Gülin Vural

Prognostic significance of FDG PET/CT on the follow-up of patients of differentiated thyroid carcinoma with negative 131I whole-body scan and elevated thyroglobulin levels: correlation with clinical and histopathologic characteristics and long-term follow-up data.

Aims This study aimed (a) to determine the clinical and histopathologic factors that are related to FDG avidity in the recurrence/metastases of patients with differentiated thyroid carcinoma (DTC) who present with elevated thyroglobulin (Tg) levels and negative 131I whole-body scans (WBSs), (b) to clarify Tg cutoff levels in this setting, and (c) to evaluate the impact of PET/CT on patient management strategies and hence to critically look into the importance of PET/CT in combination with Tg in clinical decision making. Methods A total of 105 patients with DTC with negative 131I WBS and neck ultrasound but elevated Tg, who underwent FDG PET/CT for the suspicion of recurrent/metastatic disease, were included in this analysis. All patients had previously undergone total thyroidectomy and radioiodine ablation/therapy. PET/CT results were correlated with Tg levels and clinical and histopathologic characteristics of the primary tumor compared with the follow-up data. Results PET/CT was true-positive in 69 patients (of which 23 had surgically amenable disease), true-negative in 20, false-positive in 6 patients and false-negative in 10 patients. Extrathyroidal spread was an independent risk factor related to FDG-avid recurrence. Tumor size was significantly higher in PET-positive patients than others, 2.25 (1.8) versus 1.5 (1.1) cm, P = 0.02. Significant correlation was observed between PET positivity and high Tg levels (P = 0.0001). Receiver operating characteristic curve analysis demonstrated a Tg cutoff of 1.9 ng/mL under thyroid-stimulating hormone suppression, 38.2 ng/mL with thyroid-stimulating hormone stimulation. Among PET-negative patients, no recurrence was detected in patients with undetectable/suppressible Tg in on-therapy state. Conclusions PET positivity correlated with extrathyroidal spread, and elevated Tg in recurrent/metastatic DTC. FDG PET/CT in combination with Tg levels was crucial in defining management strategies in patients with DTC with negative 131I WBS. A negative FDG PET/CT scan predicts a favorable prognosis and lack of recurrence on follow-up in patients with “suppressible Tg” levels in the on-therapy state despite significant elevation of Tg in the off-therapy state.

Evaluation of malignant and benign lung lesions with 99Tcm-tetrofosmin.

Summary99Tcm-tetrofosmin planar imaging was performed in 30 patients with malignant and benign lung lesions. There were 21 cases of primary lung cancer (10 squamous cell, 5 small cell, 4 adenocarcinoma and 2 large cell) and 9 benign lung lesions (4 pneumonia, 3 tuberculosis, 1 infected bronchiectasis and 1 bronchiolitis obliterans). Anterior and posterior planar thorax images were obtained 30 min after the intravenous injection of 740 MBq (20 mCi) of 99Tcm-tetrofosmin. Visual and quantitative evaluations were performed. For the quantitative evaluation, regions of interest were drawn over the lesioned area (L) and over the contralateral non-lesioned area (N). Of 21 malignant primary lesions, 19 (90%) showed 99Tcm-tetrofosmin accumulation. Four (44%) of the nine benign lung lesions (3 cases of pneumonia and the one case of active tuberculosis) showed uptake. The mean L/N ratios for the malignant and benign lesions were 1.63 ± 0.29 and 1.64 ± 0.19, respectively. There were no significant differences (P > 0.05) in the L/N ratios of the malignant and benign lesions or the various histological types of cancer. In conclusion, 99Tcm-tetrofosmin was highly sensitive (90%) in detecting malignant lung lesions, but it had poor specificity (55%).

TL-201 scintigraphy, mammography and ultrasonography in the evaluation of palpable and nonpalpable breast lesions: a correlative study☆

PURPOSE To determine the feasibility of Tl-201 as a tumor localizing agent in palpable and nonpalpable breast lesions, in comparison with mammography and ultrasonography (US), and to evaluate the contribution of these modalities to each other in obviating biopsy. MATERIALS AND METHODS Seventy-two palpable and nonpalpable breast lesions were prospectively classified as benign, indeterminate, or malignant according to the sonographic and mammographic criteria and were further analyzed with Tl-201 scanning. These classifications were compared with biopsy results. The sensitivity, specificity, accuracy, false positive and false negative rates (FPR, FNR), negative and positive predictive values (npv, ppv) were calculated for each individual modality and combination of modalities to evaluate the contribution of these three techniques to each other. RESULTS Of 72 lesions 52 were histologically malignant and 20 were benign. Overall, mammography was the most sensitive (92%) and Tl-201 was the most specific (75%) of the three modalities. Mammography + Tl combination was the most specific (90%) and accurate (97%) of dual combinations. In mammographically or sonographically indeterminate cases, Tl-201 was much more specific (75% versus 37% for mammography and US) and more accurate (82% versus 36% for mammography and 54% for US) than the other two modalities, and mammography + Tl combination was significantly superior to other dual combinations (87% specific and 91% accurate). Use of Tl-201 scanning as an adjunct to mammography + US combination increased the specificity, ppv, and accuracy rates overall, particularly in mammographically or sonographically indeterminate cases. CONCLUSIONS In mammographically and sonographically indeterminate breast lesions thallium scanning may be offered as a third step of investigation to obviate biopsy.

