[Radiation-induced endocrinopathy].
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Brain Neoplasms↗
Biomedical subjects
Yuta Shibamoto
Publications and source records attributed to Yuta Shibamoto.
Stereotactic radiosurgery as a salvage treatment for recurrent epipharyngeal carcinoma.
Fourteen patients with recurrent epipharyngeal carcinoma (EPC) were treated by gamma knife stereotactic radiosurgery. The tumor volume ranged from 0.3 to 80 ml (median 18.9 ml). Treatment was done with a tumor margin dose of 10-27 Gy (median 15 Gy). The median follow-up period was 15 months (range 2-47 months). Ten patients were alive and 4 were dead at the end of the follow-up period. In 6 patients (43%), the tumor disappeared or decreased in size until the end of the follow-up period. In 2 (14%), the tumor remained unchanged in size. In 6 (43%), the tumor showed regression initially but was enlarged later. A second radiosurgery was performed in 4 of those 6 cases and the tumor decreased in size again in 3 of them. Thus, the overall control rate of local tumor was 79% (11/14). In selected patients with recurrent EPC, stereotactic radiosurgery can be considered as a salvage treatment producing local control.
Adult↗
Evaluation of CH3-DTPA-Gd (NMS60) as a new MR contrast agent: early phase II study in brain tumors and dual dynamic contrast-enhanced imaging.
PURPOSE: A newly developed contrast material, CH3-DTPA-Gd (NMS60), a trimer containing 3 Gd(3+) atoms per molecule, has been shown to offer greater enhancement and longer vascular retention than gadopentetate dimeglumine (Gd-DTPA) in animals. We report on our early phase II study on NMS60 in brain tumor patients together with supplementary investigations. METHODS AND MATERIALS: The longitudinal relaxation rate (R(1)=1/T(1)) and the transverse relaxation rate (R(2)*=1/T(2)*) of NMS60 and Gd-DTPA were determined at 20 degrees C in water at 1.5 T. An NMS60 dose of 0.1 or 0.2 mmol (Gd)/kg was randomly assigned and administered to 10 patients (five women, five men; mean age: 49 years) with brain tumors. Safety and contrast-enhancing ability of NMS60 were evaluated. Dual dynamic contrast-enhanced T(1) and R(2)* studies (DUCE imaging) were also carried out in two patients. RESULTS: Regarding the relaxivity per Gd, R(1) and R(2)* of NMS60 were 9.5 and 11.0 (mmol/L x s)(-1), respectively, compared to 4.8 and 7.2 (mmol/L x s)(-1) for Gd-DTPA. Although a transient slight increase of alanine aminotransferase was observed in one case, no other adverse reactions were observed after administration of NMS60. Contrast enhancement by NMS60 was excellent at both concentrations, and when tumor detectability was assessed with a five-point scale, the diagnostic usefulness was 4 or higher in all cases. In DUCE imaging, NMS60 appeared to show high signal intensity, when compared with the data obtained separately for Gd-DTPA. CONCLUSION: NMS60 had a high contrasting effect and little toxicity, and is expected to be clinically useful.
Brain↗
Radiobiologic effect of intermittent radiation exposure in murine tumors.
PURPOSE: In stereotactic irradiation using a linear accelerator, the effect of radiation may be reduced during intermittent exposures owing to recovery from sublethal damage in tumor cells. After our previous in vitro study suggesting this phenomenon, we investigated the issue in murine tumors. METHODS AND MATERIALS: We used EMT6 and SCCVII tumors approximately 1 cm in diameter growing in the hind legs of syngeneic mice. Three schedules of intermittent radiation were investigated. First, 2 fractions of 10 Gy were given at an interval of 15-360 min to investigate the pattern of recovery from sublethal damage. Second, 5 fractions of 4 Gy were given with interfraction intervals of 2.5-15 min each. Third, 10 fractions of 2 Gy were given with interfraction intervals of 1-7 min each. Doses of 15-20 Gy were also given without interruption to estimate the dose-modifying factors. Tumors were excised 20 h later, and tumor cell survival was determined by an in vivo-in vitro assay. RESULTS: In the 2-fraction experiment, the increase in cell survival with elongation of the interval was much less than that observed in our previous in vitro study. In the 5- and 10-fraction experiments, no significant increase in cell survival was observed after the intermittent exposures. Moreover, cell survival decreased at most points of the 5-fraction experiments by interruption of radiation in both EMT6 and SCCVII tumors. In the 10-fraction experiment, cell survival also decreased when the interruption was 3 or 7 min in EMT6 tumors. CONCLUSION: The results of the present in vivo studies were different from those of our in vitro studies in which cell survival increased significantly when a few minutes or longer intervals were posed between fractions. This suggests that recovery from sublethal damage in vivo may be counterbalanced by other phenomena such as reoxygenation that sensitizes tumor cells to subsequent irradiation.
