Daily positioning accuracy of frameless stereotactic radiation therapy with a fusion of computed tomography and linear accelerator (focal) unit: evaluation of z-axis with a z-marker

To evaluate quantitative positioning errors of frameless stereotactic radiation therapy with a fusion of computed tomography (CT) and linear accelerator unit, Z-type CT markers were attached to patients, and CT images were obtained before and after daily treatment. In 40 verification tests, geometrical errors were never more than 1 mm.

Sustained elevation of plasma brain natriuretic peptide levels associated with progressive ventricular remodelling after acute myocardial infarction

Previous studies have shown that levels of plasma brain natriuretic peptide (BNP) increase in an early phase of acute myocardial infarction. However, the relations between plasma BNP levels and left ventricular remodelling, which occurs long after acute myocardial infarction, are not fully understood. Venous plasma BNP levels were measured 2, 7, 14, 30, 90 and 180 days after the onset of acute myocardial infarction in 21 patients. Left ventricular end-diastolic volume index (EDVI, ml/m2) in acute (5 days) and chronic (6 months) phases were assessed by electron-beam computed tomography using Simpson's method. The remodelling group (n=9) was defined by an increase in EDVI >/=5 ml/m2 relative to the baseline value. Plasma BNP levels on days 2, 7, 14, 30 and 90 were significantly higher in the remodelling group than in the non-remodelling group (n=12, P<0.05). Sustained elevation of plasma BNP levels was noted from day 2 (61+/-12 pmol/l) to day 90 (55+/-12 pmol/l) and significantly decreased on day 180 (24+/-3 pmol/l) in the remodelling group. In contrast, plasma BNP levels significantly decreased from day 2 (25+/-4 pmol/l) to day 90 (9+/-1 pmol/l) and reached a steady level thereafter in the non-remodelling group. Plasma BNP levels on day 7 correlated positively with an increase in EDVI (r=0.70, P<0.001) from the acute to chronic phase. More importantly, the sustained elevation of plasma BNP (percentage decrease smaller than 25%) from day 30 to day 90 identified patients in the remodelling group with a sensitivity of 100% and a specificity of 83%. In conclusion, not only the high levels of plasma BNP in an acute phase, but also the sustained elevation of plasma BNP in a chronic phase, may be associated with progressive ventricular remodelling occurring long after acute myocardial infarction.

Adenosine-enhanced ischemic preconditioning provides enhanced cardioprotection in the aged heart

BACKGROUND

Recently we have reported a novel myo-protective protocol "adenosine-enhanced ischemic preconditioning" (APC), which extends and amends the protection afforded by ischemic preconditioning (IPC) by both reducing myocardial infarct size and enhancing postischemic functional recovery in the mature rabbit heart. However, the efficacy of APC in the senescent myocardium was unknown.

METHODS

The efficacy of APC was investigated in senescent rabbit hearts and compared with magnesium-supplemented potassium cardioplegia (K/Mg) and IPC. Global ischemia (GI) hearts were subjected to 30 minutes of global ischemia and 120 minutes of reperfusion. Ischemic preconditioning hearts received 5 minutes of global ischemia and 5 minutes of reperfusion before global ischemia. Magnesium-supplemented potassium cardioplegia hearts received cardioplegia just before global ischemia. Adenosine-enhanced ischemic preconditioning hearts received a bolus injection of adenosine in concert with IPC. To separate the effects of adenosine from that of APC, a control group (ADO) received a bolus injection of adenosine 10 minutes before global ischemia.

RESULTS

Infarct size was significantly decreased to 18.9%+/-2.7% with IPC (p<0.05 versus GI); 17.0%+/-1.0% with ADO (p<0.05 versus GI); 7.7%+/-1.3% with K/Mg (p<0.05 versus GI, IPC, and ADO); and 2.1%+/-0.6% with APC (p<0.05 versus GI, IPC, ADO, and K/Mg; not significant versus control). Only APC and K/Mg significantly enhanced postischemic functional recovery (not significant versus control).

CONCLUSIONS

Adenosine-enhanced ischemic preconditioning provides similar protection to K/Mg cardioplegia, significantly enhancing postischemic functional recovery and decreasing infarct size in the senescent myocardium.

Peak negative myocardial velocity gradient in early diastole as a noninvasive indicator of left ventricular diastolic function: comparison with transmitral flow velocity indices

OBJECTIVES

We sought to assess the clinical significance of peak negative myocardial velocity gradient (MVG) in early diastole as a noninvasive indicator of left ventricular (LV) diastolic function.

BACKGROUND

Peak systolic MVG has been shown useful for the quantitative assessment of regional wall motion abnormalities, but limited data exist regarding the diastolic MVG as an indicator of LV diastolic function.

METHODS

Peak negative MVG was obtained from M-mode tissue Doppler imaging (TDI) in 43 subjects with or without impairment of systolic and diastolic performance: 12 normal subjects, 12 patients with hypertensive heart disease (HHD) with normal systolic performance and 19 patients with dilated cardiomyopathy (DCM), and was compared with standard Doppler transmitral flow velocity indices. In a subgroup of 30 patients, effects of preload increase on these indices were assessed by performing passive leg lifting. In an additional 11 patients with congestive heart failure at the initial examination, the measurements were repeated after 26+/-16 days of volume-reducing therapy.

RESULTS

Peak negative MVG was significantly depressed both in HHD (-3.9+/-1.3/s, p < 0.01 vs. normal=-7.7+/-1.5/s) and DCM (-4.4+/-1.4/s, p < 0.01 vs. normal). In contrast, transmitral flow indices failed to distinguish DCM from normal due to the pseudonormalization. Transmitral flow velocity indices were significantly altered (peak early/late diastolic filling velocity [E/A]=1.1+/-0.5 to 1.5+/-0.7, p < 0.01; E deceleration time=181+/-41 to 153+/-38 ms, p < 0.01), while peak negative MVG remained unchanged (-5.3+/-2.2 to -5.3+/-2.0/s, NS) by leg lifting. Volume-reducing therapy resulted in the apparent worsening of the transmitral flow velocity pattern toward abnormal relaxation, as opposed to peak negative MVG, which improved by the therapy (p < 0.05).

CONCLUSIONS

Peak negative MVG derived from TDI may be a noninvasive indicator of LV diastolic function that is less affected by preload alterations than the transmitral flow velocity indices, and thereby could be used for the follow-up of patients with nonischemic LV dysfunction presenting congestive heart failure.

