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Yukihisa Saida

Publications and source records attributed to Yukihisa Saida.

At least 19 recordsLinked to original sources
PubMed2006

Proton beam therapy for invasive bladder cancer: a prospective study of bladder-preserving therapy with combined radiotherapy and intra-arterial chemotherapy.

PURPOSE: To present outcomes of bladder-preserving therapy with proton beam irradiation in patients with invasive bladder cancer. METHODS AND MATERIALS: Twenty-five patients with transitional cell carcinoma of the urinary bladder, cT2-3N0M0, underwent transurethral resection of bladder tumor(s), followed by pelvic X-ray irradiation combined with intra-arterial chemotherapy with methotrexate and cisplatin. Upon completion of these treatments, patients were evaluated by transurethral resection biopsy. Patients with no residual tumor received proton irradiation boost to the primary sites, whereas patients demonstrating residual tumors underwent radical cystectomy. RESULTS: Of 25 patients, 23 (92%) were free of residual tumor at the time of re-evaluation; consequently, proton beam therapy was applied. The remaining 2 patients presenting with residual tumors underwent radical cystectomy. Of the 23 patients treated with proton beam therapy, 9 experienced recurrence at the median follow-up time of 4.8 years: local recurrences and distant metastases in 6 and 2 patients, respectively, and both situations in 1. The 5-year overall, disease-free, and cause-specific survival rates were 60%, 50%, and 80%, respectively. The 5-year local control and bladder-preservation rates were 73% and 96%, respectively, in the patients treated with proton beam therapy. Therapy-related toxicities of Grade 3-4 were observed in 9 patients: hematologic toxicities in 6, pulmonary thrombosis in 1, and hemorrhagic cystitis in 2. CONCLUSIONS: The present bladder-preserving regimen for invasive bladder cancer was feasible and effective. Proton beam therapy might improve local control and facilitate bladder preservation.

Adult↗
PubMed2006

Systemic arterial supply to the normal basal segments of the left lower lobe treated by coil embolization, with long-term follow-up.

We report a case of a 41-year-old woman who underwent therapeutic embolization of an aberrant systemic artery of the lung. Except for chest pains immediately after embolization, she recovered well and has not experienced hemoptysis in the past 6 years. In such patients, coil embolization could be an alternative choice of treatment, with the expectation of an excellent long-term result despite ischemia of the corresponding lung parenchyma.

Adult↗
PubMed2005

Clinical results of proton beam therapy for cancer of the esophagus.

PURPOSE: To present the results of proton beam therapy for patients with esophageal cancer. METHODS AND MATERIALS: This study reviewed 46 patients with esophageal cancer who were treated between 1985 and 1998 using proton beams with or without X-rays. All patients had locoregionally confined disease; all but one had squamous cell carcinoma. Of the 46 patients, 40 received combinations of X-rays (median, 48 Gy) and protons (median, 31.7 Gy) as a boost. The median total dose of combined X-ray and proton radiation for the 40 patients was 76.0 Gy (range, 69.1-87.4 Gy). The remaining 6 patients received only proton beam therapy (median, 82.0 Gy; range, 75-89.5 Gy). RESULTS: The 5-year actuarial survival rate for the 46 patients, patients with T1 (n = 23), and those with T2-T4 (n = 23) was 34%, 55%, and 13%, respectively. The 5-year disease-specific survival rate for the 46 patients, those with T1, and those with T2-T4 was 67%, 95%, and 33%, respectively. The 5-year local control rate for patients with T1 and T2-T4 lesions was 83% and 29%, respectively. The site of the first relapse was locoregional for 16 patients and distant organs for 2 patients. CONCLUSION: The results suggest that proton beam therapy is an effective treatment for patients with locally confined esophageal cancer. Additional studies are required to determine the optimal total dose, fractionation schedule, and best combinations of protons and conventional X-rays with or without chemotherapy.

Aged↗
PubMed2005

Monitoring of hepatocellular carcinoma, following proton radiotherapy, with contrast-enhanced color Doppler ultrasonography.

