Healthcare Big Data in Hong Kong: Development and Implementation of Artificial Intelligence-Enhanced Predictive Models for Risk Stratification

Routinely collected electronic health records (EHRs) data contain a vast amount of valuable information for conducting epidemiological studies. With the right tools, we can gain insights into disease processes and development, identify the best treatment and develop accurate models for predicting outcomes. Our recent systematic review has found that the number of big data studies from Hong Kong has rapidly increased since 2015, with an increasingly common application of artificial intelligence (AI). The advantages of big data are that i) the models developed are highly generalisable to the population, ii) multiple outcomes can be determined simultaneously, iii) ease of cross-validation by for model training, development and calibration, iv) huge numbers of useful variables can be analyzed, v) static and dynamic variables can be analyzed, vi) non-linear and latent interactions between variables can be captured, vii) artificial intelligence approaches can enhance the performance of prediction models. In this paper, we will provide several examples (cardiovascular disease, diabetes mellitus, Brugada syndrome, long QT syndrome) to illustrate efforts from a multi-disciplinary team to identify data from different modalities to develop models using territory-wide datasets, with the possibility of real-time risk updates by using new data captured from patients. The benefit is that only routinely collected data are required for developing highly accurate and high-performance models. AI-driven models outperform traditional models in terms of sensitivity, specificity, accuracy, area under the receiver operating characteristic and precision-recall curve, and F1 score. Web and/or mobile versions of the risk models allow clinicians to risk stratify patients quickly in clinical settings, thereby enabling clinical decision-making. Efforts are required to identify the best ways of implementing AI algorithms on the web and mobile apps.

Application of artificial intelligence in the diagnosis of sleep apnea

STUDY OBJECTIVES

Machine learning (ML) models have been employed in the setting of sleep disorders. This review aims to summarize the existing data about the role of ML techniques in the diagnosis, classification, and treatment of sleep-related breathing disorders.

METHODS

A systematic search in Medline, EMBASE, and Cochrane databases through January 2022 was performed.

RESULTS

Our search strategy revealed 132 studies that were included in the systematic review. Existing data show that ML models have been successfully used for diagnostic purposes. Specifically, ML models showed good performance in diagnosing sleep apnea using easily obtained features from the electrocardiogram, pulse oximetry, and sound signals. Similarly, ML showed good performance for the classification of sleep apnea into obstructive and central categories, as well as predicting apnea severity. Existing data show promising results for the ML-based guided treatment of sleep apnea. Specifically, the prediction of outcomes following surgical treatment and optimization of continuous positive airway pressure therapy can be guided by ML models.

CONCLUSIONS

The adoption and implementation of ML in the field of sleep-related breathing disorders is promising. Advancements in wearable sensor technology and ML models can help clinicians predict, diagnose, and classify sleep apnea more accurately and efficiently.

CITATION

Bazoukis G, Bollepalli SC, Chung CT, et al. Application of artificial intelligence in the diagnosis of sleep apnea. J Clin Sleep Med. 2023;19(7):1337-1363.

Sodium-glucose cotransporter 2 inhibitors versus dipeptidyl peptidase 4 inhibitors on new-onset overall cancer in Type 2 diabetes mellitus: A population-based study

BACKGROUND

Cancer is currently the second leading cause of death globally. There is much uncertainty regarding the comparative risks of new-onset overall cancer and pre-specified cancer for Type 2 diabetes mellitus (T2DM) patients on sodium-glucose cotransporter 2 inhibitors (SGLT2I) versus DPP4I.

METHODS

This population-based cohort study patients included patients who were diagnosed with T2DM and administered either SGLT2 or DPP4 inhibitors between 1 January 2015 and 31 December 2020 in public hospitals of Hong Kong.