Comparison of automatic boundary detection and manual tracing technique in echocardiographic determination of left atrial volume

Previous reports have indicated that echocardiography with automatic boundary detection (ABD) is useful for the noninvasive estimation of left ventricular volume. However, few data exist regarding the measurement of left atrial (LA) volume, which also provides pivotal information in the clinical setting. Therefore, the feasibility of LA volume measurement by ABD in comparison with the manual tracing using modified Simpson's method (SM) was evaluated. Fifty-nine patients with coronary artery-disease with sinus rhythm were examined. Using ABD, a region of interest was set around the LA border and mitral annulus from an apical four-chamber view. The maximal and minimal LA volume (Vmax and Vmin) were measured from the volume waveform. Using the SM, the maximal and minimal LA volume were measured by the manual tracing on frozen frames at the apical four-chamber view. The ABD displayed a curve of LA volume change that consisted of passive emptying, diastasis, and active emptying phases during the left ventricular diastolic period. Under these conditions, the Vmax and Vmin were 43.7 +/- 11.2 ml and 21.1 +/- 7.6 ml, respectively, yielding the volume change of 22.6 +/- 6.0 ml. By the SM, Vmax and Vmin were 43.1 +/- 9.9 ml (r = 0.94, p < 0.0001, y(ABD) = 0.91x (SM) + 3.6) and 22.0 +/- 9.0 ml (r = 0.91, p < 0.0001, y = 0.94x + 0.7), respectively, and the volume change was 22.8 +/- 6.1 ml (r = 0.82, p < 0.0001, y = 0.84x + 3.8). These results indicate that the ABD from the apical four-chamber approach could provide an accurate estimation of LA volume change, suggesting the potential value of this method in assessing LA function, although some technical difficulties need to be further overcome.

Impaired regional fatty acid uptake and systolic dysfunction in hypertrophied right ventricle

Little information is available regarding the determinants of systolic contractile function of the hypertrophied right ventricle (RV). The purpose of this study was to clarify the relationship between myocardial metabolism and contractile function in the hypertrophied RV due to pulmonary hypertension (PH).

METHODS

Iodine-123-labeled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-sestamibi (MIBI) SPECT were performed to calculate the RV-to-left ventricle (LV) tracer uptake ratio (RV/LV) in 21 patients with PH (6 with primary PH and 15 with chronic thromboembolic PH). The patients also underwent electron-beam CT to assess RV ejection function (RVEF) and percentage systolic wall thickening (%SWT) and right heart catheterization to measure mean pulmonary arterial pressure (mPAP).

RESULTS

There were significant positive correlations between mPAP and MIBI-RV/LV (r = 0.89, p < 0.001) and between mPAP and BMIPP-RV/LV (r = 0.86, p < 0.001). However, 8 patients showed lower BMIPP-RV/LV than MIBI-RV/LV, indicating the impairment of myocardial fatty acid uptake in the RV. These patients had lower RVEF and %SWT compared to those with normal myocardial fatty acid uptake (RVEF = 28% +/- 10% compared to 40% +/- 9% and %SWT = 33% +/- 27% compared to 74% +/- 30%, respectively; p < 0.05 for both comparisons). Although mPAP did not differ between the groups, the RVEF-mPAP and %SWT-mPAP regression lines drawn from the patients with impaired myocardial fatty acid uptake were located below the lines from the patients with normal myocardial fatty acid uptake, suggesting disproportionately decreased RV myocardial contractility for a given mPAP in patients with impaired myocardial fatty acid uptake. The patients with the impaired fatty acid uptake in the RV had a significantly higher death rate (log-rank test, p < 0.05).

CONCLUSION

The results from this preliminary study suggest that myocardial fatty acid uptake is impaired in the failing hypertrophied RV due to PH.

A modified human ureter graft tanned by a new crosslinking agent polyepoxy compound for small diameter arterial substitutions: an experimental preliminary study

The effectiveness of human ureter grafts tanned by polyepoxy compound for small diameter arterial substitution was examined in 8 carotid arteries of rabbits, followed by an observation period of either 1 month (n = 6) or 6 months (n = 2). In this model there was no evidence of rejection, aneurysm formation, or infection. The modified human ureter showed excellent patency in all cases as well as excellent function, and the histological evaluation revealed monolayer endothelial-like cells covering all of the surface of the graft as was expected. No intimal hyperplasia was demonstrated at either anastomotic site. This study suggests that our newly designed polyepoxy compound fixed human ureter could serve as a satisfactory blood conduit with good long-term patency for substitution.

[Does adenosine administration during the early reperfusion period affect ischemic preconditioning?]

We hypothesized that the adenosine administration during the early reperfusion period might affect ischemic preconditioning (IPC) and might reduce infarct size and enhance post-ischemic functional recovery. Twenty-four anesthetized rabbits underwent 30 min. normothermic global ischemia with 120 min. reperfusion in a buffer-perfused isolated, paced heart model and divided into four groups. Global ischemic hearts (GI, n = 6) were subjected to 30 min. global ischemia without intervention. Control hearts (n = 6) were subjected to perfusion without ischemia. Ischemic preconditioned hearts (IPC, n = 6) were subjected to one cycle of 5 min. global ischemia and 5 min. reperfusion prior to global ischemia. IPC + Ado hearts (n = 6) received IPC and adenosine administration (100 m mol/L) during 3 min. early reperfusion period. Post-ischemic functional recovery was better in IPC + Ado hearts as compared to GI and IPC hearts, but the effect of post-ischemic functional recovery in IPC + Ado hearts became weaker during 120 min. reperfusion after prolong ischemic insult. Infarct size were 1.0 +/- 0.3% in Control hearts, 32.9 +/- 5.1% in GI hearts, 13.8 +/- 1.3% in IPC hearts and 8.1 +/- 0.9% in IPC + Ado hearts Infarct size in IPC hearts was significantly decreased (p < 0.01) as compared to GI hearts. The reduction rate against myocardial necrosis in IPC + Ado hearts versus GI hearts was higher as compared to IPC hearts versus GI hearts (p < 0.001, IPC + Ado hearts vs GI hearts; p < 0.01, IPC hearts vs GI hearts; p = ns, IPC + Ado hearts vs Control hearts). These data suggest that adenosine administration during the early reperfusion period reinforce IPC effect and reduce myocardial reperfusion injury. Cardiomyoprotective effects of IPC and exogenous adenosine are exerted during early reperfusion after coronary occlusion in the isolated perfused rabbit hearts.

[Ischemic preconditioning in the aged heart--myocardial protective effect as compared with the mature heart]

It is now well established that pre-treatment with sublethal ischemia, followed by reperfusion, will delay myocardial necrosis during a later sustained ischemic episode, termed ischemic preconditioning (IPC); this has been confirmed experimentally and clinically. However, the effects for the senescent heart differ from those of the mature heart at both functional and cellular levels which have not yet been determined. Comparisons were made between aged (> 135 weeks, n = 18) and mature (15 approximately 20 weeks, n = 8) rabbit hearts which underwent 30 min. normothermic global ischemia with 120 min reperfusion in a buffer-perfused isolated, paced heart model, and the effects of IPC on post-ischemic functional recovery and infarct size were investigated. Ischemic preconditioned hearts (n = 6) were subjected to one cycle of 5 min. global ischemia and 5 min. reperfusion prior to global ischemia. Global ischemic hearts (n = 6) were subjected to 30 min. global ischemia without intervention. Control hearts (n = 6) were subjected to perfusion without ischemia. Post-ischemic functional recovery was better in the ischemic preconditioned hearts than in the global ischemic hearts in both aged and mature hearts. However, in the aged hearts, post-ischemic functional recovery was slightly reduced compared to that of the mature hearts, and only the coronary flow was well-preserved. In the mature hearts, myocardial infarction in the ischemic preconditioned hearts (14.9 +/- 1.3%) and in the control hearts (1.0 +/- 0.3%) was significantly decreased (p < 0.01) compared to that of the global ischemic hearts (32.9 +/- 5.1%). In the aged hearts, myocardial infarction in the ischemic preconditioned hearts (18.9 +/- 2.7%) and in the control hearts (1.1 +/- 0.6%) was significantly decreased (p < 0.001) compared to that of the global ischemic hearts (37.6 +/- 3.7%). The relationship between infarct size and post-ischemic functional recovery of left ventricularpeak developed pressure (LVDP) was linear and the correlation negative, with r = -0.934 (p < 0.001) and -0.875 (p < 0.001) for mature and aged hearts respectively. The data suggest that, in the senescent myocardium, the cellular pathways involved ischemic preconditioning responses that were post-ischemic, and that functional recovery was worse as compared to that of the mature myocardium. Furthermore, the effects of post-ischemic functional recovery became consistently weaker during the control period of 120 min. reperfusion after a prolonged ischemic insult in a buffer perfused isolated rabbit model. However, the effects of infarct size limitation were well-preserved in both senescent and mature myocardia.