BACKGROUND: We have reported that proton radiotherapy for hepatocellular carcinoma (HCC) is a safe and effective therapeutic option. However, it is difficult to evaluate its effect in certain cases. Recently, it has been reported that the usage of contrast-enhanced color Doppler ultrasonography (CECDU) can improve diagnostic accuracy, both in terms of the presence of hepatic tumor and in the evaluation of treatment. The aim of this study was to determine the usefulness of CECDU in assessing the therapeutic response of HCC treated with proton radiotherapy. METHODS: Twenty-two patients treated with the proton radiotherapy were studied. We inspected HCC lesions by CECDU, before and after the irradiation, over time. The magnitude of blood flow in the HCC was quantified on still images by CECDU. The ratio of the number of color pixels against that of the total number of pixels in the tumor area was defined as the tumor blood flow ratio (TBFR). RESULTS: Immediately after the proton treatment, a transient increase of blood flow in the tumor was recognized in more than half of the patients, while the TBFR was unchanged or decreased in the remaining patients. At longer periods after irradiation, the TBFR in all HCCs gradually decreased, and this reduction of TBFR was statistically significant from 9 months after irradiation. These findings are consistent with those obtained previously by computed tomography (CT) as well as magnetic resonance imaging (MRI). CONCLUSIONS: We propose CECDU as a useful diagnostic option for the evaluation of HCC treated with proton radiotherapy.

Aged↗
PubMed2005

Triple arterial phase dynamic MRI with sensitivity encoding for hypervascular hepatocellular carcinoma: comparison of the diagnostic accuracy among the early, middle, late, and whole triple arterial phase imaging.

OBJECTIVE: We assessed and compared the diagnostic accuracy of the early, middle, late, and whole triple arterial phase MRI with sensitivity encoding (SENSE) for the detection of hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Thirty-one patients with 102 HCCs underwent dynamic MRI with SENSE. The findings of CT examinations, combined with those of visceral angiography or histopathologic examination, were used as the gold standard. After acquisition of T1- and T2-weighted images, gadolinium-enhanced triple arterial, portal, and delayed phase images were obtained. Acquisition of the triple arterial phase imaging was started at the timing of peak aortic enhancement and completed within a single breath-hold. Acquisition time for each phase was 8.4 sec. Four image sets including the early, middle, late, and whole triple arterial phase imaging were interpreted separately by four observers. The mean values of area under alternative-free-response receiver operating characteristic (AFROC) curve and of sensitivity were compared among the four image sets. RESULTS: The mean values of area under AFROC curve were 0.52, 0.66, 0.53, and 0.68 and of sensitivity were 45%, 64%, 48%, and 65% for the image sets with the early, middle, late, and whole triple arterial phase imaging, respectively. Both mean values were significantly higher for the image sets with the middle and whole triple arterial phase imaging than for those with the early and late arterial phase imaging. CONCLUSION: The middle arterial phase imaging with k-space centered at 12.6 sec after the peak aortic enhancement was optimal for detecting HCC and showed diagnostic accuracy equivalent to that of the whole triple arterial phase imaging.

Aged↗
PubMed2004

High-resolution MR imaging of the elbow using a microscopy surface coil and a clinical 1.5 T MR machine: preliminary results.

OBJECTIVE: To obtain high-resolution MR images of the elbow using a microscopy surface coil with a 1.5 T clinical machine and to evaluate the feasibility of its use for elbow injuries. DESIGN AND PATIENTS: Five asymptomatic normal volunteers and 13 patients with elbow pain were prospectively studied with MR imaging using a microscopy surface coil 47 mm in diameter. High-resolution MR images using a microscopy coil were obtained with fast spin echo (FSE) proton density-weighted sequence, gradient recalled echo (GRE) T2*-weighted sequence, and short tau inversion recovery (STIR) sequence, with a 1-2 mm slice thickness, a 50-70 mm field of view, an imaging matrix of 140-224 x 512 using zero fill interpolation, and 2-6 excitations. RESULTS: High-resolution MR images of normal volunteers using a microscopy coil clearly showed each structure of the medial and lateral collateral ligaments on GRE T2*-weighted images and FSE proton-density weighted images. Partial medial collateral ligament injury, a small avulsion of the medial epicondyle, and osteochondritis dissecans were well demonstrated on high-resolution MR images. CONCLUSION: High-resolution MR imaging of the elbow using a microscopy surface coil with a 1.5 T clinical machine is a promising method for accurately characterizing the normal anatomy of the elbow and depicting its lesions in detail.