RESULTS

This study included 60,112 T2DM patients (mean baseline age: 62.1 ± 12.4 years, male: 56.36%), of which 18,167 patients were SGLT2I users and 41,945 patients were dipeptidyl peptidase 4 inhibitor (DPP4I) users. Multivariable Cox regression found that SGLT2I use was associated with lower risks of all-cause mortality (HR: 0.92; 95% CI: 0.84-0.99; p= 0.04), cancer-related mortality (HR: 0.58; 95% CI: 0.42-0.80; p ≤ 0.001) and new diagnoses of any cancer (HR: 0.70; 95% CI: 0.59-0.84; p ≤ 0.001). SGLT2I use was associated with a lower risk of new-onset breast cancer (HR: 0.51; 95% CI: 0.32-0.80; p ≤ 0.001), but not of other malignancies. Subgroup analysis on the type of SGLT2I, dapagliflozin (HR: 0.78; 95% CI: 0.64-0.95; p = 0.01) and ertugliflozin (HR: 0.65; 95% CI: 0.43-0.98; p = 0.04) use was associated with lower risks of new cancer diagnosis. Dapagliflozin use was also linked to lower risks of breast cancer (HR: 0.48; 95% CI: 0.27-0.83; p = 0.001).

CONCLUSION

Sodium-glucose cotransporter 2 inhibitor use was associated with lower risks of all-cause mortality, cancer-related mortality and new-onset overall cancer compared to DPP4I use after propensity score matching and multivariable adjustment.

The Role of Electrophysiological Study in the Risk Stratification of Brugada Syndrome

Brugada syndrome (BrS) is a complex arrhythmogenic disease associated with an increased risk of sudden cardiac death (SCD). The role of electrophysiological study (EPS) for risk stratification purposes of asymptomatic BrS patients remains still controversial. This study aims to summarize the existing data about the role of electrophysiological study for arrhythmic risk stratification of BrS patients without a prior history of aborted SCD or fatal arrhythmic event. Two independent investigators (G.B. and G.T.) performed a systematic search in the MedLine database and Cochrane library from their inception until April 2022 without any limitations. The reference lists of the relevant research studies as well as the relevant review studies and meta-analyses were manually searched. Nineteen studies were included in the final analysis. The included studies enrolled 6218 BrS patients (mean age: 46.9 years old, males: 76%) while 4265 (68.6%) patients underwent an EPS. The quantitative synthesis showed that a positive EPS study was significantly associated with arrhythmic events in BrS patients (RR, 1.74 [1.23-2.45]; P = 0.002; I2 = 63%]. By including the studies that provided data on the association of EPS with arrhythmic events during follow-up in patients without a prior history of aborted SCD or fatal arrhythmic event, the association between positive EPS study and future arrhythmic events remained significant (RR, 1.60 [1.08-2.36]; P = 0.02; I2 = 19%). In conclusion, EPS is a useful invasive tool for the risk stratification of BrS patients and can be used to identify the population of BrS patients who may be candidates for primary prevention of SCD with implantable cardioverter-defibrillator (ICD) implantation.

Metformin use and hospital attendance-related resources utilization among diabetic patients with prostate cancer on androgen deprivation therapy: A population-based cohort study

BACKGROUND

Androgen deprivation therapy (ADT), used increasingly in the treatment of prostate cancer (PCa), negatively influences glycemic control in diabetes and is associated with an increased risk of diabetes complications where hospitalization commonly ensues. Metformin could decrease the metabolic consequences of ADT and enhance its effect. This study examined the association of metformin use with healthcare resources utilization among diabetic, PCa patients receiving ADT.

METHODS

Diabetic adults with PCa on ADT in Hong Kong between December 1999 and March 2021 were identified. Patients with <6 months of concurrent metformin and ADT use were excluded. All included patients were followed up until September 2021. The outcomes were hospital attendances and related costs.

RESULTS

In total, 1,284 metformin users and 687 non-users were studied. Over 8,045 person-years, 9,049 accident and emergency (A&E), and 21,262 inpatient attendances, with 11,2781 days of hospitalization were observed. Metformin users had significantly fewer A&E attendances (incidence rate ratio (IRR): 0.61 [95% confidence interval 0.54-0.69], p < 0.001), inpatient attendances (IRR: 0.57 [0.48-0.67], p < 0.001), and days of hospitalization (IRR: 0.55 [0.42-0.72], p < 0.001). Annual attendance costs were lower for metformin users than non-users (cost ratio: 0.28 [0.10-0.80], p = 0.017).

