Suzuka Taki

FDG PET in the evaluation of the aggressiveness of pulmonary adenocarcinoma : correlation with histopathological features

2-[Fluorine-18]fluoro-2-deoxy-d-glucose (FDG) uptake within the primary lesion correlates with survival on positron emission tomography (PET) studies of patients with non-small cell lung cancer. The more metabolically active the tumour, the worse the outcome. The aim of this study was to determine whether a correlation exists between aggressiveness as determined by pathology and the findings of FDG PET in pulmonary adenocarcinoma. Thirty-five patients with 38 adenocarcinomas of the lung were studied. All patients underwent thoracotomy within 4 weeks of the FDG PET study. For semiquantitative analysis, standardized uptake values (SUVs) were calculated. Patients were classified into high SUV (⩾4.0) and low SUV (<4.0) groups. The degree of FDG uptake (SUVs) in primary lung lesions was correlated with the histopathological features of aggressiveness (pleural involvement, vascular invasion or lymphatic permeation). The mean SUV of aggressive adenocarcinomas (4.36±1.94, n = 22) was higher than that of non-aggressive ones (1.53±0.88, n = 16) (P<0.0001). Tumours with a high FDG uptake have a significantly higher likelihood of aggressiveness than those with a low FDG uptake (P = 0.0004). Analysis by the Kaplan-Meier methods revealed that the groups had different prognoses (log-rank test, P = 0.0099). The high SUV group had a significantly worse prognosis. In conclusion, a correlation was seen between aggressiveness as determined by pathology and glucose metabolism as measured by FDG PET in adenocarcinoma of the lung. FDG PET may be used as a non-invasive diagnostic technique in measuring aggressiveness and prognosis in patients with pulmonary adenocarcinoma.

Thyroid calcifications: Sonographic patterns and incidence of cancer

We investigated the incidence of cancer in surgically resected 151 thyroid nodules in 101 patients according to their calcification patterns on preoperative ultrasonography (US). Calcification was detected in 57 (38%) nodules, 31 (54%) of which was histologically diagnosed as cancer. According to the calcification types, 9 of 11 nodules with microcalcifications, 15 of 29 nodules with intranodular coarse calcification, 6 of 14 nodules with peripheral calcification and 1 of 3 calcified spots without surrounding tumor were diagnosed as cancer.

Cardiac 123I-MIBG scintigraphy can assess the disease severity and phenotype of PD

OBJECTIVE Cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphy studies of patients with idiopathic Parkinsons disease (PD) found decreased uptake. Whether this decrease is associated with clinical severity as assessed by the Unified Parkinsons Disease Rating Scale (UPDRS) and the phenotypes of PD has not been determined. METHODS Cardiac MIBG scintigraphy was performed on 34 patients with PD, 7 with multiple system atrophy (MSA), 4 with dementia with Lewy bodies (DLB), and 11 normal controls (NCs). Early and delayed MIBG heart/mediastinum (H/M) ratios were evaluated. PD severity was assessed by the Hoehn and Yahr (H-Y) stage and UPDRS. Patients were grouped in two phenotypes, tremor and postural instability gait difficulty (PIGD)-dominant groups based on UPDRS components. Associations between MIBG uptake and age at onset, UPDRS, and disease phenotype were analyzed in each group. RESULTS The early H/M ratio was significantly lower in patients with PD (1.45+/-0.207) than in the NCs (2.08+/-0.231), and in those with MSA (1.99+/-0.284), but not in those with DLB (1.29+/-0.0435). The delayed H/M ratio for PD (1.33+/-0.276) also was significantly decreased as compared to the ratios for NCs (2.17+/-0.286) and MSA (2.16+/-0.414) but not DLB (1.16+/-0.0949). The early H/M ratio was significantly correlated with both UPDRS score and age at onset, whereas the delayed H/M ratio only was significantly correlated with age at onset. The PIGD-dominant group had significantly higher UPDRS scores and lower H/M ratios than the tremor-dominant group. CONCLUSION Cardiac MIBG scintigraphy can be used to differentiate PD from MSA and NC, and to determine the disease severity and phenotypes of PD.

