Comparison of Factors Associated With Direct Versus Transferred-in Admission to Government-Designated Regional Centers Between Acute Ischemic Stroke and Myocardial Infarction in Korea

BACKGROUND

There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI.

METHODS

Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed.

RESULTS

Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI; additionally, age (65-74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI.

CONCLUSIONS

Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

Abstract TP312: Direct Visits to Comprehensive Stroke Centers Reduce Time Delays for Thrombolytic Therapy in Acute Ischemic Stroke

Background and Purpose The benefits of thrombolytic therapy for the treatment of acute ischemic stroke are time-dependent. However, many hospitals are not capable of performing endovascular thrombectomy, so patients are often transferred to comprehensive stroke centers, resulting in a delay of treatment. We evaluated the differences in time to thrombolytic therapy between directly admitted patients and referred patients.

Methods: Between July 2014 and February 2018, 382 patients (mean age: 69.0±11.4 years; men: 52.5%) who received thrombolytic therapies within specified therapeutic time windows were included in this study. We identified stroke patients who received intravenous tissue plasminogen activator within 4.5 hours and/or endovascular thrombectomy within 6 hours of symptom onset. We divided the patients into two groups - those who presented to our center directly, and those who were referred from outside hospitals. Baseline characteristics and time variables were compared between the two groups, and we also evaluated the factors associated with favorable outcomes at 3 months.

Results: A total of 108 (28.2%) patients were referred from other hospitals, whereas 275 (71.8%) patients presented to our hospital directly. Direct visit patients received thrombolytic therapies faster than the referred group, according to the onset-to-needle time (126 vs. 163 minutes, p < 0.001) and onset-to-puncture time (194 versus 226 minutes, p < 0.001). Younger age (odds ratio (OR) 0.94; 95% confidence interval (CI) 0.92-0.97; p<0.001), lower National Institutes of Health Stroke Scale (NIHSS) score (OR 0.86; 95% CI 0.82-0.90; p<0.001), and direct presentation to the stroke center (OR 1.75; 95% CI 1.02-3.03; p=0.044) were independently associated with favorable outcomes at 3 months.

Conclusions: Bypassing local hospitals to present directly to the comprehensive stroke center reduced time delays for thrombolytic therapies and improved favorable outcomes in patients with acute ischemic stroke.

Laboratory measurement of apixaban using anti-factor Xa assays in acute ischemic stroke patients with non-valvular atrial fibrillation

Apixaban is effective and safe for preventing stroke, and its usage has increased exponentially in recent years. However, data concerning the therapeutic range of apixaban is limited. This study determined the trough and peak levels of apixaban-specific anti-factor Xa activity (AFXaA) in acute ischemic stroke patients with non-valvular atrial fibrillation (NVAF) in Korea. The study included 85 patients who received apixaban. Blood samples were taken to measure the trough and peak levels of AFXaA using a chromogenic anti-factor assay, as well as prothrombin time (PT) and activated partial thromboplastin time (aPTT). We also reviewed complications such as major bleeding of patients treated with apixaban. In patients given a 5.0-mg apixaban dose, the median trough and peak levels of AFXaA were 104.5 and 202.0 ng/mL. In patients given a 2.5-mg apixaban dose, the median trough and peak AFXaA levels were 76.0 and 151.0 ng/mL. The PT showed a positive correlation with increased AFXaA activity at both levels (Trough R = 0.486, Peak R = 0.592), but the aPTT had no relationship with AFXaA activity at both levels (Trough R = 0.181, Peak R = 0.129). Two cases with intracranial bleeding belonged to the highest AFXaA quartile (Trough, p = 0.176; Peak, p = 0.053). In conclusion, we determined the trough and peak levels of AFXaA in patients with NVAF while being treated with the apixaban in Korea. Our results could be used as a starting point when setting the reference ranges for laboratories using anti-Xa assay. Large-scale studies are needed to establish the reference range for AFXaA in patients with NVAF.

Atorvastatin pretreatment attenuates kainic acid-induced hippocampal neuronal death via regulation of lipocalin-2-associated neuroinflammation

Statins mediate vascular protection and reduce the prevalence of cardiovascular diseases. Recent work indicates that statins have anticonvulsive effects in the brain; however, little is known about the precise mechanism for its protective effect in kainic acid (KA)-induced seizures. Here, we investigated the protective effects of atorvastatin pretreatment on KA-induced neuroinflammation and hippocampal cell death. Mice were treated via intragastric administration of atorvastatin for 7 days, injected with KA, and then sacrificed after 24 h. We observed that atorvastatin pretreatment reduced KA-induced seizure activity, hippocampal cell death, and neuroinflammation. Atorvastatin pretreatment also inhibited KA-induced lipocalin-2 expression in the hippocampus and attenuated KA-induced hippocampal cyclooxygenase-2 expression and glial activation. Moreover, AKT phosphorylation in KA-treated hippocampus was inhibited by atorvastatin pretreatment. These findings suggest that atorvastatin pretreatment may protect hippocampal neurons during seizures by controlling lipocalin-2-associated neuroinflammation.

Location of Irritative Zone in Epileptic Brains of Schizencephalic Patients

Although many schizencephaly patients suffer from epilepsy, the relationship between schizencephalic lesions and epileptic foci remains unclear. Previous studies have shown that schizencephalic lesions may be associated with, rather than contain, epileptogenic zones. Thus, the purpose of this study was to investigate the current source distribution (CSD) of epileptiform discharges in schizencephalic patients and to correlate this activity with existing structural lesions. A consecutive series of 30 schizencephalic patients who were diagnosed using brain magnetic resonance imaging (MRI) were selected retrospectively and prospectively. Of the original 30 subjects selected, 13 had epilepsy, and 6 of these patients exhibited schizencephaly, epilepsy, and interictal spikes on electroencephalograms (EEG) and were enrolled in the present study investigating the current source analysis of interictal spikes. The CSDs of the initial rising phases and the peak points of the interictal spikes were obtained using standardized low-resolution brain electromagnetic tomography (LORETA). Five patients exhibited a single focus of interictal spikes, while 1 patient showed 2 foci. Relative to the structural brain lesions, 5 patients displayed extrinsically localized CSDs, while 1 patient showed a partially intrinsically localized CSD. The present findings demonstrate that the CSDs of interictal spikes in schizencephalic patients are in general anatomically distinct from the cerebral schizencephalic lesions and that these lesions may display an extrinsic epileptogenicity.

Toxocara canis-Associated Myelitis with Eosinophilic Pneumonia

The existence of Toxocara canis-specific antibodies has recently been reported in patients with atopic myelitis. Here, we report the case of a 35-year-old male patient admitted with a chief complaint of right lower limb hypoesthesia lasting for a month. The patient was diagnosed with eosinophilic pneumonia 3 months ago, and a spine MRI revealed the presence of myelitis in the cervicothoracic cord. After confirming the presence of hyper-IgE-emia and Toxocara canis antibodies, the patient was treated with steroids and albendazole treatment, which improved his symptoms. To our knowledge, this is the first case of Toxocara canis-associated myelitis with eosinophilic pneumonia.

