18F-FDG PET/CT in evaluation of squamous cell carcinoma.

OBJECTIVE: Squamous cell carcinomas (SCC) are a number of different types of cancer that result from squamous cells. These cells form on the surface of the skin, on the lining of the respiratory and digestive tracts etc. To evaluate SCC and frequencies of their localizations based on the findings of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). SUBJECTS AND METHODS: This study included 343 consecutive patients with SCC who were sent for the 18F-FDG PET/CT. Inclusion criteria were: Pathohistologically verified SCC; absence of malignancy of any other localization, as well as absence of infection; and glycemia ≤11mmol/L. RESULTS: The pathological findings on 18F-FDG PET/CT were present in 86% of patients. There was statistically significant difference in the finding of 18F-FDG PET/CT in relation to gender (P>0.006). The disease was more often present in women. The most common localizations of disease were: lungs (70%), vagina/cervix (18%), gastrointestinal tract (18%), head and neck (5%). Highest maximum standardized uptake value (SUVmax) levels were seen in the lungs 11.78±8.38, vagina/cervix 11.21±8.10, and head and neck area 6.32±3.96. CONCLUSION: Fluorine-18-FDG PET/CT can be informative in evaluation of SCC. Disease is present usually in women, although it is the same pathohistological type of disease, different organs accumulate this radioactive contrast differently.

Muscular sarcoidosis in the eyes of 18 F-FDG PET/CT.

PURPOSE: The aim of this study was to determine the frequency, symptoms, activity and pattern of muscle sarcoidosis, correlation with laboratory parameters, and to assess its therapy response with 18 F-FDG PET/CT. METHODS: Study included 90 patients with biopsy confirmed sarcoidosis and symptoms/biochemical/imaging findings suggestive of active disease. The exclusion criteria were: presence of cancer or other diseases that resemble sarcoidosis on PET/CT (Wegener syndrome, tuberculosis, aspergillosis), and the glucose level being greater than 11 mmol/L. All patients were screened for muscle sarcoidosis with 18 F-FDG PET/CT examination. Follow-up examination was done 1 year after the baseline in order to evaluate therapy response. RESULTS: Disease was very rare and present in only 7/90 patients. Most of the patients had polysymptomatic disease, while muscle pain was less frequent, present only in one-third of the patients. The disease was usually present in the lower limbs, upper limbs, and skeletal striated muscles. The most common pattern of disease was nodular. Disease activity estimated with SUVmax was not in correlation with the ACE findings, creatine kinase, and aldolase levels (p > 0.05). Follow-up PET/CT revealed complete remission in one patient and partial remission in two. CONCLUSION: 18 F-FDG PET/CT can be useful in asymptomatic young patients with nodular pattern of disease, who have easily relapsing form of disease. It can help in further management of these patients and can affect prognosis of the disease, since most of the laboratory parameters in this entity are within normal limits.

18F-FDG PET/CT value in the detection of seminoma and correlation with CT and tumor marker levels - up to 8 years of follow-up.

OBJECTIVE: Positron emission tomography/computed tomography using fluorine-18 fluoro-deoxyglucose (18F-FDG PET/CT) is not routinely used for diagnosis of testicular carcinoma. Unlike CT which cannot confirm with certainty the nature of the lesions, especially in post-therapy setting, 18F-FDG PET/CT detects active disease by showing increased glucose metabolism within the lesions. AIM: Determination of 18F-FDG PET/CT usefulness in detection of seminoma, therapy response evaluation and comparison to CT findings and tumor marker levels. MATERIAL AND METHODS: Eighty-two men (age 39.8±10.1) after orchiectomy and histopathological confirmation of seminoma were included in this study. Indications for 18F-FDG PET/CT were initial staging, restaging after chemo/radiotherapy with positive/uncertain CT, suspected recurrence on CT, elevated tumor markers. All patients had clinical follow-up of up to 8 years (median 33.5) after the first 18F-FDG PET/CT examination. Degree of metabolic activity was analyzed visually and semi-quantitatively using maximum standardized uptake value(SUVmax). RESULTS: Fluorine-18-FDG PET/CT was true positive in 36 patients (43.9%) with average SUVmax of 7.9±4.8.Recurrence was mostly found in retroperitoneal lymph nodes and distant metastases in lungs, bones, liver. Six findings were false positive and 3 false negative. Sensitivity, specificity, accuracy of 18F-FDG PET/CT were 92.3%, 86.0%, 89.0% and of CT 60.8%, 66.6%, 63.4%. Pearson Chi-square test showed statistically significant difference between the results of 18F-FDG PET/CT and CT (P=0.016). Significant correlation was found between positive 18F-FDG PET/CT findings and levels of LDH (P=0.043), while non-significant between AFP, ß-hCG (P>0.05). CONCLUSION: Fluorine-18-FDG PET/CT was superior to CT in evaluation of therapy response, active disease in residual tissue and normal size lymph nodes, as well as when CT was negative and tumor markers were elevated. Elevated lactate dehydrogenase (LDH) contributes to positive 18F-FDG PET/CT findings.