Animals↗
[MRI-intracranial compliance analysis in patients with NPH].
We devised a method for non-invasively assessing intracranial compliance with retrospective ECG-triggered phase contrast cine MRI. This method was examined in patients with normal pressure hydrocephalus (NPH) group and those with asymptomatic ventricular dilation or brain atrophy (VD group), and in healthy volunteers (control group). Intracranial volume change (DeltaV(max)) was calculated from arterial inflow, venous outflow, cerebrospinal fluid (CSF) flow, and spinal cord motion at the C2 level during a cardiac cycle. Next, craniospinal CSF pressure gradient change (DeltaPG(max)) was calculated from measured CSF flow velocity using a simplified Navier-Stokes equation. Finally, Ci was obtained by dividing Delta V(max) into DeltaPG(max). Ci in the NPH group was significantly smaller and could be differentiated from other groups. This method makes it possible to non-invasively obtain a more detailed determination of the intracranial state and dynamics in NPH and to assist in its diagnosis.
Adolescent↗
Stereotactic radiosurgery as a salvage treatment for recurrent skull base adenoid cystic carcinoma.
Twelve patients (15 lesions) with recurrent skull base adenoid cystic carcinoma (ACC) were treated by Gamma Knife stereotactic radiosurgery (SRS). The tumor volume ranged from 2 to 103 ml (median 15 ml). Treatment was prescribed at the 40-60% isodose line and ranged from 10 to 18 Gy (median: 13.0 Gy). The median follow-up period was 18 months (range 3-55). Six patients were alive and 6 dead at the end of the follow-up period. Only 1 patient died from local tumor recurrence. Ten among 15 tumors treated by SRS decreased in size until the end of the follow-up period or the patients' death. Three remained unchanged in size. Two tumors initially regressed but then increased in size. In selected patients with recurrent skull base ACC, SRS can be considered as a salvage treatment with good local control.
Adolescent↗
Results of primary central nervous system lymphoma treated by radiation and chemotherapy: retrospective analysis of twelve institutions in the Tokai District of Japan, 1995-1999.
PURPOSE: We analyzed the therapeutic results and prognostic factors of 46 primary central nervous system lymphoma (PCNSL) patients who were treated at twelve institutions in the Tokai district of Japan between 1995 and 1999. We compared the results with those of a Japanese nationwide survey performed in the past. MATERIALS AND METHODS: We sent each institution a questionnaire about the state of patients' disease, pathological type, method and doses of radiotherapy, regimen and intensity of chemotherapy, and patients' prognoses. The range of patients' ages was 33 to 93 years (median, 61 years). Thirty-one were men and 15 were women. The most prevalent histology was diffuse large B cell type (33 patients). We used the Kaplan-Meier method to calculate the survival rate and Cox's proportional hazards model to analyze the prognostic factors. RESULTS: The five-year cumulative survival rate was 25%, and the median survival time was 22.7 months. The five-year disease-free survival rate was 23%. In monovariate analysis, patients who were both younger than 60 years old and had a WHO performance status (PS) score equal to or less than 2 showed a better survival rate. Furthermore, the patients receiving systemic chemotherapy showed a significantly better local control rate. In addition, patients who received systemic chemotherapy achieved a higher complete remission rate than those not receiving it. However, no factors that significantly influenced survival rate were identified in multivariate analysis. CONCLUSION: We demonstrated that the therapeutic outcome of PCNSL patients has recently improved. In particular, patients with good PS showed better local control than those with poor PS. However, we could not identify any significant prognostic factors in PCNSL patients.
Adult↗
Treatment of primary intraocular lymphoma with radiation therapy: a multi-institutional survey in Japan.