Abstract WP424: Prevalence and Determinants of Non-adherence to Secondary Preventive Medication in Stroke Patients

Introduction: Nonadherence to secondary preventive medication is associated with adverse outcomes and higher costs of care in stroke patients. The purpose of this study is to investigate the prevalence and major determinants of nonadherence to secondary preventive medication in stroke survivors.

Hypothesis: We assessed the hypothesis that the determinants of nonadherence to secondary preventive medication in stroke patients may be different in both intentional and nonintentional, or/and in various classes of medication.

Methods: We enrolled the 252 patients taking medicines > 1 year after stroke onset. Adherence was measured by a self-reported questionnaire, and nonadherence was classified to be intentional (e.g., deliberately choosing not to take medicines or to change medication dosage, three items) or unintentional (e.g., forgetting to take medication, four items). The devices to assess the determining factors of adherence included Belief about Medication Questionnaire, Morisky Medication Adherence Scales, Lubben Social Network Scale-6, and Geriatiric Depression Scale. We also conducted a survey to assess healthy adherence effects and satisfaction level of education program about medication and healthy behaviors.

Results: About 60% of patients were non-adherent (n=150, 59.5%). Among them, 56 (37.3%) patients were unintentionally and 94 (62.7%) patients were intentionally nonadherent to their stroke preventive medication. The determinants of nonadherence were age [Exp(B)=1.041, p=0.045], necessity [Exp(B)=1.106, p=0.057], social network [Exp(B)=1.021, p=0.044] and familial support [Exp(B)=1.032, p=0.044]. Classic oral anticoagulation therapy showed better adherence compared with antiplatelet therapy (83.6% vs. 69.7%, p =0.002). The behavioral education was a determinant for adherence to the classic oral anticoagulation therapy.

Conclusion: In conclusion, nonadherence to medication in stroke surviviors was generally high. Necessity was an important determinant of both intentional and unintentional nonadherence. Older age was predictive of unintentional nonadherence, and building social networks and familial support were important for the intentionally nonadherent patients.

Initial factors affecting the clinical outcome after successful recanalization via MR-based mechanical thrombectomy in patients with acute ischemic stroke due to basilar artery occlusion

Background and purpose

To determine the initial factors, including patient characteristics, stroke etiology and severity, time factors, and imaging findings, that could affect the clinical outcome of patients with acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) where successful recanalization was achieved via mechanical thrombectomy.

Methods

Between March 2011 and December 2014, 35 patients with AIS caused by BAO received MRI/MR angiography-based mechanical thrombectomies, and recanalization was achieved with a Thrombolysis In Cerebral Infarction score of >2b. The patients were divided into a good outcome group (n=19), defined as those with a modified Rankin Scale (mRS) score of 0–2 at 3 months after stroke onset, and a poor outcome group (n=16), defined as a mRS score of 3–6. The differences between the groups were analyzed.

Results

Initial National Institutes of Health Stroke Scale (NIHSS) score (good vs poor: 17.9±8.9 vs 27.6±8.5, p=0.003), posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) based on initial diffusion-weighted images (DWI) (good vs poor: 7.8±1.6 vs 5.4±1.8, p=0.001), pc-ASPECTS based on contrast staining on the post-thrombectomy control CT (good vs poor: 9.2±1.5 vs 6.3±2.2, p<0.001), and presence of contrast staining in the brainstem on that CT (good vs poor: 15.8% vs 81.6%, p<0.001) were significantly different between the groups.

Conclusions

Patients with AIS caused by BAO with a lower initial NIHSS score, fewer lesions on initial DWI, and less contrast staining on the post-thrombectomy control CT have higher probabilities of a good clinical outcome after successful recanalization via a mechanical thrombectomy.

Comparison of Solitaire thrombectomy and Penumbra suction thrombectomy in patients with acute ischemic stroke caused by basilar artery occlusion

Background and purpose

Acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) is a very severe neurological disease with a high mortality rate and poor clinical outcomes. In this study, we compared our experience of mechanical thrombectomy using the Solitaire stent (Solitaire thrombectomy) and manual aspiration thrombectomy using the Penumbra reperfusion catheter (Penumbra suction thrombectomy) in patients with AIS caused by BAO.

Materials and methods

Between March 2011 and December 2011, 13 patients received Solitaire thrombectomy. In January 2012, the Korean Food and Drug Administration banned the use of the Solitaire stent as a thrombectomy device, and a further 18 patients received Penumbra suction thrombectomy until December 2013. We compared parameters between patients treated with each device.

Results

Successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b: 84.6% vs 100%, p=0.168) and clinical outcomes (judged by the modified Rankin Scale scores recorded at 3 months: 3.6±2.6 vs 3.2±2.6, p=0.726) were not significantly different between the two groups. However, complete recanalization rates (TICI score of 3: 23.1% vs 72.2%, p=0.015) and total procedure times (101.9±41.4 vs 62.3±34.8 min, p=0.044) were significantly higher, and shorter, respectively, in patients treated by Penumbra suction thrombectomy.

Conclusions

The two thrombectomy devices were associated with similar recanalization rates and clinical outcomes in patients with AIS caused by BAO. However, Penumbra suction thrombectomy seemed to allow more rapid and complete recanalization than Solitaire thrombectomy.

Simultaneous event of brachial artery occlusion and acute embolic stroke

Although the rapid and accurate diagnosis of both acute ischemic stroke and extremity ischemia is essential to the timely and appropriate treatment, it is not always easy to differentiate between true stroke and stroke mimics. Although in general, limb ischemia due to extremity embolism is not included in stroke mimics or misdiagnosis, limb arterial embolism should be considered in thedifferential diagnosis of acute monoparesis because the diagnosis maybe missed if the other typical manifestations of this presentation(pain, pallor, pulselessness, sensory loss, and coolness of the arm) are overlooked. Therefore, it is important to ensure that important signsare not missed whether the evaluation of the patient is done at thebedside. We report a case of a male patient presented to an emergency department with acute right upper extremity pain with headache, gait disturbance, and confused mentality. He was diagnosed by simultaneou sbrachial artery occlusion and acute stroke, which resulted in emergency surgical embolectomy and anticoagulation therapy.

Establishment of government-initiated comprehensive stroke centers for acute ischemic stroke management in South Korea

BACKGROUND AND PURPOSE

In 2008, the Ministry of Health and Welfare of South Korea initiated the Regional Comprehensive Stroke Center (CSC) program to decrease the incidence and mortality of stroke nationwide. We evaluated the performance of acute ischemic stroke management after the Regional CSC program was introduced.