Impact of hybrid molecular imaging in retroperitoneal fibrosis: a systematic review.

The aim of this article was to critically assess the usefulness of hybrid molecular imaging (FDG PET/CT and FDG PET/MR) procedures in the evaluation of inflammatory activity in retroperitoneal fibrosis (RPF). A systematic review of the literature was performed using PubMed without timeline restriction and using the following keywords: retroperitoneal fibrosis, disease activity, diagnostic techniques, PET/CT, PET/MR. We evaluated full text articles written in the English language. Case reports, review articles or editorials and articles not in the field of interest of this review were excluded. Nine articles comprising a total of 186 patients met the inclusion criteria and were included and described in this systematic review. The new hybrid molecular imaging methods give promising results in the evaluation of the activity of the disease, quantification and prediction of therapeutic response and in tailoring medical therapy in RPF. FDG PET/CT can be a valuable tool in detecting disease activity, particularly in asymptomatic patients with RPF with acute phase reactant increase. Hybrid imaging can predict therapy response outcome and the best time for stent removal. Although PET/MR has potential advantage in small lesions and has reduced radiation exposure in comparison to PET/CT, PET quantification parameters have potentially higher diagnostic value over MR parameters in the evaluation of RPF. Acute phase reactants alone may not be reliable for the management and follow-up assessment of the disease. Hybrid imaging in RFP could be more comfortable, more accurate, with less radiation burden than different separate imaging studies acquired at different points in time.

Renal output efficiency and normalized residual activity examined by technetium-99m-DTPA renography have by far greater specificity to diagnose obstructive disease as compared to other conventional parameters of the renogram. First such study of output efficiency.

OBJECTIVE: The aim of this study was to assess the diagnostic ability of renal output efficiency (OE), normalized residual activity (NORA) and conventional interpretation of the diethylene triamine pentaacetic acid (99mTc-DTPA) diuretic renogram (CIR) in diagnosing urine flow obstruction. SUBJECTS AND METHODS: Group A consisted of 73 obstructed kidneys and Group B of 80 kidneys with dilated upper urinary tract. Forty eight kidneys were examined as the control Group C. A 40min acquisition with 240 of 10sec images was applied. Furosemide was administered after 20min (F+20). Post-void image was acquired at 50min. Output efficiency was calculated at 20min (OE20) and 20min after furosemide test (OE40) and NORA at 20min (NORA20) and on the post-micturition acquisition (NORAPM). RESULTS: Both the above parameters (OE40 and NORAPM) had high sensitivity (92% and 97%), specificity (99% for both) and accuracy (95% and 98%) in differentiating between obstructed and dilated unobstructed kidneys. The test of NORAPM correctly reclassified 40 out of 41 indeterminate or false positive results of the conventional interpretations of renograms (CIR) as obstructed (12 cases) or dilated (28 cases). Cut-off values for obstruction were <80% and ≥0.23 for OE40 and NORAPM, respectively. Compared to CIR, both parameters showed better specificity, especially NORAPM. CONCLUSION: Factors of OE40 and especially NORAPM of the renogram by 99mTc-DTPA were able to diagnose urine outflow obstruction better than CIR. Specifically, these factors well differentiated obstruction from urinary tract dilatation.

Diuresis renography and ultrasonography in children with antenatally detected hydronephrosis can support diagnoses and suggest related surgery treatment.

