Development of a new hybrid gel phantom using carrageenan and gellan gum for visualizing three-dimensional temperature distribution during hyperthermia and radiofrequency ablation.

We developed a new hybrid gel phantom using carrageenan and gellan gum for the purpose of visualizing three-dimensional temperature distribution. The phantom, which contains carrageenan, gellan gum, non-ionic surface active agent, potassium chloride, n-butanol, sodium azide, and water, shows good transparency at room temperature, and has the advantage that the heated region becomes white and opaque due to segregation of the surface active agent. Carrageenan and gellan gum were added to improve the transparency and fragility of the hybrid gel. Potassium chloride was used to adjust the electrical conductivity of the gel to a range of 5-130 MHz, so that it would be equivalent to that of muscle tissue for each frequency used by electromagnetic heating devices. N-butanol was used to adjust the clouding temperature to a range between 45 and 55 degrees C. In the present study we clarified the important properties of the new phantom, and developed formulae for easy determination of the amounts of ingredients necessary for the desired clouding temperature and electric conductivity. The characteristics of this phantom are: a) a solid form to avoid convection by heat conduction; b) sufficient strength without fragility to form a torso without the use of a reinforcing agent; c) high transparency at room temperature and visualization of the heating area as a white turbidity; d) time-lapse and accurate visualization of the changing temperature area without thermal hysteresis; e) electrical properties similar to those of human tissues; f) ease of production; and g) low cost and good safety. This phantom might assist oncologists in their routine checking and study of the performance of electromagnetic heating devices for hyperthermia and radiofrequency ablation.

Hydrogen peroxide overload increases adriamycin-induced apoptosis of SaOS(2)FM, a manganese superoxide dismutase-overexpressing human osteosarcoma cell line.

We previously developed a new microscopic observation system that enables time-lapse quantitative analysis of apoptosis and necrosis. With this system we quantitatively analyzed adriamycin (ADR)-induced cell death using manganese superoxide dismutase (MnSOD)- and wild-type p53-gene transfectants on SaOS(2), a p53-deficient human osteosarcoma cell line. A highly MnSOD-overexpressing cell line, SaOS(2)FM(H), acquired ADR-tolerance compared to the parent cell line SaOS(2). The ADR-tolerance of SaOS(2)FM(H) diminished by L-buthionine-[S,R]-sulfoximine (BSO), which did not change ADR-sensitivity of SaOS(2), to the similar ADR-sensitivity of SaOS(2). A wild-type p53-expressing cell line, SaOS(2)wtp53, significantly increased in ADR-sensitivity compared to SaOS(2). This ADR-sensitivity of SaOS(2)wtp53 was enhanced by BSO. When isosorbide 5-mononitrate was combined with BSO, isosorbide 5-mononitrate increased ADR sensitivity of a moderately MnSOD-overexpressing cell line, SaOS(2)FM(L), decreased that of SaOS(2) FM(H), and did not change those of SaOS(2) and SaOS(2)wtp53 compared to BSO alone. Time-lapse microscopic observations during ADR treatment for 24 h indicated that the most cells of each cell line underwent apoptosis, and a few cells (less than 11%) died by necrosis. When cells were treated with iso-concentration of ADR, apoptosis of SaOS(2)FM(H) was less than that of SaOS(2). BSO, which did not change ADR-sensitivity of SaOS(2), increased appearance rate of ADR-induced apoptosis, but not necrosis of MnSOD-overexpressing cell lines. When iso-survival dose of ADR, which reduced surviving fraction to 0.01, was given for each cell line, no difference was observed in appearance of either apoptosis or necrosis between SaOS(2) and MnSOD-overexpressing cell lines. On the other hands, appearance of both apoptosis and the following secondary necrosis of SaOS(2) wtp53 was significantly accelerated compared to those of SaOS(2). These findings indicate that hydrogen peroxide overload on p53-independent pathway due to MnSOD overexpression plus BSO might increase the apoptosis frequency without acceleration of apoptotic process of each cell, resulting in negating ADR-tolerance of MnSOD-overexpressing cell lines.

Manganese superoxide dismutase overexpression changes plating efficiency bidirectionally according to change in redox for SaOS2 human osteosarcoma cell line.

Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme that converts cytotoxic superoxide radicals into hydrogen peroxide. MnSOD activity is lower in tumor cells, and MnSOD overexpression reportedly ameliorates malignant phenotypes. We established stable MnSOD overexpressing cell lines from a human osteosarcoma cell line, SaOS2, and then investigated the effects of MnSOD overexpression on plating efficiency (PE) and the involvement of reactive oxygen species, including nitric oxide (NO) in those effects. The PE of SaOS2FM(L), a moderate MnSOD overexpression cell line, increased, while that of SaOS2FM(H), a high MnSOD overexpression cell line, decreased. Although we assessed PE using a colony-formation assay, time-lapse microscopic observation revealed that cells attached to the flasks had undergone neither apoptosis nor necrosis. Moreover, MnSOD overexpression did not affect cell doubling time. Therefore, MnSOD overexpression might correlate directly with cellular adhesion's effect on PE changes. When L-buthionine-[S,R]-sulfoximine (BSO) was administered to increase the intracellular concentration of hydrogen peroxide, the PEs of both cell lines decreased, and when hydrogen peroxide was eliminated by the administration of sodium pyruvate, only the PE of SaOS2FM(H) increased. The combination of BSO and NO (NOR4 or isosorbide 5-mononitrate) administration synergistically decreased PE in both cell lines. These findings suggest that changes in cellular adhesion properties correlate with the balance between increased hydrogen peroxide levels and decreased superoxide radical levels. This is the first report to indicate that PE and cellular adhesion properties change bidirectionally according to the levels of MnSOD overexpression: first increasing then decreasing as MnSOD activity increases. Our results indicate that PE changes might be decided by the balance between two cytotoxic compounds (decreased superoxide radical levels and increased hydrogen peroxide levels), and that NO loading and increased hydrogen peroxide synergistically reduce PE and cellular adhesion.

Differentiation of thyroid nodules using Tl-201 scintigraphy quantitative analysis and fine-needle aspiration biopsy.

We studied the differentiation of thyroid nodules using fine-needle aspiration biopsy (FNA) and Tl-201 scintigraphy quantitative analysis. One-hundred and thirty-one thyroid nodules were examined: 83 follicular lesions (58 benign and 25 malignant lesions) and 48 non-follicular lesions (8 benign and 40 malignant lesions). During Tl-201 scintigraphy examinations, an early and a delayed image were acquired 10 and 120 min after an intravenous injection, respectively. The T/N ratio (counts of nodular lesion/counts of contralateral normal thyroid tissue) of each image was calculated quantitatively. We assessed the ability of the Tl-201 scintigraphy and of the FNA analysis to differentiate benign and malignant lesions and determined the cut-off levels for the assays. For the follicular lesions, the area under the ROC (Receiver Operating Characteristic) curve (Az) for the Tl-201 scintigraphy data was greater than that for the FNA data. For the non-follicular lesions, the Az for the FNA data was greater than that for the Tl-201 scintigraphy data. We set cut-off levels at 1.370 for follicular lesions, and 1.070 for non-follicular lesions. The sensitivity and specificity were 76% and 82.7% for follicular lesions, and 90% and 87.5% for non-follicular lesions, respectively. The overall accuracy of the analysis was 84.0%.

Hepatic infarction following abdominal interventional procedures.

To clarify the incidence, background, and progress of hepatic infarction following interventional procedures, cases of hepatic infarction following interventional procedures at our department during the last decade were identified by reviewing the clinical records of 1982 abdominal angiography and interventional procedures and records of abdominal CT. Nine episodes (0.5%) in 8 patients were identified as hepatic infarction following an interventional procedure. Five episodes were preceded by embolization of the hepatic or celiac artery at emergency angiography for postoperative bleeding with hemorrhagic shock. Three episodes followed the elected interventional procedure for hepatocellular carcinoma, and the remaining episode occurred after 12 months of chemoinfusion through an indwelling catheter in the hepatic artery and portal vein. Hepatic arterial occlusion in all episodes and portal venous flow abnormality in 5 episodes were observed on angiography. Four patients whose liver function was initially impaired died of hepatic infarction, although the extent of the disease on CT did not appear to be related to the mortality. Multiple risk factors, including arterial insufficiency, were observed in each patient. The incidence of hepatic infarction following interventional procedures in this series was low but sometimes fatal, and occurred most frequently in emergency embolization in hemorrhagic shock.

Cepharanthin enhances adriamycin sensitivity by synergistically accelerating apoptosis for adriamycin-resistant osteosarcoma cell lines, SaOS2-AR and SaOS2 F-AR.

