Real-time beam monitoring in dynamic conformation therapy.

PURPOSE: Although portal imaging is a promising method of verification during static multiport irradiation, it cannot be applied directly to dynamic irradiation such as rotational conformation with multileaf collimator movement. A real-time beam monitoring system based on megavoltage computed tomography scanning has been developed to establish a verification method for the rotational conformation technique. METHODS AND MATERIALS: Exit beam through the patient is extracted by the same detector unit as used for megavoltage scanning during the actual treatment. Beam edge is defined as the 50% level of the maximum dose of the detector array. Megavoltage computed tomography is done after patient setup and just prior to the actual irradiation. Detected beam pathways are overlaid on this image approximately every 1 s. Therapists can monitor correlation between the target and actual beam pathways on a real-time computer display. RESULTS: The accuracy of field edge detection has been proven to be less than 2 mm from various measurements. Real-time monitoring is more useful in rotational conformation than in static multiport irradiation due to dynamic movement of the collimator. Field errors were identified in two of 54 sessions using this method. CONCLUSIONS: Although several limitations remain to be solved, the method presented is a useful tool for treatment verification of high accuracy radiation therapy, particularly rotational conformation irradiation.

Epidural hematoma of the clivus. Case report.

This 8-year-old boy presented with a rare case of epidural hematoma of the clivus and atlantoaxial dislocation caused by a hyperflexion injury sustained in a traffic accident. Magnetic resonance (MR) imaging demonstrated an epidural hematoma in the posterior fossa that compressed the pons and medulla. On admission, the patient was confused and had bilateral abducens palsy. He was treated conservatively, and 6 months after admission, the epidural hematoma on the clivus had disappeared on MR imaging and the bilateral abducens palsy was cured. Only two such cases have been reported in the literature. In this report, the authors discuss the mechanism of hematoma formation in this region of the brain.

Induction of apoptotic cell death in human leukemic cell line, HL-60, by extremely low frequency electric magnetic fields: analysis of the possible mechanisms in vitro.

The influence of extremely low frequency electric magnetic fields. (ELF EMFs) on apoptotic cell death was examined using a human leukemic cell line, HL-60 and normal human peripheral blood leukocytes. When HL-60 cells were exposed to 45 mT ELF EMFs, apoptotic cell death, characterized by cell shrinkage, nuclear fragmentation and cleavage of internucleosomal DNA to yield fragments that were multiples of 180-200 base pairs, were induced. The minimum periods required apoptotic HL-60 cell death was 1.0 hour. However, exposure to ELF EMFs could not produce detectable DNA fragmentation in human peripheral blood leukocytes. Static magnetic fields could not induce apoptotic cell death in HL-60 cells, even when the cells were exposed to 180 mT of magnetism for 3.5 hours. We further examined whether hyperthermia induced by induction current in ELF EMFs produced apoptosis in HL-60 cells. Induction current in ELF EMFs enhanced temperature of culture medium to 40.3 degrees C at 3.0 hours of exposure. However, this level of temperature could not induced apoptotic cell death in HL-60 cells, even when cells were cultured for 3.5 hours. These results suggest that induction current produced by ELF EMFs may be one of main mediator in apoptosis in HL-60 cells.

Role of 3D-TOF magnetic resonance angiography for intracranial meningioma.

Three-dimensional (3D) time of flight (TOF) magnetic resonance angiography (MRA) was performed in 13 patients with intracranial meningioma. 3D-TOF unenhanced MRA depicted arterial displacement by tumour, and poorly demonstrated the sinuses, veins and tumour mass. The direct visualization of the venous abnormalities on 3D-TOF MRA was improved by the administration of contrast material. 3D-TOF enhanced MRA simultaneously depicted tumour enhancement, arterial and/or venous displacement, and dural sinus involvement by the tumour, all of which were in good agreement with findings on conventional cerebral angiography. However, MRA tended to poorly demonstrate the feeding arteries as compared to conventional angiography. Our results indicate that multiview 3D-TOF enhanced MRA non-invasively provides important information about the topographic relationship between tumour mass and the surrounding vasculature.