OBJECTIVE: Prenatal ultrasound (US) screening detects the hydronephrosis (HN)-dilatation of fetal renal collecting system in 1%-5% of all pregnancies. In most children, HN is detected by prenatal US screening between 18-20 gestational week. Pelvi- ureteric junction (PUJ) stenosis is the most common etiological factor of prenatal HN and requires postnatal follow-up. Diuresis renography plays important role in the follow-up by complementing morphological information obtained by US with the data about differential renal function (DRF) and drainage. We studied the association between ultrasound parameters and results of diuresis renography in first diagnosed PUJ stenosis and the predictive factors of pyeloplasty in order to evaluate the usefulness of diuresis renography in these children postnatally. PATIENTS AND METHODS: Children with antenatally detected HN attributed to presumed PUJ stenosis were investigated with mercapto-acetyltriglycine (MAG3) diuresis renography. Parents gave informed consent for the procedure. The inclusion criteria were: age up to 4 years, diagnosis of prenatal HN determined by US during pregnancy based on the antero-posterior diameter (APD) of renal pyelon and at least one post-natal US which confirmed diagnosis. Exclusion criteria were: APD of pyelon <10mm, previous surgical treatment of HN, vesicoureteral reflux excluded by micturating cystourethrography, and patients having any anomaly of the contralateral kidney. Sixty two patients 43 boys, 19 girls, median age 16 months were selected. They were divided into three groups based on the size of pyelon, three groups based on the calyceal size and two groups according to thickness of parenchyma. Renography was performed for 24 minutes after the iv. application of 99mTc MAG3, 144 ten-sec images were applied. Furosemide was administered after 2 min. (F+2). Post-void static images were acquired at 60min. The non-commercial software developed by International Atomic Energy Agency was applied to process the studies. The criteria for pathological findings (poor or no drainage) were the renographic curve maintaining a plateau, Normalized Residual Activity (NORA) at 20. min.>1.62, Output efficiency (OE) at 20. min.<71%, postmicturating NORA >0.11. The DRF was considered normal within the range of 45%-55%. RESULTS: Good drainage had 74% of children, partial drainage 11%, and poor 15%. There was a clear association between the size of pyelon, calyces, parenchyma thickness and drainage. There was also a clear association between the calyceal size, parenchyma thickness and DRF. Differential renal function was <45% in 18% of children. A relation between the type of drainage and DRF was not determined. Thus, 66.7% of those with poor drainage had preserved DRF. Seven out of nine children with poor drainage underwent pyeloplasty. The threshold for pyeloplasty was the pyelon of 18mm and calyces of 10mm. The model of the multivariate logistic regression which included ultrasound parameters (APD of pyelon, calyces size and parenchymal thickness), drainage and DRF, which were significant predictors in univariate analysis, showed that only drainage was an independent predictor for the need of pyeloplasty. CONCLUSION: Antero-posterior diameter of the pyelon <15mm indicates a favorable course of congenital HN in most children. Pattern of drainage obtained by diuresis renography was the only independent predictor for the need of pyeloplasty.

The detection of endocarditis, post implantation grafts, arteritis and other related disorders by 18F-FDG PET/CT.

INTRODUCTION: Positron emission tomography with computed tomography (18F-FDG PET/CT) is a nuclear medicine diagnostic method which, unlike other technological modalities that asses anatomical features, detects increased glucose metabolism inside the cells, thus is very helpful in diagnosing cardiovascular infection and inflammation and also in therapy planning. AIM: Aim of this study was to assess the significance of 18F-FDG PET/CT in detection of an active disease in patients with infection and inflammation of cardiovascular system. MATERIAL AND METHODS: In this cohort retrospective study 73 cardiovascular patients (56.9±15.3 years; 33 male and 40 female) with persistent symptoms of inflammatory syndrome were referred to 18F-FDG PET/CT in order to evaluate active disease. Biochemical blood analyses (erytrocite sedimentation, CRP, leukocytic formula), CT, MRI, ultrasound were performed in all the patients. Out of 73 patients, 7 had a second 18F-FDG PET/CT examination (62.1±12.3 years; 6 men and 1 woman) with a previous pathological PET/CT finding after which the therapy was changed. The degree of metabolic activity was analyzed visually and quantitatively using the maximal standardized uptake value (SUVmax). 18F-FDG PET/CT findings were considered positive in case of higher focal glucose accumulation in projection of heart and diffuse uptake in blood vessels' wall than accumulation in surrounding tissue and liver. RESULTS: Vasculitis was diagnosed in 36 patients (49,3%), endocarditis in 23 (31,5%) and graft inflammation in 14 (19,2%). The results were compared to the gold standard, biopsy of the blood vessel and histopathological verification during surgical treatment, or clinical follow up. Forty nine patients with the sights of an increased FDG uptake were considered true positive (TP) (SUVmax5.7±2.9). In 21 patients 18F-FDG uptake was physiological and they were considered true negative (ТN). Two who used corticosteroid therapy which decreases inflammation, were false negative (FN), and only 1 false positive (FP) finding in the region of recent iatrogenic vein injury. Sensitivity of this method was 96.08±, specificity 95.45±, positive predictive value 98.0±, negative predictive value 91.3± and accuracy 95.89±. CONCLUSION: Our results indicate that 18F-FDG PET/CT could be useful diagnostic method for the detection of sights of metabolically active disease in patients with persistent symptoms of infection and inflammation of cardiovascular system, as well as in monitoring therapy response.