CONCLUSIONS

Metformin use was associated with decreased hospital attendances, days of hospitalization, and associated costs, which could help reduce healthcare resource utilization following ADT in the treatment of PCa.

Attendance-related Healthcare Resource Utilisation and Costs in Patients With Brugada Syndrome in Hong Kong: A Retrospective Cohort Study

Understanding health care resource utilisation and its associated costs are important for identifying areas of improvement regarding resource allocations. However, there is limited research exploring this issue in the setting of Brugada syndrome (BrS).This was a retrospective territory-wide study of BrS patients from Hong Kong. Healthcare resource utilisation for accident and emergency (A&E), inpatient and specialist outpatient attendances were analyzed over a 19-year period, with their associated costs presented in US dollars. A total of 507 BrS patients with a mean presentation age of 49.9 ± 16.3 years old were included. Of these, 384 patients displayed spontaneous type 1 electrocardiographic (ECG) Brugada pattern and 77 patients had presented with ventricular tachycardia/ventricular fibrillation (VT/VF). At the individual patient level, the median annualized costs were $110 (52-224) at the (A&E) setting, $6812 (1982-32414) at the inpatient setting and $557 (326-1001) for specialist outpatient attendances. Patients with initial VT/VF presentation had overall greater costs in inpatient ($20161 [9147-189215] vs $5290 [1613-24937],P < 0.0001) and specialist outpatient setting ($776 [438-1076] vs $542 [293-972],P = 0.015) compared to those who did not present VT. In addition, patients without Type 1 ECG pattern had greater median costs in the specialist outpatient setting ($7036 [3136-14378] vs $4895 [2409-10554],p=0.019). There is a greater health care demand in the inpatient and specialist outpatient settings for BrS patients. The most expensive attendance type was inpatient setting stay at $6812 per year. The total median annualized cost of BrS patients without VT/VF presentation was 78% lower compared to patients with VT/VF presentation.

COVID-19 vaccination and carditis in children and adolescents: a systematic review and meta-analysis

BACKGROUND

Coronavirus Disease-2019 (COVID-19) vaccination has been associated with the development of carditis, especially in children and adolescent males. However, the rates of these events in the global setting have not been explored in a systematic manner. The aim of this systematic review and meta-analysis is to investigate the rates of carditis in children and adolescents receiving COVID-19 vaccines.

METHODS

PubMed, Embase and several Latin American databases were searched for studies. The number of events, and where available, at-risk populations were extracted. Rate ratios were calculated and expressed as a rate per million doses received. Subgroup analysis based on the dose administered was performed. Subjects ≤ 19 years old who developed pericarditis or myocarditis following COVID-19 vaccination were included.

RESULTS

A total of 369 entries were retrieved. After screening, 39 articles were included. Our meta-analysis found that 343 patients developed carditis after the administration of 12,602,625 COVID-19 vaccination doses (pooled rate per million: 37.76; 95% confidence interval [CI] 23.57, 59.19). The rate of carditis was higher amongst male patients (pooled rate ratio: 5.04; 95% CI 1.40, 18.19) and after the second vaccination dose (pooled rate ratio: 5.60; 95% CI 1.97, 15.89). In 301 cases of carditis (281 male; mean age: 15.90 (standard deviation [SD] 1.52) years old) reported amongst the case series/reports, 261 patients were reported to have received treatment. 97.34% of the patients presented with chest pain. The common findings include ST elevation and T wave abnormalities on electrocardiography. Oedema and late gadolinium enhancement in the myocardium were frequently observed in cardiac magnetic resonance imaging (CMR). The mean length of hospital stay was 3.91 days (SD 1.75). In 298 out of 299 patients (99.67%) the carditis resolved with or without treatment.

CONCLUSIONS

Carditis is a rare complication after COVID-19 vaccination across the globe, but the vast majority of episodes are self-limiting with rapid resolution of symptoms within days. Central illustration. Balancing the benefits of vaccines on COVID-19-caused carditis and post-vaccination carditis.