Cepharanthin (CEP) is a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata. CEP is reported to inhibit drug resistance by inhibiting P-glycoprotein, a drug efflux pump, and recently to induce apoptosis. In the present study, we examined the effects of CEP as an inhibitor of adriamycin (ADR) resistance on ADR-induced apoptosis and necrosis. First, we established p53-deficient ADR-resistant osteosarcoma cell lines, SaOS2-AR and SaOS2 F-AR. Resistant cells showed a higher level of intracellular glutathione peroxidase activity than parent cells. P-glycoprotein was overexpressed in resistant cells. The intracellular ADR level of resistant cells was lower than that of parent cells. One micro g/ml CEP eliminated the degradation of intracellular ADR of resistant cells; that is, to a level equivalent to that of the parent cells. CEP of 0.5 micro g/ml, which was not cytotoxic when used alone, significantly increased the ADR sensitivity of resistant cells, to a level similar to the parent cell level. Isosorbide 5-mononitrate, a potential nitric oxide-generation agent, combined with CEP further increased the ADR sensitivity of resistant cells, indicating a synergistic effect of CEP and isosorbide 5-mononitrate on ADR cytotoxicity. Time-lapse microscopic observation revealed that ADR dominantly induced apoptosis much more than necrosis for both parent and resistant cells, and that the use of 0.5 micro g/ml CEP with ADR synergistically accelerated apoptosis in resistant cells. Finally, we clarified the property by which CEP synergistically accelerates ADR-induced apoptosis. This property might be a new mechanism that explains how CEP overcomes ADR resistance.

Functional evaluation of lung by Xe-133 lung ventilation scintigraphy before and after lung volume reduction surgery (LVRS) in patients with pulmonary emphysema.

We evaluated the respiratory functions of patients with pulmonary emphysema who underwent lung volume reduction surgery (LVRS) by the mean transit time (MTT) with Xe-133 lung ventilation scintigraphy, forced expiration volume in 1 sec (FEV1.0), residual volume (RV), distance walked in 6 min (6-min walk), and the Hugh-Jones classification (H-J classification) before and after LVRS. In 69 patients with pulmonary emphysema (62 men, 7 women; age range, 47-75 years; mean age, 65.4 years +/- 6.1, preoperative H-J classification, III (two were II)-V) who underwent LVRS, all preoperative and postoperative parameters (MTT 3 weeks after LVRS and the others 3 months after LVRS) were judged statistically by the Wilcoxon signed-ranks test and Odds ratio. Every postoperative parameter was improved with a significant difference (P < 0.05) compared to preoperative parameters. MTT at 3 weeks after LVRS was not associated with %FEV1.0 and the H-J classification at 3 months after LVRS, but was associated with RV and a 6-min walk at 3 months after LVRS. MTT was useful for the clinical evalution of aerobic capability after LVRS.

Thoracic tumors treated with CT-guided radiofrequency ablation: initial experience.

PURPOSE: To determine the effectiveness of computed tomography (CT)-guided radiofrequency (RF) ablation of malignant thoracic tumors. MATERIALS AND METHODS: CT-guided RF ablations of 99 malignant thoracic tumors (3-80 mm in largest diameter; mean, 19.5 mm) were performed in 35 patients in 54 sessions. Ablation was performed with an RF generator by using a single internally cooled electrode. Tumors were both primary (three lesions) and secondary (pulmonary or pleural metastases, 96 lesions). Follow-up was 1-17 months (mean, 7.1 months). Follow-up CT and histopathologic examinations were evaluated. Univariate analysis was performed with the Fisher exact test, and Welch t test was used to evaluate differences between group means. P <.05 represented a significant difference. The maximal diameter of each residual tumor or local recurrence or the proportion of primary lesions of pulmonary metastatic tumors with recurrence after RF ablation were analyzed. Complications, management, and outcomes of the complications were recorded. RESULTS: The appearance of each ablation zone, including the target tumor and surrounding normal lung parenchyma, showed involution at follow-up CT. Local recurrence was demonstrated histopathologically or radiologically in nine tumors. The other 90 tumors showed no growth progression at follow-up CT. Probable complete coagulation necrosis obtained with initial RF ablation was achieved in 91% (90 of 99) of the tumors. The mean maximal diameter of the nine tumors (19.6 mm +/- 7.7 [SD]) was not significantly different (P =.994) from that of the other 90 tumors (19.5 mm +/- 13.0). Primary lesions of those nine metastatic tumors varied and did not demonstrate a specific tendency. Complications included pneumothorax, fever higher than 37.5 degrees C, hemoptysis, cough, pleural effusion, abscess formation, and hemothorax. The overall complication rate was 76% (41 of 54 sessions). CONCLUSION: RF ablation seems to be a promising treatment for malignant thoracic tumors.

