Repeat injection following sentinel node nonvisualization on lymphoscintigraphy images can decrease axillary dissection rate in breast cancer patients.

AIM: Sentinel node biopsy is considered the standard of care in early-stage breast cancer patients. In the current study, we evaluated the effect of radiotracer reinjection in the case of sentinel node nonvisualization on preoperative lymphoscintigraphy. MATERIALS AND METHODS: Between March 2017 and March 2020, 1850 early-stage breast cancer patients were referred for sentinel node mapping. All patients received a single injected activity of Tc-99m Phytate intradermally in the periareolar area of the index lesion using an insulin syringe. Lymphoscintigraphy images of the patients were done 1-2 h postinjection. Between March 2017 and September 2017, sentinel node nonvisualization was reported to the surgeon, and for the rest of the study period, the patients received another injected activity of the radiotracer, and immediately, other lymphoscintigraphy images were taken (with the same parameters). RESULTS: A total of 255 patients entered our study. Fifty-five patients were in group I without any reinjection. The remainder of the patients were in group II. In 155 out of 200 patients of group II, a sentinel node could be visualized following reinjection of the radiotracer. The detection rate was 15 out of 45 and 15 out of 55 in group I and patients without sentinel node visualization even after reinjection, respectively. Axilla was involved in 5 out of 40 (12.5%) patients in group I with intraoperative sentinel node mapping failure. On the other hand, axilla was involved in 27 out of 30 (90%) group II patients with sentinel node nonvisualization. CONCLUSION: Reinjection of the tracer in cases of no sentinel node visualization in lymphoscintigraphy for breast cancer increases the detection rate of sentinel nodes, and therefore a high number of unnecessary axillary lymph node dissections can be avoided.

Unusual presentation of lumbar chordoma on bone scintigraphy in a young patient.

Chordoma is a rare bone cancer which arises from undifferentiated notochordal remnants in the axial skeleton. It generally has slow-growing and locally aggressive behavior. This tumor is usually diagnosed by CT and MRI modalities and the role of SPECT/CT is still debated. It shows reduced or normal uptake of radioisotope on bone scanning and increased tracer uptake is infrequently reported. Here we present a 33-year-old man with complaint of low back pain and numbness of his right leg. The whole body bone scan showed relatively uniform radiotracer activity throughout the skeleton. A focal increased uptake in the second lumbar vertebra was noted on SPECT/CT images. SPECT/CT also demonstrated multiple lytic lesions in lumbar vertebrae. The lesions were proven to be chordoma on biopsy. Lumbar chordoma could be one of the differential diagnoses for lytic lesions of the vertebrae which show absent or minimal tracer uptake on bone scintigraphy and SPECT/CT imaging. Our case was unusual as the patient was very young for chordoma diagnosis and bone scan showed increased uptake adjacent to the involved vertebral lesion detected by SPECT/CT.

Sentinel ode apping in on-small ell ung ancer sing an ntraoperative adiotracer echnique.

OBJECTIVES: Lymph node metastases are the most significant prognostic factor in localized non-small cell lung cancer (NSCLC). Identification of the first nodal drainage site (sentinel node) may improve detection of metastatic nodes. Extended surgeries, such as lobectomy or pneumonectomy with lymph node dissection, are among the therapeutic options of higher acceptability. Sentinel node biopsy can be an alternative approach to less invasive surgeries. The current study was conducted to evaluate the accuracy of sentinel node mapping in patients with NSCLC using an intraoperative radiotracer techniques. METHODS: This prospective study was conducted on 21 patients with biopsy-proven NSCLC who were candidates for sentinel node mapping during 2012-2014. All patients underwent thoracoabdominal computed tomography, based on which they had no lymph node involvement. Immediately after thoracotomy and before mobilizing the tumor, peritumoral injection of 2mCi/0.4 mL Tc-99m- phytate was performed in 4 corners of tumor. After mobilization of the tumoral tissues, the sentinel nodes were searched for in the hillar and mediastinal areas using hand-held gamma probe . Any lymph node with in vivo count twice the background was considered as sentinel node and removed and sent for frozen section evaluation. All dissected nodes were evaluated by step sectioning and hematoxylin and eosin staining (H&E).The recorded data included age, gender, kind of pathology, site of lesion, number of dissected sentinel nodes, number of sentinel nodes, and site of sentinel nodes. Data analysis was performed in SPSS software (version 22). RESULTS: The mean age of the patients was 58.52±11.46 years with a male to female ratio of 15/6. The left lower lobe was the most commonly affected site (30.09%). Squamous cell carcinoma and adenocarcinoma were detected in 11 and 10 subjects, respectively. A total of 120 lymph nodes were harvested with the mean number of 5.71±2.9 lymph nodes per patient. At least one sentinel node was identified in each patient, resulting in a detection rate of 95.2%. The mean number of sentinel nodes per patient was 3.61±2. Frozen section results showed 100% concordance with the results of hematoxylin and eosin staining. CONCLUSION: Based on the findings, sentinel node mapping can be considered feasible and accurate for lymph node staging and NSCLC treatment.