Impact of presence of abnormal wall motion on echocardiographic determination of left ventricular function with automated boundary detection technique: re-evaluation

It is still unclear whether echocardiography with an automated boundary detection technique (ABD) can accurately determine the left ventricular (LV) volume and function particularly in the presence of LV wall asynergy. We intended to re-evaluate the reliability and application of the ABD, which was based on the acoustic quantification technique (Sonos 2500, Hewlett Packard) for the LV volume measurement in patients without or with LV wall asynergy. A total of 80 patients (mean age 56 years) who underwent left ventriculography (LVG) were divided into two groups. The group A consisted of 29 patients with normal LV wall motion and the group B consisted of 51 patients with generalized or regional LV wall motion abnormality. In group A patients, the LV end-diastolic volume (LVEDV) was 96 +/- 25 ml by ABD and 112 +/- 33 ml by LVG and those of LV end-systolic volume (LVESV) were 44 +/- 14 ml by ABD and 48 +/- 17 ml by LVG, thus resulting in the underestimation of LV volume by 12% in average. Under these conditions, the LV ejection fraction (LVEF) by ABD, 54 +/- 8%, correlated well with that by LVG, 58 +/- 7%. Although underestimation of LV volume by 17% in average also occurred in groups B (N.S.), LVEF was found to correlate well with that by LVG; 27 +/- 8% vs 30 +/- 11% (r = 0.87, SEE = 3.1%) for 21 patients with the generalized LV asynergy; 39 +/- 10% vs 39 +/- 12% (r = 0.86. SEE = 3.3%) for 30 patients with the regional LV asynergy. These results demonstrate the feasibility of the ABD in determining the LVEF, although underestimation can occur in measuring the absolute LV volume in patients with or without LV asynergy.

Secretion patterns of brain natriuretic peptide and atrial natriuretic peptide in patients with or without pulmonary hypertension complicating atrial septal defect

BACKGROUND This study was designed to investigate plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in patients with atrial septal defect (ASD), whose right ventricular loading patterns vary from simple volume overloading to both volume and pressure overloading.

METHODS AND RESULTS

Plasma ANP and BNP in the pulmonary artery were measured in 31 adult patients with ASD and 11 control subjects. On the basis of the presence of pulmonary hypertension (PH, mean pulmonary arterial pressure >20 mm Hg), patients with ASD were divided into two groups, patients without PH (group 1, n = 21) and those with PH (group 2, n = 10). Cardiac catheterization was performed to measure mean pulmonary arterial pressure and pulmonary blood flow. Plasma ANP was significantly higher in both group 1 and group 2 than in the control group. Plasma BNP and BNP to ANP (BNP/ANP) ratio were significantly higher in group 2 than in the control group, although they were not significantly elevated in group 1. Plasma ANP positively correlated with the degree of pulmonary blood flow (r = 0.54, p < 0.01), whereas plasma BNP positively correlated with the magnitude of mean pulmonary arterial pressure (r= 0.73, p < 0.001). BNP/ANP >1 was a powerful marker for the presence of PH (sensitivity 90%, specificity 90%).

CONCLUSIONS

Plasma ANP levels were elevated in adult patients with ASD regardless of PH. In contrast, plasma BNP levels were elevated in proportion to the severity of PH complicating ASD. Thus BNP and ANP may represent differing aspects of cardiac response to right ventricular overload in patients with ASD.

Adenosine-enhanced ischemic preconditioning decreases infarct in the regional ischemic sheep heart

BACKGROUND

Recently we have reported a myoprotective protocol, adenosine-enhanced ischemic preconditioning, that extends the protection afforded by ischemic preconditioning in the isolated crystalloid-perfused heart. In this report the efficacy of adenosine-enhanced ischemic preconditioning in the in situ blood-perfused heart was investigated.

METHODS

Sheep were subjected to 60 minutes of regional ischemia and 120 minutes of reperfusion. Ischemic preconditioned hearts received 5 minutes of zero flow regional ischemia and 5 minutes of reperfusion before regional ischemia. Adenosine-enhanced ischemic preconditioned hearts received a bolus injection of 10 mmol adenosine at the immediate start of ischemic preconditioning. Adenosine-treated hearts received an adenosine bolus, 10 minutes before regional ischemia. The ratio of infarct size to area at risk and mechanical function were determined.

RESULTS

The infarct size to area at risk ratio in regional ischemia was 55.4%+/-2.1%. This ratio was significantly decreased with ischemic preconditioning and adenosine (22.2%+/-2.2% and 19.3%+/-1.4%, respectively; p < 0.001 versus regional ischemia) and adenosine-enhanced ischemic preconditioning (8.0%+/-2.0%, p < 0.001 versus regional ischemia and ischemic preconditioning, and p < 0.01 versus adenosine).

CONCLUSIONS

Adenosine-enhanced ischemic preconditioning significantly decreases infarct size in the in situ blood-perfused heart and provides superior protection compared with ischemic preconditioning.

Two-step approach for the operation of male breast cancer: report of a case at high risk for surgery

We report herein the rare case of a 61-year-old man with a history of dissecting aortic aneurysm as well as right breast cancer. He complained of abdominal pain due to a progress of aortic dissection in preparation for the radical operation for breast cancer. Blood pressure was initially controlled and he was administered a simple mastectomy under local anesthesia. One month after the first operation, a radical operation for breast cancer was successfully performed. The tumor was in stage II, and two years after the operation, the patient remained free of recurrent disease. This two-step approach for the operation of male breast cancer may be used as a treatment of breast cancer if a patient is too frail for normal surgery.

Adenosine-enhanced ischemic preconditioning provides enhanced postischemic recovery and limitation of infarct size in the rabbit heart

OBJECTIVE

The purpose of this study was to determine the effect of an intracoronary bolus injection of adenosine used in concert with ischemic preconditioning on postischemic functional recovery and infarct size reduction in the rabbit heart and to compare adenosine-enhanced ischemic preconditioning with ischemic preconditioning and magnesium-supplemented potassium cardioplegia.

METHODS

New Zealand White rabbits (n = 36) were used for Langendorff perfusion. Control hearts were perfused at 37 degrees C for 180 minutes; global ischemic hearts received 30 minutes of global ischemia and 120 minutes of reperfusion; magnesium-supplemented potassium cardioplegic hearts received cardioplegia 5 minutes before global ischemia; ischemic preconditioned hearts received 5 minutes of zero-flow global ischemia and 5 minutes of reperfusion before global ischemia; adenosine-enhanced ischemic preconditioned hearts received a bolus injection of adenosine just before the preconditioning. To separate the effects of adenosine from adenosine-enhanced ischemic preconditioning, a control group received a bolus injection of adenosine 10 minutes before global ischemia.