Cepharanthine enhances in vitro and in vivo thermosensitivity of a mouse fibrosarcoma, FSa-II, based on increased apoptosis.

Cepharanthine (Ce) is a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata. In our previous study, Ce significantly enhanced thermosensitivity and thereby reduced thermotolerance in vitro, and intra-peritoneal injection of Ce slightly enhanced thermosensitivity in vivo. In the present study, we investigated Ce's effect in vitro on the pattern of cell death after heating and the effect of intra-tumoral injection of Ce on in vivo thermosensitivity using a mouse fibrosarcoma, FSa-II, and C3H/He mice. Ce significantly enhanced the in vitro thermosensitivity of FSa-II cells with heating at 44 degrees C, with increased Ce concentration. Time-lapse microscopic observation of individual cells confirmed that Ce treatment hastened both apoptosis (specifically, apoptotic budding) and necrosis (as indicated by staining with propidium iodide). Staining with annexin V-enhanced green fluorescent protein indicated that Ce used concomitantly with heating significantly increased the proportion of cells in the early stage of apoptosis. Ce combined with heating also significantly increased the proportion of cells with high intracellular caspase-3 activity, as detected by a substrate of caspase-3, PhiPhiLux-G1D2. The intra-tumoral injection of Ce, followed by heating at 44 degrees C, significantly delayed in vivo tumor growth, and this delay increased in a Ce concentration-dependent manner. Ce injected 30 min before heating delayed tumor growth more than Ce injected immediately before heating. These findings suggest the potential of Ce as a thermosensitizer to increase apoptosis of tumor cells.

pEYFP-Nuc vector is a useful tool for three-dimensional and time-lapse observation of nuclear morphology of Jurkat cells during apoptosis.

Using a pEYFP-Nuc vector, which contains nucleic acid sequences of a nuclear localization signal, we established a Jurkat-YN cell line that expressed enhanced yellow fluorescent protein (EYFP) in the nucleus. We observed three-dimensional and time-lapse changes in nuclear morphology of Jurkat-YN cells during Fas-induced apoptosis using a confocal laser scanning microscope. The nuclear forms visualized by EYFP were almost equal in quality to those visualized by SYTO59, a nucleic acid stain for living cells. Three-dimensional deformities in the nuclear form were observed during apoptosis before chromatin condensation became apparent, indicating these deformities are characteristic morphological changes of the early stage of apoptosis. In conclusion, the pEYFP-Nuc vector is a useful tool in the time-lapse observation of nuclear morphology of living cells during apoptosis.

Intrapulmonary lymph nodes: thin-section CT findings, pathological findings, and CT differential diagnosis from pulmonary metastatic nodules.

We compared the thin-section CT findings of 11 intrapulmonary lymph nodes with pathological findings and evaluated the possibility of CT scan differential diagnosis from pulmonary metastatic nodules. First, we retrospectively reviewed CT scan and pathological findings of intrapulmonary lymph nodes. The median size of these nodules was 6.2 mm. The nodules appeared round (n=3) or angular (n=8) in shape with a sharp border, and they were found below the level of the carina. The median distance from the nearest pleural surface was 4.6 mm, and 3 of the 11 nodules were attached to the pleura. On thin-section CT scan, linear densities extending from the intrapulmonary lymph nodes were frequently visualized, and were pathologically proven to be ectatic lymphoid channels. We then compared the thin-section CT findings of 8 metastatic nodules less than 1 cm in diameter with those of the 11 intrapulmonary lymph nodes. The median size of these nodules was 6.8 mm, and the median distance from the nearest pleural surface was 16 mm. All nodules appeared round in shape. None of the nodules had linear densities extending from the nodules. The linear densities on thin-section CT scan may be the most useful characteristic of intrapulmonary lymph nodes, when differential diagnosis from metastatic nodules is necessary.

Percutaneous sclerotherapy for venous malformations using polidocanol under fluoroscopy.

