Toshiki Kazama

Diagnostic value of FDG PET and salivary gland scintigraphy for parotid tumors

Purpose: The purpose of this study was to examine the diagnostic value of the combination of F-18 fluorodeoxyglucose (FDG) PET and Tc-99m pertechnetate salivary gland scintigraphy in parotid tumors. Materials and Methods: Seventy-two patients with benign parotid gland tumors (n = 52), malignant parotid tumors (n = 12), and inflammation (n = 8) underwent both FDG PET and salivary gland scintigraphy within 1 week, and 66 of the patients also underwent gallium scintigraphy. All patients were negative on their first fine-needle aspiration (FNA). Results: Malignant parotid tumors showed significantly higher FDG uptake (standard uptake values [SUVs]) than both benign tumors and inflammation, except in Warthins tumor (5.82 ± 3.95 vs. 2.07 ± 1.33; P <0.01). Although the SUV values of Warthins tumor and malignant parotid tumors overlapped somewhat, Warthins tumor did demonstrate increased radiotracer uptake, and it was reliably distinguished from other parotid gland tumors by the use of salivary gland scintigraphy. Considering a SUV value >3 as being positive for malignancy and excluding Warthins tumor on the basis of salivary gland scintigraphy, sensitivity and specificity of FDG PET were 75% and 80%, respectively. These results were superior to those of gallium scintigraphy (58% and 72%, respectively). Conclusions: Although the diagnostic value of FDG PET in the differentiation of malignant from benign parotid gland tumors was limited because of the high FDG uptake in some benign tumors, and particularly pleomorphic adenomas, combining salivary gland scintigraphy with FDG PET may help to negate this drawback, and this combination may be a more promising approach for differentiation of various parotid gland tumors in patients compared with nondiagnostic needle aspiration.

Measurement of the apparent diffusion coefficient in the liver: is it a reliable index for hepatic disease diagnosis?

PurposeThe aim of this study was to determine the validity of the hepatic apparent diffusion coefficient (ADC) measurement. The influence of differences in measured location and administration of Buscopan (hyoscine butylbromide) for ADC were assessed.Materials and methodsSENSE-DWI (b = 0, 500) was obtained before and after Buscopan administration to 30 patients suspected of having a liver tumor. In this sequence, respiration gating was employed, but cardiac triggering was not. ADC measurement was performed in the hepatic parenchyma of both right and left lobes in selected slices. A statistical analysis was performed to estimate the correlation among ADC, measured location, Buscopan, and pulse rate. The images were visually evaluated to categorize the subcardiac signal loss in the left lobe.ResultsThe ADC showed higher values in the left lobe than in the right lobe in both pre- and postloaded studies (P < 0.001). In a comparison between ADCs in the pre- and postloaded studies, the differences were not significant in the left lobe (P = 0.93) or the right lobe (P = 0.41). No correlation was noted between ADCs and the pulse rate. Visual evaluation revealed that the subcardiac signal loss was more prominent in the postloaded study.ConclusionADC measurement of the left hepatic lobe was far more incorrect than that of the right lobe if cardiac gating was not employed. The administration of Buscopan worsened the image quality of the left lobe and made visual evaluation difficult.

Efficacy of 3D-MR mammography for breast conserving surgery after neoadjuvant chemotherapy.

BackgroundOne of the main roles of neoadjuvant chemotherapy for breast cancer is to shrink large tumors to increase patient eligibility for breast conserving surgery. Three dimensional MR Mammography (3D-MRM) can detect tumor extension more accurately compared with mammography and Ultrasonography (US). Therefore, the shrinkage pattern observed on 3D-MRM was analyzed with regard to several pathological factors.MethodsA total of 27 breast cancer cases were examined by 3D-MRM before and after neoadjuvant chemotherapy. The volume reduction and shrinkage patterns were assessed and compared with the pathological diagnosis.ResultsThere were two shrinkage patterns. Twelve of 25 evaluable breast cancers (48%) showed a concentric shrinkage pattern while 13 cases (52%) showed a dendritic shrinkage pattern. The cases with concentric shrinkage were good candidates for breast coserving surgery, But tumors showing dendritic shrinkage often had positive margins necessitating mastectomy. Pathologically, tumors with a papillotubular pattern, Estrogen receptor (ER) positivity, low nuclear grade and c-erbB 2 negativity tended to show dendritic shrinkage.Conclusions3D-MRM is a useful modality for evalumting whether breast conserving surgery can be safely done in the neoadjuvant setting.