Changes in regional cerebral blood flow in irradiated regions and normal brain after stereotactic radiosurgery

Objective: To elucidate the radiation effect on the normal brain after stereotactic radiosurgery (SRS), we evaluated the change in regional cerebral blood flow (CBF) in targeted and extra-targeted areas according to the radiation dose given.Methods: Thirteen patients who underwent SRS for brain tumors or arteriovenous malformations were included in this study. Maximum radiation doses to the lesion ranged from 24 to 37 Gy. Mean and regional CBF were measured by99mTc-HMPAO scintigraphy with graphic analysis, performed at before, 2 weeks and 3 months (5 patients) after SRS. Under the co-registration with the CT with superimposed isodose distribution, ROIs were set on target (37-20 Gy), peri-target (20-5 Gy) and out-of-field (5-2 Gy and less than 2 Gy) areas on the quantitative SPECT images.Results: Significant reductions in mean CBF (by 7%) and regional CBF in the peri-target areas (by 5–7%) and out-of-field areas (by 6–22%) were recognized at 2 weeks and 3 months after SRS. Regional CBF in the target and peri-target areas did not significantly change, presumably because there was little or no normal tissue in these areas.Conclusion: These results suggest that subclinical regional CBF reduction occurs after SRS in the normal brain in out-of-field of radiation.

Thallium-201 brain SPECT to diagnose aggressiveness of meningiomas

This investigation was conducted to determine the ability of201Tl brain SPECT with respect to preoperative prediction of lesional aggressiveness of meningioma. Fifty-nine lesions in 42 patients were examined. Early (15 min) and late (3h) SPECT were obtained. Early uptake ratio (ER; lesion to normal brain average count ratio), late uptake ratio (LR) and the ratio of LR to ER (L/E ratio) were calculated. Twenty-three lesions exhibited malignant features based on histologic or clinical course such as recurrence or skull invasion. Both ER and LR of malignant meningiomas were significantly higher than those in thirty-six benign lesions. Benign lesions were classified into two groups for further analysis: meningotheliomatous type, which is the most common histology, and benign lesions other than the meningotheliomatous (other benign) type. ER in other benign type was lower than the meningotheliomatous and the malignant type. LR afforded differentiation of the malignant type from the two benign types. These two benign types could be distinguished on the basis of the L/E ratio. These results indicate that high pre-operative ER and LR values in patients with meningioma are indicators of the aggressiveness of lesions, i.e., malignant meningioma, recurrence or skull invasion.

Scintigraphic prediction of therapeutic outcomes of splenectomy in patients with thrombocytopenia.

In patients with thrombocytopenia, platelet scintigraphy has been used to locate the site of platelet sequestration and destruction and to determine whether splenectomy will be of benefit. However, its efficacy in predicting the outcome of splenectomy is controversial. We assessed the feasibility of platelet scintigraphy in this regard.Methods: Platelet scintigraphy was performed in five patients (2 women, 3 men, mean age 48 years) before splenectomy. Four patients were diagnosed with idiopathic thrombocytopenic purpura and one with hypersplenism due to portal hypertension caused by intrahepatic chemotherapy against metastatic liver tumors of rectal cancer. Platelets labeled with 37 MBq of In-111 oxine or 1110 MBq of Tc-99m HMPAO were intravenously injected. Anterior images were obtained with a gamma camera 3–5 and 23–29 hours post-injection in five patients. Additional images were obtained 48 hours post-injection in three patients. For the analysis, a spleen/liver ratio (S/L ratio) was calculated using mean counts in regions of interest defined on the spleen and the liver. Serum platelet counts were measured before and after the operation; in three patients, splenectomy effectively resolved the thrombocytopenia (Group A), while it was ineffective in two patients (Group B).Results: The S/L ratios were apparently higher in group A than in Group B; in Group A, the ratios were 6.05, 6.97 and 3.16 at 3–5 hours, 12.67, 7.48 and 3.46 at 23–29 hours and 17.66, and 8.12 at 48 hours, whereas, in Group B, they were 0.67 and 0.66 at 3–5 hours, 0.52 and 0.54 at 24 hours, and 0.42 at 48 hours.Conclusion: The results of this study indicate that platelet scintigraphy is of value in predicting the therapeutic efficacy of splenectomy in patients with thrombocytopenia.