Diagnosis of Raynaud's phenomenon by 99mTc-pertechnetate hand perfusion scintigraphy: a pilot study.

We assess the usefulness of 99mTc-pertechnetate hand perfusion scintigraphy in patients with Raynaud's phenomenon (RP). The study population consisted of 18 patients with primary RP, 25 patients with secondary RP within systemic sclerosis (SSc), and ten healthy individuals. Gamma camera dynamic first-pass study during the first 60 s and a static scintigraphy after 5 min were recorded following a bolus injection of 99mTc-pertechnetate via a cubital vein. Regions of interest were drawn on the summed images around the fingers and the palmar region. The fingers-to-palm ratios were then calculated. The mean fingers-to-palm ratio for dynamic study (blood flow) was 0.58 ± 0.19 for the healthy group, 0.45 ± 0.18 for the primary RP, and 0.43 ± 0.21 for the SSc patients. The mean fingers-to-palm ratio for static study (blood pool) was 0.44 ± 0.06 for the healthy group, 0.42 ± 0.06 for the primary RP, and 0.36 ± 0.07 for the SSc patients. Analysis of variance showed these differences to be significant (p = 0.039 from blood flow and p = 0.004 from blood pool). The receiver operating characteristic curve showed sensitivity of 80% and a specificity of 60% when using cutoff values of 0.40 for blood flow and sensitivity of 79% and a specificity of 70% when using cutoff values of 0.37 for blood pool. Our method is able to differentiate between patients with normal and those with abnormal microcirculation of the hands. Dynamic study separates the healthy subjects from patients with RP, while static study separates primary from secondary RP.

Validation of numerical outputs of IAEA software by the analysis of diuretic nephrogram in children with antenatally detected hydronephrosis.

UNLABELLED: Diuretic nephrogram is important diagnostic tool in the postnatal follow-up of asymptomatic antenatally detected hydronephrosis (HN). In the last decades, two quantitative indices of renal excretion, output efficiency and the residual kidney counts normalized to the 1-2min counts (normalized residual activity, NORA) have been proposed, that enhance the accuracy of technique to detect kidneys with obstruction. Unfortunately, in many nuclear medicine departments in developing countries the obsolete computer systems do not give the opportunity of sophisticated analysis of nephrogram. Almost a decade ago, the Nuclear Medicine Section of the International Atomic Energy Agency (IAEA) has developed non-commercial software for nephrogram processing on a simple p-computer, which allows access to the developments in this field. However, till now, the software has not been widely implemented in the nuclear medicine institutions in developing countries. Furthermore, the accuracy of numerical outputs of the software has not been assessed in comparison with commercial software. The aims of this study in children were: a) to calculate, by means of the International Atomic Energy Agency (IAEA) software, the values of the technetium-99m mercapto-acetyl-triglycine ((99m)Tc MAG3) parameters in three categories of kidneys: normal kidneys, obstructed kidneys and hypotonic unobstructed kidneys and b) to assess the accuracy of the obtained numerical parameters by comparing with the values published by other authors. Investigation was carried out on a sample of 62 children: 43 boys and 19 girls (median age: 16 months) with antenatally detected HN attributed to pelviureteric junction (PUJ) stenosis. Neither of kidneys had undergone pyeloplasty prior to our investigation. 130 nephrogram curves were analyzed. 22-minutes acquisition with 132 10sec images was applied. Furosemide was administered after 2min (F+2). Post-void static image was acquired at 60min. Two observers analyzed each study and classified kidneys into three categories. Group 1: 84 kidneys contralateral to hydronephrotic kidney, without structural abnormality on previous diagnostics; Group 2: 30 hypotonic non-obstructed kidneys; Group 3: 16 obstructed kidneys. Parameters analyzed were: output efficiency (OE), residual kidney counts at 20min normalized to the 1-2min counts (NORA20) and residual kidney counts on post-micturition acquisition normalized to the 1-2min counts (NORAPM). Results were presented as mean±SD. For group 1 they were: OE: 95±1.5%; NORA20: 0.25±0.06; NORAPM: 0.02±0.007. Results for group 2 were: OE: 87±7.8%; NORA20: 0.57±0.19; NORAPM: 0.03±0.02. For group 3: OE: 56±9.6%; NORA20: 2.16±0.33; NORAPM: 0.27±0.13. Linear regression analysis showed significant inverse linear correlation between NORA20 and ROE20 (R=-0.982; y=99.6-21.1x) at 0.01 level. ROC analysis revealed cutoff values of predicting obstruction at 71%, 1.62 and 0.11 for OE, NORA20 and NORAPM, respectively. CONCLUSION: We have calculated in children by means of the IAEA software the values of three advanced parameters of the (99m)Tc MAG3 F+2 diuresis nephrogram for normal kidneys, hypotonic non-obstructed and obstructed kidneys. The overall results provided evidence of excellent agreement of obtained results with previously reported values of the quantitative parameters of renal washout. The parameters of IAEA software has been shown to be reliable in assessing kidney drainage. The nuclear medicine section of the IAEA should be encouraged to produce final version of the software and to release it through IAEA Web site.

