were independently interpreted without prior knowledge of the results of studies performed with concurrent techniques, and all imaging techniques were scheduled within a mean interval of 7 days. The overall and site-specific diagnosis performances of each imaging modality were studied, as well as the interest of combined MRI VIBE and diffusion sequences. RESULTS: The number of visceral or lymph node metastases spotted was, respectively, 218, with 125 metastases for wbMRI, 191/103 for PET-CT, 209/115 for CT and 33/13 for lymph node US. No statistically significant difference (P < 0.05) of overall diagnostic performances between wbMRI (Se 84%, Sp 87.1%, PPV 89.8%, NPV 80.2%) and PET-CT (Se 79.8%, Sp 93.1%, PPV 93.2%, NPV 79.4%) was observed. No statistically significant difference was found between wbMRI and PET-CT with two channels for CT with respect to different metastatic sites. Compared with the CT, wbMRI had significantly better overall specificity (P = 0.0011) and PPV (P = 0.02). For lung exploration, sensitivity of wbMRI (51.6%) was inferior to CT (71.4%). To detect superficial metastatic lymph nodes, wbMRI and US both showed high diagnostic accuracy with no statistically significant difference. Intra-observer agreement was almost perfect for all imaging modalities considering the overall staging. Inter-observer agreement for wbMRI and diffusion alone was almost perfect except for bone and lymphatic sites. Overall diagnostic performance of diffusion alone was significantly inferior to those of combined VIBE and diffusion sequences. CONCLUSIONS: Whole-body MRI, using diffusion weighted sequences, was a reliable non-radiating imaging for staging of melanoma and offers the same diagnostic performances than combined CT, PET-CT and lymph node US.

[Detection of the sentinal node by lymphoscintigraphy in squamous-cell carcinoma of the oral cavity: a prospective study of 31 patients]. / Détection du ganglion sentinelle par lymphoscintigraphie dans les cancers epidermoïdes de la cavité buccale: étude prospective de 31 patients.

INTRODUCTION: This study aimed at evaluating the relevance of sentinel node detection by lymphoscintigraphy in patients diagnosed with squamous-cell carcinoma of the oral cavity in the absence of neck adenopathy. PATIENTS AND METHODS: A prospective study was carried out in 31 patients diagnosed with T1 to T3 squamous-cell carcinoma of the oral cavity without any clinically detectable neck adenopathy. A lymphoscintigraphy was performed the day before surgery. All patients underwent sentinel lymph node biopsy guided by a gamma-ray detecting probe and modified neck dissection. Pathologic evaluation of the sentinel lymph node included, in addition to the standard protocol, immunohistochemical analysis and thin sections of E stained preparations. RESULTS: In 3 patients, the lymphoscintigraphy failed to detect any sentinel lymph node. In the remaining group of 28 patients, 20 patients showed a negative sentinel node concordant with a histologically negative neck dissection. In 5 patients, a positive lymph node was found although the rest of the neck dissection was negative. In 3 patients, sentinel lymph node was found to be negative but other neck nodes were positive. The overall sensitivity of lymphoscintigraphy in our study was 62%. DISCUSSION: Surprisingly, the results of our study do not support the clinical usefulness of sentinel lymph node detection as a reliable and accurate staging method in patients with oral squamous cell carcinoma. We observed that lymphoscintigraphy was not a reliable method for detecting micrometastases in patients diagnosed with a squamous-cell carcinoma of the oral cavity without clinical evidence of neck matastases.