Tamio Aburano

Diagnosis and treatment of progressive space-occupying radiation necrosis following stereotactic radiosurgery for brain metastasis: Value of proton magnetic resonance spectroscopy

Summary¶Background. There have been some reports that radiation necrosis can be controlled conservatively. There are rare cases showing progressive space-occupying radiation necrosis (PSORN). It is very difficult to control PSORN by conservative treatment. The purpose of this study was to evaluate the early diagnosis of those cases and the timing of surgery for patients with PSORN.Method. We have experienced some cases where quality of life was improved by the removal of PSORN after stereotactic radiosurgery (SRS) for brain metastases. Therefore, we evaluated retrospectively the diagnosis and treatment of six cases of symptomatic PSORN at approximately 6–12 months after SRS for metastatic brain tumours.Findings. In all six cases, on Magnetic Resonance Imaging with Gd contrast material (Gd-MRI), PSORN was revealed as a ring-like enhanced mass with large perifocal oedema coupled with the appearance of neurological deficit. Proton Magnetic Resonance Spectroscopy (1H-MRS) enabled us to differentiate PSORN from recurrence of metastases in all six cases. Single Photon Emission Computed Tomography with thallium-201 chloride (201TlCl-SPECT) enabled us to do this in four cases of the six. In four cases of the six, lesionectomy of the ring-like enhanced mass (PSORN) was performed, and in two of these cases the removal was performed within 4 weeks from the time when conservative treatment became ineffective, and the neurological deficit and perifocal oedema was improved as was the quality of life. However, in the other two patients who were left for more than 16 weeks, the deficit was gradually progressive. The two patients who did not receive lesionectomy were treated by conservative means with steroids and/or heparin and warfarin and they had progressive neurological symptoms.Interpretation. Although, the number of patients is small in this study, and more data will be needed, it is recommended that lesionectomy is performed at an early stage, if possible, when conservative management has failed.

Evaluation of normal fatty replacement of the thymus with chemical‐shift MR imaging for identification of the normal thymus

To clarify the influences of age and gender on normal fatty replacement of the thymus in childhood, adolescence, and early adulthood using chemical‐shift MRI.

Venous Sac Embolization of Pulmonary Arteriovenous Malformation: Preliminary Experience Using Interlocking Detachable Coils

AbstractPurpose: To evaluate the indication and advantages of venous sac embolization of pulmonary arteriovenous malformations (PAVMs) using interlocking detachable coils (IDCs).n Methods: We performed percutaneous embolization in 12 PAVMs in four patients using IDCs, initially placed in the venous sac or at the feeding artery to prevent systemic migration of additional coils. We placed the IDCs in the venous sac in PAVMs with the following vascular architecture: the draining vein was larger than the feeding arteries and both vessels were interposed with the venous sac or there were short feeding arteries.n Results: Complete occlusion was achieved in all 12 PAVMs without significant complications. We deployed IDCs in the venous sac in eight PAVMs and in the feeding artery in four.n Conclusion: Venous sac embolization may be beneficial in PAVMs with large out-flow vessels or short feeding arteries. IDCs are suitable for this procedure.

Paravertebral neurinoma associated with aggressive intravertebral extension

Abstractu2002Neurinomas are relatively common benign tumors thought to arise from nerve sheath cells. Although intraosseous neurinomas may destroy the bone, extraosseous neurinomas with extensive destruction and invasion of bone are considered rare. We present two unusual cases of a benign extraosseous neurinoma that extensively invaded the vertebral body through the nutrient canal.

Efficacy, toxicity and mode of interaction of combination radioimmunotherapy with 5-fluorouracil in colon cancer xenografts

Purpose:The feasibility of radioimmunotherapy (RAIT) combined with 5-fluorouracil (5-FU) was examined in colon cancer xenografts. The mode of interaction of the two treatments was also investigated. Methods: Mice bearing human colon cancer were treated with a combination of 4.63u2009MBq (L-RAIT) or 9.25u2009MBq (H-RAIT) 131I-A7, an IgG1 against 45-kDa glycoprotein, and 5-FU at a dose of 30u2009mgu2009kg−1u2009day−1 for 5 days. Myelotoxicity was monitored by blood cell counts and intestinal toxicity was assessed by the dosimetry. The results were compared with those of a single-modality therapy. Results: The combination of 5-FU with H-RAIT enhanced the antitumor effect, improving the tumor quadrupling time from 25.3u2009±u20099.59 days to 31.3u2009±u20098.32 days (Pu2009<u20090.05) and inducing tumor regression in 7 out of 10 mice, compared to 3 out of 9 mice treated with H-RAIT alone. The efficacy of L-RAIT was also improved by the combination. Analysis of the dose/response relationship showed an additive interaction of the two modalities. The combination of 5-FU with RAIT induced slightly more severe myelotoxicity than a single-modality treatment, but blood cell counts recovered similarly. Dose estimation suggested that RAIT does not increase the intestinal toxicity of 5-FU. Conclusion: The combination of two modalities would be feasible for the treatment of colon cancer, increasing antitumor effect with minor effect on toxicity.

The growing teratoma syndrome secondary to immature teratoma of the ovary.

