Variations in (18)F-FDG uptake in breast cancer depending on PET/CT acquisition position.

AIM: To evaluate the variability of quantitative 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) combined with computed tomography (CT) parameters depending on acquisition position in a dual-position protocol for breast cancers. MATERIALS AND METHODS: For initial staging work-up, whole-body PET/CT was first acquired in a supine position, and then followed by a regional breast scan in a prone position. The maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured on both acquisition positions. MTV50 and TLG50 were calculated with a threshold set to be 50% of SUVmax, and MTV2.5 and TLG2.5 with a fixed SUV threshold of 2.5. RESULTS: The median SUVmax of breast cancers measured on the supine scans was 4.88, and 4.49 on the prone images (p<0.05). MTV and TLG also yielded significantly lower values from supine images. Regarding the tendency for the acquisition position to yield different results, a significant disagreement was observed between SUVmax and MTV50 and between SUVmax and TLG50 (kappa = -0156 and -0.001, respectively), while MTV2.5 and TLG2.5 showed a fair to moderate agreement with SUVmax (kappa = 0.311 and 0.416, respectively). CONCLUSIONS: SUVmax, MTV, and TLG yielded lower values when acquired in the prone position compared to in the supine position. This observation could be due to the partial volume effect. When using 50% of SUVmax as a threshold, there was a significant discordance between SUVmax and volumetric parameters. Thus, acquisition position may affect quantitative PET/CT parameters and the clinical implications.

Frequent visualization of thyroglossal duct remnant on post-ablation 131I-SPECT/CT and its clinical implications.

AIM: To evaluate the frequency of thyroglossal duct remnant (TGDR) uptake on post-therapy (131)I-scintigraphy in thyroid cancer patients, to analyse the rate of persistent TGDR uptake on follow-up combined (131)I-single-photon emission CT/CT (SPECT/CT), and to identify the differential clinical characteristics between patients with positive and negative TGDR uptake on (131)I-SPECT/CT. MATERIALS AND METHODS: A total of 179 patients treated with total thyroidectomy for thyroid cancer were enrolled in the study. At (131)I-whole-body scan (WBS), TGDR uptake was defined as an increase in radioactivity at the midline of the neck versus the thyroid bed. TGDR uptake on (131)I- SPECT/CT was defined as the presence of radioactivity at the expected pathway of the thyroglossal duct without evidence of metastatic foci. Persistent TGDR uptake was confirmed when TGDR uptake on follow-up (131)I-SPECT/CT corresponded to previous TGDR uptake detected by post-therapy (131)I-SPECT/CT. RESULTS: At SPECT/CT, TGDR uptake was noted in 86 of 179 patients. Stimulated thyroglobulin (sTg) levels were significantly higher (p = 0.02) in patients with positive TGDR uptake. Persistent TGDR uptake on follow-up (131)I-SPECT/CT was noted in 15 of 86 patients; sTg levels were significantly higher (p = 0.03) in the patients with persistent TGDR uptake. CONCLUSION: TGDR uptake is frequently visualized on post-therapy (131)I-SPECT/CT images and can be resistant to (131)I ablation. TGDR uptake has the potential to result in an elevation of serum thyroglobulin levels. (131)I-SPECT/CT clarifies TGDR uptake without additional invasive procedures or imaging studies, eliminating confusion among clinicians for managing differentiated thyroid cancer patients.

A survival benefit of major hepatectomy for hepatocellular carcinoma identified by preoperative [18F] fluorodeoxyglucose positron emission tomography in patients with well-preserved hepatic function.