This study evaluated the clinical features and treatment outcome of 15 patients with primary intraocular lymphoma. There were nine females, with a median age of 68 years. Thirteen patients presented with bilateral lesions and median time from the onset of symptoms to diagnosis was 12 months. All but one showed the B-cell phenotype. All patients received radiation therapy (RT) with a median of 41 Gy and 10 were administered chemotherapy as well. Three patients were treated with high-dose methotrexate and nine received prophylactic cranial irradiation (PCI) with a median of 30.6 Gy. Thirteen patients obtained a complete remission. The 2-year overall and disease free survival were 74% and 58%, respectively. Although only one patient experienced local recurrence, PCI did not prevent intracranial recurrence. One patient developed a grade 3 cognitive disturbance. It was concluded that ocular RT was effective to control primary lesions. However, some modifications are indispensable to improve outcomes.
Adult↗
Absence of radioadaptive responses in four cell-lines in vitro as determined by colony formation assay.
The purpose of this study was to investigate radioadaptive response in 4 cell-lines under identical conditions using a colony assay. First, 4 cell-lines (V79, HeLa S3, EMT6 and SCCVII) were exposed to 8 Gy at various intervals after pretreatment with an adapting dose of 50 mGy or without it. Second, V79 cells were exposed to 8 Gy at 4.5 hrs after an adapting dose of 0 to 400 mGy. Third, V79 cells were exposed to 2, 4 or 6 Gy at 6 hrs after an adapting dose of 0 or 50 mGy. In the last experiment, an adapting dose was given either immediately after cell plating or 24 hrs later. Cell survival was assessed by a standard colony assay. Adaptive response was not observed in any of the 4 lines tested. In V79 cells, no adaptive response was seen even by changing the adapting dose, challenging dose, and timing of adapting radiation after cell plating. Although radioadaptive response has been reported for the V79 cell-line, we could not reproduce the result. We also failed to demonstrate the phenomenon in the other 3 tumor cell-lines in culture.
Adaptation, Physiological↗
Development of water-soluble metallofullerenes as X-ray contrast media.
Fullerenes are a new carbonic allotrope having a cage structure. We investigated whether fullerenes containing one or two atoms of heavy metals could be an X-ray contrast material with little adverse effects. One or two atoms of dysprosium (Dy), erbium (Er), gadolinium (Gd), europium (Eu) and lutetium (Lu) were encapsulated into fullerene (C(82)), which was synthesized as a polyhydroxyl form (e.g., Gd@C(82)(OH)n, n=40, Gd - fullerenols). They were dissolved in water at maximum soluble concentrations and subjected to CT number analysis. The CT numbers of the solutions were measured using a 4- or 16-row multidetector CT scanner. The CT number of the water-soluble metallofullerenes were 56.0 HU for Dy@C(82)(OH)(40), 111.5 HU for Er@C(82)(OH)(40), 58.4 HU for Gd@C(82)(OH)(40), 100.9 HU for Eu@C(82)(OH)(40) and 23.3 HU for Lu(2)@C(82)(OH)(40). The CT numbers of the metallofullerenes investigated in the present study were not high enough to be used in the clinic in place of iodinated contrast materials. However, if nanotechnology progresses in the near future, it may prove to have a possibility as an X-ray contrast material.
Contrast Media↗
CNS germinoma with elevated serum human chorionic gonadotropin level: clinical characteristics and treatment outcome.
PURPOSE: The prognostic significance of human chorionic gonadotropin (HCG) level in central nervous system germinoma remains controversial. The purpose of this study was to compare clinical characteristics and prognosis of germinoma patients with normal and high HCG titers in the serum. METHODS AND MATERIALS: We undertook a multi-institutional retrospective analysis of 103 patients with central nervous system germinoma whose serum HCG and/or beta-HCG level had been measured before treatment between 1984 and 2002. All patients had been treated with radiation therapy either alone (n = 66) or in combination with chemotherapy (n = 37) with a median dose of 47.8 Gy. RESULTS: HCG and/or beta-HCG level in the serum was high in 39% of all patients. The proportion of HCG-producing tumors was higher in the lesions at the basal ganglia than in the lesions at the other sites. No correlation was found between tumor size and HCG level, but there seemed to be a weak correlation between size and beta-HCG. The 5- and 10-year survival rates were 96% and 94%, respectively, in both patient groups with normal and high HCG (p = 0.99). The 5- and 10-year relapse-free survival rates were 87% and 82%, respectively, in patients with normal HCG level and were both 87% in patients with high HCG (p = 0.74). Also, no other patient-, tumor-, or treatment-related factors seemed to influence the prognosis of the patients. CONCLUSION: Serum HCG level does not seem to influence patient prognosis when treated with sufficient doses of radiation. Relationship between tumor size and site and HCG level should be investigated further.