The diagnostic performance and added value of (18)F-FDG PET/CT in the detection of liver metastases in recurrent colorectal carcinoma patients.

OBJECTIVE: The aim of this study was to assess the value of (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT in detection of liver metastases in patients with suspected recurrent colorectal carcinoma, as well as to compare diagnostic performance of (18)F-FDG PET/CT with conventional imaging methods (MDCT). SUBJECTS AND METHODS: This study included 73 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013, with suspicion of recurrence. The patients underwent (18)F-FDG PET/CT examination on a 64-slice hybrid PET/CT scanner (Biograph, TruePoint64, Siemens Medical Solutions, Inc. USA). Prior to (18)F-FDG PET/CT all patients underwent contrast-enhanced MDCT. Findings of (18)F-FDG PET/CT and MDCT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up over at least six months. Final diagnosis of liver metastases of colorectal cancer was made either by histopathological examination of specimen after biopsy or surgery, or based on clinical, laboratory and imaging evaluation during first six months after PET/CT scan. RESULTS: In detection of liver metastases (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 83.3%, 95.3%, 92.6%, 89.1% and 90.4%, respectively. In addition, MDCT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy in detection of liver metastases of 60%, 88.4%, 78.3%, 76% and 76.7%, respectively. There was significant difference in sensitivity (83.3% vs 60%; P=0.045) between these two methods. In addition, significant difference was observed in accuracy between PET/CT and MDCT (90.4% vs 76.7%; P=0.016). The higher specificity in visualization of liver metastases was also achieved by (18)F-FDG PET/CT compared to MDCT (95.3% vs 88.4%), but this difference was not significant (P=0.37). CONCLUSION: (18)F-FDG PET/CT was highly sensitive, specific and accurate method in detection of liver metastases in patients with suspected recurrent colorectal carcinoma in our study. This hybrid imaging showed superior diagnostic performance in evaluation of suspected colorectal cancer liver metastases compared to conventional imaging.

Can (18)F-FDG PET/CT scan change treatment planning and be prognostic in recurrent colorectal carcinoma? A prospective and follow-up study.

OBJECTIVE: To prospectively study whether in patients with resected primary colorectal cancer fluorine- 18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) examination could diagnose the stage, specify treatment procedure and be prognostic. SUBJECTS AND METHODS: This prospective study included 75 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013. Findings of (18)F-FDG PET/CT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up. Patients were followed after PET/CT examination for a mean follow-up time of 16.7±5.9 months. RESULTS: In the detection of recurrent disease (18)F-FDG PET/CT showed overall sensitivity, specificity, PPV, NPV and accuracy of 96.6%, 82.4%, 94.9%, 87.5% and 93.3%, respectively. In the detection of stages I and II sensitivity, specificity and accuracy of (18)F-FDG PET/CT were: 88%, 96.6% and 94.7%, respectively, and in the detection of stages III and IV sensitivity, specificity and accuracy were 94.9%, 87.5% and 93.3%, respectively. These findings prevented or changed intended surgical treatment in 12/32 cases. Univariate and multivariate Cox proportional regression analyses revealed that metastatic recurrence (stages III and IV) was the only and independent prognostic factor of disease progression during follow-up (P=0.012 and P=0.023, respectively). Although, survival seemed better in patients with local recurrence compared to metastatic recurrent disease, this difference did not reach significance (Log-rank test; P=0.324). In addition, progression-free survival time was significantly longer in patients in whom (18)F-FDG PET/CT scan led to treatment changes (Log-rank test; P=0.037). CONCLUSION: (18)F-FDG PET/CT was sensitive and accurate for the detection and staging of local and metastatic recurrent colorectal carcinoma, with higher specificity in the detection of local recurrences. The (18)F-FDG PET/CT scan induced treatment changes in 30/75 patients, including 12/32 patients in which surgical treatment was previously planned, and progression free survival time was significantly longer in these patients.

