Ozlem Kucuk

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.

Radioiodine whole-body scans, thyroglobulin levels, 99mTc-MIBI scans and computed tomography : results in patients with lung metastases from differentiated thyroid cancer

ObjectivesThe correlation between a 131I whole-body scan (WBS), a 99mTc sestamibi (99mTc-MIBI) WBS, a computed tomography (CT) scan and the value of routine follow-up for 131I WBS and thyroglobulin (Tg) levels in patients with lung metastases from differentiated thyroid cancer was assessed. MethodPulmonary metastases were detected in 32 patients out of 583 with differentiated thyroid cancer (DTC) who were admitted to our clinic between 1985 and 2004 (age range, 22–79 years; mean, 58±19 years; 15 women and 17 men). Pulmonary metastases were diagnosed by considering the 131I WBS, increased Tg levels and/or other positive radiological findings. Papillary carcinoma was diagnosed in 15/32 patients and follicular carcinoma in 13/32. A mixed type found in 4/32 patients was classified histopathologically. A total of 3.7–53.65 GBq (100–1450 mCi) 131I was given to each patient. The duration of follow-up ranged from 36 to 240 months. A 131I WBS, the determination of Tg levels and/or a CT scan were carried out in the assessment of a diagnosis and follow-up of patients with lung metastases. A 99mTc-MIBI WBS was performed on 19 patients who were chosen at random from the 583. ResultsNineteen of 32 patients had lung metastases before they received the first 131I treatment. Six of the 32 had distant-organ metastases other than in the lungs. Four of these six patients had only lung and bone metastases. Pulmonary metastases were observed on the 131I WBS patients 31/32 (96.8%) whereas no pulmonary metastases, were detected on the CT scans in 3/32 patients. The last diagnostic whole-body scan (DWBS) was normal in 13/32 patients. At the first examination, the Tg levels in 27/32 (84.4%) patients were below 30 ng · ml−1. At the final examination, 20/32 (62.5%) patients had Tg levels higher than 30 ng · ml−1, while Tg levels were lower than 30 ng · ml−1 in 12/32 patients. Tg levels decreased in 21/32 and increased in 3/32 patients. The 131I WBS continued to be abnormal in 2/3 patients with increased Tg levels but became normal in one patient whose CT scan still showed macro-nodular lesions. Tg levels did not change significantly in 8/32 patients. The 131I WBS became normal in 5/8 patients, while the CT scans for 4/5 showed micro-nodules. Metastases were detected in 12/19 patients who underwent 99mTc-MIBI whole-body scanning: 18/19 showed metastases on the 131I WBSs and 17/19 on the CT scans. Of the seven patients without a sign of metastasis on the 99mTc-MIBI WBS, one was negative in terms of metastasis on the 131I WBS and one on the CT scan. Fibrosis was observed on the CT scans of 2/32 patients. One patient developed dedifferentiation, as determined by the negative 131I WBS and positive CT scan. Conclusion131I whole-body scanning and the determination of Tg levels are the most important procedures for the evaluation of lung metastases in differentiated thyroid cancer. Computed tomography is a useful addition to 131I whole-body scanning. MIBI imaging alone may not be enough to detect lung metastases from differentiated thyroid cancer.

The role of 18F–NaF PET/CT in metastatic bone disease

Aim To investigate the role of 18F–NaF PET/CT and compare it with 99m Tc-MDP whole body bone scintigraphy and 18F-FDG PET/CT in detecting the extent of metastatic bone disease and to present our first experience with 18F–NaF PET/CT in our country. Materials and methods A total of 37 histopathologically proven cancer patients (22 male, 15 female) with bone metastasis detected on Tc-99m MDP whole body bone scan were prospectively enrolled Cebeci, following ethics committee approval. 18F–NaF PET/CT was performed to the participants in Ankara University Medical Faculty Nuclear Medicine Department for evaluation of symptomatic skeletal sites which were negative on Tc-99m MDP whole body bone scan. A lesion based comparison was made between 18F–NaF PET/CT and Tc-99m MDP whole body bone scan for each patient and between 18F–NaF PET/CT and 18F-FDG PET/CT in 12/37 patients. Results The number of lesions demonstrated by 99m Tc-MDP bone scan and 18F–NaF PET/CT was equal in 4/37 (%11) of the cases. 18F–NaF PET/CT showed a greater number of pathological foci in 89% of participants. 18F–NaF PET/CT was able to show both lytic and blastic lesions and small lesions were better visualized due to the advantage of sectional imaging with much better resolution and higher target/background ratio. 18F–NaF PET/CT demonstrated a greater number of metastases in 10/12 (83%) of the patients when compared to 18F-FDG PET/CT. In the other two patients, bone metastasis could be demonstrated only by 18F–NaF PET/CT. The uptake of 18F-FDG was variable in blastic lesions and cranial bone involvement was missed by 18F-FDG PET/CT in some cases due to physiological brain metabolism. Conclusion Although further prospective clinical studies in specific cancer populations are indicated to set the place of 18F–NaF PET/CT in diagnostic scheme, the results of this pilot study from our country support the superiority of 18F–NaF PET/CT in investigation of bone metastasis over 99mTc-MDP bone scan and 18F-FDG PET/CT in various malignancies. 18F–NaF PET/CT is coming forward as a single step bone seeking study, considering all the advantages, but especially potential of detecting occult metastases and reliably directing patient management.