AIMS: Hepatic resection can cure hepatocellular carcinoma (HCC). However, the optimal extent of resection remains controversial. Major hepatectomy could minimize a tumor recurrence, but it is harmful due to decreased hepatic functional reserve. [18F] fluorodeoxyglucose positron emission tomography (FDG-PET) scans are known as their reflection tumor differentiation and biological activity in HCC. To evaluate a benefit of major hepatectomy for HCC, we performed this retrospective analysis in patients with well-preserved hepatic function, and further analyzed in the subset identified by preoperative FDG-PET. METHODS: We reviewed the medical records of 189 patients with HCC who underwent curative resection between August 2004 and December 2010 at two institutes. All patients underwent anatomical resection, either by major or minor hepatectomy. RESULTS: Median overall survival did not differ significantly between the major and minor hepatectomy groups (29.4 versus 26.3 months, p = 0.269). However, the major hepatectomy group had a better recurrence-free survival (24.5 versus 19.9 months, p = 0.004). On multivariate analysis, the presence of intrahepatic metastasis independently predicted overall survival (p = 0.009), but other examined variables did not. Overall survival and recurrence-free survival were significantly better following major hepatectomy rather than minor hepatectomy in patients whose preoperative FDG-PET indicated that the maximum standardized uptake value of the tumor (SUVtumor) was ≥4 and the tumor-to-nontumor SUV ratio (TNR) was ≥1.5. CONCLUSIONS: Our findings suggest that preoperative FDG-PET may be useful in identifying patients with favorable hepatic reserve who are most likely to benefit from major rather than minor hepatectomy.

Weekly full-dose gemcitabine and single-dose cisplatin with concurrent radiotherapy in patients with locally advanced pancreatic cancer.

The aim of this study was to evaluate the efficacy and the toxicity of a full dose of gemcitabine and a single dose of cisplatin with concurrent radiotherapy in patients with locally advanced pancreatic cancer. Forty-one patients with locally advanced pancreatic cancer were enrolled. Patients received gemcitabine (1000 mg m(-2) on days 1, 8, 15, 29, and 36) and cisplatin (70 mg m(-2) on days 1 and 29) with concurrent radiotherapy (45 Gy in 25 fractions). Treatment was completed in 38 out of 41 patients (92.7%). The overall response rate was 24.4% (two complete and eight partial). Six patients (14.6%) underwent definite pancreatic resection and four had negative surgical margins. The intention of the treatment analysis showed that the median survival time and median time to tumour progression were 16.7 and 8.9 months. The 1- and 2-year survival rates were 63.3 and 27.9%, respectively. Overall survival was significantly longer in the low baseline CA19-9 group and therapeutic responders. Toxicities were tolerable and successfully managed by conservative treatments. The therapeutic scheme of a weekly full dose of gemcitabine and a single dose of cisplatin combined with external radiation is effective and might prolong the survival of patients with locally advanced pancreatic cancer.

Radionuclide cisternography in spontaneous intracranial hypotension with simultaneous leaks at the cervicothoracic and lumbar levels.

This case report clearly illustrates defined simultaneous cerebrospinal fluid leaks at the cervicothoracic and upper lumbar areas. A 53-year-old woman without a remarkable medical history was hospitalized for sudden onset of severe headache. The headache lasted more than 1 week and standing or sitting positions exaggerated the symptoms, although it was relieved when the patient was recumbent. Radionuclide cisternography was performed using 150 MBq (4 mCi) Tc-99m DTPA. It revealed two cerebrospinal fluid leaks from the cervicothoracic junction bilaterally and the left side of the upper lumbar area. Epidural blood patching was tried at the lumbar level (L1-L2) and showed only a transient effect. A second trial of this method at the level of C7-T1 performed 2 days later resulted in immediate improvement of the symptoms without recurrence. The simultaneous cerebrospinal fluid leaks were detected successfully with radionuclide cisternography using Tc-99m DTPA, which provided a useful guideline for treatment despite the limitations of delayed scanning.

Evaluation of ictal brain SPET using statistical parametric mapping in temporal lobe epilepsy.