Adolescent↗
PubMed2004

Three-dimensional fast field echo MR myelography using water excitation.

The purpose of this study is to determine if 3D FFE MRM using WE provides better image quality in comparison with that using SPIR. Twenty subjects were referred for the MRM images using SPIR, and WE with different TR. SNR and CNR were measured in the ganglions and adjacent tissues, in addition, the uniformity of the fat tissues was scored on a three-point scale by two radiologists with consensus. The WE sequence showed the higher SNR and CNR values than that using SPIR, in addition, the WE technique was helpful to achieve the shorter acquisition time of MRM.

Adolescent↗
PubMed2004

Effect of postoperative chemotherapy on the serum alpha-fetoprotein level in hepatoblastoma.

PURPOSE: It is generally accepted that postoperative chemotherapy does not affect the serum alpha-fetoprotein (AFP) level. The authors report on 3 patients who supposedly showed chemotherapy-related changes in their AFP levels after operation. METHODS: This study included 3 patients with hepatoblastoma (1 case of PRETEXT III and 2 cases of PRETEXT IV). RESULTS: One patient with PRETEXT III underwent a complete tumor resection, and the postoperative AFP level decreased until it reached the normal range. However, he consistently exhibited a transient, 2- to 3-fold increase in the AFP after each course of chemotherapy for 3 courses. The chemotherapy regimen had to be stopped because of drug-induced encephalopathy, but he has been followed up for 5 years without any evidence of recurrence, and his AFP level has also remained stable and in the normal range. Two patients with PRETEXT IV, who underwent a curative tumor resection, also showed similar chemotherapy-related changes in AFP levels. Both of these cases were observed only after the administration of routine postoperative chemotherapy instead of administering further high-dose chemotherapy. The AFP level remained stable for 17 months and 7 months after the cessation of chemotherapy in 2 cases, respectively. CONCLUSIONS: Regarding the postoperative chemotherapy of hepatoblastoma, we have to pay close attention to both the AFP status during chemotherapy as well as the absolute AFP level.

Child, Preschool↗
PubMed2004

Dual double arterial phase dynamic MR imaging with sensitivity encoding (SENSE): which is better for diagnosing hypervascular hepatocellular carcinomas, in-phase or opposed-phase imaging?

The purpose of this study was to investigate the efficacy of sensitivity encoding (SENSE) dynamic magnetic resonance imaging (MRI) with the dual (in-phase and opposed-phase) double arterial phase to detect hypervascular hepatocellular carcinomas (HCCs). MR images of the liver from 44 consecutive patients were obtained. Dynamic MRI with SENSE was performed six times (precontrast, early arterial, late arterial, 1 min, 3 min and 5 min after contrast injection) at 11 s per scan using the gradient recalled echo sequence (TR/TE/flip angle = 168/2.3 and 4.6/70). In-phase and opposed-phase images were obtained simultaneously each scan. For the quantitative analysis, the signal-to-noise ratio (S/N) of HCC and tumor-to-liver contrast-to-noise ratio (C/N) were analyzed for 55 HCCs. The mean S/N of HCCs on in-phase images showed significantly higher values than that on opposed-phase images regarding all phases (P < 0.001). In arterial phases, the mean tumor-to-liver C/N for in-phase images was significantly higher than that for opposed-phase images (P < 0.05). In portal and delayed-phase images, the mean tumor-to-liver C/N in opposed-phase images showed a negative value. In six HCCs with fatty metamorphosis, the mean tumor-to-liver C/N on arterial phase images approached zero in opposed-phase, while it showed a positive value in-phase. In dual double arterial phase dynamic MRI of the liver, in-phase images were superior to opposed-phase images for detecting early enhancement of hypervascular HCCs, while the latter were superior for detecting washout of contrast media from HCCs in the portal and delayed phase. The combination of both images overcomes the difficulty of diagnosing hypervascular HCCs with fatty metamorphosis.

