Radiolocalized sentinel lymph node biopsy in squamous cell carcinoma of the oral cavity and analysis of various parameters.

BACKGROUND: Sentinel lymph node (SLN) biopsy seems to be a method that solves the problem of neck management with oral squamous cell carcinoma. Using blue dye methods for detection of neck SLNs from the surface of the operative field seems difficult; therefore, we used radiolocalization alone to detect and extract sentinel nodes. Aside from the various histological and clinical parameters examined in this procedure, we also determined whether they had any clinical significance in relation to the detection of SLNs during the operation. METHODS: Enrolled subjects had preoperative clinical N0 stage squamous cell carcinoma of the oral cavity and had received an unfiltered (99m)Tc sulfur colloid peritumoral injection. Localization of the SLNs was performed by using lymphoscintigraphy and a handheld gamma probe. RESULTS: In total, 28 oral squamous cell carcinoma patients were included in this prospective study. Sixty-four SLNs in 27 patients were identified by this method. The identification rate was 96.4%. No false-negative predictions of SLN were noted among any of the patients studied. The numbers of the SLNs found during the operation were larger in patients with positive findings than those with negative findings (P < .05 by the Mann-Whitney U-test). CONCLUSIONS: SLN radiolocalization provided an acceptable identification rate. The cases of positive findings for metastasis seemed to statistically have more SLNs than did those with negative findings, but more evidence is needed to prove this point. Therefore, SLN biopsies for extracting all possible high-risk nodes may be conducive for oral squamous cell carcinoma surgery.

Utility of FDG-PET for investigating unexplained serum AFP elevation in patients with suspected hepatocellular carcinoma recurrence.

UNLABELLED: The aim of this study was to evaluate the potential role of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with unexplained rising serum alpha-fetoprotein (AFP) levels after the treatment of hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Thirty-one FDG-PET studies were performed in 26 patients (age range, 45-83; 21 men and 5 women), who had undergone either surgical resection or interventional therapy for HCC, but were subsequently noted to have high AFP serum levels on routine follow-up examinations, although imaging studies and physical examinations were normal. The FDG-PET results were correlated with histological findings, as well as long-term radiological and clinical follow-up (shortest follow-up period after FDG-PET was 6 months). RESULTS: FDG-PET was abnormal in 22 of the 31 studies (71.0%) among the 26 patients. Intrahepatic lesions were detected in 20 of a total 30 lesions (66.7%) in 18 studies of FDG-PET among 26 patients. Ten FDG-PET studies among 9 patients identified one intrahepatic lesion, while 3 studies among 3 patients identified more than one intrahepatic lesion. Extrahepatic metastases were found in 9/31 studies of FDG-PET (29.0%) among 8 patients. These metastatic foci, composed of increased FDG accumulation, were identified in several locations; lung (4 studies among 4 patients), bone (2 studies among 2 patients) and the peritoneum (4 studies among 3 patients). Overall, FDG-PET for detecting HCC recurrence demonstrated 22 true-positives, 8 false-negatives, 1 true-negative and 0 false-positive results., The sensitivity, specificity and accuracy of FDG-PET for detecting HCC recurrence was 73.3%, 100% and 74.2%, respectively. CONCLUSION: When conventional examinations are normal, FDG-PET is a valuable imaging tool in patients who have rising AFP levels after HCC treatment. FDG-PET whole-body scan also provides an important and valuable imaging study for detecting extrahepatic metastasis.

In vivo quantification by SPECT of [123I] ADAM bound to serotonin transporters in the brains of rabbits.

BACKGROUND: A novel radioiodine ligand [(123)I] ADAM (2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine) has been suggested as a promising serotonin transporter (SERT) imaging agent for the central nervous system. In this study, the biodistribution of SERTs in the rabbit brain was investigated using [(123)I] ADAM and mapping images of the same animal produced by both single-photon emission computed tomography (SPECT) and microautoradiography. A semiquantification method was adopted to deduce the optimum time for SPECT imaging, whereas the input for a simple fully quantitative tracer kinetic model was provided from arterial blood sampling data. METHODS: SPECT imaging was performed on female rabbits postinjection of 185 MBq [(123)I] ADAM. The time-activity curve obtained from the SPECT images was used to quantify the SERTs, for which the binding potential was calculated from the kinetic modeling of [(123)I] ADAM. The kinetic data were analyzed by the nonlinear least squares method. The effects of the selective serotonin reuptake inhibitors fluoxetine and p-chloroamphetamine (PCA) on rabbits were also evaluated. After scanning, the same animal was sacrificed and the brain was removed for microautoradiography. Regions-of-interest were analyzed using both SPECT and microautoradiography images. The SPECT images were coregistered manually with the corresponding microautoradiography images for comparative study. RESULTS: During the time interval 90-100 min postinjection, the peak specific binding levels in different brain regions were compared and the brain stem was shown to have the highest activity. The target-to-background ratio was 1.89+/-0.02. Similar studies with fluoxetine and PCA showed a background level for SERT occupation. Microautoradiography demonstrated a higher level of anatomical details of the [(123)I] ADAM distribution than that obtained by SPECT imaging of the rabbit brain. CONCLUSION: SPECT imaging of the rabbit brain with [(123)I] ADAM showed high affinity, high specificity, and favorable kinetics. The time-activity curve showed that the accumulation of the [(123)I] ADAM in the brain stem reached a maximum between 90 and 100 min postinjection. The microautoradiography provides high-resolution images of the rabbit brain. Our results for the [(123)I] ADAM biodistribution in the rabbit brains demonstrate that this new radioligand is suitable as a selective SPECT imaging agent for SERTs.

Evaluation of nasal mucociliary clearance function in allergic rhinitis patients with technetium 99m-labeled macroaggregated albumin rhinoscintigraphy.

Nasal mucociliary clearance is the first line of defense of the ciliated epithelium of the respiratory tract against inhaled particles. Several rhinopathic conditions involve alterations in nasal mucociliary clearance. The purpose of this study was to assess the clinical role of rhinoscintigraphy in evaluation of nasal mucociliary clearance function in allergic rhinitis patients and in sinusitis patients and healthy controls for comparison. A technetium 99m-labeled macroaggregated albumin (Tc-99m MAA) drop was deposited on the floor of the nasal meatus about 1 cm behind the mucocutaneous junction, and its course was followed with a gamma camera. The nasal mucociliary clearance function was measured as the velocity of the nasal mucociliary transport of the Tc-99m MAA droplet. The mean velocity of nasal mucociliary transport in the allergic rhinitis patients was 2.71 +/- 0.76 mm/min (2.65 +/- 0.76 mm/min in the right nostril; 2.77 +/- 0.76 mm/min in the left nostril). The mean velocity of nasal mucociliary transport in the sinusitis patients was 1.80 +/- 0.64 mm/min (1.79 +/- 0.65 mm/min in the right nostril; 1.82 +/- 0.63 mm/min in the left nostril). The mean velocity of nasal mucociliary transport in the 25 healthy controls was 4.28 +/- 1.38 mm/min (4.30 +/- 1.35 mm/min in the right nostril; 4.27 +/- 1.42 mm/min in the left nostril). A significant difference in nasal mucociliary clearance was observed among the 3 groups. We suggest that Tc-99m MAA rhinoscintigraphy may be a useful noninvasive tool to evaluate the nasal mucociliary clearance function in allergic rhinitis patients.