An automated voxel-based analysis of brain images using statistical parametric mapping (SPM) is accepted as a standard approach in the analysis of activation studies in positron emission tomography and functional magnetic resonance imaging. This study aimed to investigate whether or not SPM would increase the diagnostic yield of ictal brain single-photon emission tomography (SPET) in temporal lobe epilepsy (TLE). Twenty-one patients (age 27.14 +/- 5.79 years) with temporal lobe epilepsy (right in 8, left in 13) who had a successful seizure outcome after surgery and nine normal subjects were included in the study. The data of ictal and interictal brain SPET of the patients and baseline SPET of the normal control group were analysed using SPM96 software. The t statistic SPM¿t¿ was transformed to SPM¿Z¿ with various thresholds of P<0.05, 0.005 and 0.001, and corrected extent threshold P value of 0.05. The SPM data were compared with the conventional ictal and interictal subtraction method. On group comparison, ictal SPET showed increased uptake within the epileptogenic mesial temporal lobe. On single case analysis, ictal SPET images correctly lateralized the epileptogenic temporal lobe in 18 cases, falsely lateralized it in one and failed to lateralize it in two as compared with the mean image of the normal group at a significance level of P<0.05. Comparing the individual ictal images with the corresponding interictal group, 15 patients were correctly lateralized, one was falsely lateralized and four were not lateralized. At significance levels of P<0.005 and P<0.001, correct lateralization of the epileptogenic temporal lobe was achieved in 15 and 13 patients, respectively, as compared with the normal group. On the other hand, when comparison was made with the corresponding interictal group, only 7 out of 21 patients were correctly lateralized at the threshold of P<0.005 and five at P<0.001. The result of the subtraction method was close to the single case analysis on SPM at P<0.05. However, at higher thresholds (P<0.005 and 0.001) the subtraction method was comparable to the SPM results only when individual ictal images were compared with the normal control group, and not when comparison was with the interictal group. It is concluded that SPM is an alternative diagnostic method for the localization or lateralization of the seizure focus in temporal lobe epilepsy and that interictal SPET could be omitted if a normal brain SPET database were to be established. The medical cost of seizure localization would thereby be reduced.

Evaluation of cardiac adrenergic neuronal damage in rats with doxorubicin-induced cardiomyopathy using iodine-131 MIBG autoradiography and PGP 9.5 immunohistochemistry.

Doxorubicin is one of the most useful anticancer agents, but its repeated administration can induce irreversible cardiomyopathy as a major complication. The purpose of this study was to investigate doxorubicin toxicity on cardiac sympathetic neurons using iodine-131-metaiodobenzylguanidine (MIBG) and protein gene product (PGP) 9.5 immunohistochemistry, which is a marker of cardiac innervation. Wistar rats were treated with doxorubicin (2 mg/kg, i.v.) once a week for 4 (n=5), 6 (n=6) or 8 (n=7) weeks consecutively. Left ventricular ejection fraction (LVEF), calculated by M-mode echocardiography, was used as an indicator of cardiac function. Plasma noradrenaline (NA) concentration was measured by high-performance liquid chromatography (HPLC). 131I-MIBG uptake of the left ventricular wall (24 ROIs) was measured by autoradiography. 131I-MIBG uptake pattern was compared with histopathological results, the neuronal population on PGP 9.5 immunohistochemistry and the degree of myocyte damage assessed using a visual scoring system on haematoxylin and eosin and Masson's trichrome staining. LVEF was significantly decreased in the 8-week group (P<0.05). The serum NA level also showed no statistical difference until 4 weeks and was significantly increased in the 8-week group (P<0.05). MIBG uptake was decreased in the 6- and 8-week groups (P<0.05), and was closely correlated with the reduction in the number of nerve fibres on PGP 9.5 stain. Myocyte damage was seen only in the 8-week group. Neuronal population and the 131I-MIBG uptake ratio of subepicardium to subendocardium were significantly increased (P<0.05) in the 8-week group as compared with the control group. It may be concluded that radioiodinated MIBG is a reliable marker for the detection of cardiac adrenergic neuronal damage in doxorubicin-induced cardiomyopathy; it detects such damage earlier than do other clinical parameters and in this study showed a good correlation with the reduction in the neuronal population on PGP 9.5 stain. The subendocardial layer appeared to be more vulnerable to doxorubicin than the subepicardium.

Perirolandic hypoperfusion on single-photon emission computed tomography in term infants with perinatal asphyxia: comparison with MRI and clinical findings.

We describe the findings on single-photon emission computed tomography (SPECT) in patients with perinatal asphyxia at term, with perirolandic cortico-subcortical changes on MRI, and to correlate them with clinical features. SPECT of 7 patients was obtained after injection of 185-370 MBq of Tc-99m-ECD (ethyl cysteinate dimer). The patients had spastic quadriplegia (7/7) with perinatal asphyxia (6/7) at term (7/7). The results were correlated with the MRI findings. Hypoperfusion of the perirolandic cortex was clearly seen on SPECT in all patients, even in two with subtle changes on MRI. SPECT demonstrated a more extensive area of involvement than MRI, notably in the cerebellum (in 4), the thalamus (in 7) and basal ganglia (in 5), where MRI failed to show any abnormalities.