METHODS

The Ministry of Health and Welfare established 9 Regional CSCs in different provinces from 2008 to 2010. All Regional CSCs have been able to execute the critical processes independently for stroke management since 2011. The Ministry of Health and Welfare was responsible for program development and financial support, the Regional CSC for program execution, and the Korea Centers for Disease Control and Prevention for auditing the execution. We analyzed prospectively collected data on the required indices from 2011 and repeated the analysis the following year for comparison.

RESULTS

After the Regional CSCs were established, the first brain image was taken within 1 hour from arrival at the emergency room for all patients with stroke; the length of hospital stay decreased from 14 to 12 days; for the rapid execution of thrombolysis, the first brain image was taken within 12 minutes; intravenous and intra-arterial thrombolysis were started within 40 and 110 minutes, respectively, after emergency room arrival; and the hospital stay of thrombolytic patients decreased from 19 to 15 days.

CONCLUSIONS

The Regional CSC program has improved the performance of acute stroke management in South Korea and can be used as a model for rapidly improving stroke management.

Carotid stent infection: a rare but potentially fatal complication of carotid artery stenting

Infections involving endovascular devices are rare and, to our knowledge, only three cases of infection with an inserted carotid stent have ever been reported. A 68-year-old man underwent carotid artery stenting (CAS) of the left proximal internal carotid artery. Two days after CAS the patient developed a high fever and investigation showed that the inserted carotid stent was infected. The infection could not be controlled despite adequate antibiotic therapy. Eventually a rupture of the carotid artery occurred and the patient underwent emergency resection of the left carotid bifurcation in addition to stent removal and reconstruction with a saphenous vein interposition graft. The patient recovered fully without any neurological sequelae.

Carotid stent infection: a rare but potentially fatal complication of carotid artery stenting

Infections involving endovascular devices are rare and, to our knowledge, only three cases of infection with an inserted carotid stent have ever been reported. A 68-year-old man underwent carotid artery stenting (CAS) of the left proximal internal carotid artery. Two days after CAS the patient developed a high fever and investigation showed that the inserted carotid stent was infected. The infection could not be controlled despite adequate antibiotic therapy. Eventually a rupture of the carotid artery occurred and the patient underwent emergency resection of the left carotid bifurcation in addition to stent removal and reconstruction with a saphenous vein interposition graft. The patient recovered fully without any neurological sequelae.

Emergency carotid artery stenting in patients with acute ischemic stroke due to occlusion or stenosis of the proximal internal carotid artery: a single-center experience

BACKGROUND

The feasibility, safety and effectiveness of emergency carotid artery stenting (eCAS) in patients with acute ischemic stroke (AIS) due to proximal internal carotid artery (ICA) stenosis or occlusion are still controversial. In this study we analyzed our experience with eCAS in patients with AIS.

METHODS

Twenty-two eCAS procedures for proximal ICA stenosis or occlusion were performed in 22 patients at our institution between January 2011 and November 2013. The mean time from stroke symptom onset to presentation was 204 min (range 50-630 min) and the mean initial score on the National Institutes of Health Stroke Scale (NIHSS) was 12.55 (range 5-23). Ten patients had total occlusion of the proximal ICA and the remaining 12 patients had near total occlusion or severe stenosis (mean degree 90.7%, range 80-100%). Eleven patients also had tandem occlusion on the more distal intracranial arteries.

RESULTS

Successful stent insertion was achieved in all patients and additional thrombectomy using a Solitaire stent or Penumbra aspiration catheter achieved a Thrombolysis In Cerebral Infarction grade of more than 2a in all patients with distal tandem occlusion. Procedure-related complications occurred in one patient (cerebral hyperperfusion syndrome) who recovered successfully. The mean NIHSS score at discharge was 3.55 (range 0-18). The mean modified Rankin Scale score at 3 months was 1 ± 1.67 (range 0-6).

CONCLUSIONS

eCAS in patients with AIS due to proximal ICA stenosis or occlusion appears to be a technically feasible and effective method for achieving good clinical outcomes.

Relationship between Hyperventilation-Induced Electroencephalographic Changes and PCO2 Level

Background and Purpose:

We conducted this study to define the relationship between the hyperventilation-induced EEG changes (HV-EEG changes) and PCO₂

Methods:

In consecutive EEG recordings of 190 patients, we gathered data on PCO₂ during the hyperventilation procedure. The data included baseline PCO₂ (B-PCO₂), PCO₂ after 5 min of hyperventilation (5 min-PCO₂), the mean value of the PCO₂ (M-PCO₂), and the difference between B-PCO₂ and 5 min-PCO₂ (ΔPCO₂). We divided the enrolled patients into two groups by hyperventilation response (response group and no-response group), presence of epilepsy (epileptic group and non-epileptic group) and age (child-adolescent group and adult group) repeatedly. We compared the four variables between the two groups in each pair.

Results:

ΔPCO₂ was 14.2±5.0 mmHg (mean±SD) in response group (n=48) and 12.4±5.0 in no-response group (n=142; p=0.033) for all the patients. For adult patients only, 5 min-PCO₂ was 24.3±3.4 in response group (n=30) and 26.2±4.6 in no-response group (n=115; p=0.048), and ΔPCO₂ was 15.8±4.0 and 12.9±5.0, respectively (p=0.004). In non-epileptic patients, 5min-PCO₂ was 23.4±2.2 in response group (n=7) and 26.3±3.8 in no-response group (n=44; p=0.026), and ΔPCO₂ was 15.9±4.3 and 12.7±3.9, respectively (p=0.053).

Conclusions:

In adults and non-epileptic patients, ΔPCO₂ and 5 min-PCO₂ may be crucial to the induction of EEG changes by hyperventilation. PCO₂ could be a crucial factor for provoking HV-EEG changes in a limited group of patients.

Serial magnetic resonance images of a right middle cerebral artery infarction : persistent hyperintensity on diffusion-weighted MRI over 8 months

A lesion that is hyperintense on diffusion-weighted imaging (DWI) and hypointense on the apparent diffusion coefficient (ADC) map is a characteristic magnetic resonance imaging (MRI) finding in acute ischemic infarction. In some cases, however, these findings can persist for a few months after infarct onset. It is thought that these finding reflect the different evolution speeds of the infarcted tissue. We report a patient with a right middle cerebral artery territory infarction with persistent hyperintensity on DWI and hypointensity on the ADC map for over 8 months. To our knowledge, this is the most persistent case of hyperintensity lesion on DWI and the serial MRI images of this patient provide important information on the evolution of infarcted tissue.

Implementing multiplexed genotyping of non-small-cell lung cancers into routine clinical practice

BACKGROUND

Personalizing non-small-cell lung cancer (NSCLC) therapy toward oncogene addicted pathway inhibition is effective. Hence, the ability to determine a more comprehensive genotype for each case is becoming essential to optimal cancer care.

METHODS

We developed a multiplexed PCR-based assay (SNaPshot) to simultaneously identify >50 mutations in several key NSCLC genes. SNaPshot and FISH for ALK translocations were integrated into routine practice as Clinical Laboratory Improvement Amendments-certified tests. Here, we present analyses of the first 589 patients referred for genotyping.

