Cigdem Soydal

The role of 18f-fdg Pet/ct in detecting colorectal cancer recurrence in patients with elevated Cea levels

IntroductionIn this study we aimed to define the success of fluorine-18 (18F) fluorodeoxyglucose (FDG) PET/computed tomography (PET/CT) in detecting recurrent disease in our patient group with colorectal cancer (CRC) and elevated carcinoembryonic antigen (CEA) levels. Material and methodPatients who had a previous diagnosis of CRC were searched retrospectively in our PET center database. Seventy-six 18F-FDG PET/CT studies between October 2006 and December 2010 of 69 patients (25 women, 44 men; mean age: 61.61±4.1 years) with elevated CEA levels were evaluated. 18F-FDG PET/CT findings and concurrent abdominopelvic contrast-enhanced computed tomography (ceCT) findings were compared with histopathological findings and/or clinical follow-up data as the ‘gold standard’. ResultsIn the patient-based analysis, the sensitivity and specificity of 18F-FDG PET/CT in the detection of disease recurrence were calculated as 97 and 61%, respectively. A statistically significant difference was found in frequencies of positive and negative 18F-FDG PET/CT findings between patients with or without recurrent disease by gold standard (P<0.05). There was no correlation between patients’ serum CEA levels and lesions’ maximum standardized uptake values (P=0.85). The sensitivity and specificity of ceCT were computed as 51 and 60%, respectively. In the evaluation of separate patient groups, although the sensitivity and specificity of 18F-FDG PET/CT were calculated as 100 and 60% in the group whose CEA level elevation was less than two-fold (5–9.9 ng/ml), these were 100 and 75% in the group with CEA elevation less than three-fold (10–14.9 ng/ml) and 95 and 62% in the group with elevation more than three-fold (≥15 ng/ml). The sensitivity and specificity of 18F-FDG PET/CT were computed as 98 and 85% in the lesion-based evaluation. The sensitivity and specificity of ceCT were 73 and 86%, respectively. Conclusion18F-FDG PET/CT is a safe imaging method that can be used in the determination of CRC recurrence in patients with elevated CEA levels, regardless of the CEA level.

The additive clinical value of 18F-FDG PET/CT in defining the recurrence of disease in patients with differentiated thyroid cancer who have isolated increased antithyroglobulin antibody levels.

Aim The aim of this study was to investigate the additive clinical value of 18F-FDG PET/CT in defining the recurrence of disease in patients with differentiated thyroid cancer (DTC) who have isolated increased antithyroglobulin antibody (TgAb) levels with undetectable thyroglobulin (Tg) levels and negative 131I whole-body scintigraphy (wbs). Materials and Methods Clinical follow-up data of 231 patients with DTC who underwent 18F-FDG PET/CT between June 2006 and March 2011 were evaluated retrospectively. There were a total of 48 patients who underwent 18F-FDG PET/CT for isolated increased serum TgAb levels. When 17 patients who have lymphocytic thyroiditis were excluded, the remaining 31 patients [27 women and 4 men; mean (SD) age, 50.29 (15.2) y] were included in this study. The inclusion criteria were undetectable serum Tg and increased TgAb levels under the condition of thyroid-stimulating hormone greater than 30 IU/mL with negative 131I wbs and absence of pathologic findings in neck ultrasound and thoracic CT if performed. Findings from the 18F-FDG PET/CT were compared with the clinical follow-up data and the results of histopathologic examinations. Results Results of 18F-FDG PET/CT were negative in 15 and positive in 16 patients. Sixteen FDG-positive sites (15 lymph nodes and 1 bone) were seen in 16 patients who had positive findings in 18F-FDG PET/CT. In the comparison with 18F-FDG PET/CT findings and clinical follow-up data and histopathologic examination results, 4, 12, 2, and 13 patients were false-positive, true-positive, false-negative and true-negative retrospectively. In the receiver operating characteristic analysis, a 5.4 cutoff SUVmax value was calculated with 82% sensitivity and 81% specificity in distinguishing malignant and benign lesions. As a result, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG PET/CT in the detection of recurrent disease were calculated as 75%, 76%, 75%, 86%, and 80%, respectively. Conclusions Isolated increased TgAb levels might be a predictor of the recurrent DTC and 18F-FDG PET/CT might be an additive imaging method in detecting the recurrent disease in patients with DTC who have increased TgAb levels with undetectable Tg levels and negative 131I wbs.