Apparent Diffusion Coefficient Values Measured by Diffusion-Weighted Imaging Predict Chemoradiotherapeutic Effect for Advanced Esophageal Cancer

Background: The purpose of this study was to assess whether apparent diffusion coefficient (ADC) values of esophageal squamous cell carcinoma (ESCC) predict responses to chemoradiotherapy (CRT) and/or patient prognosis. Methods: Magnetic resonance images were acquired to construct the diffusion-weighted images, and the ADC values were calculated before CRT in 80 patients with ESCC. A high-ADC group responded better to CRT than did a low-ADC group (p < 0.01). We divided the 80 patients into two groups based on the operating characteristic analysis: one group comprised patients with ADC values higher than the average ADC of the esophageal cancer tissue (1.10 × 10–3 mm2/s), and the other group comprised those whose ADC values were less than the average value. A Kaplan-Meier analysis showed that the survival rate in the high-ADC group was significantly better than that in the low-ADC group (p = 0.04). Conclusion: Our results indicate that the ADC value may be a useful marker to predict treatment response as well as survival for patients with ESCC.

Breast-Conserving Surgery Using Projection and Reproduction Techniques of Surgical-Position Breast MRI in Patients with Ductal Carcinoma In Situ of the Breast

BACKGROUND In this study, we report a breast-conserving surgery (BCS) approach that uses projection and reproduction techniques of breast MRI obtained in the surgical position to the breast surface in patients with ductal carcinoma in situ (DCIS) of the breast. STUDY DESIGN Between February 2005 and January 2007, a total of 104 patients with operable breast cancer at our hospital had surgical-position breast MRI examinations. The 24 patients with relatively localized DCIS received BCS using the projection and reproduction techniques of the surgical-position breast MRI. During the same time period, 28 patients with relatively localized DCIS in whom prone-position breast MRI was performed, had conventional BCS using mammography-guided hookwires. In this study, we compared the surgical outcomes of our surgical approach with those of the conventional approach in a total of 52 patients with relatively localized DCIS. RESULTS Average volume of the pathologic specimens in the new technique group (27.5 cm(3)) was substantially smaller than that in the conventional BCS group (57.6 cm(3), p = 0.0007). In addition, the positive margin rate was substantially lower in the new technique group (12.5%) than in the conventional BCS group (39.3%; p = 0.029). CONCLUSIONS This study demonstrates that BCS can be done guided by the precise projection and reproduction techniques of the lesion obtained by surgical-position breast MRI. To the best of our knowledge, this is the first report of BCS technique for DCIS in this manner. Our surgical approach can be clinically useful in surgical planning and management in patients with DCIS.

Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

AbstractObjectiveBecause diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis.MethodsSeventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis.ResultsThe ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = −0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026).ConclusionOur results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer.Key Points• Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen • There is also negative correlation between ADCs and vascular endothelial growth factor • ADC values may contribute to the treatment of oesophageal cancer.

Dynamic enhanced MRI predicts chemosensitivity in breast cancer patients

BACKGROUND Primary chemotherapy for breast cancer is effective as postoperative adjuvant therapy. However, one of the critical disadvantages was a treatment delay for patients with progressive disease. The present study attempts to clarify quantitative parameters on MRI which can be used to predict the sensitivity to treatment in breast cancer patients. METHODS The subjects consisted of 26 patients with invasive ductal breast cancer who received primary chemotherapy before surgery. The mean maximum tumor dimension was 3.3cm, and 21 cases had nodal involvements. Three cases demonstrated histological grade 3. Dynamic enhanced MRI was evaluated at three different time periods; prior to, in the midst of preoperative chemotherapy, and just before the initial operation. The signal intensity ratio (SIR) and early contrast uptake (ECU) were calculated, as well as the correlation between these dynamic data and the tumor reduction rates were analyzed retrospectively. P-values of less than 0.05 were considered to indicate statistically significant. RESULTS Responders to chemotherapy had the significantly higher SIR and ECU values than non-responders (p=0.0454 and 0.0334, respectively). ECU value significantly decreased as tumor reduction by chemotherapy (p=0.0028). Pathological tumor dimension was significantly correlated with the tumor size estimated on presurgical MRI (p<0.0001). CONCLUSIONS Our current series demonstrated the significant correlation between pretreatment MRI data and tumor reduction by chemotherapy in breast cancer patients. With these results, it seems possible to define good and non-responders prior to treatment.