Adolescent↗
Results of radiation monotherapy for primary central nervous system lymphoma in the 1990s.
PURPOSE: Results of radiation therapy for primary central nervous system lymphoma (PCNSL) were poor in the 1970-1980s, with most reported 5-year survival rates being less than 10%. To investigate whether the prognosis of PCNSL patients treated by radiation alone remains still poor, we investigated the results of radiation monotherapy in the 1990s. METHODS AND MATERIALS: We collected data on 132 patients with histologically proven PCNSL treated by radiation alone in the 1990s from three nationwide or regional multiinstitutional studies conducted by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) Lymphoma Study Group or the Chubu Radiation Oncology Group. Follow-up data were updated as far as possible. Eleven patients who did not complete planned radiotherapy were included. The data were analyzed in relation to patient and tumor characteristics. The median patient age was 63 years, and the World Health Organization performance status (PS) was 3 or 4 in 40% of the patients. Multiple tumors were seen in 34%. Whole-brain irradiation with or without focal boost was used in 92%. The median radiation dose to the tumor site was 50 Gy (range, 8-74 Gy). RESULTS: For all 132 patients, the median survival time was 18 months and the 5-year survival rate was 18.0%. For 62 patients with PS 0-3 and aged 16-65 years (i.e., those eligible for the European Organization for Research and Treatment of Cancer 20962 study), the median survival was 26 months and 5-year survival was 24%. The 5-year survival was 25% for patients 63 years old or younger, and 9.8% for those older than 63 years (p = 0.0005). The 5-year survival was 22% for patients with PS 0-2 and 13% for those with PS 3 or 4 (p = 0.0040). Multivariate analysis confirmed the negative influence of higher age on patient prognosis. CONCLUSIONS: The results of radiation monotherapy for PCNSL appear to have improved as compared with those reported previously. The results of new treatment should be evaluated in light of this finding. Since most prospective studies on the combined treatment exclude poor PS and high-age patients, the 5-year survival rate of 30% may not be regarded as a marked improvement over radiation alone.
Adolescent↗
F-18 FDG uptake in a malignant localized fibrous tumor of the pleura.
In the case presented here, FDG-PET was performed to evaluate the possibility of malignancy. High FDG accumulation, with a standardized uptake ratio (SUR) of 3.0, was noted in an upper nodular compartment of the mass that exhibited malignant features histopathologically. It was suggested that FDG-PET is helpful to know which parts of lesions are benign or malignant in patients with LFTP whose prognoses are usually difficult to predict.
Aged↗
Biological effects of intermittent radiation in cultured tumor cells: influence of fraction number and dose per fraction.
In intensity-modulated radiation therapy (IMRT) and stereotactic irradiation using a linear accelerator, radiation is administered intermittently and one treatment session often requires 30 min or a longer time. The purpose of the present study was to investigate the effect of fractionation and dose per fraction on cell killing by irradiation in intermittent exposure. Murine EMT6 and SCCVII cells were used. The cells were irradiated to a total dose of 8 Gy in 2, 5, 10, 20 and 40 fractions over 15, 30 and 46 min. The cells were also given 8 Gy in a single fraction over 15, 30 and 46 min using lower dose rates (continuous prolonged radiation groups). As compared with the control group receiving a single dose of 8 Gy at 1.55 Gy/min, the cell surviving fraction generally increased in groups receiving fractionated or continuous prolonged radiation. There was a general trend for cell survival to increase with the fraction number up to 20 or 40 fractions in both cell lines. The effects of IMRT and linear accelerator radiosurgery given over 15 min or longer may be less than those of 1- or 2-fraction irradiation. There was a trend for radiation effect to decrease with fraction number.
Animals↗
Reevaluation of the radiosensitizing effects of sanazole and nimorazole in vitro and in vivo.