RESULTS

Infarct volume in global ischemic hearts was 32.9% +/- 5.1% and 1.03% +/- 0.3% in control hearts. The infarct volume decreased (10.23% +/- 2.6% and 7.0% +/- 1.6%, respectively; p < 0.001 versus global ischemia) in the ischemic preconditioned group and control group, but this did not enhance postischemic functional recovery. Magnesium-supplemented potassium cardioplegia and adenosine-enhanced ischemic preconditioning significantly decreased infarct volume (2.9% +/- 0.8% and 2.8% +/- 0.55%, respectively; p < 0.001 versus global ischemia, p = 0.02 versus ischemic preconditioning and p = 0.05 versus control group) and significantly enhanced postischemic functional recovery.

CONCLUSIONS

Adenosine-enhanced ischemic preconditioning is superior to ischemic preconditioning and provides equal protection to that afforded by magnesium-supplemented potassium cardioplegia.

Intravascular ultrasound evaluation of plaque distribution at curved coronary segments

Although the distribution of atherosclerosis at the curved coronary segments has implications for atherogenesis and interventional procedures, few data exist regarding the plaque distribution in these sites. Therefore, we prospectively analyzed the intravascular ultrasound images of 55 coronary sites from 37 patients where the atherosclerotic plaque and pericardium were simultaneously demonstrated by intravascular ultrasound. The pericardial images were defined as a high-intensity linear echo image moving during cardiac cycles outside the vessel wall. By the line that was parallel to the pericardial image, the vessel area was divided into 2 semicircles with the same area, namely myocardial and pericardial sides. In each side, the maximal thickness, area, and percent area of plaque were measured. The plaque thickness and area of the myocardial side were significantly greater (1.5 +/- 0.5 mm, 4.9 +/- 2.1 mm or 66%, mean +/- SD) than those of the pericardial side (1.1 +/- 0.4 mm, 3.5 +/- 2.1 mm2 or 45%, p < 0.01). The maximal plaque thickness was positioned at the point with a mean angle of 139 +/- 37 degrees from the point just facing the pericardial image, indicating that atherosclerosis was eccentrically located on the opposite side of the pericardium in these coronary segments, and suggesting that the side of the pericardial image represents the outer curvature of the coronary artery. These results indicate that the pericardial images can be seen by intravascular ultrasound, facilitating the recognition of the disease distribution in situ. The eccentric plaque located on the inner wall at the curved coronary segments, probably due to uneven local shear stress, may have implications for the interventional procedures for these segments.

[Color Doppler signal enhancement with SH/TH-508 in pancreatic tumors]

In this report, we showed the efficacy of a new contrast agent (SH/TA-508, Schering AG, Germany) for color Doppler imaging of the pancreatic tumors. In pancreatic ductal cancer, no enhancement of the lesion was observed, but vascular invasion by cancer became to be easily evaluated. On the other hand, hypervascular tumors such as islet cell tumor and cystadenocarcinoma, were increased in color Doppler signals of vessels by SH/TA-508. We concluded that SH/TA-508 was useful for evaluating the vascular invasion by pancreatic cancer as well as vascularity of hypervascular mass and solid component of cystic neoplasma.

Focal, high dose, and fractionated modified stereotactic radiation therapy for lung carcinoma patients: a preliminary experience

BACKGROUND

Stereotactic radiation therapy is highly effective in the treatment of small brain metastases, regardless of the histology. This suggests that small extracranial malignancies may be curable with similar radiation therapy. The authors developed a novel treatment unit for administering such therapy.

METHODS

The unit consisted of a linear accelerator (linac), an X-ray simulator (X-S), computed tomography (CT), and a table. The gantry axes of the three machines were coaxial and could be matched by rotating the table. Patients were instructed to perform shallow respiration with oxygen. The motion of the tumor was monitored with the X-S. When the motion was slight enough, the table was rotated to the CT. To include all geometric movement on the CT images, each scan was made while the patient was performing shallow respiration. After the CT positioning, the table was rotated to the linac, and non-coplanar treatment was given. Beginning in October 1994, 45 patients with 23 primary or 43 metastatic lung carcinomas were treated. Radiation doses at the 80% isodose line were 30-75 gray in 5-15 fractions over 1-3 weeks with or without conventional radiation therapy.

RESULTS

The treatment was performed with no or minimal adverse acute symptoms. The daily treatment time was short. During a median follow-up of 11 months, local progression occurred in 2 of 66 lesions. Interstitial changes in the lung were limited.

CONCLUSIONS

With this unit and procedure, focal radiation therapy similar to stereotactic radiation therapy is possible for extracranial sites. The preliminary experience appeared safe and promising, and further exploration of this approach is warranted.

Focal, high dose, and fractionated modified stereotactic radiation therapy for lung carcinoma patients: a preliminary experience

BACKGROUND

Stereotactic radiation therapy is highly effective in the treatment of small brain metastases, regardless of the histology. This suggests that small extracranial malignancies may be curable with similar radiation therapy. The authors developed a novel treatment unit for administering such therapy.

METHODS

The unit consisted of a linear accelerator (linac), an X-ray simulator (X-S), computed tomography (CT), and a table. The gantry axes of the three machines were coaxial and could be matched by rotating the table. Patients were instructed to perform shallow respiration with oxygen. The motion of the tumor was monitored with the X-S. When the motion was slight enough, the table was rotated to the CT. To include all geometric movement on the CT images, each scan was made while the patient was performing shallow respiration. After the CT positioning, the table was rotated to the linac, and non-coplanar treatment was given. Beginning in October 1994, 45 patients with 23 primary or 43 metastatic lung carcinomas were treated. Radiation doses at the 80% isodose line were 30-75 gray in 5-15 fractions over 1-3 weeks with or without conventional radiation therapy.

RESULTS

The treatment was performed with no or minimal adverse acute symptoms. The daily treatment time was short. During a median follow-up of 11 months, local progression occurred in 2 of 66 lesions. Interstitial changes in the lung were limited.

CONCLUSIONS

With this unit and procedure, focal radiation therapy similar to stereotactic radiation therapy is possible for extracranial sites. The preliminary experience appeared safe and promising, and further exploration of this approach is warranted.