RESULTS

Pathologic prescreening identified 552 (95%) tumors with sufficient tissue for SNaPshot; 51% had ≥1 mutation identified, most commonly in KRAS (24%), EGFR (13%), PIK3CA (4%) and translocations involving ALK (5%). Unanticipated mutations were observed at lower frequencies in IDH and β-catenin. We observed several associations between genotypes and clinical characteristics, including increased PIK3CA mutations in squamous cell cancers. Genotyping distinguished multiple primary cancers from metastatic disease and steered 78 (22%) of the 353 patients with advanced disease toward a genotype-directed targeted therapy.

CONCLUSIONS

Broad genotyping can be efficiently incorporated into an NSCLC clinic and has great utility in influencing treatment decisions and directing patients toward relevant clinical trials. As more targeted therapies are developed, such multiplexed molecular testing will become a standard part of practice.

Incidentally discovered a self-inflicted a nail in the brain of schizophrenia patient

The self-infliction of foreign bodies into the brain represents rare a clinical phenomenon that has been reported primarily in cases involving accidents and suicide attempts. However, various motivations for self-injurious behaviors as well as suicide attempts have been reported, especially in patients with psychotic illnesses. A 47-year-old man with a history of schizophrenia presented to our hospital due to the presence of a nail on his plain skull X-ray. He diagnosed paranoid type of schizophrenia about 17 years earlier, and his psychiatric symptoms were well controlled by medication. Interestingly, he was not aware of the presence of the nail in his brain and showed no neurological deficits. In the course of detailed history taking, we discovered that the nail was driven into his brain during a hallucinatory experience that had occurred more than 10 years earlier. Because we believed that removing the nail from his brain would be more dangerous than maintaining the status quo, the nail was not removed. This is a very rare case of a self-inflicted injury involving inserting a nail into the brain under the influence of hallucinations. The absence of adverse effects or neurological symptoms/signs related to the presence of a foreign metallic body in the brain for over 10 years is exceptional.

A case of broncho-paraspinal fistula induced by metallic devices: delayed complication of thoracic spinal surgery

We present a case report of a 45-year-old woman with spontaneous pneumocephalus accompanied by pneumorrhachis of the thoracic spine, which is a very rare condition generally associated with trauma and thoracic or spinal surgery. The patient had undergone an operation about 10 years earlier to treat a giant cell tumor of the thoracic spine. During the operation, a metallic device was installed, which destroyed the bronchus and caused the formation of a broncho-paraspinal fistula. This is the suspected cause of her pneumocephalus and pneumorrhachis. To our knowledge, this is a very rare case of pneumocephalus accompanied by pneumorrhachis induced by metallic device, and when considering the length of time after surgery these complications presented are also exceptional.

Toxicity and outcomes after chemoradiation for esophageal cancer in patients age 75 or older

Randomized trials of chemoradiation for esophageal cancer have included very few patients age > or = 75. In this retrospective study, we describe the outcomes and toxicity of full-dose chemoradiation in elderly patients with esophageal cancer. Patients, age > or = 75, treated with full-dose chemoradiation for esophageal carcinoma from 2002 to 2008 were retrospectively reviewed. Thirty-four patients were identified with a median age of 79.5 (range 75-89). The median Eastern Cooperative Oncology Group performance status was 1 (range 0-3) and the median Adult Comorbidity Evaluation-27 score was 1 (range 0-3). Twenty-eight patients received definitive and six received neoadjuvant chemoradiation. The median radiation dose delivered was 50.4 Gray (range 3.6-68.4 Gray). Platinum-based chemotherapy was used in 79.4% of patients. Fifty percent of the patients completed all planned radiation therapy (RT) and chemotherapy; 85.3% completed RT. Acute toxicity > or = grade 4 occurred in 38.2% of patients, and 70.6% of the patients required hospitalization, emergency department visit, and/or RT break. Median follow-up was 14.5 months among 7 survivors, and median survival was 12.0 months (95% confidence interval [CI]: 9.7 to 24.1 months). The actuarial overall survival at 2 years was 29.7% (95% CI: 16.6 to 52.6%). There were four treatment-related deaths. The median time to any recurrence was 10.4 months. Nineteen patients had a local and/or distant recurrence. In conclusion, elderly patients experienced substantial morbidity from chemoradiation, and long-term survival was low. Future efforts to improve treatment tolerability in the elderly are needed.

Two-dimensional modelling of benzene transport and biodegradation in a laboratory-scale aquifer

In this study biodegradation of aqueous benzene during transport in a laboratory-scale aquifer model was investigated by conducting a 2-D plume test and numerical modelling. Benzene biodegradation and transport was simulated with the 2-D numerical model developed for solute transport coupled with a Haldane-Andrews type function for inclusion of an inhibition constant which is effective for high concentrations. Experimental data revealed that in the early stages the benzene plume showed a rather clear shape but lost its shape with increased travel time. The mass recoveries of benzene at 9, 16, and 22 h were 37, 13 and 8%, respectively, showing that a significant mass reduction of aqueous benzene occurred in the model aquifer. The major processes responsible for the mass reduction were biodegradation and irreversible sorption. The modelling results also indicated that the simulation based on the microbial parameters from the batch experiments slightly overestimated the mass reduction of benzene during transport. The sensitivity analysis demonstrated that the benzene plume was sensitive to the maximum specific growth rate and slightly sensitive to the half-saturation constant of benzene but almost insensitive to the Haldane inhibition constant. The insensitivity to the Haldane inhibition constant was due to the rapid decline of the benzene peak concentration by natural attenuation such as hydrodynamic dispersion and irreversible sorption. An analysis of the model simulation also indicated that the maximum specific growth rate was the key parameter controlling the plume behaviour, but its impact on the plume was affected by competing parameter such as the irreversible sorption rate coefficient.

MRI in Tolosa-Hunt Syndrome Associated With Facial Nerve Palsy

A 44-year-old woman developed a severe right frontotemporal headache, retro-orbital pain, and, later, diplopia owing to right sixth nerve palsy. The brain MRI demonstrated strong enhancement of the right cavernous sinus. The sixth nerve palsy and headache improved with steroid therapy after 6 weeks. At that time, she suffered right peripheral facial nerve palsy. Enhancement of the distal canalicular and labyrinthic segment of the right facial nerve was found on contrast-enhanced MRI. To our knowledge, this is a very rare case of Tolosa-Hunt syndrome with facial nerve palsy, with simultaneous enhancement of the cavernous sinus and facial nerve on contrast-enhanced MRI.

Correlative assessment of hemodynamic parameters obtained with T2*-weighted perfusion MR imaging and SPECT in symptomatic carotid artery occlusion

BACKGROUND AND PURPOSE

Perfusion MR imaging and single-photon emission CT (SPECT) are commonly used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. These techniques rely on different underlying physiological mechanisms, and the data may not correspond. We studied the relationship between hemodynamic parameters obtained with these two methods.