Radioembolization with yttrium-90 resin microspheres for neuroendocrine tumor liver metastases

PURPOSE We aimed to evaluate the effectiveness and safety of radioembolization with yttrium-90 (90Y) microspheres in cases with unresectable neuroendocrine tumor liver metastases (NETLMs). METHODS Thirty patients (mean age, 55 years) underwent resin-based 90Y radioembolization for unresectable NETLM at a single institution between April 2008 and June 2013. Post-treatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST). Prognostic variables that affected survival were determined. RESULTS The mean follow-up was 23.0±19.4 months and the median overall survival was 39 months (95% CI, 12.6-65.4 months), with one- and two-year survival rates of 71% and 45%, respectively. Imaging follow-up using RECIST at three-month intervals demonstrated partial response in 43%, complete remission in 3%, stable disease in 37%, and progressive disease in 17% of patients. Extent of tumor involvement was found to have a statistically significant influence on overall survival (P = 0.03). The existence of extrahepatic disease at the time of radioembolization, radiographic response, age, and primary neuroendocrine tumor site were not significant prognostic factors. CONCLUSION The current study demonstrates the effectiveness and safety of radioembolization for the treatment of unresectable NETLMs. We identified that the extent of tumor involvement has a significant effect on overall survival. The use of imaging methods reflecting metabolic activity or cellularity such as scintigraphy or diffusion-weighted MRI would be more appropriate, for the response evaluation of liver metastases after radioembolization.

The role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the primary staging of rectal cancer

BackgroundIn this study we aimed to determine the need for 18F-flourodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the preoperative staging of rectal carcinoma in our large patient group according to level and location of tumor.MethodTotally, 97 patients diagnosed with primary rectal adenocarcinoma between May 2009 and July 2011 were included in the study. Preoperative staging was performed by evaluating contrast-enhanced thoracic, abdominal, and pelvic computed tomographies. After staging by conventional methods, all patients underwent an 18F-FDG PET/CT. In all cases, the relationship between 18F-FDG uptake and gender, tumor height at the anal canal, localization in the rectal wall, plasma carcinoembryonic antigen levels, histopathological tumor type, and tumor stage were examined.ResultsWhile the ceCT was normal in 4 (4%) patients, it was positive for the rectum in 93 (95%), pelvic lymph nodes in 22 (22%), and distant metastases in 14 (14%) (liver (8), lung (8), bone (2), distant lymph nodes (6), and uterus (1)). Using computed tomography, disease stages were determined as stage 0, 1, 2, 3, and 4 in 4, 8, 48, 23, and 14 patients, respectively; 18F-FDG PET/CT was normal in two (2%) patients. The mean SUVmax of FDG-positive rectal tumors was calculated as 17.31 ± 9.37. Additionally, 18F-FDG uptake was seen in pelvic lymph nodes in 15 (15%) patients and in distant organs in 24 (24%) patients (liver (9), lung (12), bone (5), distant lymph nodes (11), uterus (1), and sigmoid colon (1)). According to an 18F-FDG PET/CT, 2, 7, 47, 20, and 21 patients were staged as stage 0, 1, 2, 3, and 4, respectively. In 14 patients (14.4%), the stage of the disease was either changed, and there was a need to make adjustments to the patient’s treatment strategy (n = 10), or the type of operation was changed (n = 4). In seven patients (0.7%), findings from 18F-FDG PET/CT images did not require any changes of the treatment plan.ConclusionF-FDG PET/CT provides new findings in addition to conventional techniques in the staging of primary rectal cancer. These findings could change the patients’ treatment strategies.