Regional cerebral blood flow in children with ADHD: changes with age

The aim of this study was to investigate the changes in regional cerebral blood flow (rCBF) with age in patients with attention deficit hyperactivity disorder (ADHD). Twenty-nine drug-naive ADHD subjects (24 boys, 5 girls; age 7-13; mean+/-SD=age 9.2+/-2.1) and 12 subjects with epilepsy (all diagnosed as having complex partial seizure, 6 boys, 6 girls; age 7-14; mean+/-SD=8.5+/-2.1) were included in the study. All cases of ADHD were diagnosed according to DSM-IV criteria. Cerebral blood flow was evaluated with Tc-99m-hexamethylpropyleneamine oxime (Tc99m HMPAO) brain single photon emission tomography (SPECT) during standard resting condition in all of the cases. Asymmetry indices for each region of interest were calculated. Absolute rCBF values were normalized as the absolute rCBF values divided by the whole brain absolute value. The prefrontal lobe asymmetry indices were significantly negatively correlated with age in ADHD cases (r=-0.408, P=0.025), which indicated the increased prefrontal rCBF lateralization from the right to the left side with age. When ADHD cases older than 7 years of age were compared with those with epilepsy, the ADHD cases had lower right prefrontal and frontal rCBF and higher left parietal rCBF. The epilepsy group showed no significant correlations between age and asymmetry indices and showed a different developmental trajectory for prefrontal asymmetry and right prefrontal rCBF values. The results indicated that the left hemisphere dominance in the prefrontal cortex significantly increases with age in ADHD cases.

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.

Impact of ¹⁸F-FDG PET/CT for detecting recurrence of medullary thyroid carcinoma.

ObjectiveThe aim of this study was to evaluate the value of fluorine-18 (18F) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the detection of recurrent medullary thyroid carcinoma (MTC) in patients with elevated calcitonin levels. MethodsThirty-three patients (nine men, 24 women; mean age: 50.3±12 years) who were referred to undergo 18F-FDG PET/CT for restaging of MTC in patients with high calcitonin levels were included in this study. Five patients also had suspected lymph nodes detected by neck ultrasonography. The results of 18F-FDG PET/CT and clinical follow-up data were reviewed retrospectively. Histological analysis has been accepted as the gold standard in the confirmation of 18F-FDG PET/CT results. Patients were followed up for 45.6±4.2 months. ResultsThere were 14 negative and 19 positive scans for possible recurrence of MTC. In the positive scans, the possible recurrence sites were neck lymph nodes, thyroid bed, mediastinal lymph nodes, and the lung in 14, two, two, and one patient, respectively. Disease recurrence in 13 patients was confirmed histologically by surgical excision or fine-needle aspiration biopsy. In the remaining six patients, recurrence was excluded as it was reactive as a result of pathological examination. However, one patient had a negative scan, underwent neck lymph node excision after 18F-FDG PET/CT examination, and lymph node recurrence was detected histologically. According to these results, the sensitivity and specificity of PET/CT were calculated as 93 and 68%, respectively. According to the recommended calcitonin level by the American Thyroid Association (calcitonin levels higher than 150 pg/ml), sensitivity was calculated as 90%. Although the mean maximum standardized uptake values of the true-positive and false-positive groups were calculated as 4.72±2.17 and 4.22±1.02, respectively, the difference between the two groups was not statistically significant (P>0.05). ConclusionPET/CT is a sensitive imaging tool in the detection of MTC recurrence, especially in patients with high calcitonin levels, and it gives additional information in one third of all patients on an average by detecting an occult disease or confirming findings of other imaging tools.