Clinical value of immunoscintigraphy in the rectal carcinomas: immunoscintigraphy of rectal carcinomas.

BACKGROUND/AIM: The aim of this study was to evaluate the clinical reliability of the immunoscintigraphy with radiolabeled monoclonal antibodies for the detection of metastases and recurrences of rectal carcinomas. METHODOLOGY: A total of 65 patients underwent immunoscintigraphy with radiolabeled monoclonal antibodies. Indication for that examination was suspicious rectal cancer or suspicious rectal cancer recurrence and/or metastases. RESULTS: The method proved to have 92.7% sensitivity, specificity 83.3%, positive predictive value 90.5%, negative predictive value 87.0% and accuracy 89.2%. There was a statistically significant relationship between immunoscintigraphy findings and rectoscopy findings (rs=0.415, p=0.013), as well as significant relationship between immunoscintigraphy findings and US findings (rs=0.332, p=0.001). Tumor marker levels were in positive correlation with findings of immunoscintigraphy (rs=0.845, p=0.001), especially raised CEA level (rs=0.816, p=0.004). Patients with higher CA19-9 level had higher Duke's stage (p=0.025). CONCLUSIONS: We can conclude that immunoscintigraphy can be helpful in the detection of metastases and recurrences of colon carcinomas.

Prediction of Cervical Lymph Node Metastasis in Clinically Node-Negative T1 and T2 Papillary Thyroid Carcinoma Using Supervised Machine Learning Approach.

Papillary thyroid carcinoma (PTC) is generally considered an indolent cancer. However, patients with cervical lymph node metastasis (LNM) have a higher risk of local recurrence. This study evaluated and compared four machine learning (ML)-based classifiers to predict the presence of cervical LNM in clinically node-negative (cN0) T1 and T2 PTC patients. The algorithm was developed using clinicopathological data from 288 patients who underwent total thyroidectomy and prophylactic central neck dissection, with sentinel lymph node biopsy performed to identify lateral LNM. The final ML classifier was selected based on the highest specificity and the lowest degree of overfitting while maintaining a sensitivity of 95%. Among the models evaluated, the k-Nearest Neighbor (k-NN) classifier was found to be the best fit, with an area under the receiver operating characteristic curve of 0.72, and sensitivity, specificity, positive and negative predictive values, F1 and F2 scores of 98%, 27%, 56%, 93%, 72%, and 85%, respectively. A web application based on a sensitivity-optimized kNN classifier was also created to predict the potential of cervical LNM, allowing users to explore and potentially build upon the model. These findings suggest that ML can improve the prediction of LNM in cN0 T1 and T2 PTC patients, thereby aiding in individual treatment planning.

Gallbladder motility disorders estimated by non-invasive methods.

BACKGROUND/AIMS: The aim is to compare the radionuclide (DC) and ultrasonographic (US) method in the assessment of gallbladder (GB) motility. METHODOLOGY: The study was performed in 15 controls (C), 10 patients with acute cholecystitis (AC), 20 patients with chronic acalculous cholecystitis (CAC), 26 patients with chronic cholecystitis with calculosis (CCC) as well as in 15 patients with GB dyskinesia (D). GB emptying period (EP), ejection fraction (EF) and ejection rate (ER) were estimated with dynamic cholescintigraphy (DC) and US. RESULTS: The DC and US finding in the patients with AC was typical in all the patients, i.e. GB was not visualized at all on DC, while on US, stone was visible in the cystic duct. There were significant differences (p<0.05) between the EF and ER values obtained between C and the three groups of patients CAC, CCC and D, using both methods. However, there were no significant differences in EF, EP and ER values among CAC, CCC and D (p>0.05). There was also high correlation between the results obtained with both methods in all the groups of patients studied. CONCLUSIONS: The results obtained by both methods are valuable for the assessment of GB motility. Although there are no significant differences and there is a high correlation between the values, radionuclide method is more precise, because it can register motility continuously.

