Evrim Sürer Budak

Evaluation of factors affecting tumor response and survival in patients with primary and metastatic liver cancer treated with microspheres.

Objective Radioembolization with the yttrium-90 (Y-90) microspheres is being used increasingly more often in the treatment of patients with primary or metastatic liver cancer. Although technetium-99m macroaggregated albumin (Tc-99m MAA) scintigraphy performed following diagnostic angiography has an important role in predicting the effectiveness of treatment and in dose estimation, the number of studies using quantitative assessment of Tc-99m MAA scintigraphy is limited in this field. In the present study, the aim was to assess whether a tumor dose is required to obtain objective tumor response and to check whether this threshold value is predictive in terms of tumor response, survival, and liver toxicity by using Tc-99m MAA single-photon emission computed tomography (SPECT) images. Materials and methods Overall, 54 patients (20 women and 34 men; median age: 60 years) who underwent Y-90 Resin (SIR-Spheres) and Glass (TheraSphere) microsphere treatment with a diagnosis of unresectable liver cancer between August 2010 and April 2013 were included in the study. The mean doses to normal liver and tumor were estimated for each patient using Tc-99m MAA SPECT images and the medical internal radiation dosimetry method. The responses were assessed according to Response Evaluation Criteria In Solid Tumors (RECIST) and European Organisation for Research and Treatment of Cancer (EORTC) criteria. Kaplan–Meier survival curves and univariate Cox regression analysis were used in survival analysis. The relationship between treatment response and other parameters included was assessed using logistic regression analysis. The variables with a P value less than 0.01 in univariate analysis were assessed with multivariate analysis. Results Fifty-four Y-90 microsphere treatments (eight by using a Y-90 glass microsphere and 46 by using a Y-90 resin microsphere) were performed. In the multivariate analysis, the only parameter related to response was tumor dose (P<0.01). With a tumor dose of 280 Gy or higher, objective tumor response was observed in 59 and 77% of the patients according to RECIST and EORTC criteria, respectively, and the tumor control rate was found to be 95% according to both criteria. In addition, it was found that only tumor dose was correlated with progression-free survival (PFS) (P<0.001) and overall survival (OS) (P=0.018). When the tumor dose was 280 Gy or higher, median PFS increased from 2 to 10.7 months (P<0.001), whereas median OS increased from 9 to 17.6 months (P=0.018). However, reversible ≥G2 liver toxicity was observed in 3.7% (2/54) of the patients within 3 months after radioembolization with a median normal liver dose of 40 Gy (10–102 Gy). There was reversible ≥G3 liver toxicity in 3.7% (2/54) of patients, but no G4 liver toxicity was observed. Clinical radiation hepatitis and treatment-induced liver failure were not observed in any of these patients. Conclusion Tc-99m MAA SPECT has a predictive value in terms of response to radioembolization, PFS, and OS. Dosimetry based on Tc-99m MAA SPECT images can be used in the selection of patients and, in particular, to adaptation of treatment plan in selected patients.

Measurements of tumor size using CT and PET compared to histopathological size in non-small cell lung cancer

PURPOSE In this study, we aimed to compare the tumor sizes determined by maximum morphological computed tomography (CT) and functional positron emission tomography (PET) with the histopathological size to determine which method provides the best correlation with the histopathological size in lung carcinoma patients. MATERIALS AND METHODS Forty lung carcinoma patients (39 males, one female) diagnosed histopathologically from surgical resection materials were included in this retrospective study. The mean age (±standard deviation, SD) of the patients was 67.8±10.3 years with a range of 44 to 81 years. The PET scans were performed within the same week as the CT scan. In the CT scans, the morphological tumor sizes were measured three-dimensionally by the longest transaxial section in the parenchymal and mediastinal screening window. The functional tumor sizes were also measured three-dimensionally in the PET scans. These two measurement values were compared with the histopathological size using Bland-Altman plotting. Bland-Altman plotting was also performed to define the 95% limits of agreement, which was presented as the bias ±1.96 SD. RESULTS The histopathological sizes were measured in a range of 1.2 to 7.5 cm. The maximum measurement of the tumors on the CT scans showed a lower concordance (mean difference, -0.30) than that obtained from PET, and the SD was found to be larger than the PET (1.96 SD was 3.50 for CT and 2.50 for PET). CONCLUSION The PET measurements of tumor size were more compatible with the histopathological sizes than the CT measurements in patients with non-small cell lung cancer.