The role of 18F-FDG-PET/CT in the preoperative staging and posttherapy follow up of gastriccancer:Comparison with spiral CT

BackgroundThe aim of this study was to investigate the role of F-18 fluoro-deoxy-glucose (FDG) positron emission tomography and computed tomography (PET/CT) in the preoperative and posttherapy restaging of gastric cancer and to compare with spiral computerized tomography (CT).MethodA total of 42 PET/CT scans of 36 gastric cancer patients (28M, 8F; mean age: 56,0 ± 15) were included in the study. A retrospective analysis of the PET/CT results of the patients were compared with concurrent CT results. Confirmation was made by clinical course and serial imaging studies in the follow up. The compatibility ratios were calculated and the accuracy of the PET/CT was assessed. Agreement between PET/CT and concurrent CT was calculated using kappa statistics.ResultsPatients were separated into 3 groups: the patients who were referred to our clinic for preoperative staging (4 patients), for posttherapy evaluation (24 patients) and for the suspicion of local recurrence and/or metastasis exploration after a disease free period (8 patients). Groups 1 and 3 included a small number of patients so they were omitted from the statistical analysis. Focusing on Goup 2, the overall concordance rate was 50% (12 patients). Region based analysis showed the rates of concordance for local recurrence, local lymph node metastasis and distant metastasis were 91% (Kappa: 0.70), 95% (Kappa:0.86) and 50% (Kappa:0.26) respectively. Distant metastases were also investigated in detail and the two techniques showed a concordance of 91% (Kappa: 0.75) for liver, 79%(Kappa:0.31) for distant lymph node, 79% (0.42) for lung, 87%(Kappa:0.33) for bone and 95% for intestinal wall metastasis.ConclusionPET/CT is a complementary imaging method which can be successfully used in both preoperative and posttherapy evaluation of gastric cancer.

The prognostic value of quantitative parameters of 18f-fdg Pet/ct in the evaluation of response to internal radiation therapy with yttrium-90 in patients with liver metastases of colorectal cancer

IntroductionThe aim of this study was to evaluate tumor response using fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients who received yttrium-90 selective internal radiation therapy (SIRT) for colorectal liver metastases. The initial and sixth-week tumor lesion glycolysis values were calculated to evaluate the success of the treatment and compare it with patient survival. Materials and methodsThirty-five patients (15 female, 20 male, mean age: 61.9±9.0 years, range: 33–76 years) who received SIRT treatment for unresectable colorectal cancer liver metastases in our hospital between June 2008 and May 2011 were included in the study. All patients included in the study had liver-only or liver-dominant disease. The treatment response was evaluated by 18F-FDG PET/CT in the sixth week after treatment. Response was evaluated according to the change in total lesion glycolysis (&Dgr;TLG). The &Dgr;TLG was calculated using the following formula: &Dgr;TLG=100×[standardized uptake value (SUV)mean1×total functional tumor volumes (FTVs)1−SUVmean2×FTV2]/SUVmean1×FTV1. ResultsMean FTV1 and FTV2 values were calculated to be 235.7±203 and 107.3±67 mm3, respectively (P=0.04). The mean &Dgr;TLG was 43±35 (range: 0–100). Mean overall survival time was 12.7±8.0 months (range: 3–31 months). The cutoff value of &Dgr;TLG was calculated to be 26.5 using receiver operating characteristic analysis (sensitivity 64%; specificity 85%; AUC=0.717±0.087, P=0.034). Patients were allocated into those having values greater than the cutoff value (group 1) and those having values lower than the cutoff value (group 2) in order to calculate the effect of &Dgr;TLG on survival. Survival was 11.32±1.18 (95% CI 9.02–13.62) months in group 2 and 20.76±2.71 (95% CI 15.46–26.06) months in group 1 (P=0.016). &Dgr;TLG was found to be a significant factor in univariate analysis (P=0.01). ConclusionAn 18F-FDG PET/CT scan with calculation of &Dgr;SUVmax, &Dgr;FTV, and &Dgr;TLG before and at the sixth week after SIRT may play an important role in evaluating early tumor response and survival expectancy in these patients and help decide whether these patients should be referred to other treatment modalities or to follow-up.

The Role of 18F-FDG PET/CT in the Primary Staging of Gastric Cancer.