This retrospective study evaluated the safety and efficacy of using polidocanol with X-ray fluoroscopy for percutaneous sclerotherapy of venous malformations of the limbs, head, and neck. The subjects were 16 of 18 patients who presented to our department with venous malformations. Two patients were excluded because they were unlikely to benefit from the treatment. Of the 16 included in the study, 1 could not be treated because of inaccessibility, and another was lost to follow-up. Among the 14 cases that we were able to follow-up, 11 cases had had pain as their primary symptom. Following treatment, this symptom remained unchanged in 1 patient, was improved in 4, and had disappeared in 6; however, there was a recurrence of pain for 3 of these patients. Two patients had sought treatment for cosmetic purposes; following treatment, the lesion disappeared in one and showed a significant reduction in the other. The remaining patient presented with a primary symptom of mouth bleeding, which disappeared following treatment. There were no critical complications. Percutaneous sclerotherapy of venous malformations using polidocanol is safe and effective, and permits repeat treatments. The efficacy is especially good for resolving pain, and complications are minor. It is desirable to use fluoroscopy for these procedures

Differential diagnosis of adrenal masses by chemical shift and dynamic gadolinium enhanced MR imaging.

Chemical shift MRI is widely used for identifying adenomas, but it is not a perfect method. We determined whether combined dynamic MRI methods can lead to improved diagnostic accuracy. Fifty-seven adrenal masses were examined by chemical shift and dynamic MR imaging using 2 MR systems. The masses included 38 adenomas and 19 non-adenomas. In chemical shift MRI studies, the signal intensity index (SI) was calculated, and the lesions classified into 5 types in the dynamic MRI studies. Of the 38 adenomas studied, 37 had an SI greater than 0. In the dynamic MRI, 34 of 38 adenomas showed a benign pattern (type 1). If the SI for the adenomas in the chemical shift MRI was considered to be greater than 0, the positive predictive value was 0.9, and the negative predictive value was 0.94 and kappa = 0.79. If type 1 was considered to indicate adenomas in the dynamic MRI, the corresponding values were 0.94, 0.81 and kappa = 0.77 respectively. The results obtained when the 2 methods were combined were 1, 0.95 and kappa = 0.96 respectively. The chemical shift MRI was found to be useful for identifying adenomas in most cases. If the adrenal mass had a low SI (0 < SI < 5), dynamic MRI was also found to be helpful for making a differential diagnosis.

MR imaging of renal cell carcinoma: associations among signal intensity, tumor enhancement, and pathologic findings.

The purpose of this study was to compare the MR characteristics of renal cell carcinomas against histologic findings and to assess the correlations among signal intensity, tumor enhancement, and pathologic findings. Fifty-four patients (56 lesions) were examined by MR imaging and then underwent partial or radical nephrectomy. The pathologic diagnosis of all lesions was renal cell carcinoma. All MR examinations were performed as dynamic studies using the same 1.5-T scanner. MR characteristics were compared against pathologic findings after resection, and the correlations among signal intensity, tumor enhancement, and pathologic findings were then assessed. A significant correlation was observed between tumor grade and tumor enhancement, with G3 lesions tending to show little enhancement. Regardless of the histologic classification, G3 tumors were found to contain highly heterotypic cancer cells and very few vessels by histopathologic examination. No significant correlations were noted between the other MR characteristics and pathologic findings. Renal cell carcinomas showing little enhancement tend to be highly malignant lesions based on the pathologic findings. Special consideration is required for these tumors with regard to the selection of surgical intervention and follow-up observation.

Development of a tissue-equivalent MRI phantom using carrageenan gel.

A new tissue-equivalent MRI phantom based on carrageenan gel was developed. Carrageenan gel is an ideal solidifying agent for making large, strong phantoms in a wide variety of shapes. GdCl(3) was added as a T(1) modifier and agarose as a T(2) modifier. The relaxation times of a very large number of samples were estimated using 1.5-T clinical MRI equipment. The developed phantom was found to have a T(1) value of 202-1904 ms and a T(2) value of 38-423 ms when the GdCl(3) concentration was varied from 0-140 mumol/kg and the agarose concentration was varied from 0-1.6% in a carrageenan concentration that was fixed at 3%. The range of measured relaxation times covered those of all types of human tissue. Empirical formulas linking the relaxation time with the concentration of the modifier were established to enable the accurate and easy calculation of the modifier concentration needed to achieve the required relaxation times. This enables the creation of a phantom having an arbitrary combination of T(1) and T(2) values and which is capable of retaining its shape.

Comparison of Tc-99m-GSA scintigraphy with hepatic fibrosis and regeneration in patients with hepatectomy.