18FDG PET/CT in pulmonary arcinosarcoma and rain etastasis.

Carcinosarcoma is a rare type of cancer that is composed of a mixture of sarcomatous and carcinomatous elements. Pulmonary carcinosarcoma has a 25% five-year survival rate with a prognosis poorer than other non-small cell lung carcinomas. Herein, we report a case of pulmonary carcinosarcoma and its 18F-FDG PET/CT findings. A 61-year-old male patient presented with brain symptoms, including headache, nausea, right hemiplegia, and few attacks of seizures. He underwent brain computed tomography (CT) scan showing a brain lesion in the left parietal lobe. The patient underwent excisional biopsy, and brain lesion was removed. The results of tissue sampling were indicative of carcinosarcoma. Based on anatomical imaging and evidence of pulmonary lesion, the patient underwent 18FDG PET/CT that revealed a heterogeneous mass on the upper lobe of the left lung. An intense FDG uptake was observed along the rim of the mass; however, no FDG uptake was observed in the center of the mass. There were multiple mediastinal lymph nodes with a high FDG uptake. Pulmonary carcinosarcoma was confirmed by tissue sampling.

99mTc-TRODAT-1 SPECT Imaging in Early and Late Onset Parkinson's Disease.

OBJECTIVES: 99mTc-TRODAT-1, which binds to the dopamine transporter, could be used to image the dopaminergic system in diagnosis of Parkinson's disease (PD). PD can be classified into two groups: late onset Parkinson's disease (LOPD) and early onset Parkinson's disease (EOPD). In this study we tried to determine the TRODAT SPECT findings in EOPD as compared to LOPD. METHODS: Fifteen patients were studied. The diagnosis of PD was defined by clinical criteria based on UK Parkinson's Disease Society Brain Bank criteria. Six patients whose age at onset of PD were younger than 50 were defined as patients with EOPD and 9 patients with older than 50 years were defined as patients with LOPD. All patients underwent 99mTc-TRODAT Brain SPECT. RESULTS: There was a significant decrease of striatal 99mTc-TRODAT-1 (TRODAT) binding in PD patients in both EOPD and LOPD. No significant difference was noticed between EOPD and LOPD in disease stage and symptoms. In visual analysis, 20 (66.67%) caudate nucleuses had decreased tracer uptake while all 30 (100%) putamens had decreased or absent tracer uptake. No significant difference between EOPD and LOPD was noticed in visual analysis. Striatum, Caudate and Putamen uptake ratio to background were calculated. No significant difference was noticed between EOPD and LOPD in these ratios. However there was significant difference in visual analysis (tracer uptake) as well as in uptake ratio between putamen and caudate nucleuses in both groups (P=0.001). On the other word, we found more diminished uptake in putamen as compared the caudate. Frequency and severity of putamen involvement were much more than caudate. CONCLUSION: 99mTc-TRODAT-1 SPECT imaging showed lower presynaptical dopami-nergical terminals density in both EOPD and LOPD. There was no difference between EOPD and LOPD in TRODAT uptake. Putamen showed more involvement and more diminished TRODAT uptake.

Relationship between gated myocardial perfusion SPECT findings and hemodynamic, electrocardiographic, and heart rate changes after Dipyridamole infusion.