Intravascular ultrasound evidence for importance of plaque distribution in the determination of regional vessel wall compliance

Regional vessel wall distensibility was determined by measuring luminal area and pressure, using intravascular ultrasound (Sonicath; Boston-Scientific, Watertown, MA, USA; 3.5 Fr, 30 MHz) in 45 left coronary sites from 40 patients. Luminal area in diastole (A) and in systole was measured at the diseased sites. With the ratio of luminal area changes (dA) to coronary pressure changes (dP) during a cardiac cycle, the total distensibility index was calculated by the formula: [(dA/A)/dP] x 10(3). At sites with non-circumferential disease, perimeters in diastole (L) and in systole were measured at the normal and diseased portions, and the changes in perimeters (dL) during a cardiac cycle were calculated. The regional distensibility index was obtained by the formula: [(dL/L)/dP] x 10(3). In 22 sites with circumferential disease, the total distensibility index was 1.03 +/- 0.61/mmHg, significantly lower than that for 23 sites with non-circumferential disease (1.45 +/- 0.89/mmHg; P < 0.05). In non-circumferential disease, the regional distensibility index at the diseased portion was significantly lower (0.33 +/- 0.47/mmHg) than that at the normal portion (1.11 +/- 0.75/mmHg; P < 0.01). Coronary sites with residual non-circumferential disease after angioplasty also exhibited heterogeneity of regional distensibility (0.73 +/- 0.76 at disease sites versus 1.58 +/- 0.95/mmHg at normal sites, n = 10, P < 0.05). These results indicate that heterogeneous regional wall distensibility exists at sites with non-circumferential disease where the total vessel distensibility is preserved by the presence of compliant normal portion. This heterogeneity of regional wall distensibility may represent a biomechanical factor that explains the mechanism of plaque rupture that occurs mainly at the shoulder of the non-circumferential disease.

Plasma brain natriuretic peptide levels increase in proportion to the extent of right ventricular dysfunction in pulmonary hypertension

OBJECTIVES

This study sought to investigate the influence of right ventricular (RV) hemodynamic variables and function on the secretion of brain natriuretic peptide (BNP) in patients with isolated RV overload.

BACKGROUND

Plasma BNP is known to increase in proportion to the degree of left ventricular (LV) overload. However, whether BNP secretion is also regulated in the presence of RV overload remains unknown.

METHODS

Plasma BNP and atrial natriuretic peptide (ANP) levels in the pulmonary artery were measured in 44 patients with RV overload: 18 with RV volume overload (RVVO) due to atrial septal defect and 26 with RV pressure overload (RVPO) due to primary or thromboembolic pulmonary hypertension. Right heart catheterization was performed in all patients. RV and LV ejection fraction, myocardial mass and volume of the four chambers were determined by using electron beam computed tomography.

RESULTS

Although both plasma BNP and ANP levels were significantly elevated in patients with RV overload compared with values in control subjects, plasma BNP and the BNP/ANP ratio were significantly higher in patients with RVPO than with RVVO (BNP 294 +/- 72 vs. 48 +/- 14 pg/ml; BNP/ANP 1.6 +/- 0.2 vs. 0.8 +/- 0.2, both p < 0.05). Plasma BNP correlated positively with mean pulmonary artery pressure (r = 0.73), total pulmonary resistance (r = 0.79), mean right atrial pressure (r = 0.79), RV end-diastolic pressure (r = 0.76) and RV myocardial mass (r = 0.71); it correlated negatively with cardiac output (r = -0.33) and RV ejection fraction (r = -0.71). Plasma BNP significantly decreased from 315 +/- 120 to 144 +/- 54 pg/ml with long-term vasodilator therapy (total pulmonary resistance decreased from 23 +/- 4 to 15 +/- 3 Wood U).

CONCLUSIONS

Plasma BNP increases in proportion to the extent of RV dysfunction in pulmonary hypertension.

Application of tissue Doppler imaging technique in evaluating early ventricular contraction associated with accessory atrioventricular pathways in Wolff-Parkinson-White syndrome

To examine the feasibility of a tissue Doppler imaging (TDI) technique for evaluating the early contraction sites in Wolff-Parkinson-White (WPW) syndrome, we analyzed the time-sequential changes in ventricular wall motion in WPW syndrome by TDI. Fifty patients with WPW syndrome were examined by the TDI system in which the high-speed scanning technique allowed for a frame rate up to 38 frames/sec. Among 42 patients in whom the acceptable images were obtained by TDI, the early contraction, which was represented by a red or blue spot appearing on the subendocardial side at the time of the delta wave in the electrocardiogram, was demonstrated in 25 of 29 patients with left-sided accessory pathways. However, in 13 patients with right-sided pathways, the early contraction sites could be identified in only five patients. The TDI-determined early contraction sites were well coincided with the sites of the accessory pathways determined by the electrophysiologic examination (p < 0.01). After the successful radiofrequency catheter ablation, early contraction sites were found to disappear by TDI in all patients. These results demonstrate the feasibility of the TDI technique to evaluate the early ventricular contraction associated with the atrioventricular accessory pathways. We suggest that the TDI system is helpful to localize the accessory pathways and to evaluate the results after radiofrequency ablation, although further studies are necessary to demonstrate the advantage of TDI over conventional echocardiography and electrophysiologic study in the evaluation of the accessory pathways in WPW syndrome.

Comparative usefulness of myocardial velocity gradient in detecting ischemic myocardium by a dobutamine challenge

OBJECTIVES

We tested the hypothesis that ischemic myocardium can be sensitively detected using tissue Doppler-derived myocardial velocity gradient (MVG) by a dobutamine challenge.

BACKGROUND

Although tissue Doppler imaging (TDI) has recently emerged to quantify regional myocardial contraction, increased translational motion during a dobutamine challenge may affect the measurements. MVG is an indicator of regional myocardial contraction independent of the translational motion.

METHODS

We studied 19 patients with (n = 13) and without (n = 6) confirmed single-vessel coronary artery disease. Left ventricular short-axis tissue Doppler images were obtained along with conventional echocardiograms during a submaximal two-step dobutamine challenge (10 and 30 microg/kg body weight per min). Endocardial velocity as well as MVG were derived from TDI using computer analysis in the anteroseptal and posterior segments and were compared with visual interpretation.

RESULTS

MVG demonstrated a significant dose-responsive increase in the nonischemic segments (anteroseptal: 2.6 +/- 0.8/s to 6.0 +/- 1.0/s [mean +/- SD], p < 0.05; posterior: 3.9 +/- 0.7/s to 7.6 +/- 1.8/s, p < 0.05) but remained unchanged in the ischemic segments (anteroseptal: 2.5 +/- 0.8/s to 2.7 +/- 0.7/s, p = NS; posterior: 3.4 +/- 1.0/s to 4.1 +/- 0.9/s, p = NS). Endocardial velocity failed to clearly demonstrate the differing responses between the nonischemic (anteroseptal: -2.3 +/- 1.2 to -2.7 +/- 1.6 cm/s, p = NS; posterior: 3.8 +/- 1.1 to 73 +/- 2.7 cm/s, p < 0.05) and ischemic segments (anteroseptal: -2.1 +/- 0.5 to -2.8 +/- 0.8 cm/s, p = NS; posterior: 4.2 +/- 0.8 to 6.5 +/- 2.6 cm/s, p = NS). Wall motion abnormality was hardly detectable with visual interpretation (wall motion score range 1.00 to 1.33).

CONCLUSIONS

Abnormal segments could be sensitively detected by using MVG in a submaximal dobutamine challenge, even where conventional methods failed to detect the abnormality.