Aged↗
PubMed2004

Functioning ovarian tumors: direct and indirect findings at MR imaging.

There are many kinds of ovarian tumors and tumorlike conditions that produce estrogen or androgen. Magnetic resonance imaging can demonstrate not only ovarian tumors but also an enlarged uterus with a thick endometrium, even in cases of a clinically latent excess of estrogen. These clinical and indirect imaging findings can aid in the differential diagnosis of ovarian tumors. Granulosa cell tumor and thecoma are well-known estrogen-producing tumors. In pediatric or postmenopausal patients, they manifest as precocious pseudopuberty or postmenopausal bleeding, respectively. Conversely, Sertoli-Leydig cell tumor is representative of hormone-producing tumors that cause virilization. However, there are other functioning ovarian tumors besides the sex cord-stromal tumors. It is well known that metastatic ovarian tumors often have androgen-producing stroma and that mucinous cystadenoma sometimes produces estrogens. Most other ovarian tumors can produce sexual hormones in their stroma. In addition, some endocrinologic abnormalities (eg, polycystic ovary syndrome) also cause virilization.

Adolescent↗
PubMed2003

MR findings of spinal muscular atrophy Type II: sibling cases.

We present magnetic resonance (MR) findings of siblings affected by spinal muscular atrophy (SMA) Type II. MRI of their thighs showed severe muscle atrophy and fatty infiltration. Selective preservation of the adductor longus muscle, the gracilis muscle, and the sartorius muscles was observed, suggesting a characteristic finding of SMA Type II. These findings were more severe in the older patient.

Child, Preschool↗
PubMed2003

MR imaging of epidermoids at the cerebellopontine angle.

The most common location of intracranial epidermoid is the cerebellopontine angle (CPA). The present study compared the visibility of epidermoid at the CPA in various pulse sequences. Seven patients with epidermoid at the CPA underwent conventional MR imaging (T(1)-, T(2)- and proton density-weighted imaging) as well as diffusion-weighted echo-planar imaging. Fast fluid-attenuated inversion recovery (FLAIR) sequences, magnetization transfer contrast (MTC) sequences, and MR cisternography were employed for selected patients. The signal intensity of the lesions relative to cerebrospinal fluid (CSF), the degree of lesion demarcation and the displacement of surrounding structures were evaluated. Proton density-weighted imaging depicted the lesions as hyper-intense to CSF with clearer delineation than T(1)- and T(2)-weighted imaging. Diffusion-weighted imaging depicted all lesions as strongly hyper-intense relative to CSF and brain tissue. FLAIR sequences depicted the lesions with mixed signal intensities but with poor-to-medium demarcation. MTC imaging increased delineation of the lesions to some degree. MR cisternography depicted the lesions as hypo-intense to CSF and clearly showed the anatomical relation to neighboring nerves and vessels. We concluded that diffusion-weighted imaging could specifically reveal an epidermoid at the CPA as a strongly hyper-intense lesion, and that MR cisternography is mandatory for preoperative planning.

Adolescent↗
PubMed2003

A thickened or indistinct junctional zone on T2-weighted MR images in patients with endometrial carcinoma: pathologic consideration based on microcirculation.

Thickened or indistinct junctional zone (JZ) is a problematic finding in staging endometrial carcinoma. We studied the incidence, pathological cause of this condition correlated to microcirculation, and the utility of dynamic contrast MRI for differential diagnosis. T2-weighted images were analyzed in 119 cases with endometrial carcinoma. The enhancement of the JZ during the dynamic contrast MRI, histopathological causes, and the density of arterioles in the JZ were retrospectively analyzed in cases with thickened or indistinct JZ. The MRI histopathological correlation of all 31 patients with a thickened or indistinct JZ were analyzed, in which it was corresponded to myometrial cancer invasion only in 22%. The sensitivity of a poor early enhancement pattern on dynamic study for detecting myometrial invasion was 71.4%, the specificity was 100%, and the overall accuracy was 92.5%. Although only weak relationship between the contrast enhancement and the arteriole density was revealed, the arteriole density within the JZ with cancer invasion was significantly decreased. Poor enhancement of JZ in early dynamic phase was correlated with the decreased density of arterioles within the myometrium which was invaded by endometrial carcinoma. Dynamic contrast study should be performed in staging endometrial carcinoma especially when JZ was thickened or indistinct.