Risk factors of pancreatic cancer in patients with type 2 diabetes mellitus: The Hong Kong Diabetes Study

Background & Aim

Diabetes mellitus is associated with the development of pancreatic cancer, but few large-scale studies have examined its predictive risk factors. The present study aims to examine the predictors for PaC in patients with type 2 diabetes mellitus in a territory-wide retrospective cohort study.

Methods

This was a territory-wide retrospective cohort study of patients with type 2 diabetes mellitus over the age of 40 and no prior history of pancreatic cancer. Baseline demographics, use of anti-diabetic medications, comorbidities and biochemical parameters were extracted. Cox regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI). Subgroup analyses based on chronic kidney disease stages were performed.

Results

This study consisted of 273738 patients (age = 65.4 ± 12.7 years old, male = 48.2%, follow-up duration = 3547 ± 1207 days, disease duration = 4.8 ± 2.3 years), amongst which 1148 developed pancreatic cancer. The number of anti-diabetic medications prescribed (HR: 1.20; 95% CI: 1.01-1.42; P = 0.040), diabetic microvascular complications (HR: 1.91; 95% CI: 1.30-2.81; P &lt; 0.001), chronic kidney disease (HR: 1.81; 95% CI: 1.25-2.64; P = 0.002), use of acarbose (HR: 2.24; 95% CI: 1.35-3.74; P = 0.002) and use of glucagon-like peptide-1 receptor agonist (HR: 4.00; 95% CI: 1.28-12.53, P = 0.017) were associated with pancreatic cancer development on multivariable Cox regression adjusting for the duration of diabetes mellitus, mean HbA1c, and history of pancreatic diseases. Stage 3A chronic kidney disease or below was associated with pancreatic cancer but not stage 3B or beyond.

Conclusion

Diabetic microvascular complications, especially stage 1, 2 and 3A chronic kidney disease, were associated with pancreatic cancers.

Predictors of fatal arrhythmic events in patients with non-compaction cardiomyopathy: a systematic review

Left ventricular non-compaction cardiomyopathy (LVNC) is a congenital heart disease with autosomal dominant inheritance. This review aims to summarize the existing data about the predictors of fatal arrhythmias in patients with LVNC. Medline and Cochrane library databases were searched from inception to November 2021 for articles on LVNC. The reference lists of the relevant research studies as well as the relevant review studies and meta-analyses were also searched. Clinical symptoms and electrocardiogram findings such as left bundle branch block are significantly associated with ventricular arrhythmias. Other non-invasive tools such as Holter monitoring, echocardiography, and cardiac magnetic resonance (CMR) can provide additional value for risk stratification. CMR-derived left and right ventricular ejection fraction, left ventricular end-diastolic diameter, late gadolinium enhancement, and non-compacted to compacted myocardium ratio are predictive of ventricular arrhythmias. An electrophysiological study can provide additional prognostic data in patients with LVNC who are at moderate risk of ventricular arrhythmias. Risk stratification of LVNC patients with no prior history of a fatal arrhythmic event remains challenging. Symptoms assessment, electrocardiogram, Holter monitoring, and cardiac imaging should be performed on every patient, while an electrophysiological study should be performed for moderate-risk patients. Large cohort studies are needed for the construction of score models for arrhythmic risk stratification purposes.

Machine learning techniques for arrhythmic risk stratification: a review of the literature

Ventricular arrhythmias (VAs) and sudden cardiac death (SCD) are significant adverse events that affect the morbidity and mortality of both the general population and patients with predisposing cardiovascular risk factors. Currently, conventional disease-specific scores are used for risk stratification purposes. However, these risk scores have several limitations, including variations among validation cohorts, the inclusion of a limited number of predictors while omitting important variables, as well as hidden relationships between predictors. Machine learning (ML) techniques are based on algorithms that describe intervariable relationships. Recent studies have implemented ML techniques to construct models for the prediction of fatal VAs. However, the application of ML study findings is limited by the absence of established frameworks for its implementation, in addition to clinicians’ unfamiliarity with ML techniques. This review, therefore, aims to provide an accessible and easy-to-understand summary of the existing evidence about the use of ML techniques in the prediction of VAs. Our findings suggest that ML algorithms improve arrhythmic prediction performance in different clinical settings. However, it should be emphasized that prospective studies comparing ML algorithms to conventional risk models are needed while a regulatory framework is required prior to their implementation in clinical practice.