Dopamine transporter imaging (123)I-FP-CIT (DaTSCAN) SPET in differential diagnosis of dopa-responsive dystonia and young-onset Parkinson's disease.

Dopa-responsive dystonia (DRD) is a genetic disorder characterized by childhood onset dystonia, dominant inheritance, diurnal symptoms fluctuation and positive levodopa response. Adult-onset DRD is frequently combined with parkinsonism and can be mistaken with young onset Parkinson's disease (YOPD). Both conditions are caused by dopamine deficiency, due to nigral cells' loss in YOPD, and due to enzymatic defects in dopamine synthesis in DRD. Single photon emission tomography (SPET) with (123)I-N--fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) nortropane ((123)I-FP-CIT)-DaTSCAN is a sensitive neuroimaging method for the assessment of nigrostriatal dopaminergic system integrity and degeneration. Our aim was to evaluate the usefulness of (123)I-FP-CIT( DaTSCAN) SPET in the differential diagnosis of DRD and YOPD in clinical practice. Brain SPET with (123)I-FP-CIT was performed in 13 patients (7 males, 6 females), age 20-58 years, with mean age of onset of their disease, 29 years, eleven patients with early onset parkinsonian symptoms and 2 with genetically proved DRD. The images were evaluated by visual and semiquantitative analyses (ROI). The ratio of specific-striatal to non specific-occipital binding was calculated. Ten out of 11 patients with YOPD had decreased accumulation of DaTSCAN in striatum, especially in putamen, that is typical findings for Parkinson's disease. In three patients DaTSCAN was normal with symmetric tracer uptake in both striata, caudate nucleus and putamen and the diagnosis of DRD was suspected. Two patients with initial dystonic symptoms and genetically proved DRD had normal DaTSCAN. In one patient after normal DaTSCAN findings the initial diagnosis of YOPD was changed to the diagnosis of DRD. Region of interest (ROI) analyses have shown significantly lower(123)I-FP-CIT binding ratios in YOPD than in DRD in all 3 regions of interest: striatum (1.95±0.32) vs (2.76±0.10) P<0.001, putamen (1.76±0.25) vs (2.84±0.14) P<0.0001 and caudate nucleus (2.37±0.51) vs (3.27±0.14) P<0.01. In conclusion, our results indicate that DaTSCAN is an objective neuroimaging method able to distinguisch neurodegenerative disease YOPD from DRD and clarify a clinical dilemma, which is important for the treatment, prognosis and genetic counseling of patients and their families.

FDG PET-CT as an important diagnostic tool and prognostic marker in suspected recurrent cervical carcinoma after radiotherapy: comparison with MRI.

BACKGROUND: Recurrent disease in post-irradiation patients with cervical cancer is often difficult to delineate on magnetic resonance imaging (MRI), because posttreatment changes can have a similar appearance, and further evaluation is often required. The aims of the study were to evaluate positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (FDG PET-CT) diagnostic role in suspected recurrent cervical cancer after radiotherapy, compare it to MRI, and assess their prognostic impact in these patients. PATIENTS AND METHODS: This cohort retrospective study included patients previously treated with radiotherapy for carcinoma of uterine cervix with suspected recurrence, who had undergone MRI of abdomen and pelvis, and were subsequently evaluated on FDG PET-CT, with minimum follow-up period of 12 months. RESULTS: In the total of 84 patients included in analysis, MRI vs. FDG PET-CT showed sensitivity, specificity and accuracy of 80.1%, 52.4% and 66.7%, vs. 97.6%, 61.9% and 79.8%, respectively. Patients with positive findings on MRI (Log Rank, p = 0.003) and PET-CT (Log Rank, p < 0.001) had shorter progression-free survival (PFS) than those with negative results. In univariate Cox regression models, MRI and FDG PET-CT results were found to be related to PFS (p = 0.005 and p < 0.001, respectively). However, multivariate analysis proved only FDG PET-CT to be independent prognostic factor, where patients with positive FDG PET-CT results had almost nine times higher risk of progression (p < 0.001). CONCLUSION: FDG PET-CT represents useful diagnostic tool in suspected recurrent cervical cancer after radiotherapy, showing high sensitivity in its detection. In addition, it is an independent factor in predicting progression-free survival in these patients.