After dipyridamole infusion, electrocardiographic (ECG), blood pressure and heart rate (HR) changes were seen. We tried to investigate whether there is a relationship between hemodynamic, ECG and HR changes after dipyridamole infusion and gated myocardial perfusion SPECT findings. We studied 206 consecutive patients which underwent a 2-day protocol Dipyridamole Stress/Rest Tc99m-Sestamibi gated myocardial perfusion SPECT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and ECG were recorded. HR was mildly increased while SBP and DBP were mildly decreased after Dipyridamole infusion. There was only statistically significant difference between ECG changes as well as transient ischemic dilation (TID) ratio between normal scans and scans with ischemia (P = 0.02 and P = 0.01 respectively). There was correlation between these variables and summed stress score (SSS) and summed difference score (SDS). Patients with ischemia in their scans, 44.3% had ST depression after Dipyridamole infusion. Also ST depression most frequently was seen in patients with left anterior descending artery disease. From patients with abnormal scan + ST depression after Dipyridamole infusion (33 patient), 27 patient (81.81%) had ischemia. There was an association between TID ratio as well as ECG changes after Dipyridamole infusion and SSS, SDS and coronary artery territory abnormality. Difference between calculated left ventricular ejection fraction using stress and rest images had significant correlation with SSS and SDS. ST depression after Dipyridamole infusion and TID ratio had association with ischemia, SSS and SDS. So in equivocal Gated SPECT findings, they could be very useful for interpretation.

99mTc-Labeled Ubiquicidin Accumulation in a Retained Surgical Gauze.

A 31-year-old woman underwent Tc-labeled UBI scanning for diagnosis of possible prosthesis infection evaluation in our department. The scan showed an area of increased tracer uptake in the mid-lateral portion of the left thigh. This was proven to be due to a retained surgical gauze in her left thigh.

Nano Liposomes Labeled with (99m)Tc-HMPAO, a Novel Agent for Blood Pool Imaging.

In-vitro labeling of RBC with (99m)Tc is an intricate procedure and there is always a need for an alternate blood pool imaging agent. The aim of this study was to prepare an effective nano sized liposome (NLs) similar to human RBC for blood pool scintigraphy. This study formulates PEG-NLs and non-PEG-NLs using film method plus high pressure homogenization technique. Biodistribution studies were performed on BALB/C mice 1, 4 and 24 h after tail vein injection of labeled NLs with (99m)Tc hexamethylpropylene-amine-oxime ((99m)Tc-HMPAO). Planar images were acquired using a 256 × 256 matrix following(99m) Tc-HMPAO-NLs injection into ear vein of rabbits 1, 2 and 24 h later. SPECT images were obtained 15 minutes after the injection (64 slices, 30 second/projection). The mean diameter, zeta potential and polydispersity index (PDI) of the PEG-NLs and the NLs were (80.88 ± 0.594 nm, -12.5 ± 0.56 mv, 0.158 ± 0.025) and (94.14 ± 0.114 nm, -35.5 ± 0.67 mv and 0.198 ± 0.007), respectively. (99m)Tc-HMPAO-PEG-NLs showed a significant circulation tracer activity (7.74 ± 1.63%ID/g at 1 h and 4.9 ± 0.77 %ID/g at 4 h), with low liver accumulation (12.07 ± 3.66 %ID/g at 1 h and 14.85 ± 1.3 %ID/g at 4 h). Heart to liver, spleen and background ROIs (region of interests) for (99m) Tc-HMPAO-PEG-NLs were 1.25, 4 and 4.28 respectively at 2 h which changed to 1.06, 1.75 and 2.51 respectively at 24 h. The (99m)Tc-HMPAO-PEG-NLs with a prolonged blood circulation time could be an excellent RBC alternative for scintigraphy and gastrointestinal bleeding.

Comparison between fragmented QRS and Q waves in myocardial scar detection using myocardial perfusion single photon emission computed tomography.