Clinical significance, challenges and limitations in using artificial intelligence for electrocardiography-based diagnosis

Cardiovascular diseases are one of the leading global causes of mortality. Currently, clinicians rely on their own analyses or automated analyses of the electrocardiogram (ECG) to obtain a diagnosis. However, both approaches can only include a finite number of predictors and are unable to execute complex analyses. Artificial intelligence (AI) has enabled the introduction of machine and deep learning algorithms to compensate for the existing limitations of current ECG analysis methods, with promising results. However, it should be prudent to recognize that these algorithms also associated with their own unique set of challenges and limitations, such as professional liability, systematic bias, surveillance, cybersecurity, as well as technical and logistical challenges. This review aims to increase familiarity with and awareness of AI algorithms used in ECG diagnosis, and to ultimately inform the interested stakeholders on their potential utility in addressing present clinical challenges.

Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia.

Enhanced apoptosis and radiosensitization by combined 13-cis-retinoic acid and interferon-alpha2a; role of RAR-beta gene

PURPOSE

Combined use of 13-cis-retinoic acid (cRA) and interferon-alpha2a (IFNalpha) induced significant radiosensitization in human cervical cancer ME-180 cell line, whereas it failed to achieve similar radiation enhancement in HeLa cells. The differential radiosensitization could be from the difference of retinoic acid receptor (RAR) expression because RAR-beta was highly expressed in ME-180 cells in contrast to the HeLa cells where RAR-beta was not detectable. We examined the role of this gene in mediating radiosensitization by cRA and IFNalpha, and explored the mechanism of radiation-induced cell killing.

METHODS AND MATERIALS

Human cervical cancer cell lines, ME-180 and HeLa, were treated with cRA and IFNalpha followed by radiation. Apoptosis and radiosensitization were quantitated by TUNEL assay (in situ DNA nick end labeling) and colony-forming ability of surviving cells. The cells were transfected with bcl-2 gene and RAR-beta gene to test the role of these genes in mediating radiosensitization and apoptosis.

RESULTS

Synergistic radiosensitization and apoptosis was observed by combined use of cRA and IFNalpha with radiation in ME-180 cells which express high level of RAR-beta mRNA, whereas these were not seen in HeLa cells where RAR-beta mRNA is not detectable. Both radiosensitization and apoptosis were abolished by bcl-2 gene in ME-180 cells. RAR-beta gene transfection induced similar radiation enhancement and apoptosis in HeLa cells.

CONCLUSION

Apoptosis and radiation response were enhanced in the cells with high level of RAR-beta mRNA expression. The RAR-beta gene appears to mediate the radiation-induced apoptosis by cRA and IFNalpha. These findings indicate that presence of RAR-beta in the cancer cells could be exploited for patient selection in using these drugs for apoptosis and radiosensitization.

Management of craniopharyngioma

PURPOSE

The management of craniopharyngioma does not have a consensus. Extensive surgery may be associated with major complications. The purpose of this study was to evaluate local tumor control and survival after limited surgery and postoperative radiotherapy.

METHODS AND MATERIALS

Thirty patients with craniopharyngioma were treated at SUNY Upstate Medical University in Syracuse, NY from 1967 to 2000. The group consisted of 13 males and 17 females, and the median age was 35 years. The median follow-up was 71 months. Only two patients underwent complete tumor resection. Eighteen patients underwent subtotal resection, and 10 underwent decompressive surgery (ventriculoperitoneal shunt or cyst aspiration). Most (20/ 28) patients who had less than total resection received immediate postoperative radiotherapy. Four patients received conventional radiotherapy for recurrence. Gamma knife radiosurgery was used as part of the primary treatment in two patients and at the time of local tumor recurrence in three patients.