Diagnosis of mesh infection after abdominal wall hernia surgery - role of radionuclide methods.

BACKGROUND/AIMS: The aim of this investigation was to evaluate the role of detection of late mesh infection following incisional hernia repair with radiolabeled antigranulocyte antibodies. METHODOLOGY: Mesh infection diagnoses were set up with clinical examination and laboratory analysis and confirmed by ultrasonography (US), computerized tomography (CT), scintigraphy with 99mTc-antigranulocyte antibodies and microbiological examination. RESULTS: Of the 17 patients investigated, 6 had a late mesh infection, and 11 had both mesh infection and recurrent incisional hernia. Clear clinical signs of late mesh infection were present in 13 patients. Four remaining patients had non-specific discomfort and recurrent incisional hernia without clinical manifestation of mesh infection ('silent infection'). US was positive in 12/17 patients, CT in 13/17 patients, while scintigraphy with antigranulocyte antibodies in 17/17 patients. Therefore, sensitivity of US was 71%, of CT 76% and of scintigraphy 100%. In four patients late mesh infection was confirmed exclusively by 99mTc-antigranulocyte antibody scintigraphy, while US and CT did not indicate the infection. CONCLUSIONS: According to the present results, scintigraphy with 99mTc antigranulocyte antibodies is a useful method for the detection of 'silent' abdominal wall infections after surgery, which is very important for prompt and appropriate therapy.

Radioimmunoscintigraphy of colorectal carcinomas with 99mTc-labelled antibodies.

BACKGROUND/AIMS: The aim of the study was the evaluation of the clinical validity of immunoscintigraphy with 99mTc labeled antibodies for the detection of metastases and recurrences of colorectal carcinomas. METHODOLOGY: We examined 17 patients with colorectal carcinomas. Scintigraphy was performed with anti-CEA MoAb 99mTc-BW 431/26. RESULTS: Recurrences of carcinomas were detected and confirmed by surgery in 6 patients, recurrences with liver metastasis in 5 patients, and only liver metastases in 3 patients. Planar immunoscintigraphy was positive in 5/8 patients with liver metastases and 8/11 patients with recurrences, whereas in 1/8 liver metastases and 3/11 recurrences were detected only by tomography. In two patients with metastases in the abdominal lymph nodes immunoscintigraphic findings both on planar scintigraphy and tomoscintigraphy were false negative. CONCLUSIONS: Immunoscintigraphy with 99mTc labeled antibodies can be useful in the diagnosis of recurrences and metastases of colorectal carcinoma, viability assessment after radiotherapy and in the choice of the adequate surgical treatment.

Diagnostic significance of magnetic resonance imaging in preoperative evaluation of patients with laryngeal tumors.

To evaluate the diagnostic accuracy of pretreatment surgical magnetic resonance images (MRI) in the assessment of patients with laryngeal tumors. The prospective study included 34 patients (mean age 62.2 ± 5.1 years) with suspected tumors of the larynx who underwent laryngeal endoscopy, followed by MRI. The MRI images were evaluated for the invasion of anterior commissure, subglottis, paraglottic and preepiglotic space, cartilage invasion, extension to extralaryngeal tissue and lymph nodes, and were compared to pathological examination of surgical specimen. In 15 patients (44%) the tumor was glottic, in 10 patients (29%) supraglottic, in 9 (27%) patients tumor was transglottic. No statistical difference was seen in the number of patients with positive MRI findings in comparison to postsurgical pathohistology for extension to subglottic subside (29 vs. 38%), growth to the anterior commissure (48 vs. 48%), preepiglottic space (33 vs. 29%), and cartilage infiltration (19 vs. 14%), respectively. However, infiltration of the paraglottic spaces was observed more frequently on MRI (71 vs. 47%), p < 0.05. According to MR findings, 4 (12%) patients were classified as T2, 26 (76%) patients as T3 and 4 (12%) patients as T4, while on pathohystological specimens after surgery, 12 patients were classified as T2 (35%), 18 as T3 (53%), and 4 as T4 (12%). Based on MRI, 76% of the patients were correctly classified, which was shown to be statistically significant (ρ = 0.56, <0.05). Fifteen patients had metastases in regional lymph nodes and only two were detected on MRI. MRI has been shown to be a method that contributes to presurgical assessment of patients with tumor of the larynx.