Objective: The aim of this study is to explore the role of 18F-FDG PET/CT in the primary staging of gastric cancer in the comparison of ceCT as routine staging method and evaluate influencing parameters of 18F-FDG uptake. Methods: Thirty-one patients (mean age: 58.9±12.6) who underwent 18F-FDG PET/CT for primary staging of gastric cancer between June 2011 and June 2012 were included to the study. 18F-FDG PET/CT findings were compared with pathological reports in patients who underwent surgery following PET/CT. 18F-FDG PET/CT findings of primary lesions, lymph nodes and adjacent organs were compared with ceCT findings and pathological reports. Since 6 patients were accepted as inoperable according to 18F-FDG PET/CT and/or ceCT and/or laparotomy and/or laparoscopy findings, pathological confirmation could not be possible. Results: In the postoperative TNM staging of patients, while 1 (4%), 1 (4%), 4 (16%), 2 (8%), 12 (48%) and 5 (20%) patients were staged as T0, Tis, T1, T2, T3 and T4, respectively, 8 (32%), 6 (24%), 6 (24%) and 5 (20%) patients were N0, N1, N2 and N3 respectively. 18F-FDG PET/CT was totally normal in 2 patients. While primary tumors were FDG avid in 27 patients, in 17 and 6 patients FDG uptake was observed in perigastric lymph nodes and distant organs, respectively. Mean SUVmax of FDG avid tumors was calculated as 13.49±9.29 (3.00-44.60). However, SUVmax of lymph nodes was computed as 9.28±6.92 (2.80-29.10). According to sub-analysis of histopathological subtypes of primary tumors, SUVmax of adenocarsinomas was calculated as 15.16 (3.00-44.60), of signet ring cells as 9.90 (5.50-17.70), of adenocarcinomas with signet ring cell component as 11.27 (6.20-13.90) (p=0.721). In the comparison with histopathological examination while ceCT was TP, TN, FN in 23, 1 and 1 patients, 18F-FDG PET/CT was TP, FP, FN in 20, 1 and 4 patients, respectively. Sensitivity, specificity, accuracy, PPD and NPV of ceCT in the detection of lymph node metastasis was calculated as 83.3%, 75%, 80%, 87.5% and 66.6%, respectively. These parameters for 18F-FDG PET/CT were 64.7%, 100%, 76%, 100% and 57.1%. Conclusion: Despite lower sensitivity than ceCT, diagnostic power of 18F-FDG PET/CT in the preoperative staging of gastric cancer is acceptable. Because of its high PPV, it might be beneficial in the evaluation of patients with suspected lymph nodes. The role of 18F-FDG PET/CT seems to be limited in the early stage and signet ring cell carcinomas due to lower 18F-FDG uptake.

Comparison of survival, safety, and efficacy after transarterial chemoembolization and radioembolization of Barcelona Clinic Liver Cancer stage B-C hepatocellular cancer patients.

AimThis study aimed to compare the overall survival (OS) times, long-term complications, and recurrence rates of chemoembolization and radioembolization for Barcelona Clinic Liver Cancer (BCLC) stage B-C hepatocellular cancer patients. Materials and methodsThis retrospective study included 80 BCLC stage B-C hepatocellular cancer patients who received chemoembolization (group 1) or radioembolization (group 2). The OS times, long-term complications, and disease recurrence rates of the two groups were compared. The prognostic role of sex, age, presence of underlying chronic liver disease, BCLC stage, dimension and number of liver lesions, tumor load, and presence of extrahepatic disease were also analyzed for each group. ResultsEach group included 40 (67 men, 13 women, mean age: 41.9±21.9 years) patients. During the follow-up period, 22 patients died in group 2 and 30 patients died in group 1. The overall mean survival of the entire patient group was calculated to be 37.31±3.94 months [95% confidence interval (CI), 30.46–44.1 months], with 30.63±3.68 months (95% CI, 23.42–37.84 months) for group 1 and 39.24±4.62 months (95% CI, 30.18–48.29 months) for group 2 (P=0.014). The 1- and 2-year survival rates were 72 versus 74% and 47 versus 59% for groups 2 and 1, respectively. There was no significant difference between the chronic complication (P=0.32) and disease recurrence (P=0.65) rates of the groups. Whereas the dimension of the largest lesion was the most significant predictor (P=0.01) in group 2, female sex (P=0.008), dimension of the largest lesion (P=0.03), and BCLC stage (P=0.01) were significant in group 1. ConclusionAlthough chemoembolization and radioembolization for BCLC Stage B-C patients have similar levels of safety and efficacy, they differ in OS. In this retrospective study, patients undergoing radioembolization had a longer survival rate.