Incidental Detection of a Benign Thymoma on Tc-99m MIBI Myocardial Perfusion Study

Technetium-99m methoxy-isobutylisonitrile (Tc-99m MIBI) is a routinely used radiopharmaceutical for myocardial perfusion scintigraphy (MPS). It is also a tumor seeking agent. Here, we present a case of 51 year old male who underwent Tc-99m MIBI myocardial perfusion study due to permanent chest pain after coronary angiography. Abnormal MIBI uptake in the thorax was detected in the raw images. This single finding led to further investigation and thoracotomy proved that the lesion was benign thymoma. Thymomas are often asymptomatic or have a non-specific presentation. They are often detected coincidentally on images performed for any other reasons. We wanted to emphasize that during of MPS, the raw data should always be reviewed as occasionally valuable additional information on noncardiac pathology could be recognized by extracardiac uptake, as in this case. Conflict of interest:None declared.

Clinical value of cystatin C and beta-trace protein in glomerular filtration rate in renal transplant cases with stable renal graft functions: comparison by the 99mTc-DTPA plasma sample method.

AimThe aim of this study was to investigate the value of cystatin C and beta-trace protein (BTP) levels in determination of the glomerular filtration rate (GFR) by accepting the technetium-99m diethylenetriamine pentaacetic acid (99mTc-DTPA) method as the gold standard for GFR measurement in renal transplant patients with stable renal functions and to investigate the value of cystatin C and BTP levels in the determination of GFR in cases with or without renal tubular injury. MethodsA total of 89 (60 men and 29 women) renal transplant patients aged 19–67 years (mean 38.15 years) with stable graft functions were included in the study. GFR was calculated using three different methods: (a) the 99mTc-DTPA two plasma sample method; (b) eight different formulas containing cystatin C; and (c) three different formulas containing BTP. In addition, the cases were divided into two groups on the basis of N-acetyl-&bgr;-D-glucosaminidase and &bgr;2 microglobulin levels showing tubular damage. ResultsGFR values obtained with cystatin C had a better correlation with the gold standard method compared with those obtained with BTP, and the GFR value obtained with cystatin C had the most reliable consistency. We found that cystatin C provided more accurate results in GFR follow-up in renal transplant patients with no tubular injury compared with those with tubular injury. ConclusionCystatin C is a good marker of GFR in renal transplant patients, especially in those with no tubular injury; however, BTP is not as good as cystatin C in that regard.

Correlation of Minimum Apparent Diffusion Coefficient and Maximum Standardized Uptake Value of the Primary Tumor with Clinicopathologic Characteristics in Endometrial Cancer

Objective: To explore the correlation of the primary tumor’s maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin) with clinicopathologic features, and to determine their predictive power in endometrial cancer (EC). Methods: A total of 45 patients who had undergone staging surgery after a preoperative evaluation with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) were included in a prospective case-series study with planned data collection. Multiple linear regression analysis was used to determine the correlations between the study variables. Results: The mean ADCmin and SUVmax values were determined as 0.72±0.22 and 16.54±8.73, respectively. A univariate analysis identified age, myometrial invasion (MI) and lymphovascular space involvement (LVSI) as the potential factors associated with ADCmin while it identified age, stage, tumor size, MI, LVSI and number of metastatic lymph nodes as the potential variables correlated to SUVmax. In multivariate analysis, on the other hand, MI was the only significant variable that correlated with ADCmin (p=0.007) and SUVmax (p=0.024). Deep MI was best predicted by an ADCmin cutoff value of ≤0.77 [93.7% sensitivity, 48.2% specificity, and 93.0% negative predictive value (NPV)] and SUVmax cutoff value of >20.5 (62.5% sensitivity, 86.2% specificity, and 81.0% NPV); however, the two diagnostic tests were not significantly different (p=0.266). Conclusion: Among clinicopathologic features, only MI was independently correlated with SUVmax and ADCmin. However, the routine use of 18F-FDG PET/CT or DW-MRI cannot be recommended at the moment due to less than ideal predictive performances of both parameters.

Efficacy of 18F-2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computerized Tomography for Bone Marrow Infiltration Assessment in the Initial Staging of Lymphoma