Clinical impact of ¹⁸F-FDG PET/CT in the pretreatment evaluation of patients with locally advanced cervical carcinoma.

AimThe aim of this study was to evaluate the impact of 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) on the pretreatment evaluation of patients with locally advanced cervical carcinoma. MethodForty-seven patients with stage 2b–4a cervical carcinoma underwent 18F-FDG PET/CT for initial staging and pretreatment evaluation. Concomitant pelvic/abdominal MRI was performed in 38 patients. The contribution of PET/CT to treatment planning was evaluated, and the prognostic performance of PET/CT was compared with that of MRI. Lymph node (LN) status on PET/CT was correlated with patient follow-up data. ResultsPET/CT detected hypermetabolic LNs in 39/47 patients. In 24/39 patients (62%), PET/CT was found to be superior to MRI. In 13/24 patients (54%), PET/CT detected para-aortic±pelvic LNs, which were not found on MRI. PET/CT successfully detected distant metastases in 10 patients and peritonitis carcinomatosa in one patient; these patients were upstaged clinically. Overall, PET/CT has led to modifications in the extent of the radiotherapy field in 34% of patients and to major alterations in treatment plans in 23% of patients with widespread disease. The frequency of PET-positive LNs was significantly lower in patients who were alive without disease at the time of last follow-up (60%) compared with patients with persistent disease and nonsurvivors (100%, P=0.012). ConclusionThe presence of PET-positive LNs has prognostic significance in patients with cervical carcinoma. PET/CT has the potential to show both lymphatic and distant metastases, which results in modifications to the chemoradiotherapeutic regimen. The use of PET/CT must be included in the initial workup of patients with locally advanced cervical carcinoma.

Clinical factors related with helicobacter pylori infection--is there an association with gastric cancer history in first-degree family members?

BACKGROUND The aim of this study was to assess clinical factors associated with Helicobacter pylori positivity and to evaluate the incidence of gastric carcinoma in first-degree family members of infected patients. A total of 580 patients (mean age:38±17) with gastrointestinal complaints underwent C-14 urea breath test (UBT). Patients were grouped as: Group-1, untreated patients (n:384); and Group-2, patients who previously treated with eradication triple therapy (n:196). C-14 UBT was performed 1-2 months after the completion of eradication therapy. Associations of H pylori positivity with age, gender, ABO and Rhesus groups, smoking, dietary habits, and history of gastric cancer in first-degree family members were evaluated. The frequency of H pylori positivity was significantly higher in group-1 (58%) compared to group-2 (20%), p=0.001. There were no correlations between H pylori positivity and age, gender, ABO groups, Rhesus subgroups, smoking and dietary habits in both patient groups. The frequency of gastric cancer in family members was significantly higher in patients with H pylori infection among group-1, compared to infected patients among group-2 (56% vs. 28.6% respectively, p=0.03). We observed a significant association between H pylori positivity and the presence of gastric cancer in first-degree relatives of group-1 patients. Our results provide some confirmation of the presence of a link between gastric cancer development and H pylori. C-14 UBT is a sensitive, reliable and a widely recommended test for the detection of H pylori infection and recurrence. We suggest that detection and eradication of H pylori may contribute to a reduced risk of gastric cancer in the family members of infected patients.

Comparison of indium-111 octreotide and thallium-201 scintigraphy in patients mammographically suspected of having breast cancer: preliminary results

Indium-111 octreotide and thallium-201 scintigraphic studies were compared in 21 patients (16 with palpable and five with non-palpable lesions) suspected of having breast malignancies on the basis of mammography. Early (15 min) and late (3 h)201Tl (111 MBq) and 4-h and 24-h111In-octreotide (111–148 MBq) static planar anterior images (matrix 256×256) were obtained on separate days. Images were evaluated both visually and quantitatively. Biopsy was performed following the imaging studies. Histopathology revealed 17 breast carcinomas (15 cases of invasive ductal carcinoma, one mucinous adenocarcinoma and one intraductal carcinoma) and four benign breast lesions (two fibroadenomas, one abscess and one case of fat necrosis). The means histopathologcial tumour size (mean largest diameter) was 3.38±1.9 cm.111In-octreotide detected 16 of the 17 breast cancers (94%) while201Tl detected 13 of them (76%). Both111In-octreotide and201Tl missed one nonpalpable carcinoma showing only an isolated cluster of microcalcifications on mammography. The smallest tumour size detected by both agents 1.5×1.5 cm. Of the four benign lesions, only the breast abscess revealed both201Tl and111In-octreotide uptake.111In-octreotide scan also showed tracer uptake in five of the six patients with histologically proven axillary metastases, while four of these six patients showed201Tl uptake. The tumour/background (T/B) ratios of late111In-octreotide and201Tl images were 1.71±0.38 and 1.46±0.30 respectively (P=0.039). In this preliminary study,111In-octreotide yielded more favourable results than201Tl in the detection of breast carcinomas. However, the diagnostic efficacy of111In-octreotide imaging needs to be investigated in larger patient series.