Abstract.nThe growing teratoma syndrome (GTS) secondary to a testicular nonseminomatous germ cell tumor has been well described since the first case was reported in 1982. In addition, radiological findings of male GTS have also reported in several studies; however, its occurrence secondary to an ovarian germ cell tumor is extremely rare. We experienced a 5-year-old girl who had GTS secondary to immature teratoma of the right ovary. In this article we present radiological findings of female GTS with clinical and pathological correlation.

Comparison of myocardial fatty acid metabolism with left ventricular function and perfusion in cardiomyopathies: by 123 I-BMIPP SPECT and 99m Tc-tetrofosmin electrocardiographically gated SPECT

Objective: To investigate myocardial fatty acid metabolism and its relationship with left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM).Methods: Thirty-nine patients with cardiomyopathies (58±14 y), comprising 15 DCM and 24 HCM, and 9 age-matched healthy controls were studied with123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and99mTc-tetrofosmin (TF) electrocardiographically gated SPECT. As parameters of myocardial fatty acid metabolism, the heart-to-mediastinum ratio (H/M) and global washout of BMIPP were calculated from early and delayed planar images, while regional BMIPP uptake and washout were calculated from SPECT. In TF study, the H/M (H/M-TF) and LV ejection fraction (LVEF) were calculated as global parameters of perfusion and function, while regional TF uptake and wall thickening index were calculated as regional parameters of perfusion and function using the Quantitative Gated SPECT software. The differences in the parameters and the correlations between the parameters from the 2 studies were investigated by one-way ANOVA and multiple linear regression analysis.Results: BMIPP uptake was decreased (p<0.05), and its washout was increased (p<0.05) in DCM and HCM. In multiple linear regression analysis, global BMIPP parameters showed no significant correlation with LVEF (p>0.05), but showed a significant correlation with H/M-TF (p<0.05) in DCM and HCM. According to the partial correlation coefficient, early H/M was the only significant factor (p<0.05) for predicting H/M-TF in DCM and HCM. Multiple linear regression analysis on regional parameters showed regional BMIPP parameters had no correlation with regional function (p>0.05) but had a significant correlation with regional perfusion (p<0.0001) in DCM. In HCM, regional BMIPP parameters showed significant multiple linear correlations with both regional function (p<0.005) and perfusion (p<0.0001). According to the partial correlation coefficients, delayed regional BMIPP uptake was the most significant factor for predicting regional function in HCM, while early regional BMIPP uptake was the only or the most significant factor for predicting regional perfusion in DCM and HCM, respectively.Conclusion: In DCM, BMIPP uptake and washout could not reflect LV function. In HCM, regional delayed BMIPP uptake might be useful for evaluating regional function. In DCM and HCM, early BMIPP uptake might be largely determined by myocardial perfusion.

Solitary fibrous tumor of the pleura: Apparent diffusion coefficient (ADC) value and ADC map to predict malignant transformation

Solitary fibrous tumors (SFTs) of the pleura are rare soft‐tissue tumors that are presumed to be of mesenchymal origin. Most SFTs are histologically benign, but up to 20% of SFTs may be malignant. In addition, malignant transformation may occur within histologically benign SFTs, though it is rare. However, it is difficult to diagnose malignant SFTs of the pleura by means of conventional computed tomography and magnetic resonance imaging (MRI). In this article we present the first case of malignant SFT of the pleura in an 81‐year‐old man in which the apparent diffusion coefficient (ADC) value and ADC map based on diffusion‐weighted MRI were very useful for identifying malignant transformation. J. Magn. Reson. Imaging 2007;26:155–158.

Combination radioimmunotherapy with local hyperthermia: increased delivery of radioimmunoconjugate by vascular effect and its retention by increased antigen expression in colon cancer xenografts

Hyperthermia (HT) may increase tumor targeting of a radiolabeled antibody by its effects on tumor vasculature and antigen expression. Expression of a 45-kDa glycoprotein antigen on LS180 colon cancer cells was 2.7-fold enhanced 2 days after heating at 43 degrees C for 1 h. Preferential tumor accumulation of 125I-A7 recognizing this antigen was doubled and the antitumor effect of 131I-A7 was significantly improved by HT. Hyperthermia also increased tumor uptake of an irrelevant antibody but its radioactivity was rapidly cleared. These results indicate that HT increased the initial delivery of an antibody to a tumor by its vascular effect, and radioactivity was retained in tumors by increased specific binding, resulting in a better radioimmunotherapy outcome.

Acute rhabdomyolysis of the soleus muscle induced by a lightning strike: magnetic resonance and scintigraphic findings.

Among natural disasters, a lightning strike is a rare but potentially life-threatening phenomenon. If victims survive a cardiac arrest due to instantaneous passage of an exceptionally high voltage electric charge through the whole body, they may be afflicted with various complications such as muscle necrosis resulting in acute renal failure. In this article, we report a case of a 54-year-old man with acute rhabdomyolysis of the left soleus muscle associated with a lightning strike. T2-weighted and short-tau inversion recovery MR images showed a high signal intensity in the left soleus muscle. A whole-body bone scintigram showed abnormal uptakes in the left soleus muscle and the dorsal aspect of the left foot. MR and scintigraphic evaluations were very useful in depicting the site and extent of muscle damage. Since the patient showed a surprisingly high level of serum creatine kinase, the added information was very valuable for determining the patient’s management.