Impaired left ventricular myocardial metabolism in patients with pulmonary hypertension detected by radionuclide imaging

To assess whether left ventricular myocardial metabolism is affected by the presence of right ventricular pressure overload, we performed 123I-beta-methyl-iodophenyl pentadecanoic acid (123I-BMIPP) and 99Tc(m)-sestamibi (99Tc(m)-MIBI) single photon emission tomography in 24 patients with pulmonary hypertension and in 10 control subjects. The left ventricle was divided into six regions using a short-axis tomogram at the mid-ventricular level. The relative regional uptake (RRU, %) was determined for each region as the ratio of the regional uptake per pixel to the maximum uptake in the six regions. Right heart catheterization was performed to obtain mean pulmonary arterial pressure. 123I-BMIPP uptake in the septum and the adjacent myocardium of the left ventricle was lower in patients with pulmonary hypertension than in control subjects (septal RRU, 75 +/- 6 vs 85 +/- 4%; anteroseptal RRU, 76 +/- 6 vs 86 +/- 3%; posteroseptal RRU, 75 +/- 4 vs 84 +/- 4%; P < 0.001). The reduction in 99Tc(m)-MIBI uptake was confined to the septum in patients with pulmonary hypertension (79 +/- 5 vs 85 +/- 5%; P < 0.05). Interestingly, the septal RRU of 123I-BMIPP and the sum of the septal, anteroseptal and posteroseptal RRUs of 123I-BMIPP were negatively correlated with mean pulmonary arterial pressure (r = -0.70 and -0.55, respectively; P < 0.01). In conclusion, myocardial metabolism in the interventricular septum and the adjacent regions of the left ventricle may be impaired in proportion to the degree of pulmonary hypertension.

The role of low-dose hemithoracic radiotherapy for thoracic dissemination of thymoma

We retrospectively reviewed the records of 11 thymoma patients to clarify the role of hemithoracic irradiation and chemotherapy for patients with thoracic dissemination at the initial presentation. Radiotherapy was administered postoperatively in all but two patients who were not candidates for surgical treatment. Radiotherapy doses ranged from 10 to 17 Gy for the entire hemithorax of the disseminated site and from 30 to 55 Gy to the primary tumor bed. Chemotherapy of various protocols was also employed preceding radiotherapy in seven cases. Cumulative 5- and 10-year survival rates were 80% and 64%, respectively. Regrowth-free 5- and 10-year survival rates were 55% and 37%, respectively. Six of the 11 patients were free from regrowth at a median follow-up interval of 60 months. The role of chemotherapy remained unclear. Acute or late sequelae were modest and acceptable. In conclusion, entire hemithoracic irradiation is justified as postoperative or definitive radiotherapy treatment for disseminated thymoma unless there is a risk of radiation pneumonitis. Further evaluation should be conducted.

Shortening of Doppler-derived deceleration time of early diastolic transmitral flow in the presence of pulmonary hypertension through ventricular interaction

Deceleration time (DT) of the early transmitral flow velocity has recently been highlighted as a simple, noninvasive indicator of pulmonary arterial wedge pressure. In patients with pulmonary hypertension without left-sided heart disease, however, increased right ventricular pressure may result in an abnormal ventricular septal motion, which may impact on left ventricular (LV) early diastolic filling. We sought to determine if DT may be influenced by the severity of pulmonary hypertension in patients without left-sided heart disease. Doppler-derived transmitral flow and hemodynamic parameters were simultaneously assessed in 26 patients with pulmonary hypertension (primary pulmonary hypertension = 11; chronic thromboembolism = 15). Transmitral Doppler variables including DT were correlated with hemodynamics and LV deformity index measured in early diastole with 2-dimensional echocardiography. DT significantly correlated with the total pulmonary resistance (r = -0.70, p <0.001). Multivariate analysis revealed that DT was independently determined by total pulmonary resistance, but not by pulmonary arterial wedge pressure, heart rate, or patient's age in our study population. DT showed a correlation with LV deformity index (r = -0.74, p <0.001). These results indicate that DT may shorten in association with the severity of pulmonary hypertension and that the shortened DT in pulmonary hypertension may be attributable to right ventricular pressure overload which causes geometric changes.

[Surgical treatment of primary pulmonary malignant lymphoma: a report of successful case]

A 73-year-old male was admitted to our hospital because of abnormal shadow in the lung field. The pathological report of the percutaneous needle lung biopsy specimen under the CT scan was suggested lymphoma (lymphomatoid granulomatosis suspected), and the right middle lobectomy was performed. Histological and immunohistochemical examinations of the operative specimen revealed B-cell type malignant lymphoma (diffuse pleomorphic lymphoma, large cell type, high grade lymphoma). Primary pulmonary malignant lymphoma is a rare disorder, and it is difficult utilized to distinguish between true malignant lymphoma and lymphomatoid granulomatosis, or pseudolymphoma. Anyway, the first choice of the treatment is surgical excision, because of its satisfactory prognosis.

Usefulness of myocardial velocity gradient derived from two-dimensional tissue Doppler imaging as an indicator of regional myocardial contraction independent of translational motion assessed in atrial septal defect

Independence of myocardial velocity gradient from translational motion of the heart was tested by comparing normal subjects and patients with atrial septal defect. Myocardial velocity gradient obtained from patients fit within the normal range, even though the translation of the left ventricle was exaggerated in patients, demonstrating the translation independence of myocardial velocity gradient in clinical settings.

[Prognostic factors of cervical carcinoma treated with postoperative radiotherapy]

We analyzed 119 patients with cervical carcinoma treated by postoperative radiotherapy from 1983 to 1993. Five- and 10-year survival rates of all patients were 77% and 67%, respectively. The 10-year survival rates for stage I (54 patients) and stage II (65 patients) were 76% and 58%, respectively. Ten-year survival rate for patients with both deep stromal invasion and lymph node metastasis was 37% which was much lower than in those without them (more than 90 %), indicating that they seemed to be factors related to poor prognosis. The results of multivariate analysis showed that the number of metastatic lymph nodes was the most important prognostic factor. Leg edema and intestinal and urinary insufficiency as late complications of postoperative radiotherapy occurred at low incidences and were well tolerated.

Attenuated inhibition of adrenergic contraction by nitric oxide in injured guinea pig femoral artery

The present study aimed to examine the altered modulation of adrenergic contraction by nitric oxide and sensory neuropeptides in balloon-injured muscular artery. A guinea pig femoral artery (GPFA) was injured by a newly developed silastic microballoon catheter. The contralateral GPFA served as the control. The studied GPFAs consisted of six groups; control (C) and injured (I) GPFA, isolated at 0 days, and 2 and 8 weeks after injury (C0, I0, C2, I2, C8, and I8). Isometric tension was measured in the presence of indomethacin (10(-5) M), to exclude effects of cyclooxygenase-generated eicosanoids. Endothelial removal with the catheter was confirmed by histological examination. In each group, except for 10, NG-nitro-I-arginine methyl ester (L-NAME, 10(-6) M) induced significant augmentation of perivascular nerve stimulation (PNS)-evoked adrenergic contraction, which was blocked by L-arginine (3 x 10(-4) M). The degree of L-NAME augmentation in I8 was significantly smaller than that in C8 and I2. Capsaicin (10(-6) M) did not significantly affect PNS-contraction in any group, indicating that there was no sensory neuropeptide involvement in this contraction. In I8, acetylcholine (10(-6) M)-induced relaxation after noradrenaline (10(-5) M)-precontraction was significantly smaller than that seen in the other groups, except for I0, which was lacking in acetylcholine-induced relaxation. Histologically, injured GPFAs showed progressive intimal thickening. The present findings thus showed attenuated nitric oxide-mediated inhibition of adrenergic contraction, accompanying intimal thickening, in balloon-injured muscular artery, 8 weeks after injury.