Prognostic importance of 18F-FDG uptake pattern of hepatocellular cancer patients who received SIRT.

Purpose The aim of the study was to evaluate the effect of 18F-FDG uptake pattern of liver lesions to treatment response of patients who received yttrium-90 (Y-90) selective internal radiation therapy (SIRT) for hepatocellular cancer (HCC). Patients and Methods Nineteen patients (5F, 14M, mean age: 64.5 ± 14.7 years old, range: 57–73 years) who received SIRT treatment in our department for HCC between June 2008 and May 2011 were included in the study. All patients underwent 18F-FDG PET/CT before SIRT for evaluation of disease stage and metabolic activity of liver lesions. Patients were divided into 3 groups according to FDG uptake patterns of primary liver lesions (hypoactive, nonhomogenous, and focal intense). Progression-free survival (PFS) times of each group and patients with hepatic only and hepatic with extrahepatic disease were analyzed. Disease progression criteria were increase in tumor volume, progressive elevation of serum alpha-fetoprotein levels, and detection of extrahepatic metastases. Kaplan-Meier analysis was used for comparison of PFS times. Results The mean treatment dose was calculated as 1.4 ± 1.0 GBq. While liver lesions of 4 patients were hypoactive in pretreatment 18F-FDG PET/CT, liver lesions of 6 and 9 patients had nonhomogenous and intense FDG uptake, respectively. Mean PFS time of patients who had hypoactive liver lesions was 5.25 ± 1.52 months. In patients who had liver lesions with nonhomogenous uptake, mean PFS time was 12.3 ± 2.6 months. Lastly, in patients with intense uptake in liver lesions, PFS time was calculated as 19.8 ± 5.0 months. Difference between each group was statistically significant (P = 0.017). There was no significant difference in the PFS of the patients with limited hepatic disease and patients with extrahepatic involvement. Conclusion In patients with unresectable HCC, higher SUVmax lesions unexpectedly had better PFS rates after SIRT, suggesting SIRT has a treatment advantage over other therapeutic options in these patients.

Serum carcinoembryonic antigen measurement, abdominal contrast-enhanced computed tomography, and fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of colorectal cancer recurrence: a correlative study.

IntroductionThe aim of this study was to evaluate the correlative role of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in carcinoembryonic antigen (CEA) measurement and contrast-enhanced abdominal computed tomography (ceCT) in the detection of colorectal cancer (CRC) recurrence. Materials and methodsA total of 96 patients (40 female, 56 male; mean age, 60.6±12 years) with a previous diagnosis of CRC underwent 18F-FDG PET/CT on suspicion of recurrence and were evaluated retrospectively. Inclusion criteria were accepted as the presence of increased serum CEA levels or positive findings on abdominal ceCT or both. 18F-FDG PET/CT findings were compared with histopathological findings and/or clinical follow-up data as the gold standard. Patients were divided into three groups: group 1, with increased CEA levels and normal abdominal ceCT; group 2, with normal CEA levels and positive ceCT; and group 3, with increased CEA levels and positive ceCT. ResultsWhereas sensitivities of CEA, ceCT, and 18F-FDG PET/CT in the three patient groups were calculated as 91, 67, and 96%, specificities were 13, 51, and 62%, respectively. There were 35, 14, and 46 patients in groups 1, 2, and 3, respectively. In separate analyses conducted on the groups, sensitivity of 18F-FDG PET/CT was computed as 100 and 100% and specificity as 88 and 80% for groups 1 and 2. In group 3, which comprised four patients with secondary malignancies, sensitivity and specificity of 18F-FDG PET/CT were 94 and 16%, respectively. Conclusion18F-FDG PET/CT has an additional role in the detection of CRC recurrence with a higher sensitivity compared with CEA and ceCT alone, and 18F-FDG PET/CT is especially more successful in patients with isolated elevated CEA levels or positive ceCT findings without accompanying CEA elevation.