METHODS

We performed perfusion MR imaging and SPECT in 10 patients with symptomatic unilateral internal carotid artery occlusion. Relative cerebral blood volume (rCBV) and uncorrected mean transit time (uMTT) were obtained with dynamic contrast-enhanced T2*-weighted MR imaging. Relative cerebral blood flow (rCBF) and vascular reserve capacity were measured with 99mTc-HMPAO SPECT; vascular reserve capacity was calculated by the difference in CBF before and after acetazolamide challenge. Ratios of these hemodynamic parameters between the affected and contralateral vascular territories were calculated and compared.

RESULTS

Normal-to-increased CBV, prolonged uMTT, decreased CBF, and normal-to-diminished vascular reserve capacity were observed in the affected vascular territories. Reduction of vascular reserve capacity corresponded well with uMTT but not with CBF and CBV. CBF, CBV, and uMTT did not correspond to one another.

CONCLUSION

uMTT is more sensitive than the other parameters in estimating vascular reserve capacity. The relationship between parameters obtained with perfusion MR imaging and SPECT should be considered in assessing the hemodynamic status of patients with symptomatic occlusive cerebrovascular disease.

Triphasic perfusion computed tomography in acute middle cerebral artery stroke: a correlation with angiographic findings

OBJECTIVE

To evaluate the usefulness of triphasic perfusion computed tomography (TPCT) in diagnosing middle cerebral artery (MCA) occlusion and in assessing the perfusion deficit and collateral circulation in patients with acute ischemic stroke.

BACKGROUND

Conventional angiography is the criterion standard for the diagnosis of MCA occlusion and for the assessment of perfusion deficit and collateral blood supply. The risk of hemorrhagic transformation after recanalization of occluded arteries by thrombolytic therapy is considered high when pretherapeutic residual flow is markedly reduced.

PATIENTS AND METHODS

In 8 patients within 3 hours of onset of acute MCA stroke, precontrast computed tomographic scans were taken, and then TPCT was performed after power-injector controlled intravenous administration of contrast media. Sequential images of early, middle, and late phases were obtained. The whole procedure took 5 minutes. Perfusion deficit on TPCT was graded as "severe" or "moderate," depending on the state of collateral flow. Digital subtraction angiography (DSA) was performed in all patients within 6 hours of acute stroke. Direct intra-arterial urokinase infusion was begun immediately after the angiographic superselection of the MCA occlusion site in 6 of the 8 patients within 7 hours of onset (range, 4.3-6.2 hours).

RESULTS

The DSA findings showed occlusion of the MCA stem (n = 1) and at the bifurcation (n = 4). The sites of proximal MCA occlusion could be identified on the early and middle images of TPCT in all 5 patients. On DSA findings, all 8 patients had a zone of perfusion deficit with markedly slow leptomeningeal collaterals and a zone of perfusion deficit with no collaterals. The zone of severe perfusion deficit on TPCT corresponded to the zone of perfusion deficit with no or few collaterals on angiography, and the zone of moderate perfusion deficit on TPCT corresponded to that of perfusion deficit with markedly slow leptomeningeal collaterals. Early parenchymal hypoattenuation on precontrast computed tomography was confined to the zone of severe perfusion deficit on TPCT. The initial National Institutes of Health Stroke Scale score correlated better with the total extent of severe perfusion deficit and moderate perfusion deficit on TPCT than that of severe perfusion deficit alone. After direct intra-arterial thrombolysis within 7 hours of onset, symptomatic hemorrhagic transformation did not develop in 4 patients with small severe perfusion deficit (33% or less of the presumed MCA territory). However, the remaining 2 patients with large severe perfusion deficit (more than 50% of the presumed MCA territory) deteriorated to death with hemorrhagic transformation.

CONCLUSIONS

Triphasic perfusion computed tomography is useful for diagnosing proximal MCA occlusion and assessing perfusion deficit and collateral circulation as reliably as DSA. The zone of severe perfusion deficit on TPCT may be presumed to be the ischemic core, and that of moderate perfusion deficit, the penumbra zone. Triphasic perfusion computed tomography may be used as a rapid and noninvasive tool to make thrombolysis safer.

Stage III thymoma: pattern of failure after surgery and postoperative radiotherapy and its implication for future study

PURPOSE

With the conventional approach of surgery and postoperative radiotherapy for patients with Masaoka Stage III thymoma, progress has been slow for an improvement in the long-term survival rate over the past 20 years. The objective of this study was to evaluate the pattern of failure and survival after surgery and postoperative radiotherapy in Stage III thymoma and search for a new direction for better therapy outcome.

METHODS AND MATERIALS

Between 1975 and 1993, 111 patients with thymoma were treated at Massachusetts General Hospital. Of these, 32 patients were determined to have Masaoka Stage III thymoma. The initial treatment included surgery for clinically resectable disease in 25 patients and preoperative therapy for unresectable disease in 7 patients. Surgical procedure consisted of thymectomy plus resection of involved tissues. For postoperative radiotherapy (n = 23), radiation dose consisted of 45-50 Gy for close resection margins, 54 Gy for microscopically positive resection margins, and 60 Gy for grossly positive margins administered in 1.8 to 2.0 Gy of daily dose fractions, 5 fractions a week, over a period of 5 to 6.6 weeks. In preoperative radiotherapy, a dose of 40 Gy was administered in 2.0 Gy of daily dose fractions, 5 days a week. For patients with large tumor requiring more than 30% of total lung volume included in the target volume (n = 3), a preoperative radiation dose of 30 Gy was administered and an additional dose of 24-30 Gy was given to the tumor bed region after surgery for positive resection margins.

RESULTS

Patients with Stage III thymoma accounted for 29% (32/111 patients) of all patients. The median age was 57 years with a range from 27 to 81 years; gender ratio was 10:22 for male to female. The median follow-up time was 6 years. Histologic subtypes included well-differentiated thymic carcinoma in 19 (59%), high-grade carcinoma in 6 (19%), organoid thymoma in 4 (13%), and cortical thymoma in 3 (9%) according to the Marino and Müller-Hermelink classification. The overall survival rates were 71% and 54% at 5 and 10 years, respectively. Ten of the 25 patients who were subjected to surgery as initial treatment were found to have incomplete resection by histopathologic evaluation. The 5- and 10-year survival rates were 86% and 69% for patients (n = 15) with clear resection margins as compared with 28% and 14% for those (n = 10) with incomplete resection margins even after postoperative therapy, p = 0.002. Survival rates at 5 and 10 years were 100% and 67% for those with unresectable disease treated with preoperative radiation (n = 6) and subsequent surgery (n = 3). Recurrence was noted in 12 of 32 patients and 11 of these died of recurrent thymoma. Recurrences at pleura and tumor bed accounted for 77% of all relapses, and all pleural recurrences were observed among the patients who were treated with surgery initially.