Surgical treatment of refractory venous stasis ulcer due to a severe impairment of calf muscle pump function: evaluation by air plethysmography. A case report

The authors encountered a forty-nine-year-old man with a lower limb ulcer refractory to intensive conservative therapy. No varicose vein was found anywhere, and the usual phlebographies and foot venous pressure measurement failed to diagnose it as a venous stasis ulcer. A direct phlebography method developed by the authors, in which a thin catheter is inserted into the deep vein, disclosed a reflux of the popliteal vein or a deep muscle branch from which an incompetent perforator arose toward the superficial vein above the ulcer. Air plethysmography (APG) showed a severe impairment of the calf muscle pump function. He underwent a subfascial ligation of two incompetent perforators together with a stripping of the great saphenous vein passing under the ulcer. Postoperatively, this ulcer was cured in an early phase, and the calf muscle pump function showed improvement in the APG.

[Prognostic factors of nasopharyngeal carcinoma treated by radiotherapy]

This study was a retrospective analysis of 82 patients with histologically confirmed nasopharyngeal carcinoma, who were treated at Keio University Hospital from March 1983 to March 1993. We studied all cases(62% of them were stage IV) with regard to their prognostic factors and chronic side effects induced by radiation. All patients were received extended-field radiotherapy from the base of the skull to the supraclavicular lymph node area. The five- and ten-year overall survival rates for the entire group were 59% and 49%, respectively. Three stage I patients were alive without recurrence or metastases for more than 5 years. The ten-year survival rate stage II-III for patients (23 patients) was 78%, and for stage IV (56 patients) 37%. The five-year survival rate of patients in T2-3 group without lymph node metastasis was 88%, while it was reduced to 55% for patients with metastasis. The prognosis of T4 patients was very poor: their five-year survival rate was 37% with lymph node metastasis, and 35%, without lymph node metastasis. Patients under 46 years old showed an increased survival rate compared with patients over 46 years old. Patients who completed less than 52 days of radiation therapy found to have a better prognosis than those receiving radiation for a longer period. Our multivariate analysis indicated that age, radiation period and N-factor were statistically significant in influencing prognosis. Hearing loss occurred relatively high with 20% of cumulative incidence in our study, probably because they received radiation therapy with the extended field including bilateral middle and inner ear. Extended-field radiotherapy for patients with nasopharyngeal carcinoma might contribute to improving their cure-rate, and precise radiation planning is warranted to avoid the late complications such as hearing loss.

Experimental studies on modified human ureter as an arterial substitution for reconstruction of small caliber vessels

Human ureters were experimentally employed as vascular biografts for small-caliber vessels. They were produced by tanning with polyepoxy compound or glutaraldehyde, and also were compared with saphenous veins tanned by polyepoxy compound and/or ready-made vascular graft of polytetrafluoroethylene (e-PTFE). These produced grafts, which had enough elasticity and excellent durability were successfully implanted to the carotid arteries in Japanese white rabbits. The grafts were sacrificed after 1 month observation. In this model there were no evidence of rejection, aneurysmal formation and/or infection. Polyepoxy compound fixed human ureter (n = 6), polyepoxy compound fixed saphenous vein (n = 6) and e-PTFE (n =3) showed good patency, but all glutaraldehyde fixed human ureters (n = 3) were completely occluded with severe intimal hyperplasia. Especially, polyepoxy compound fixed human ureter showed excellent patency as well as function, and the histological findings revealed monolayer endothelial cells covering the surface of the graft. No intimal hyperplasia was demonstrated at the anastomotic site. This study suggested that the polyepoxy compound fixed human ureter could serve as a satisfactory blood conduit of reconstruction for the small caliber vessels. Our preliminary data also suggests that longer observation up to 6 months in polyepoxy compound fixed human ureter graft and 18 months in polyepoxy compound fixed saphenous vein graft after surgery, arteriovenous shunt (A-V shunt), long bypass with a graft length of 2 to 5 cm), Y-graft model, sequential model and reinforcement graft by dacron cloth give good results.

Does bone SPECT actually have lower sensitivity for detecting vertebral metastasis than MRI?

We compared the ability of bone SPECT and MRI to detect vertebral metastasis.

METHODS

Skeletal scintigraphy, including planar and SPECT imaging, and spinal MRI examinations, were performed in 22 cancer patients in whom a total of 88 metastatic foci and 12 degenerative joint disease lesions were detected. Metastatic foci were defined as lesions that suggested metastasis on MRI and/or bone destruction on radiographs or CT and/or aggravation of increased tracer uptakes on serial bone scans. Image reconstruction of axial, coronal and sagittal sections was processed in a 128 X 128 matrix. MRI studies were performed with a 1.5 tesla signal scanner using fast spin-echo sequences. T1- and T2-weighted images were obtained in the sagittal plane.

RESULTS

Twenty patients had at least one vertebral metastasis. MRI diagnosed 86 of the 88 (97.7%) metastatic foci; bone SPECT correctly diagnosed 81 of 88 (92.0%); and planar imaging detected 62 of 88 (70.4%). The two vertebrae with metastasis not detected by MRI were clearly seen by bone SPECT. Extra-vertebral body metastases (e.g. in the pedicle, lamina, transverse and spinous processes) were, however, most often detected by SPECT, followed by MRI and planar imaging (40 versus 32 versus 4).

CONCLUSION

Vertebral SPECT, using high-resolution SPECT equipment, produced excellent results that were comparable to and complementary with MRI in detecting vertebral metastasis. Our data suggest that vertebral SPECT is superior to MRI in detecting extra-vertebral body metastasis.

A dual computed tomography linear accelerator unit for stereotactic radiation therapy: a new approach without cranially fixated stereotactic frames

PURPOSE

To perform stereotactic radiation therapy (SRT) without cranially fixated stereotactic frames, we developed a dual computed tomography (CT) linear accelerator (linac) treatment unit.

METHODS AND MATERIALS

This unit is composed of a linac, CT, and motorized table. The linac and CT are set up at opposite ends of the table, which is suitable for both machines. The gantry axis of the linac is coaxial with that of the CT scanner. Thus, the center of the target detected with the CT can be matched easily with the gantry axis of the linac by rotating the table. Positioning is confirmed with the CT for each treatment session. Positioning and treatment errors with this unit were examined by phantom studies. Between August and December 1994, 8 patients with 11 lesions of primary or metastatic brain tumors received SRT with this unit. All lesions were treated with 24 Gy in three fractions to 30 Gy in 10 fractions to the 80% isodose line, with or without conventional external beam radiation therapy.

RESULTS

Phantom studies revealed that treatment errors with this unit were within 1 mm after careful positioning. The position was easily maintained using two tiny metallic balls as vertical and horizontal marks. Motion of patients was negligible using a conventional heat-flexible head mold and dental impression. The overall time for a multiple noncoplanar arcs treatment for a single isocenter was less than 1 h on the initial treatment day and usually less than 20 min on subsequent days. Treatment was outpatient-based and well tolerated with no acute toxicities. Satisfactory responses have been documented.

CONCLUSION

Using this treatment unit, multiple fractionated SRT is performed easily and precisely without cranially fixated stereotactic frames.