OBJECTIVE: Liver regeneration after hepatectomy is correlated with liver fibrosis. Retrospectively, we compared three quantitative indices (HH15, LHL15 and LU15) of Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (Tc-99m-GSA) liver scintigraphy with liver fibrosis; in particular, we compared the HH15 index and the rate of remnant liver regeneration. METHODS: Fifty-three patients who had undergone hepatectomy were enrolled in this study. The non-neoplastic parts of their resected specimens were divided into 5 groups (F0-F4) according to the degree of liver fibrosis, as determined using the New Inuyama classification system: F0, no fibrosis (n = 12); F1, portal fibrosis widening (n = 12); F2, portal fibrosis widening with bridging fibrosis (n = 14); F3, bridging fibrosis plus lobular distortion (n = 7); F4, liver cirrhosis (n = 8). RESULTS: When the cases were divided into a no or mild fibrosis group (F0 and F1) and a moderate or severe fibrosis or cirrhosis group (F2, F3 and F4), all of the indices were significantly different between the two groups. In this analysis, the areas (Az) under the receiver operating characteristic (ROC) curves for the HH15 and LHL15 indices were very similar, while the Az for the LU15 index was smaller. An HH15 index equal to 0.52 was the most accurate, producing a 79.3% sensitivity and a 75.0% specificity rating. When 18 patients that had received a CT scan one month after hepatectomy were divided into 2 groups according to their HH15 value (group A, HH15 < or = 0.52; group B, HH15 > 0.52), group A exhibited a better regeneration rate. CONCLUSION: Tc-99m-GSA scintigraphy is well correlated with liver fibrosis and may be useful for non-invasive, preoperative evaluations of liver fibrosis. The HH15 index, in particular, may be useful for predicting the rate of liver regeneration after hepatectomy.

Phase I/II study of altered schedule of cisplatin and etoposide administration and concurrent accelerated hyperfractionated thoracic radiotherapy for limited-stage small-cell lung cancer.

To improve the efficacy of a combination of cisplatin and etoposide and concurrent accelerated twice-daily thoracic radiotherapy against limited-stage small-cell lung cancer, we conducted a phase I/II study using an altered schedule of chemotherapy administration. Chemotherapy consisted of four cycles of cisplatin (days 1 and 8) and etoposide (days 1, 2, 8, and 9) every 4 weeks. Accelerated hyperfractionated thoracic radiation (1.5 Gy twice daily x 30 fractions, total dose of 45 Gy) was concurrently given with the first cycle of chemotherapy. The recommended doses of cisplatin and etoposide determined in the phase I study were 40 and 80 mg/m(2), respectively. In the phase II study, the overall response rate was 100% (complete response: 32%, partial response: 68%). By a median follow-up time of 29 months, median radiation-outfield progression-free survival was 13.4 months, while radiation-infield progression-free survival did not reach median value. The median overall survival time was 22.9 months, with survival rate of 48.4% at 2 years. Major toxicities were leukopenia and neutropenia (>/=grade 3, 92% each). The local control and overall survival demonstrated in this study were excellent. However, the insufficient distant control suggests a need for development of more active chemotherapy regimens.

[Linear-accelerator-based stereotactic irradiation for metastatic brain tumors].

To assess the safety and availability of stereotactic radiotherapy (SRT) for metastatic brain tumors, we reviewed 54 consecutive cases with a total of 118 brain metastases treated with linear-accelerator-based stereotactic irradiation (STI). Nineteen patients with a total of 27 brain tumors that were larger than 3 cm or close to critical normal tissues were treated with SRT. The marginal dose of SRT was 15-21 Gy (median 21 Gy) in 3 fractions for 3 days. The median marginal dose of stereotactic radiosurgery (SRS) was 20 Gy. Effective rates of imaging studies were 72.7% and 94.4%, and those of clinical symptoms were 46.7% and 55.6% for SRT and SRS, respectively. One-year and two-year survival rates of SRT were 40.9% and 17.6%, respectively, and the median follow-up period was 6.4 months. The one-year survival rate of SRS was 32.7%, with a median follow-up of 4.6 months. Fourteen cases (7 cases each) had recurrent tumors at STI sites. Early complications were observed in one case of SRT and 8 cases of SRS, and late complications occurred in 3 cases of SRS. There were no significant differences among effective rates, survival rates, median follow-up times, recurrence rates, and complications between SRT and SRS. We concluded that SRT is a safe, effective therapy for large or eloquent area metastases.