BACKGROUND: Accurate diagnosis of myocardial infarction (MI) is of paramount importance in patient management, which necessitates the development of efficient and accurate diagnostic methods. Q wave is not present in all patients with MI, and its prevalence is declining. Recently, fragmented QRS (fQRS) complex has been introduced as a marker of prior MI. AIM: To investigate diagnostic value of fQRS compared to Q wave. METHODS: We included 500 consecutive patients with known or suspected coronary artery disease who underwent two days of gated myocardial perfusion imaging using dipyridamole pharmacologic stress. Electrocardiogram (ECG) was evaluated to detect fQRS as well as Q-wave. Finally, subjects were compared in terms of ventricular perfusion and function indices. RESULTS: A total of 207 men and 269 women with mean age of 57.06 ± 12 years were studied. ECG analysis showed that 14.3% of the patients had both fQRS and Q waves, 30.7% had fQRS, and 3.8% had Q waves. Fixed myocardial perfusion defect was noted in 22.3% of patients according to MPIs. Sensitivity, specificity, and positive and negative predictive values for myocardial scar detection were 78%, 65%, 39%, and 91%, respectively, for fQRS and 61%, 94%, 76%, and 89%, respectively, for Q wave. CONCLUSIONS: Although fQRS had lower specificity compared to Q wave in the detection of myocardial scar, due to higher sensitivity and negative predictive value can be an invaluable diagnostic index. There is also an incremental value for fQRS in association with Q-wave in myocardial scar assessment.

Intra-Operative Lymphatic Mapping and Sentinel Node Biopsy in Laryngeal Carcinoma: Preliminary Results.

INTRODUCTION: Sentinel node mapping has been used for laryngeal carcinoma in several studies, with excellent results thus far. In the current study, we report our preliminary results on sentinel node mapping in laryngeal carcinoma using intra-operative peri-tumoral injection of a radiotracer. MATERIALS AND METHODS: Patients with biopsy-proven squamous cell carcinoma of the larynx were included in the study. Two mCi/0.4 cc Tc-99m-phytate in four aliquots was injected on the day of surgery, after induction of anesthesia, in the sub-mucosal peri-tumoral location using a suspension laryngoscopy. After waiting for 10 minutes, a portable gamma probe was used to search for sentinel nodes. All patients underwent laryngectomy and modified radical bilateral neck dissection. All sentinel nodes and removed non-sentinel nodes were examined by hematoxylin and eosin (H&E) staining. RESULTS: Ten patients with laryngeal carcinoma were included. At least one sentinel node could be detected in five patients (bilateral nodes in four patients). One patient had pathologically involved sentinel and non-sentinel nodes (no false-negative cases). CONCLUSION: Sentinel node mapping in laryngeal carcinoma is technically feasible using an intra-operative radiotracer injection. In order to evaluate the relationship of T-stage and the laterality of the tumor with accuracy, larger studies are needed.

99mTc-Pertechnetate imaging for detection of ectopic gastric mucosa: a systematic review and meta-analysis of the pertinent literature..

BACKGROUND AND AIMS: 99mTc-pertechnetate scintigraphy has long been used for detection of ectopic gastric mucosa (EGM) in the medical practice and evaluation of children with lower gastrointestinal bleeding. In the current study, we reviewed the available medical literature in this regard. METHODS: Medline and SCOPUS were searched for relevant studies. Studies with sample size of at least 5 patients which provided enough numerical data to calculate the sensitivity and/or specificity of 99mTc-pertechnetate for detection of EGM were includ ed in the systematic review. RESULTS: Overall 40 studies were included in our systematic review. Overall diagnostic indices of the 99mTc-pertechnetate scintigraphy for EGM diagnosis were: sensitivity 92.1% [95% CI: 90.2-93.8], specificity 95.4% [943-963], positive likelihood ratio 16.5 [9.9-27.], negative likelihood ratio 0.15 [0.1-0.2], diagnostic odds ratio 120.7 [73-199]. The pooled sensitivity was higher for studies using H2 blockers as a premedication (92.4% vs. 86.4%), studies using delayed imaging (943% vs. 88.4%), children (92.3% vs. 81.8%), and patients with gastrointestinal bleeding (953% vs. 75.3%). CONCLUSIONS: 99mTc-pertechnetate imaging is a highly accurate diagnostic modality for detection of EGM. This imaging is more accurate in children and patients presenting with gastrointestinal bleeding. Premedication with H2 blockers and delayed imaging can increase the diagnostic accuracy and should be routinely included in the imaging protocol.

Comparison between 99mTc-sestamibi gated myocardial perfusion SPECT and echocardiography in assessment of left ventricular volumes and ejection fraction--effect of perfusion defect and small heart.