CONCLUSION

Incomplete resection leads to poor results even with postoperative radiotherapy or chemoradiotherapy in Stage III thymoma. Pleural recurrence is also observed more often among patients treated with surgery first. These findings suggest that preoperative radiotherapy or chemoradiotherapy may result in an increase in survival by improving the rate of complete resection and reducing local and pleural recurrences.

Superior sulcus lung tumors: impact of local control on survival

OBJECTIVES

Our goal was to assess patient survival and response to treatment for superior sulcus tumors treated with combined radiation therapy and surgery when possible, or with radiation alone when surgery was not possible.

METHODS

Seventy-three patients were treated for primary non-small cell carcinoma of the superior pulmonary sulcus. Thirty-four patients received combined resection and irradiation. Thirty-nine patients who had extensive primary disease, distant metastases, or who were medically unfit for surgery were treated with radiation alone. Thirty-one patients (91%) assigned to the resection/irradiation group completed treatment. Combined therapy patients routinely received 40 Gy before the operation, with additional postoperative irradiation based on the surgical findings.

RESULTS

Overall survival at 5 years was 19% and disease-specific survival was 20% for all patients. Overall survival and disease-specific survival at 5 years for the resection/irradiation group were 33% and 38%, respectively. Significant indicators of poor prognosis included unresected primary disease, low performance score, T4 stage, or positive node status. Eighty-two percent of the patients who received irradiation alone were treated with palliative intent. Freedom from local-regional progression, achieved initially in 66% of these patients, was associated with a median survival of 8 months. Median survival for 7 patients considered for definitive irradiation was 25 months. During the first 18 months, distant failures occurred in approximately 35% of patients in each treatment group.

CONCLUSIONS

Selection of medically fit patients with resectable disease for combined surgery and aggressive radiation therapy resulted in a high likelihood of local control. Overall survival for the resection/irradiation group was significantly poorer for patients with T4 stage, nodal disease, or Horner's syndrome. Distant metastases eventually developed in 56% of patients undergoing resection. Median survival in the resection/irradiation group was significantly prolonged for those patients who could tolerate high-dose radiation treatment.

Various patterns of perfusion-weighted MR imaging and MR angiographic findings in hyperacute ischemic stroke

BACKGROUND AND PURPOSE

Various clinical subtypes of patients presenting with sudden-onset ischemic stroke have been recognized, but classification of those types is not simple. We identified various patterns of perfusion-weighted MR imaging and MR angiographic findings in hyperacute ischemic stroke with relation to clinical outcomes.

METHODS

Twelve patients with symptoms of acute ischemic stroke due to middle cerebral artery occlusion underwent perfusion-weighted MR imaging and MR angiography within 6 hours after the onset of symptoms. Perfusion-weighted imaging was performed with a conventional dynamic contrast-enhanced T2*-weighted sequence, and cerebral blood volume (CBV) maps were then created. CBV maps and MR angiographic findings were compared with 99mTc-HMPAO brain SPECT scans, short-term outcomes, and follow-up imaging findings.

RESULTS

The combined CBV and MR angiographic findings were classified into three patterns: arterial occlusion and decreased CBV (n = 8), arterial occlusion and increased CBV (n = 2), and no arterial occlusion and normal CBV (n = 2). These three patterns were strongly related to SPECT findings, short-term outcomes, and follow-up imaging findings. Perfusion on SPECT decreased markedly in the affected regions in all patients with the first pattern, decreased slightly in the second pattern, and was normal in the third pattern. Symptoms were not significantly changed at 24 hours after onset in any of the patients with the first pattern, but resolved completely in all patients with the latter two patterns. Follow-up imaging showed large infarctions in all patients with the first pattern. Initially, no infarction was seen in the second pattern, but watershed infarction developed later in one of these patients.

CONCLUSION

Hyperacute ischemic stroke may be differentiated into three imaging patterns with different clinical outcomes. The combined use of perfusion-weighted MR imaging and MR angiography may play a substantial role in guiding the choice of treatment of this disease.

Phase I study to determine the maximum-tolerated dose of radiation in standard daily and hyperfractionated-accelerated twice-daily radiation schedules with concurrent chemotherapy for limited-stage small-cell lung cancer

PURPOSE

An improvement in radiation dose schedule is necessary to increase local tumor control and survival in limited-stage small-cell lung cancer. The goal of this study was to determine the maximum-tolerated dose (MTD) of radiation (RT) in both standard daily and hyperfractionated-accelerated (HA) twice-daily RT schedules in concurrent chemoradiation.

METHODS

The study design consisted of a sequential dose escalation in both daily and HA twice-daily RT regimens. RT dose to the initial volume was kept at 40 to 40.5 Gy, while it was gradually increased to the boost volume by adding a 7% to 11 % increment of total dose to subsequent cohorts. The MTD was defined as the radiation dose level at one cohort below that which resulted in more than 33% of patients experiencing grade > or = 4 acute esophagitis and/or grade > or = 3 pulmonary toxicity. The study plan included nine cohorts, five on HA twice-daily and four on daily regimens for the dose escalation. Chemotherapy consisted of three cycles of cisplatin 33 mg/m2/d on days 1 to 3 over 30 minutes, cyclophosphamide 500 mg/m2 on day 1 intravenously (IV) over 1 hour, and etoposide 80 mg/m2/d on days 1 to 3 over 1 hour every 3 weeks (PCE) and two cycles of PE. RT was started at the initiation of the fourth cycle of chemotherapy.

RESULTS

Fifty patients were enrolled onto the study. The median age was 60 years (range, 38-79), sex ratio 2.3:1 for male to female, weight loss less than 5% in 73%, and performance score 0 to 1 in 94% and 2 in 6% of patients. In HA twice-daily RT, grade > or = 4 acute esophagitis was noted in two of five (40%), two of seven (29%), four of six (67%), and five of six patients (86%) at 50 (1.25 Gy twice daily), 45, 50, and 55.5 Gy in 1.5 Gy twice daily, 5 d/wk, respectively. Grade > or = 3 pulmonary toxicity was not seen in any of these 24 patients. Therefore, the MTD for HA twice-daily RT was judged to be 45 Gy in 30 fractions over 3 weeks. In daily RT, grade > or = 4 acute esophagitis was noted in zero of four, zero of four, one of five (20%), and two of six patients (33%) at 56, 60, 66, and 70 Gy on a schedule of 2 Gy per fraction per day, five fractions per week. Grade > or = 3 pneumonitis was not observed in any of the 19 patients. Thus, the MTD for daily RT was judged to be at least 70 Gy in 35 fractions over 7 weeks. Grade 4 granulocytopenia and thrombocytopenia were observed in 53% and 6% of patients, respectively, during the first three cycles of PCE. During chemotherapy cycles 4 to 5, grade 4 granulocytopenia and thrombocytopenia were noted in 43% and 29% of patients at 45 Gy in 30 fractions over 3 weeks (MTD) by HA twice-daily RT and 50% and 17% at 70 Gy in 35 fractions over 7 weeks (MTD) by daily RT, respectively. The overall tumor response consisted of complete remission (CR) in 51% (24 of 47), partial remission (PR) in 38% (1 8 of 47), and stable disease in 2% (one of 47). The median survival time of all patients was 24.4 months and 2- and 3-year survival rates were 53% and 28%, respectively. With regard to the different radiation schedules, 2- and 3-year survival rates were 52% and 25% for the HA twice-daily and 54% and 35% for the daily RT cohorts.