Neuropsychological changes after surgery for anterior communicating artery aneurysm.

Neuropsychological disturbances following surgery for anterior communicating artery aneurysms were analyzed in 26 patients (11 males, 15 females) using the Hasegawa dementia scale-revised (HDS-R) over a 3-year period. The patients were aged from 34 to 76 years (mean 54.1 years). Lesions in the frontal lobe were evaluated using computed tomography (CT). Twenty-three patients had symptoms over the course. Four patients had basal forebrain lesion, five had ventral frontal lesion, and 12 had no lesion. Patients with basal forebrain lesion and no lesion tended to show disorientation. The mean HDS-R score was 10.2 points in the patients with ventral frontal lesion, and 13.5 points in the patients with no lesion. These scores are within the range for dementia. The mean HDS-R score in patients with basal forebrain and striate lesions was over 25 points and beyond the range for dementia. Significant differences were observed in the HDS-R score between patients with ventral frontal lesion and basal forebrain lesion, and between patients with no lesion and basal forebrain lesion (p < 0.05). Recovery from neuropsychological disturbances was poorer in patients with ventral frontal lesion and no lesion compared to those with basal forebrain and striate lesions, and their symptoms tended to persist.

Acute subdural hematoma due to near-drowning--case report.

A 46-year-old male was transferred to our hospital after near-drowning when swimming. Examination found no subcutaneous hematoma or abrasion on his head. Cardiopulmonary resuscitation was started immediately. Emergent computed tomography (CT) revealed no abnormalities. The next day, his consciousness level improved and repeat CT suggested an acute spontaneous subdural hematoma in the parieto-occipital region. The acute subdural hematoma was evacuated. The source of bleeding was probably an abnormally large vein located in the center of the hematoma. The patient was discharged without neurological deficit. Repeat CT is needed even if there were no abnormality on initial CT after drowning.

[A case of agranulocytosis and jaundice due to cellulitis caused by insect bite].

A 58-year-old female was introduced to our hospital for admission on April 22, 1988, because of high grade fever and agranulocytosis. She had eschers on her left zygomatic region and medial region of the right thigh. The latter lesion was accompanied by cellulitis. Laboratory tests showed her WBC was 600/mm3 and T-Bil was 6.51 mg/dl. By using minocyclin, piperacillin and other drugs, her general condition and laboratory data became better in a few days. Although her skin lesions resembled "Tsutsugamushi disease", serological tests showed no evidence for Rickettia infection. So we could not rule out that another kind of insect bite may also develop such a severe clinical course. Furthermore, Staphylococcus aureus or Clostridium spp., which were detected in her pus, might have the toxic effects of inducing agranulocytosis, which might mainly be the result from the local WBC emigration, and jaundice, just like the effects of the endotoxin of Gram negative bacteria.

[High uptake on 11C methionine PET scan in the pituitary gland of a patient with cerebral glioma after surgical abortion].

Positron emission tomography (PET) with various tracers provides physiologic and biochemical information of living organs. Since radiologic examinations are usually avoided in pregnant women, mainly because of the radiation risk to the fetus, little is known about the effect of pregnancy on cerebral blood flow and metabolism. This paper reports findings of a 11C methionine PET scan of the pituitary gland in a woman after an abortion. The patient was a 31-year-old woman who suffered a seizure in the 9th week of her second pregnancy. On admission, computed tomography showed an abnormal mass lesion in the right frontal lobe, and a brain tumor was suspected. The patient and her family asked that that pregnancy be terminated. Seven days after a surgical abortion, methionine PET was performed. The scan showed high methionine uptake in the pituitary gland as well as in the right frontal lobe tumor. We suspected that another tumor was present in the pituitary gland. The right frontal tumor was partially resected, and pathologic examination of the resected specimen showed an astrocytoma (grade 2). After the operation, the patient received 50 Gy irradiation and chemotherapy. Two months after the operation, we performed a second methionine PET scan, which showed high uptake in the residual right frontal tumor but not in the pituitary gland. Results of other radiologic studies of the pituitary gland were normal. These findings suggest that the transport of 11C methionine into the pituitary gland may increase during pregnancy. Moreover, the pituitary gland of pregnancy should be a part of the differential diagnosis of pituitary adenomas in PET scanning. The change in physiologic uptake by the female pituitary gland should be taken into account in the diagnosis of pituitary adenoma with methionine PET.