BACKGROUND: Agreement between gated myocardial perfusion SPECT (GSPECT) and echocardiography (ECHO) in the calculation of left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and LVEF was assessed. Effect of perfusion defect and small hearts on this agreement was obtained. Because ECHO is a routine and widely used noninvasive modality for this purpose, we chose this technique for comparison with GSPECT. MATERIAL AND METHODS: In a prospective study, 50 consecutive patients (age = 59.7 ± 10.64 years) underwent rest Tc99m-sestamibi GSPECT and 2-D ECHO. The LVEF, EDV and ESV were calculated using QGS (Quantitative Gated SPECT) software. RESULTS: Fourteen (28%) patients had perfusion defect in rest phase tomograms, while 36 (72%) had no perfusion defect. There was a significant correlation between two modalities in calculation of EDV, ESV and LVEF (all: p < 0.001, Pearson's correlation coefficients: r = 0.764, 0.831 and 0.813, respectively). A good correlation was noticed even in small hearts or in patients with or without previous myocardial infarction. There was a significant difference between GSPECT and ECHO in patients with no perfusion defect as well as in patients with small heart (ESV < 25 ml). On the other hand, no remarkable difference was noticed between two techniques in the presence of perfusion defect or in patients with ESV ≥ 25 ml. CONCLUSION: There was a good agreement between EDV, ESV and LVEF derived from GSPECT and ECHO. There was a significant difference between two modalities in small hearts and in patients without perfusion defect, although in larger ventricles or in the presence of myocardial infarction no remarkable difference between two modalities was noticed.

Accuracy of sentinel node biopsy in esophageal carcinoma: a systematic review and meta-analysis of the pertinent literature.

The use of sentinel node surgery for esophageal carcinoma is still under investigation. We evaluated the data available in the literature on this topic, and herein present the results in a systematic review format. PUBMED, SCOPUS, the ISI web of knowledge and the information from the annual meetings of the Japan Esophageal Society were searched using the search terms: "(esophagus OR esophageal) AND sentinel". The outcomes of interest were the detection rate and sensitivity. Overall, 18 studies were included. The pooled detection rate was 89.2% [82.6-93.5]. Patients with T1 and two tumors had a 17% higher detection rate compared to those with T3 and four tumors. The pooled sensitivity was 84% [78-88%]. The sensitivity was higher for adenocarcinoma compared to squamous cell carcinoma (SCC) (91 vs. 81%). In the SCC patients, there was a trend toward decreased sensitivity associated with an increasing tumor depth (T1:88%, T2:76%, T3:50%). Our analysis indicated that sentinel node biopsy is useful in adenocarcinoma patients. For SCC patients, including only cN0 patients (preferably T1 and 2) would increase the detection rate and sensitivity. Due to the limited number of high-quality studies, drawing any more definite conclusions is impossible. Large cohort studies with a standardized and consistent design will be needed in the future.

Diagnostic performance of fluorine 18 fluorodeoxyglucose positron emission tomography imaging for detection of primary lesion and staging of endometrial cancer patients: systematic review and meta-analysis of the literature.

OBJECTIVES: Fluorine 18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) imaging has been used for staging of endometrial cancer. In the current study, we systematically searched the available literature on the accuracy of (18)F-FDG PET imaging for staging of endometrial cancer. METHODS: PubMed, SCOPUS, ISI Web of Knowledge, Science Direct, and Springer were searched using "endometr* AND PET" as the search terms. All studies evaluating the accuracy of (18)F-FDG PET in the staging of endometrial carcinoma were included. Statistical pooling of diagnostic accuracy indices was done using random-effects model. Cochrane Q test and I(2) index were used for heterogeneity evaluation. RESULTS: Sixteen studies (807 patients in total) were included in the meta-analysis. Sensitivity and specificity for detection of the primary lesions were 81.8% (77.9%-85.3%) and 89.8% (79.2%-96.2%); for lymph node staging were 72.3% (63.8%-79.8%) and 92.9% (90.6%-94.8%); and for distant metastasis detection were 95.7% (85.5%-99.5%) and 95.4% (92.7%-97.3%). CONCLUSIONS: Because of low sensitivity, diagnostic utility of (18)F-FDG PET imaging is limited in primary tumor detection and lymph node staging of endometrial cancer patients. However, high specificities ensure high positive predictive values in these 2 indications. Diagnostic performance of (18)F-FDG PET imaging is much better in detection of distant metastases. Larger studies with better design are needed to draw any more definite conclusion.