Objective: Currently 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computerized tomography (PET/CT) is being successfully used for staging and follow-up of Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL). Various studies have demonstrated that PET/CT effectively detects bone marrow involvement (BMI) and is concordant with bone marrow biopsy (BMB) findings, thus it is deemed as a complementary method. This study was aimed to evaluate 18F-FDG-PET/CT efficiency for detection of BMI in HL and NHL. Methods: The study included 172 lymphoma cases who were admitted to Akdeniz University Medical School Department of Nuclear Medicine for initial staging with PET/CT. Visual and semiquantitative assessments were performed for PET/CT scan findings of the cases. The maximum standard uptake (SUVmax) value was the quantitative parameter used for 18F-FDG-PET scan. In visual assessment, bone marrow metabolic activity that is greater than the liver was considered as pathologic. For semiquantitative assessment, regions of interest were drawn for SUVmax estimation, which included iliac crest in cases with diffusely increased metabolic activity and the highest activity area in cases with focal involvement. BMB was considered as the reference test. Results: On visual assessment of all the cases, PET/CT was found to yield 31% sensitivity and 85% specificity rate for detection of BMI. On visual assessment of HL cases, sensitivity rate was determined as 80%, and specificity as 78%, while in NHL cases the corresponding values were 24% and 90%, respectively. On semiquantitative assessment of HL cases, considering SUVmax≥4, sensitivity was found as 80% and specificity as 68%. In NHL patients, considering SUVmax≥3.2, sensitivity rate was detected as 65% and specificity as 58%. Conclusion: In this study, a moderately high concordance was observed between PET/CT and BMB findings. PET/CT appears to be a significant method for detecting BMI. Although PET/CT is not a substitute for BMB, we suggest it can be used as a guide to biopsy site and a complementary imaging technique for BMB.

Two Uncommon Sites of Metastasis: Breast and Hypophysis Metastases of Head and Neck Adenoid Cystic Carcinoma Detected by FDG PET/CT

Adenoid cystic carcinoma (ACC) is a rare epithelial malignancy arising from secretory glands, particularly the salivary glands. It tends to invade nerves and has a high potential for distant hematogenous metastasis, especially to the lungs, bone, liver and brain. The breast and hypophysis are not common sites of ACC metastatic disease. Herein, we report a case of ACC of the head and neck region with two unusual sites of metastases, the hypophysis and breast.

Comparison of Cystatin C and β-Trace Protein Versus 99mTc-DTPA Plasma Sampling in Determining Glomerular Filtration Rate in Chronic Renal Disease.

Glomerular filtration rate (GFR) is the best indicator of renal function. The gold standard for GFR measurement is inulin clearance. However, its measurement is inconvenient, time-consuming, and costly. Thus, in both scientific studies and routine clinical practice nuclear medicine methods (99mTc-diethylenetriaminepentaacetic acid [99mTc-DTPA] and 51Cr-ethylenediaminetetraacetic acid [51Cr-EDTA]) are preferred, and they correlate strongly with inulin clearance. In addition, cystatin C and β-trace protein have also recently been used for this purpose. In the literature, however, data are limited about the clinical value of cystatin C and β-trace protein in GFR measurement in chronic renal disease (CRD), and the results have been inconclusive. In this study, we aimed to determine the efficiency of cystatin C and β-trace protein in the determination of GFR in CRD patients. Methods: Eighty-four patients with CRD were included in the study (59 men and 25 women; age range, 21–88 y; mean age, 61 y). GFR was calculated using the gold-standard 99mTc-DTPA 2-sample plasma sampling method (TPSM) and 2 alternative methods: a formula using cystatin C and a formula using β-trace protein. The correlation between TPSM and the cystatin C and β-trace protein methods was assessed, and Bland–Altman analysis was used to graph scatterplots of the differences at a confidence interval of 95% (mean difference ± 1.96 SDs). Results: GFRs calculated using both alternative methods correlated strongly with those calculated using the gold standard. However, the correlation was stronger for the cystatin C method than for the β-trace protein method, and neither method produced reliably consistent GFRs. Conclusion: This study demonstrated that cystatin C and β-trace protein do not reflect GFR with sufficient accuracy.

Left Vocal Cord Paralysis Detected by PET/CT in a Case of Lung Cancer

We report a patient with lung cancer. The first PET/CT imaging revealed hypermetabolic mass in the left aortopulmonary region and hypermetabolic nodule in the anterior segment of the upper lobe of the left lung. After completing chemotherapy and radiotherapy against the primary mass in the left lung, the patient underwent a second PET/CT examination for evaluation of treatment response. This test demonstrated, compared with the first PET/CT, an increase in the size and metabolic activity of the primary mass in the left lung in addition to multiple, pathologic-sized, hypermetabolic metastatic lymph nodes as well as multiple metastatic sclerotic areas in bones. These findings were interpreted as progressive disease. In addition, an asymmetrical FDG uptake was noticed at the level of right vocal cord. During follow-up, a laryngoscopy was performed, which demonstrated left vocal cord paralysis with no apparent mass. Thus, we attributed the paralytic appearance of the left vocal cord to infiltration of the left recurrent laryngeal nerve by the primary mass located in the apical region of the left lung. In conclusion, the knowledge of this pitfall is important to avoid false-positive PET results.