RESULTS

The local control rate, including after salvage treatment, was 91% and 83% at 5 and 10 years, respectively. Salvage was radiotherapy, gamma knife or surgery. Ultimate local tumor control appeared better for patients who underwent subtotal resection (100% and 89% at 5 and 10 years, respectively) than for those who did not undergo resection (61% and 61% at 5 and 10 years, respectively). The overall survival was 93% and 83% at 5 and 10 years, respectively. Two patients underwent gross total resection, and one patient experienced recurrence 6 years after the surgery and was treated by gamma knife radiosurgery. Both patients are well without recurrence at 3 and 7 years after the initial surgery. Survival also appeared to be improved for the group who underwent subtotal resection (100% and 90% at 5 and 10 years, respectively) versus those who did not undergo surgery (73% and 73% at 5 and 10 years, respectively). The dose of radiotherapy > or = 50 Gy had no impact on local control or survival. Ten patients experienced surgery-related complications, and five had radiotherapy-related complications, including visual, cranial nerve, motor, and endocrine deficits.

CONCLUSION

The extent of surgery appears to be an important prognostic factor for predicting outcome, although this may represent selection bias. Long-term disease control is excellent after subtotal resection and postoperative radiotherapy. Encouraging initial results have been seen with gamma knife radiosurgery, and the potential for gamma knife radiosurgery to replace more extensive surgical resection should be further explored.

Neurogenic intermittent claudication related to spinal stenosis

BACKGROUND

The pathophysiology of neurogenic intermittent claudication (NIC) is not very well understood. We examined the theory of "two-level" spinal stenosis as the pathologic cause of NIC.

METHODS

Forty-five consecutive patients with NIC were chosen for the study group and another 45 patients with chronic low back pain, but without NIC, were consecutively chosen for the control group. All the patients were examined using several methods that included a personal history survey, physical examination, X-ray studies, computed tomography (CT) and magnetic resonance imaging (MRI).

RESULTS

Two-level central canal stenosis was found on MRI in 88.9% of the study group compared to only 37.8% of the control group (Fisher's exact two-tailed test, P = 0.0000). In the study group, 77.8% of the patients had severe or moderate facet joint degeneration on CT. The remaining 22.2% of patients had mild facet joint degeneration. In the control group, 40% of the patients had severe or moderate facet joint degeneration, while it was mild or normal in the remaining 60% (Fisher's exact two-tailed test, P = 0.0005). On X-ray, 42.2% of the study group compared with 17.7% of the control group had spondylolisthesis (Fisher's exact two-tailed test, P = 0.0129). In 35% of the study group compared with 11.1% of the control group, X-ray findings showed scoliosis (Fisher's exact two-tailed test, P = 0.0115). The lumbosacral angle in the study group was 35.8 degrees +/- 6.1 degrees compared to 33.1 degrees +/- 7.5 degrees in the control group (independent Student's two-tailed t-test, P > 0.05).

CONCLUSIONS

Our study strongly supports pathophysiology for NIC that is closely related to two-level spinal canal stenosis. Degenerative joint disease, spondylolisthesis and scoliosis of the lumbar spine are predisposing factors of NIC.

Aggressive radiotherapy adjuvant to peripheral blood stem cell transplant for relapsed Hodgkin's disease

The role of radiotherapy in conjunction with high-dose chemotherapy and autologous bone marrow transplant for relapsed Hodgkin's disease remains to be clearly defined. Although there is substantial evidence that radiotherapy enhances local tumor control, prospective trials in the transplant setting have not been reported, and the potential toxicity of radiotherapy need to be considered. However, certain patients are at high risk of posttransplant tumor recurrence, most notably those with tumors unresponsive to pretransplant chemotherapy. We report the use of aggressive radiotherapy in three high-risk patients, including the first reported case of whole lung irradiation after a high-dose carmustine-based chemotherapy regimen. Two of these patients received repeat partial lung irradiation, including one patient with carmustine-related pulmonary toxicity. Radiotherapy (30-34.5 Gy; 1.5 Gy/fraction) was tolerated well without significant acute or late toxicity, and all patients remain disease free 40 to 62 months after irradiation without severe sequelae. We conclude that radiotherapy may be of benefit for patients at high risk of local tumor relapse, and should be considered in such cases despite potential toxicity.