Tc-99m HMPAO brain perfusion imaging in young Down's syndrome patients

Downs syndrome (DS) is characterized by moderate mental retardation and a variety of abnormalities involving multiple organ systems. There is a high incidence of Alzheimers disease (AD) type dementia beyond the age of 35. In this study, single photon emission computed tomography (SPECT) brain perfusion imaging of young Downs syndrome patients was performed to define the perfusion pattern. Tc-99m HMPAO brain perfusion SPECT was performed on 17 young DS patients, aged 3-24 years (mean: 10.9+/-5.9 years). None of the patients had dementia symptoms. Brain perfusion scans were acquired 15 min after i.v. injection of 12 MBq/kg of Tc-99m HMPAO using a single head rotating gamma camera. Images were analyzed visually and semiquantitatively by defining side-to-side asymmetry index. Nine DS cases showed normal brain perfusion. Eight of the 17 cases revealed mostly unilateral parieto-temporal, parieto-occipital and frontal hypoperfusions. The side-to-side asymmetry indices for these visually interpreted regional brain perfusion abnormalities ranged from 6 to 15%. These findings revealing mostly unilateral parieto-temporal and frontal hypoperfusions may not be considered as predictive patterns of dementia related Alzheimer type perfusion deficits in DS. However, such findings may connect to other functional imaging studies related to the higher cortical dysfunction in mental retardation.

Positron emission tomography/computerized tomography in lung cancer

Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer.

The incidence of secondary central nervous system involvement in patients with non-Hodgkin's lymphoma as detected by 18F-FDG PET/CT.

AimSecondary central nervous system (CNS) involvement is a devastating and usually fatal complication of non-Hodgkin’s lymphoma (NHL). We aimed to evaluate the incidence of secondary CNS involvement and the value of 18F-FDG PET/computed tomography (CT) imaging in the detection of secondary CNS involvement in patients with NHL. MethodsA total of 123 immunocompetent patients (58 men, 65 women; mean age: 56.5±19.2) with biopsy-proven NHL who underwent 18F-FDG PET/CT for primary staging (n=68) and restaging (n=55) of recurrent disease were reviewed retrospectively. Those with secondary CNS involvement as diagnosed on PET/CT were identified. CNS involvement was confirmed by MRI and cerebrospinal fluid cytology. ResultsThe clinical Ann Arbor stages of the patient population were as follows: stage I – 10 patients; stage II – 44 patients; stage III – 32 patients, and stage IV – 37 patients. PET/CT detected CNS involvement in six patients. The ages of patients with CNS disease ranged from 23 to 68 (mean: 47.2) years. Three patients presented with CNS involvement associated with systemic disease manifestation at initial diagnosis; one patient had isolated CNS relapse and two had relapsed systemic NHL with progression to CNS involvement. Relapse interval was 8–12 months following initial diagnosis. The types of CNS involvement in patients were as follows: parenchymal (n=2), leptomeningeal (n=2), both parenchymal and leptomeningeal (n=1), and pituitary gland involvement (n=1), which is an uncommon manifestation. Median duration of survival was 2.5 months after the diagnosis of CNS involvement. ConclusionThe incidence of secondary CNS involvement was 4.4% at initial diagnosis and 5.4% among patients with relapse of lymphoma in our study. PET/CT is a sensitive, objective, and valuable method for the diagnosis of secondary CNS involvement in patients with NHL. In addition, pituitary gland involvement, as a very rare manifestation of secondary CNS lymphoma, has been shown.

Tc-99m MIBI bone marrow uptake in bone marrow fibrosis secondary to metastatic breast carcinoma.

A 59-year-old woman with inoperable breast carcinoma, and who was receiving chemotherapy, underwent Tc-99m MIBI myocardial perfusion scintigraphy for ischemic heart disease. Whole-body Tc-99m MIBI imaging was performed before the myocardial study showed bone marrow activity. Tc-99m MDP bone scan findings were well adjusted with superscan. Diffuse bone marrow activity seen with Tc-99m MIBI may be due to bone marrow expansion and increased metabolic activity. Bone marrow biopsy revealed secondary myelofibrosis.