[Metastatic skull tumors from cancers associated with subcutaneous mass lesions].

The incidence of metastatic brain tumors is increasing because of the recent progress in the detection and management of primary cancer. However, metastatic skull tumors from cancers associated with giant subcutaneous mass lesions are rare. We present four patients with metastatic skull tumors: two from hepatic cancer, one from lung cancer, and one from mamma cancer. In these patients, plain skull X-ray and bone CT showed osteolytic lesions. Angiograms revealed a tumor stain fed by abnormal vessels from the external carotid artery. MRI demonstrated masses with marked homogeneous enhancement with the "dural tail sign" in the dura adjacent to the tumors in three skull tumors from hepatic and mamma cancers, and a mass with slightly enhancement without the "dural tail sign" in a skull tumor from lung cancer. At surgery, hemorrhagic well-demarcated tumors were totally removed. The histological diagnosis was skull metastases from cancers in all cases. In cases with the "dural tail sign" on MRI, no tumor cells were seen in the inner layer of the dura and the dura adjacent to the tumors. It is possible that the "dural tail" is due to increased vascular permeability of the dural vessels. The recurrence of these skull tumors was not observed during the follow-up period. Surgical treatment for the metastatic skull tumors from cancers may be indicated to prevent deteriorating neurological symptoms affecting the quality of life.

[Detection of ventricular late potentials comparison of 4 commercial high-resolution systems].

UNLABELLED: The purpose of this study was to evaluate the methodologic problems of noninvasive registration of ventricular late potentials. METHODS: we compared the results obtained in the same patients with four different systems which were Marquette MAC1, MAC12, ART LP101 and FUKUDA VCM 3000. Filtering was employed digital forward direction, 100-300 Hz in MAC1, digital FFT, 40-250 Hz in MAC12, digital, bidirectional, 40-250 Hz in ART and analogue, forward direction 40-300 Hz in FUKUDA VCM 3000. DEFINITION OF LATE POTENTIALS (LPs): Filtered QRS duration (FQRSD) was 120 msec or more, root mean square voltage in the last 40 msec (RMSV) was 15 microV or less in MAC12 and ART. FQRSD was 130 msec or more, RMSV was 15 microV or less in FUKUDA. FQRSD was 20 msec or more after QRS obtained from low resolution leads in MAC1. SUBJECTS: 163 patients [control 13, PVCs 23, myocardial infarction 55, others 51, IVCD (RBBB, LBBB, IVCD) 21] were included in this study. RESULTS: 17.6% of all patients (except for IVCD) showed LPs with MAC12, 20.0% with ART, 30.3% with FUKUDA, and 14.1% with MAC1. 23.1% of the control group showed LPs with MAC12 and FUKUDA, but no cases showed LPs with ART and FUKUDA. 4.3% of the PVC group showed LPs with MAC12, 13.0% with ART and FUKUDA, but no cases showed LPs with MAC1. 25.5% of the myocardial infarction group showed LPs with MAC12 and MAC1, 30.9% with ART and 36.3% with FUKUDA. All four methods gave corresponding results in 65.4% of patients, 7.0% positive and 58.4% negative findings. FQRSD of MAC12, ART and FUKUDA was 110.2 +/- 18.1 msec, 105.2 +/- 20.4 msec and 125.8 +/- 22.8 msec respectively. Correlation coefficient (r value) in FQRSD was 0.90 between ART and MAC12, 0.74 between ART and FUKUDA, and 0.75 between FUKUDA and MAC12. RMSV of MAC12, ART and FUKUDA was 49.2 +/- 30.2 microV, 43.7 +/- 37.8 microV and 22.5 +/- 10.6 microV respectively. R value in RMSV was 0.59 between ART and MAC12, 0.38 between ART and FUKUDA and 0.43 between FUKUDA and MAC12. R value in high frequency low amplitude signals duration under 40 microV of LPs positive patients in MAC1 was 0.51 between ART and MAC 12, 0.18 between MAC12 and MAC1, and 0.32 between ART and MAC1. Most of the differences result from a different interpretation of the tracings. Especially LPs far from QRS offset could be registered with neither MAC12, ART nor FUKUDA.