Quantitative evaluation by Tl-201 scintigraphy in the diagnosis of thyroid follicular nodules.

We examined the diagnostic capability of a quantitative evaluation by determining the optimum area for comparisons with nodule and optimum imaging time by Tl-201 scintigraphy in thyroid follicular nodules, retrospectively. Ninety-one thyroid follicular nodules, for which the pathological diagnosis had been established, were examined (60 benign, 31 malignant). After 74 MBq of Tl-201 chloride was injected intravenously, Tl-201 scintigrams were obtained at 10, 20, 30, and 120 min. For the quantitative evaluation, the area with the greatest accumulation in the nodule and a comparative region in the contralateral thyroid and the soft tissues in the cervical region were manually selected as the region of interest (ROI) referring to Tc-99m pertechnetate scintigrams and ultrasonographic findings as a guide by two radiologists, and the T/N ratio (tumor/normal tissue ratio) and T/S ratio (tumor/soft tissue ratio) were calculated. The pixel counts were determined for all ROI. A summary index of overall test performance can be calculated as the area under the receiver operating characteristic (ROC) curve (Area (Az)), and the likelihood ratios were also calculated. We estimated the cut-off on a fitted binormal ROC curve. Multiple regression analyses were used to investigate the relationships between the optimum quantitative evaluation and 5 independent variables. A p value below 5% was considered to be significant. The T/N ratio and T/S ratio were significantly higher in the malignant group at 10 min (0.844 and 0.702), 20 min (0.844 and 0.704), 30 min (0.841 and 0.670), and 120 min (0.887 and 0.733), respectively (p < 0.01). The Az for the T/N ratio was greatest at 120 min. The multiple regression analysis showed that only 'benign or malignant' was a significant variable in the T/N ratio at 120 min. It correlated significantly in interobserver (r = 0.80) and intraobserver (r = 0.80) studied (p < 0.001). An assessment of the cut-off value of the T/N ratio at 120 min, at the cut-off of 1.255, the likelihood ratio for positive test result was greatest at 8.56, while at the cut-off of 1.010, the likelihood ratio for negative test result was lowest at 0.165. The T/N ratio at 120 min was more useful than the other condition to distinguish between benign and malignant thyroid follicular nodules.

Hepatectomy simulation discrepancy between radionuclide receptor imaging and CT volumetry: influence of decreased unilateral portal venous flow.

BACKGROUND: Regional dysfunction demonstrated by Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin (GSA) scintigraphy due to regional decrease in the portal venous flow has previously been reported. In this study, we call attention to the significance of unilateral portal venous flow decrease for preoperative hepatectomy simulation, and evaluate the hepatectomy simulation discrepancy between Tc-99m-GSA single-photon emission computed tomography (SPECT) and CT volumetry. METHODS: Twenty-four hepatectomy candidates underwent preoperative hepatectomy simulation by both Tc-99m-GSA SPECT and CT volumetry. Both anatomical and functional resection ratios were calculated by means of CT volumetry and Tc-99m-GSA SPECT, respectively. The differences and ratios between anatomical and functional resection ratios were calculated in all patients, and compared in patients with and without unilateral portal venous flow decrease. RESULTS: Anatomical resection ratios were 28.0 +/- 11.7 (mean +/- standard deviation) in patients with unilateral portal venous flow decrease, and 42.1 +/- 15.7 in patients without unilateral portal venous flow decrease (p = 0.0127). Functional resection ratios were 14.7 +/- 12.8 in patients with unilateral portal venous flow decrease and 40.5 +/- 14.6 in patients without (p = 0.0004). The differences between anatomical and functional resection ratios were 13.0 +/- 7.9 in patients with unilateral portal venous flow decrease and 5.6 +/- 3.1 in patients without (p = 0.0099). The ratios between anatomical and functional resection ratios were 0.48 +/- 0.29 in patients with unilateral portal venous flow decrease and 0.86 +/- 0.10 in patients without (p = 0.0018). In 12 of the 13 patients with unilateral portal venous flow decrease, anatomical resection ratios were found to be larger than functional resection ratios, whereas this happened in only 6 of 11 patients without unilateral portal venous flow decrease (p = 0.0063). CONCLUSION: Unilateral portal venous flow decrease is suspected to be a major factor in the discrepancy between hepatectomy simulations with radionuclide receptor imaging and CT volumetry.