Sanazole (AK-2123, 3-nitrotriazole derivative, N1-(3-methoxypropyl)-2-(3-nitro-1 H-1,2,4-triazol-1-yl)acetamide) and nimorazole (5-nitroimidazole derivative, 4-(2-(5-nitro-1H-1-imidazolyl)ethyl)morpholine) have been tested clinically as hypoxic cell radiosensitizers, mainly outside Japan. To determine if these sensitizers deserve clinical investigation in Japan, we reevaluated the radiosensitizing effects of these compounds in vitro and in vivo, in comparison with a fluorinated 2-nitroimidazole derivative KU-2285 (N1-(2-hydroxyethyl)-1,2-difluoro-3-(2-nitro-1 H-1-midazolyl)propanamide). KU-2285 is a known and established radiosensitizer, but is not suitable for clinical studies because of the high cost of synthesis. In vitro, the radiosensitizing effects of the three compounds on SCCVII (squamous cell carcinoma line in C3H mice) tumor cells were examined at 0.5 and 1 mM under aerobic or hypoxic conditions, using a colony assay. In vivo, SCCVII tumors grown subcutaneously in the hind legs of C3H/HeN mice were irradiated with or without prior intraperitoneal administration of 100, 200 or 400 mg/kg of the drugs. Thereafter, tumor growth delay was measured. In vitro, no sensitizing effect was observed under aerobic conditions at 1 mM. Under hypoxic conditions, the sensitizer enhancement ratio (SER) determined at 1% cell survival level for sanazole, nimorazole and KU-2285 was 1.55, 1.45 and 1.95, respectively, at 1 mM, and 1.40, 1.40 and 1.75, respectively, at 0.5 mM. In vivo, all three compounds had significant radiosensitizing effects; their effects appeared to decrease in the order of KU-2285, sanazole, and nimorazole. It was suggested that sanazole may be more suitable for clinical trials than nimorazole.
Animals↗
[Intensity-modulated radiation therapy (IMRT)].
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Astrocytoma↗
[The frontiers of diagnostic radiology--PET/CT, 3DCT--].
Recently, positron-emission tomography (PET) systems have been introduced in many institutions around Japan and their clinical importance should increase in the management of many malignant diseases particularly systems using 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG). Since March 2004, we have been using the first PET/computed tomography (CT) scanner in Japan with 4-slice multidetector CT (MDCT) and now have introduced a second PET/CT scanner with 8-slice MDCT because of its excellent diagnostic capability and higher throughput capacity than that of the ordinal PET scanner. MDCT was a landmark in the history of CT in 1998. Subsequently, 8-, 16-, 32-, and 40-slice MDCT was developed in rapid succession. Finally, 64-slice MDCT became commercially available in 2005. In the future, 256-slice MDCT and flat-panel CT will appear in the clinical setting. Using these MDCT systems, we can now obtain multidimensional CT images very easily. These multidimensional images are less-invasive methods that are gradually phasing out the use of invasive angiography including digital subtraction angiography. In this article we describe the current features of PET/CT and multidimensional CT using MDCT.
Fluorodeoxyglucose F18↗
Comparison of two contrast materials with different iodine concentrations in enhancing the density of the the aorta, portal vein and liver at multi-detector row CT: a randomized study.
This work investigates differences in contrast enhancement of the aorta, portal vein and liver by two different concentrations of contrast materials using an automatic bolus tracking technique. Seventy patients were assigned randomly into one of two groups. Contrast materials with iodine concentrations of 300 and 370 mg/ml were administered to patients in groups A and B, respectively. The total iodine load (600 mg/kg) and injection time (30 s) were identical. Differences in the increase of the Hounsfield unit of the aorta, portal vein and liver between the two groups were examined by t-test. There were no significant differences between the two groups in any of the contrast enhancements of the aorta, portal vein and liver parenchyma at all phases, except for enhancement of the portal vein at the late arterial phase. Females showed better contrast enhancement of the aorta and portal vein than males. With the same iodine dose and injection time, the concentration of contrast materials did not seem to influence the efficacy of contrast enhancement of the aorta, portal vein and liver, except for the portal vein at the late arterial phase. Planning of protocols for contrast media injection may be made irrespective of the iodine concentrations.
Adolescent↗