Effect of reperfusion by direct percutaneous transluminal coronary angioplasty on ventricular late potentials in cases of total coronary occlusion at initial coronary arteriography.

The relationship between the time required for reperfusion and the incidence of late potentials was studied in 94 patients who survived a first acute myocardial infarction (AMI) and who showed total occlusion of the infarct-related artery at an initial coronary arteriography. Sixty-three patients who successfully underwent direct percutaneous transluminal coronary angioplasty (PTCA), and 31 who were treated conventionally (controls), underwent signal-averaged electrocardiography. Direct PTCA patients were classified into 5 groups according to the time required for reperfusion: < or = 4, 4-6, 6-8, 8-10, and > or = 10 h. The incidence of late potentials in these groups was 8%, 12%, 14%, 33%, and 43%, respectively, and 48% in the controls. Late potentials were recorded more frequently as the period until successful reperfusion increased: the incidence of late potentials was significantly lower in the < or = 4 and 4-6 h groups than in the controls (p < 0.005 and p < 0.05, respectively). Therefore, reperfusion achieved within 6 h reduced the incidence of late potentials in AMI patients and may be effective for preventing malignant ventricular arrhythmias.

Normal limits of high-resolution signal-averaged ECG parameters of Japanese adult men and women.

High-resolution signal-averaged electrocardiography (Hi-Res ECG) has been found useful in measuring ventricular late potentials for identifying patients prone to life-threatening ventricular arrhythmias. Several studies have reported cut-off values (normal limits) of Hi-Res ECG parameters, including sex-specific limits, for adult population. However, there are no such studies reporting such limits in the Japanese population. Hi-Res ECGs were recorded from 482 normal healthy patients (204 men; 278 women) with no cardiac disease and normal electrocardiogram. Three Hi-Res ECG parameters filtered QRS duration (FQRSD), low amplitude signal duration under 40 microV of terminal QRS (LASD), and root mean square voltage in the terminal 40 milliseconds (RMSV) were analyzed. FQRSD was longer in men than in women (P < .0001). RMSV was larger in men than in women (P < .0001). There was no significant difference in LASD between men and women. The upper limit (90th percentile) of FQRSD was 116 milliseconds for women. The upper limit of LASD was 42 milliseconds for both men and women. The lower limit (10th percentile) of the RMSV was 14 microV for both men and women. There was no significant difference in the distributions of the Hi-Res ECG parameters between our study and an earlier study on mostly whites from the United States and Europe. The upper limits (90th percentile) of FQRSD and LASD in the Japanese normal patients were nearly the same as for whites. But, the lower limit (10th percentile) of RMSV in our Japanese normals was significantly smaller than that for whites. Therefore, it may be necessary to use race-specific normal limits for late potential analysis. Criteria for abnormal late potentials (defined as abnormal values in at least 2 of the 3 Hi-Res ECG parameters) were met in 18 of 482 (3.7%) normal healthy patients. Further studies are needed to evaluate the role of these criteria in identifying cardiac patients with life-threatening arrhythmias in the Japanese population.