Differential diagnosis in patients with ring-like thallium-201 uptake in brain SPECT

This study was performed to investigate lesions with ring-like thallium-201 (201Tl) uptake and to determine whether SPECT provides any information in differential diagnosis.Methods: A total of 244201Tl SPECT images were reviewed. In each study, early (15 min postinjection) and late (3 hr) brain SPECT images were obtained with 111 MBq of201Tl. The early uptake ratio (ER; lesion to normal brain average count ratio) and the late uptake ratio (LR) and the L/E ratio (ratio of LR to ER) were calculated.Results: Ring-like uptake was observed in pre-therapeutic 26 SPECT images, including ten glioblastoma multiformes (ER, 3.45±0.64; LR, 2.74±0.54; L/E ratio 0.80±0.13), five meningiomas (6.48±2.34; 4.41±1.41; 0.72±0.19), four metastatic lung cancers (3.47±1.23; 2.40±0.98; 0.70±0.14), four brain abscesses (2.48±1.06; 1.59±0.30; 0.78±0.15), one invasive lesion of squamous cell carcinoma from the ethmoid sinus (1.54; 1.52; 0.99), one medulloblastoma (3.53; 3.52; 1.00) and one hematoma (3.32; 2.36; 0.71). The ER of meningioma was significantly higher than those of glioblastoma multiforme (p<0.0005), metastatic lung cancer (p<0.005) and brain abscess (p<0.0005). There were no significant differences among these three entities. The LR of meningioma was significantly higher than those of glioblastoma multiforme (p<0.005), metastatic lung cancer (p<0.005) and brain abscess (p<0.0001). The LR of brain abscess was significantly lower than that of glioblastoma multiforme (p<0.05). The L/E ratio could not differentiate these four entities.Conclusion: High ER and high LR in a lesion with ring-like uptake is likely an indicator of meningioma. The LR of brain abscess was significantly lower than that of glioblastoma multiforme, but201Tl SPECT has still difficulty in differentiating abscess from brain tumor.

Acute subendocardial infarction with diffuse intense Tc-99m PYP uptake and minimal Tl-201 abnormality.

Tc-99m PYP scintigraphy performed on a patient with severe anterior chest pain showed diffuse intense uptake with central decreased activity corresponding to the left ventricular cavity. Tl-201 myocardial perfusion scintigraphy at rest revealed a minimal perfusion abnormality with decreased apical uptake in the lateral view. Because of these findings, diffuse subendocardial infarction was suggested.

Tumor-like accumulation on Tl-201 SPECT in subacute hemorrhagic cerebral infarction.

A 75-year-old woman was hospitalized for left hemiplegia. Intratumoral hematoma was considered likely based on the findings of computed tomographic (CT) images, and T1-201 SPECT was performed for further differentiation. Early SPECT images showed tumor-like accumulation in the right basal ganglia. However, the accumulation was washed out on delayed SPECT. Final diagnosis by a follow-up study was subacute hemorrhagic infarction. Although early T1-201 SPECT may show positive results for subacute hemorrhagic infarction, a delayed T1-201 SPECT can show a wash-out pattern that may be specific for this infarction. Early T1-201 SPECT may show tumor-like accumulation for subacute hemorrhagic infarction. This should be kept in mind in the analysis of T1-201 SPECT studies when cerebral infarction is being differentiated from brain tumor.

Intense accumulation of Tc-99m MDP and Ga-67 in multiple periapical cemental dysplasia

A case of multiple periapical cementai dysplasia is presented and intensive accumulation of Tc-99m MDP and Ga-67 is described. A 53-year-old woman was admitted with an intermittent pain and swelling of the left buccal region. The radiograph showed multiple sclerotic masses covering entire periapical regions of the teeth, in both the maxilla and mandibula. Biopsy of the maxilla facilitated a definitive diagnosis of multiple periapical cementai dysplasia.