Sentinel node mapping in anal canal cancer: systematic review and meta-analysis.

BACKGROUND & AIMS: The pathological condition of inguinal lymph nodes is an independent prognostic factor in predicting tumor recurrence and overall survival in anal canal cancer. Sentinel node mapping is a non-invasive method for the detection of inguinal lymph node involvement in anal cancer. In the current study, we conducted a comprehensive search of literature in this regard and then interpreted the final results in a systematic review and meta-analysis format. METHODS: Medline, SCOPUS, and ISI Web of Knowledge were searched with the following search terms: (anal OR anus) AND sentinel. Outcomes of interest were inguinal detection rate and inguinal recurrence in patients receiving inguinal sparing radiotherapy due to pathologically negative inguinal sentinel nodes (false negative cases). RESULTS: Overall 16 studies (323 patients) were included in the meta-analysis. Pooled inguinal detection rate was 86.2%: 73.4-93.4%: for studies using both blue dye and radiotracer it was 90.1% [78.7-95.8] and for studies using radiotracer alone it was 72.4% [46.3-88.9]. Pooled sensitivity was 90% [79-97%]. CONCLUSIONS: Sentinel node biopsy is a promising method for inguinal lymph node staging in anal cancer. Combined blue dye and radiotracer technique can maximize the inguinal detection rate. Location of the tumor is highly associated with the detection of inguinal sentinel nodes. Despite fairly high pooled sensitivity, no definite conclusion can be made regarding false negative rate of this technique due to low sample size and sub-optimal quality of the included studies. Large multicenter studies with long and consistent follow up are needed to definitely validate this technique in the future.

Pattern and distribution of bone metastases in common malignant tumors.

BACKGROUND: Bone scan is a sensitive but not specific method for evaluation of bone metastases. However, the clinical data and the pattern of bone scan findings help the physician to narrow the diagnostic differentials. We tried to investigate the distribution of bone metastases in common cancers using bone scintigraphy. MATERIAL AND METHODS: 160 consecutive patients with malignancy (prostate cancer: 32, breast cancer: 107, lung cancer:8, and gastrointestinal cancers: 13) underwent bone scan. RESULTS: From the 160 patients, 58 patients (36.3%) had abnormal bone scans attributable to metastatic tumor. Bone metastases were found in 32.7%, 40.6%, 38.5% and 62.5% of patients with breast, prostate, GI and lung cancers, respectively (P = 0.35). The most frequently involved area was the spine, followed by ribs and pelvic bones. Spine was the most frequent site of bone metastases in breast and GI cancers. Except for the spine, common locations of bone metastases from breast cancer were ribs and sternum. In prostate cancer, the most frequent site were spine and pelvis, with similar incidences. In lung cancer, ribs followed by spine were most frequent sites of bone metastases. 97 (60.6%) of the cancer patients studied had symptoms of bone pain. The highest incidence was associated with metastatic lesions in bone scan (P = 0.004). Significant correlation between location of bone pain and evidence of bone metastasis in the same region was noticed in the pelvis (P =0.001), skull (P = 0.04), sternum (P = 0.01), spine (P = 0.003) and femur (P < 0.001). CONCLUSIONS: Our results indicate that the spine and pelvis in prostate carcinoma and the spine, ribs and sternum in breast carcinoma as well as ribs and spine in lung cancer are most frequently invaded. Bone pain in the skull, sternum, lumbar vertebrae, pelvis and proximal portion of femurs are more important to keep in mind for metastatic bone involvement.

Diagnostic performance of fluorine-18-fluorodeoxyglucose positron emission tomography in patients with Merkel cell carcinoma: a systematic review and meta-analysis.