[Palliation of brain metastases: factors associated with survival]

One hundred ten patients with brain metastases (76 lung cancer, 11 breast cancer, 7 colorectal cancer and others) were treated with radiotherapy, and the results were retrospectively evaluated. Neurologic symptoms were improved in 66% of patients. The relationship between improvement of neurologic symptoms and several factors, including irradiation dose, primary lesion, histology, term between first treatment and recurrence, clinical symptoms and CT findings, was analyzed. There was no significant correlation between symptom relief and these factors except for the number of metastatic lesions. Four of 110 patients could survive more than 2 years after radiotherapy: one with lung cancer, one with breast cancer, one with rectum cancer and one with uterine cancer. The factors that were analyzed for symptom relief were also studied to determine their effect on the survival of lung cancer patients with brain metastases. The patients who had higher dose irradiation (50 Gy) of improvement of neurological symptoms after radiotherapy survived significantly longer than those who had 30 Gy of irradiation or no symptom relief. Multivariate analysis of these factors showed that improvement of symptoms and irradiation dose were similarly important prognostic factors, whereas the others were not correlated with survival.

[A case of intrathoracic goiter]

Intrathoracic goiter is an uncommon conditional lesion. A case of intrathoracic goiter in a 66-year-old woman is herein described. Her chief complaint was anterior chest opplession. A computed tomographic scan and magnetic resonance imaging (MRI) revealed intrathoracic goiter pressed the trachea to the right side. The tumor was safety and completely took by collar incision without thoracotomy. Histologically, the mass was diagnosed the adenomatous goiter. In this case, MRI was very useful to be determined the surgical approach.

Entire hemithorax irradiation following complete resection in patients with stage II-III invasive thymoma

PURPOSE

To evaluate the feasibility and efficacy of prophylactic entire hemithorax irradiation (EH) in addition to mediastinal irradiation (MRT) following a complete resection in Stage II-III invasive thymoma.

METHODS AND MATERIALS

Forty-three patients with invasive thymoma treated with surgery and radiation therapy between 1978 and 1993 were analyzed retrospectively. All 43 patients underwent a complete surgical resection and were judged to have Masaoka's Stage II-III invasive thymoma. Of these, 23 patients received EH and MRT (EH-MRT) and the remaining 20 received MRT. Of the 23 patients with EH-MRT, 11 were Stage II and 12 Stage III. Of the 20 with MRT, 11 were Stage II and 9 Stage III. In most cases, EH was 15 Gy per 15 fractions over 3 weeks (without lung compensation calculation). In both the EH-MRT and MRT group, the total radiation doses to the mediastinum were similar with a median of 40 Gy. The median follow-up time after surgery was 63 months and no patients were lost to follow-up.

RESULTS

Only one of the 23 patients with EH-MRT relapsed. On the other hand, eight of the 20 with MRT relapsed, six of whom died of disease. The pleura was the most common site of failure. At 5 years, the relapse-free rate was 100% for those receiving EH-MRT and 66% for those with MRT (p = 0.03); the overall survival rate was 96% for those with EH-MRT, and 74% for those with MRT (p: not significant). The only significant treatment-related complication was radiation pneumonitis requiring treatment, in one patient who received MRT and three who received EH-MRT, including one death of a 72-year-old man and one 68-year-old woman with severe lung fibrosis.

CONCLUSION

Except for elderly patients, EH-MRT following a macroscopically complete resection appears to be safe and feasible, and can reduce intrathoracic relapses.

Endothelins contract guinea-pig pulmonary artery and enhance its adrenergic response via ET(A) receptors

1. This study has pharmacologically characterized endothelin (ET) receptor subtype(s) mediating contraction and enhancement of adrenergic contraction in guinea-pig pulmonary artery. Isometric tension of the isolated endothelium-denuded ring preparations was measured in the presence of indomethacin (10(-5) mol/L) and N(G)-nitro-L-arginine methyl ester (L-NAME; 3 x 10(4) mol/L) to exclude a mechanism via endothelium, cyclo-oxygenase-generated eicosanoids and nitric oxide. 2. In the additional presence of tetrodotoxin (TTX; 3 x 10(-7) mol/L), ET-1 (10(-11)-10(-7) mol/L) concentration-dependently contracted the preparations. The rank order of potency to contract the preparations among ET receptor agonists was ET-1, sarafotoxin (STX)6b > ET-3 > IRL 1620, STX 6c. BQ-123 (7 x 10(-7)-7 x 10(-6) mol/L) concentrations-dependently shifted the concentration-contraction curve for ET-1 to the right in a parallel manner. Pretreatment with STX 6c (3 x 10(-7) mol/L for 30 min) did not significantly desensitize contractions to ET-1, ET-3 or IRL 1620 (P > 0.05; t-test, 10 d.f). 3. ET-1 (10(-10)-10(-9) mol/L) and STX 6b (10(-9)-10(-8) mol/L) significantly enhanced the electrical field stimulation-induced contraction in a BQ-123-sensitive manner (P < 0.05: t-test, 24-38 d.f), while ET-3 (10(-11)-10(-8) mol/L) and STX 6c (10(-11)-10(-7) mol/L) did not affect contractions. ET-1 (10(-11) mol/L) significantly enhanced contractions to exogenous noradrenaline in the presence of TTX (3 x 10(-7) mol/L) (P < 0.05; t-test, 16 d.f.). 4. These data indicate that the BQ-123-sensitive ET(A) receptor mediates both contraction and enhancement of adrenergic contractions in the guinea-pig pulmonary artery.

Regulation of endothelial cell nitric oxide synthase mRNA expression by shear stress

Shear stress enhances expression of Ca(2+)-calmodulin-sensitive endothelial cell nitric oxide synthase (ecNOS) mRNA and protein in bovine aortic endothelial cells (BAEC). The present studies were performed to investigate mechanisms responsible for regulation of ecNOS mRNA expression by shear stress and to determine if this induction of ecNOS mRNA is accompanied by an enhanced nitric oxide (NO) production. Shear stresses of 15 dyn/cm2 for 3-24 h resulted in a two- to threefold increase of ecNOS mRNA content quantified by Northern analysis in BAEC. Shear stresses (1.2-15 dyn/cm2) for 3 h resulted in an induction of ecNOS mRNA in a dose-dependent manner. In human aortic endothelial cells, shear stresses of 15 dyn/cm2 for 3 h also resulted in ecNOS mRNA induction. In BAEC, this induction in ecNOS mRNA was prevented by coincubation with actinomycin D (10 micrograms/ml). The K+ channel antagonist tetraethylammonium chloride (3 mM) prevented increase in ecNOS mRNA in response to shear stress. The ecNOS promotor contains putative binding domains for AP-1 complexes, potentially responsive to activation of protein kinase C (PKC). However, selective PKC inhibitor calphostin C (100 nM) did not inhibit ecNOS induction by shear stress. Finally, production of nitrogen oxides under both basal conditions and in response to the calcium ionophore A-23187 (1 microM) by BAEC exposed to shear stress was increased approximately twofold compared with cells not exposed to shear stress. These data suggest that ecNOS mRNA expression is regulated by K+ channel opening, but not by activation of PKC, and that shear not only enhances ecNOS mRNA expression but increases capacity of endothelial cells to release NO.