CONCLUSION

The MTD of HA twice-daily RT was determined to be 45 Gy in 30 fractions over 3 weeks, while it was judged to be at least 70 Gy in 35 fractions over 7 weeks for daily RT. A phase III randomized trial to compare standard daily RT with HA twice-daily RT at their MTD for local tumor control and survival would be a sensible research in searching for a more effective RT dose-schedule than those that are being used currently.

Temporal pattern of blood volume change in cerebral infarction: evaluation with dynamic contrast-enhanced T2*-weighted MR imaging

OBJECTIVE

The purposes of this study were to evaluate the temporal pattern of blood volume change in cerebral infarction and to provide a guideline in the interpretation of blood volume data, which are known to vary according to the stage of infarction.

SUBJECTS AND METHODS

Thirty-three patients with large middle cerebral infarctions were examined one to three times (one time in 20 patients, two times in eight patients, and three times in five patients) after the onset of stroke by dynamic contrast-enhanced T2*-weighted MR imaging and MR angiography. A total of 54 infarctions (29 in an acute stage [up to 7 days], 15 in a subacute stage [8-21 days], and 10 in a chronic stage [22-35 days]) were included. After blood volume maps were created, blood volume ratios (blood volume of the infarcted region divided by blood volume of corresponding contralateral region) were compared at different stages. Likewise, findings on MR angiography were compared at different stages.

RESULTS

Mean blood volume ratios in each stage of infarction were 0.46 in the acute stage, 1.48 in the subacute stage, and 0.73 in the chronic stage (p < .001). Recanalization of occluded arteries occurred in 21% of infarctions in the acute stage and 80% in the subacute stage. Infarctions with recanalization had higher blood volume ratios than did those without recanalization (p < .001). A biphasic pattern of blood volume ratios was found in 13 patients who underwent at least two MR examinations: increased blood volume in the subacute stage and decreased blood volume in the chronic stage, regardless of recanalization (p < .01).

CONCLUSION

Blood volume that initially decreases in cerebral infarction increases in the subacute stage, reflecting reperfusion hyperemia. Blood volume decreases again in the chronic stage. The time interval between onset of stroke and MR examination must be considered for correct interpretation of blood volume data in cerebral infarction at various stages.

Induction therapy for esophageal cancer with paclitaxel and hyperfractionated radiotherapy: a phase I and II study

OBJECTIVE

Induction chemoradiotherapy followed by surgery may improve survival rates among patients with esophageal carcinoma. We designed a novel intense induction regimen with paclitaxel and high-dose hyperfractionated radiotherapy to maximize complete response rates.

METHODS

Forty patients with esophageal cancer were treated in a phase I and II trial of induction chemotherapy (cisplatin, 5-fluorouracil, and paclitaxel) at three dosage levels (75, 125, and 100 mg/m2) and concurrent hyperfractionated radiotherapy (45 Gy to the mediastinum, 58.5 Gy to the tumor). The mean age was 62 years, and 32 patients (80%) had adenocarcinoma. Twenty-eight of 40 (70%) patients had locally advanced tumors (T3, or stage IIB or greater).

RESULTS

The average hospitalization for induction treatment was 17 days. Toxicity was substantial, with esophagitis necessitating nutritional support the most common complication. The maximum tolerated dose of paclitaxel was 100 mg/m2. Two patients died during induction treatment. Thirty-six patients (90%) underwent resection. The median length of stay was 10 days, and two patients died after the operation. Fourteen of 36 patients (39%) had a pathologic complete response. Patients who received all prescribed chemotherapy had a higher pathologic complete response rate (50%) than did patients who required dose reduction (17%; p = 0.076). The 2-year survival rate was 61% (95% CI 35% to 86%) with a median follow-up of 11.9 months.

CONCLUSIONS

Paclitaxel at a dose of 100 mg/m2 appears to have acceptable toxicity. The high pathologic complete response rate in this regimen is encouraging, but it is associated with substantial toxicity. The toxicity of this regimen is not acceptable and will require substantial reduction in the radiation component. Survival data are too short-term to confirm enhanced survival.

Potential impact on survival of improved tumor downstaging and resection rate by preoperative twice-daily radiation and concurrent chemotherapy in stage IIIA non-small-cell lung cancer

PURPOSE

The main objectives of this study were (a) to ascertain the feasibility and toxicity of preoperative twice-daily radiation therapy and concurrent chemotherapy, surgery, and postoperative therapy in stage IIIA (N2) non-small-cell lung cancer (NSCLC), and (b) to evaluate tumor response, resection rate, pathologic tumor downstaging, and survival.

METHODS

Eligibility included biopsy-proven N2 lesion (stage IIIA) by mediastinoscopy, Karnofsky performance score > or = 70, and weight loss less than 5% in the 3 months before diagnosis. The treatment program consisted of two courses of preoperative cisplatin, vinblastine, and fluorouracil (5-FU); 42 Gy concurrent radiation at 1.5 Gy per fraction in two fractions per day; surgery on day 57; and one more course of postoperative chemotherapy and 12 to 18 Gy of concurrent twice-daily radiation.

RESULTS

Forty-two patients with stage IIIA (N2) NSCLC (27 men and 15 women, age 38 to 77 years) were enrolled onto this prospective study. Forty of 42 patients tolerated the intended dose (42 Gy) of preoperative radiation and 37 of 39 resected patients received prescribed postoperative radiation. The intended dose of chemotherapy was given in 100%, 70%, and 60% of patients for the first, second, and third courses of chemotherapy. Marked dysphagia that required intravenous hydration was noted in 14% of patients (six of 42). Myelotoxicities included grade > or = 3 granulocytopenia in 23% and thrombocytopenia in 6% of 113 chemotherapy courses. Febrile neutropenia that required hospital admission was noted in 9% of 113 chemotherapy courses. Surgical resection was performed in 93% of patients. Treatment-related mortality was noted in 7% of patients. The overall survival rates by the Kaplan-Meier method were 66%, 37%, and 37% at 2,3, and 5 years, respectively, with a median follow-up time of 48 months. Pathologic examination of the surgical specimen showed a downward shift in tumor extent from stage IIIA (N2) to stage II (N1) in 33%, to stage I (NO) in 24% (10 of 42), and to stage 0 (TONO) in 9.5%, for a total of 67%. The degree of tumor downstaging was also translated into a survival benefit: 5-year survival rates from the time of surgery were 79%, 42%, and 18% for postoperative tumor stages 0 and I, II, and III, respectively (P = .04).