Application of spatial modulation of magnetization to cervical spinal stenosis for evaluation of the hydrodynamic changes occurring in cerebrospinal fluid.

OBJECTIVE: To evaluate the hydrodynamic changes occurring in cerebrospinal fluid (CSF) flow in cervical spinal stenosis using the spatial modulation of magnetization (SPAMM) technique. MATERIALS AND METHODS: Using the SPAMM technique, 44 patients with cervical spinal stenosis and ten healthy volunteers were investigated. The degree of cervical spinal stenosis was rated as low-, intermediate-, or high-grade. Lowgrade stenosis was defined as involving no effacement of the subarachnoid space, intermediate-grade as involving effacement of this space, and high-grade as involving effacement of this space, together with compressive myelopathy. The patterns of SPAMM stripes and CSF velocity were evaluated and compared between each type of spinal stenosis and normal spine. RESULTS: Low-grade stenosis (n = 23) revealed displacement or discontinuity of stripes, while intermediate- (n = 10) and high-grade (n = 11) showed a continuous straight band at the stenotic segment. Among low-grade cases, 12 showed wave separation during the systolic phase. Peak systolic CSF velocity at C4-5 level in these cases was lower than in volunteers (p <.05), but jet-like CSF propulsion was maintained. Among intermediate-grade cases, peak systolic velocity at C1-2 level was lower than in the volunteer group, but the difference was not significant (p >.05). In high-grade stenosis, both diastolic and systolic velocities were significantly lower (p <.05). CONCLUSION: Various hydrodynamic changes occurring in CSF flow in cervical spinal stenosis were demonstrated by the SPAMM technique, and this may be a useful method for evaluating CSF hydrodynamic change in cervical spinal stenosis.

Application of magnetization transfer imaging for intracranial lesions of tuberous sclerosis.

PURPOSE: Our goal was to assess the effectiveness of magnetization transfer imaging (MTI) and the usefulness of the magnetization transfer ratio (MTR) in tuberous sclerosis (TS). METHOD: T2- and T1-weighted SE images with saturation pulse on/off before and after gadolinium enhancement in 10 patients with TS were obtained. The numbers of subependymal nodule (SEN), cortical tuber, and white matter (WM) abnormality detected on T1-, proton density, T2-, and MT T1-weighted SE images were compared. The contrast-to-noise ratio (C/N) on T1-, MT T1-, Gd T1-, and Gd MT T1-weighted SE images and MTR (1-Msat/MO) on each set of saturation/nonsaturation images for each lesions were calculated. Mean MTRs (mMTRs) of WM and gray matter (GM) from seven normal volunteers were also obtained. RESULTS: MT T1-weighted SE images always depicted all lesions seen on conventional MRI and allowed depiction of more SENs (n = 80), cortical tubers (n = 197), and WM abnormalities (n = 82) than did T1-weighted (n = 58/85/33), proton density (n = 41/108/36), or T2-weighted (n = 48/121/46) SE images. The best C/N was obtained from Gd MT T1-weighted SE images in SENs and from MT T1-weighted SE images in other lesions. mMTRs of normal WM and GM were 36.43 and 29.42%, respectively. Cortical tubers and WM abnormalities had measured MTRs that were statistically equal to MTRs of GM in normal subjects (p < 0.005). MTRs of SENs showed lower mean (25.55%) and greater diversity (SD +/- 5.30), compared with MTRs of other lesions and normal GM and WM. One SEN with MTR of 20.72% was pathologically confirmed to be subependymal giant cell astrocytoma (SGCA). Nine SENs had measured MTR below 20.72% and six nodules among these were located in the region of the foramen of Monro, which is the characteristic location of SGCA. CONCLUSION: MTI may be effective in detecting all cranial lesions of TS. MTR may increase the specificity of MRI because it can differentiate the histopathologic subtypes and track and evolution of SEN into SGCA.