BACKGROUND: Some studies reported the usefulness of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) in patients with Merkel cell carcinoma (MCC). OBJECTIVE: The aim of this study was to systematically review and meta-analyze published data about the diagnostic performance of 18F-FDG PET and PET/CT in patients with MCC. METHODS: A comprehensive literature search of studies published through June 2013 regarding 18F-FDG PET and PET/CT in patients with MCC was performed. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR−) and diagnostic odds ratio (DOR) of 18F-FDG PET or PET/CT in patients with MCC on a per examination-based analysis were calculated. The area under the summary receiver operating characteristic (ROC) curve was calculated to measure the accuracy of 18F-FDG PET or PET/CT in these patients. RESULTS: Ten studies comprising 329 patients (549 scans) with MCC were included in the qualitative analysis (systematic review) and discussed. The quantitative analysis (meta-analysis) of six selected studies (including 92 patients with MCC) provided the following results on a per examination-based analysis: sensitivity was 90 % (95 % CI 80­96), specificity 98 % (95 % CI 90­100), LR+ 12 (95 % CI 4.3­33.0), LR− 0.15 (95 % CI 0.08­0.28), and DOR 86.8 (95 % CI 23­327). The area under the summary ROC curve was 0.96. No significant statistical heterogeneity between the studies was found. CONCLUSIONS: In patients with MCC, 18F-FDG PET or PET/CT demonstrated high sensitivity and specificity, being accurate methods in this setting. Nevertheless, the literature focusing on the use of PET and PET/CT in MCC still remains limited. Prospective studies are needed to substantiate the high diagnostic accuracy of these methods in MCC.

Effect of radiotracer injection volume on the success of sentinel node biopsy in early-stage breast cancer patients.

OBJECTIVE: The volume of radiotracer to be injected for sentinel node mapping is a controversial issue in breast cancer patients. In the current study, we evaluated the effect of radiotracer injection volume on the success rate of sentinel node mapping in early-stage breast cancer patients. MATERIALS AND METHODS: A total of 383 patients with early-stage breast cancer (cN0) were included in the study. The patients received an intradermal injection of Tc-antimony sulfide colloid for sentinel node mapping. The volume of injection was 0.1 ml for 102 patients, 0.2 ml for 221 patients, 0.5 ml for 30 patients, and 1 ml for 30 patients. The detection rate of the sentinel nodes during surgery was compared between the different injection volume groups. RESULTS: The overall detection rate was 93.9%. Detection rates were 95.1, 95, 90, and 86.7% for 0.1, 0.2, 0.5, and 1 ml volumes, respectively, which did not show a statistically significant difference despite minimal decrease in detection at higher volumes (P=0.214). The time of sentinel node visualization was not statistically different between the studied groups either (P=0.65). CONCLUSION: Increasing the volume of radiotracer in intradermal injections does not have a statistically significant effect on the sentinel node detection rate (despite minimal decrease in detection at higher volumes), nor on the time of sentinel node visualization. A low volume (0.1 ml) of radiotracer for intradermal injections can be as successful as higher volumes for sentinel node mapping with the added benefit of reduced pain from injections.

Accuracy of hepatobiliary scintigraphy for differentiation of neonatal hepatitis from biliary atresia: systematic review and meta-analysis of the literature.

Hepatobiliary scintigraphy is an important diagnostic modality for work-up of neonatal cholestasis. Therefore, our objective was to evaluate the literature regarding the accuracy of hepatobiliary scintigraphy in differentiating biliary atresia from non-biliary atresia causes of cholestasis (collectively called neonatal hepatitis). Our search included Medline, SCOPUS and Google Scholar. Only studies using Tc-99 m-labeled immunodiacetic acid (IDA) derivatives were included. Overall, 81 studies were included in the meta-analysis. Pooled sensitivity and specificity were 98.7% (range 98.1-99.2%) and 70.4% (range 68.5-72.2%), respectively. Factors that increased specificity included the use of radiotracers with high hepatic extraction, administration of hepatic-inducing drugs (such as phenobarbital), use of a calculated dose/kg and administration of a booster dose in cases of non-excretion of the tracer in the bowel. SPECT imaging and duodenal fluid sampling also had high specificity; however, they need further validation because of the low number of studies. Semiquantitative imaging methods do not seem to have any incremental value. We conclude that hepatobiliary scintigraphy using IDA derivatives can be very useful for diagnostic work-up of neonatal cholestasis. To improve the specificity, several measures can be followed regarding type and dose of the radiotracer and imaging protocols. Non-imaging methods seem to be promising and warrant further validation.