Endometrial Neoplasms↗
PubMed2003

Accelerated dynamic MR imaging with a parallel imaging technique for hypervascular hepatocellular carcinomas: usefulness of a test bolus in examination and subtraction imaging.

PURPOSE: To assess the impact of the accelerated dynamic MR imaging (ADMRI) approach using parallel imaging for detecting hypervascular hepatocellular carcinomas (HCCs) and to evaluate the usefulness of a test bolus in examination and subtraction imaging in this setting. MATERIALS AND METHODS: Thirty patients with 135 HCCs underwent ADMRI using a two-dimensional gradient-recalled echo sequence with parallel imaging. Seventeen patients were evaluated without a test bolus and 13 patients with a test bolus. The detectability of HCCs was calculated between the groups with and without a test bolus. ADMRI was evaluated regarding the signal-to-noise ratio (SNR) of the lesion and the liver, the contrast-to-noise ratio (CNR) of the lesion vs. the liver, and the feasibility of subtraction images. RESULTS: ADMRI with and without a test bolus had almost equal sensitivity (92.5% and 92.6%). No significant difference was seen in the SNR of lesions and the CNR of lesions vs. livers between both groups. With a test bolus, ADMRI could depict the peak enhancement of nodules on the 2nd or 3rd dynamic phases and optimized the timing of peak lesion enhancement. Subtraction images could be obtained regarding minimal slice misregistration. CONCLUSION: ADMRI had high detectability of HCCs with and without a test bolus.

Adult↗
PubMed2002

Pitfalls in liver imaging.

Localized, abnormal attenuation/intensity areas on unenhanced and/or enhanced study of CT/MR imaging do not necessarily correspond to tumors themselves or real tumor size. Pitfalls in the diagnosis of liver tumor are described dividing into enhanced study (vascular variants, vascular abnormalities, hyperplastic nodules, around the tumor, and miscellaneous) and unenhanced study (fatty change, focal spared area of diffuse fatty liver, and miscellaneous).

Diagnosis, Differential↗
PubMed2002

Double arterial phase dynamic MRI with sensitivity encoding (SENSE) for hypervascular hepatocellular carcinomas.

PURPOSE: To investigate the efficacy of SENSE MRI, including the double arterial phase dynamic study, to detect hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: MRI of the liver was performed in 40 consecutive patients (20 by conventional MRI and 20 by SENSE MRI). The SENSE technique was used to obtain breath-hold T1-weighted FSE images (TR/TE = 556/12 msec), respiratory-triggered T2-weighted FSE images (TR/TE = 1800/90 msec) with and without fat suppression, and dynamic MR images (TR/TE/FA = 160-168/4.6 msec/70 degrees ). In each arterial dominant phase and portal dominant phase, two scans were consecutively performed with one breath-hold, leading to the double arterial phase and double portal phase images with SENSE. RESULTS: The sensitivity of SENSE MRI for HCCs diagnosed from all MR images, including dynamic study, T1-weighted images, and T2-weighted images, was 91.7%, while that of conventional MRI was 76.3%. The positive predictive value of SENSE MRI for HCCs was 91.7%, while that of conventional MRI was 87.9%. In terms of HCCs < or = 10 mm, the sensitivity and positive predictive values of SENSE MRI were 78.6% and 78.6%, respectively, while those of conventional MRI were 27.3% and 60.0%, respectively. The number of detected HCCs < or = 10 mm was significantly larger in SENSE MRI than in conventional MRI (P < 0.05). The cause of false-positive lesions on SENSE MR images was an arterioportal shunt. CONCLUSION: SENSE MRI with double arterial phase dynamic study showed higher sensitivity compared to the conventional technique. Therefore, SENSE MRI is a promising method for the detection of HCC.

Carcinoma, Hepatocellular↗