CONCLUSION

Concurrent chemoradiotherapy using twice-daily radiation is an effective induction regimen that resulted in 67% tumor downstaging, and an encouraging 37% 5-year survival rate. The degree of tumor downstaging may be a useful intermediate end point for survival benefit in stage IIIA (N2) NSCLC.

Simplified measurement of deoxyglucose utilization rate

The reliability of the dose uptake ratio (DUR), a widely used index of 18F-fluoro-2-deoxy-D-glucose (18FDG) metabolism in a variety of tumors, depends on the overall rate of removal of 18FDG from the circulation. Correcting for this factor is important if DUR is to be used quantitatively for pre- and post-treatment assessments of tumors.

METHODS

We developed a simplified kinetic method (SKM), based on measured blood curves from a control group, which requires one venous blood sample. We compared the simplified method to the conventional kinetic method and the widely used DUR index in 13 patients with grade 3 or 4 non-small-cell lung carcinoma. Studies were obtained before and after treatment. In all patients, dynamic PET imaging and blood activity measurement was performed for 80 min. The utilization rate of 18FDG (MRDGlc) was calculated by using a three-compartment model and correlated with a 55-min measurement of DUR and with the simplified kinetic method.

RESULTS

Coefficients of determination (R2) between MRDGlc and DUR before and after treatment were 0.53 and 0.71, respectively. Using the SKM, these values improved significantly (p < 0.0001) to 0.96 and 0.94, respectively. The pooled pre- and post-treatment coefficient of determination for DUR versus MRDGlc was 0.81; for SKM, it improved significantly (p < 0.001) to 0.98.

CONCLUSION

These results indicate that the observed tumor tissue uptake of 18FDG, corrected for blood 18FDG activity and glucose concentration, can reliably predict glucose metabolic rate from a single static image acquired at between 45 min and 1 hr after injection. This has substantial implications for the quantitative use of 18FDG PET to diagnose and manage malignancy.

Evolution of treatment strategies for adenocarcinoma of the esophagus and gastroesophageal junction

Between 1980 and 1988, 91 patients with adenocarcinoma of the esophagus were treated by surgical resection and selective postoperative therapy. Operative mortality was 2%. Pathologic stage was I in 4, II in 26, and III in 61. Actuarial 2- and 5-year survival was 24% and 8%. From 1987 to 1989, 16 patients with adenocarcinoma of the esophagus were treated with two cycles of 5-fluorouracil and cisplatin followed by surgical resection. There was 1 complete response (6%), 5 partial responses (31%), and 10 with no response (63%). Twelve patients had resection. Pathologic stage was I in 1, II in 4, and III in 8. There was one chemotherapy-related death and one surgical death. Actuarial 4-year survival is 42%. From 1990 to 1993, 22 patients with adenocarcinoma of the esophagus were treated with two cycles of etoposide, doxorubicin, and cisplatin followed by surgical resection. There was 1 complete response (5%), 11 partial responses (50%), and 10 with no response (45%). Eighteen patients had resection. Pathologic stage was 0 in 1, II in 8, and III in 9. There were no treatment-related deaths. The actuarial 2-year survival is 58%. Conclusions are necessarily limited because the patients were not treated in a randomized fashion. These preliminary results with preoperative chemotherapy appear improved (p = 0.04 and p = 0.004, respectively) as compared with results from 1980 to 1988 without preoperative chemotherapy.

The dose uptake ratio as an index of glucose metabolism: useful parameter or oversimplification?

The dose uptake ratio (DUR) has been used as a quantitative index of glucose metabolism for tumor classification and monitoring response to treatment. In order to provide consistent results, DUR measurements should be made when the concentration of tracer has reached a plateau. The time of this plateau cannot be identified from a single static acquisition.

METHODS

In this study, we investigated the changes in DUR as a function of time in eight patients with stage III lung cancer. All patients underwent a quantitative dynamic 18F-FDG PET study before and after treatment and the data were analyzed with a three-compartment model. Using the fitted model parameters, the DUR was predicted at the plateau and intermediate times.

RESULTS

Tumor concentrations of 18F-FDG did not reach a plateau within the 90 min of imaging in any of the pre-treatment studies and only in one case post-treatment. The average time to reach 95% of the plateau value pre-treatment was 298 +/- 42 min (range: 130-500 min); in post-treatment, it was 154 +/- 31 min (range: 65-240 min). The difference between the plateau DUR and the 60-min value was 46% +/- 6% pre-treatment and 17% +/- 5% post-treatment.

CONCLUSIONS

These data indicate that DUR can vary widely with the time of measurement and that DUR should be interpreted with caution in any individual patient.

Toxicity of thoracic radiotherapy on pulmonary function in lung cancer

Physiological changes in pulmonary function (PF) as a result of radiation therapy (RT) or radiation therapy plus chemotherapy (RT + CT) for unresectable lung cancer were evaluated in an ongoing prospective study and an attempt was also made to define a guideline which can be used to minimize adverse effect of RT on pulmonary function before RT is given. The study design consisted of: (a) standard overall pulmonary function test (PFT); (b) regional PFT, i.e. a quantitative analysis of regional distribution of ventilation, perfusion and volume using 13N and a positron camera before RT; and (c) follow-up studies of standard PFT every 6 months for 3 years after RT or RT + CT. Predicted post-RT PF prior to RT was calculated by a formula: predicted FEV1 after RT = FEV1 before RT x (1 - an average of the percent of ventilation and perfusion contributed by lung tissue within the RT treatment volume). A total of 267 patients with unresectable, but still potentially curable lung cancer by RT were entered into this study, and 135 patients who were free of recurrence underwent repeat studies. Loss of PF as a result of RT is closely related to the degree of PF reserve prior to RT. Patients with FEV1 > 50% of the predicted showed a statistically significant decrease in FEV1, FVC, MBC, peak expiratory flow rate and DLCO, i.e. a 22% loss of the initial value. Airway resistance was increased by 31%. Two-thirds of this group of patients showed a decrease in PF as predicted by the above formula. For patients with limited PF reserve defined by FEV1 < 50% of the predicted, the pattern of PF loss after RT was quite different. An improvement in PF although it was < or = 10%, contrary to the prediction, was noted in 50% of patients, and another 37% of patients showed a small decrease in PF (< or = 10% of the initial value). Only 13% of patients showed a loss of pulmonary function as predicted by regional PF data. Patients with a significant shift (> 10%) of ventilation and/or perfusion to the uninvolved side of the lung by centrally located primary tumor or involved lymph nodes showed an increase in PF in 60% of patients after RT, and another 20% of patients showed a minor decrease in PF (< 10% of the initial value). Only 20% of these patients showed a decrease in pulmonary function as predicted by regional PF data. Guidelines for minimizing adverse effect of RT on PF, which are based on the initial PF reserve and regional PF data, are presented.