Comparison of diffusion-weighted images using short inversion time inversion recovery or chemical shift selective pulse as fat suppression in patients with breast cancer

PurposeFat suppression is essential for diffusion-weighted imaging (DWI) in the body. However, the chemical shift selective (CHESS) pulse often fails to suppress fat signals in the breast. The purpose of this study was to compare DWI using CHESS and DWI using short inversion time inversion recovery (STIR) in terms of fat suppression and the apparent diffusion coefficient (ADC) value.Materials and methodsDWI using STIR, DWI using CHESS, and contrast-enhanced T1-weighted images were obtained in 32 patients with breast carcinoma. Uniformity of fat suppression, ADC, signal intensity, and visualization of the breast tumors were evaluated.ResultsIn 44% (14/32) of patients there was insufficient fat suppression in the breasts on DWI using CHESS, whereas 0% was observed on DWI using STIR (P < 0.0001). The ADCs obtained for DWI using STIR were 4.3% lower than those obtained for DWI using CHESS (P < 0.02); there was a strong correlation of the ADC measurement (r = 0.93, P < 0.001).ConclusionDWI using STIR may be excellent for fat suppression; and the ADC obtained in this sequence was well correlated with that obtained with DWI using CHESS. DWI using STIR may be useful when the fat suppression technique in DWI using CHESS does not work well.

3D-MR mammography-guided breast conserving surgery after neoadjuvant chemotherapy: clinical results and future perspectives with reference to FDG-PET.

BackgroundsThree dimensional MR Mammography (3D-MRM) can detect tumor extension more accurately than mammography or ultrasound. There are two shrinkage patterns observed by 3D-MRM after neoadjuvant chemotherapy. Concentric shrinkage is a good indication for breast conserving surgery. On the other hand, a dendritic pattern was represent ductal spread. Therefore, we developed MRM guided mapping to aid BCS for tumors showing a dendritic pattern.MethodsFifteen patients consisting of 8 stage II (T>3.5 cm) cases and 7 stage Ma cases aged 39 to 61 years (mean 47-8 years) were treated with AT neoadjuvant chemotherapy with the aim of performing breast conserving surgery. All patients were examined by 3D-MRM before and after neoadjuvant chemotherapy. Breast conserving surgery indications were determined by tumor volume reduction and shrinkage patterns on 3D-MRM. Supine position mapping using MRM was performed for dendritic type tumors. FDG-PET was simultaneously performed for one case with bilateral breast cancer.ResultsBreast conserving surgery was performed for 13 of the 15 cases. One case underwent re-operating and mastectomy because of a positive margin. One case had microscopically positive margin and received boost radiation. Therefore, 11 of 15 cases (73.3%) underwent BCS and achieved negative margins under MRM guidance. PET scanning can detect residual tumor and occult metastasis but it is not suitable for mapping because of its spatial resolution.Conclusions3D-MRM is a useful modality to select appropriate cases for breast conserving surgery after neoadjuvant chemotherapy. FDG-PET can also detect residual tumor or occult metastasis but it may not be suitable for mapping. Because both examinations have potential, further evaluation of their clinical efficacy is necessary.

Surrounding rim formation and reduction in size after radiofrequency ablation for primary breast cancer

PurposeRadiofrequency ablation (RFA) has recently been used to treat small breast cancer. However, there are no data on the long-term morphological features after the procedure. The present study attempts to clarify the characteristics of and changes in the ablated lesion.Materials and methodsA total of 17 breast cancer patients underwent RFA using a single needle featuring an internally cooled electrode; this was followed by whole-breast irradiation and adjuvant systemic therapy. Magnetic resonance imaging (MRI) using a 1.5-T system was performed before and 1, 3, 6, and 12 months after ablation, and the morphological characteristics and the size of the ablated lesion were evaluated. Mammography was also performed for a comparison with the MRI measurement.ResultsMRI displayed no residual enhancement of the tumor after RFA; there was an altered signal intensity with peripheral enhancement, however, and the area decreased in size gradually at a rate of 3.3% per month. Mammography showed a ring surrounding a roundish area whose size was equal to that seen with MRI.ConclusionOur current series demonstrated the morphological characteristics on breast imaging after RFA plus radiation therapy. The size of the ablated area decreased over time. These findings are valuable for clinical follow-up of breast cancer patients undergoing RFA.