Hematologic toxic reaction to radiation therapy adjuvant to autologous peripheral blood stem cell transplantation for recurrent or refractory Hodgkin disease

PURPOSE

To evaluate the hematologic toxic reaction to external-beam radiation therapy after high-dose chemotherapy with peripheral blood stem cell (PBSC) support in patients with Hodgkin disease.

MATERIALS AND METHODS

A retrospective study of 30 cases of Hodgkin disease in patients who underwent high-dose carmustine, etoposide, and cyclophosphamide chemotherapy with PBSC support was performed. Thirteen patients underwent radiation therapy (28.8-39.0 Gy) a median of 45 days after PBSC repeat infusion.

RESULTS

Radiation therapy was delivered as planned, without interruption, in all patients. Five patients developed thrombocytopenia (one with grade 1 thrombocytopenia; two, grade 2; and two, grade 3) and included three with progressive disease prior to radiation therapy and two with a history of prior irradiation. None developed a bleeding complication or required transfusion support. Five patients who underwent irradiation had thrombocytopenia (three with grade 1 and two with grade 2) 100 days after PBSC repeat infusion, compared with three patients (two with grade 1 and one with grade 3) who did not undergo posttransplantation irradiation. At the most recent follow-up, no patient without evidence of disease had a platelet count of less than 100 x 10(9)/L.

CONCLUSION

External-beam radiation therapy was well tolerated in the posttransplantation setting in patients with Hodgkin disease. Thrombocytopenia was common but was not related to clinical complications.

'Full dose' reirradiation of human cervical spinal cord

With the progress of modern multimodality cancer treatment, retreatment of late recurrences or second tumors became more commonly encountered in management of patients with cancer. Spinal cord retreatment with radiation is a common problem in this regard. Because radiation myelopathy may result in functional deficits, many oncologists are concerned about radiation-induced myelopathy when retreating tumors located within or immediately adjacent to the previous radiation portal. The treatment decision is complicated because it requires a pertinent assessment of prognostic factors with and without reirradiation, radiobiologic estimation of recovery of occult spinal cord damage from the previous treatment, as well as interactions because of multimodality treatment. Recent studies regarding reirradiation of spinal cord in animals using limb paralysis as an endpoint have shown substantial and almost complete recovery of spinal cord injury after a sufficient time after the initial radiotherapy. We report a case of "full" dose reirradiation of the entire cervical spinal cord in a patient who has not developed clinically detectable radiation-induced myelopathy on long-term follow-up of 17 years after the first radiotherapy and 5 years after the second radiotherapy.

Sequential chemotherapy (etoposide, vinblastine, and doxorubicin) and subtotal lymph node radiation for patients with localized Hodgkin disease and unfavorable prognostic features: A phase II Cancer and Leukemia Group B Study (9051)

BACKGROUND

The aim of this study was to evaluate a regimen of sequential chemotherapy and radiotherapy for patients with Hodgkin disease.

METHODS

The Cancer and Leukemia Group B conducted a Phase II study of three cycles of etoposide, vinblastine, and doxorubicin (EVA) chemotherapy followed by subtotal lymph node radiation for patients with localized Hodgkin disease and unfavorable prognostic features. Fifty-nine patients were enrolled in the study. Fifty-three patients met all study eligibility criteria; 48 of them (91%) had mediastinal disease and 29 (55%) had bulky mediastinal disease.

RESULTS

A complete response (CR) occurred in 35 of the patients (66%). Of all patients who had CR, 26% had the CR after the chemotherapy and before the radiation, and 74% after the chemotherapy and radiation. Twenty percent of the patients who had CR experienced disease progression; in these patients, the progression was outside the radiotherapy field in the lung and involved widespread disease.

CONCLUSIONS

EVA offers a nonbleomycin-containing alternative for patients in whom preexisting pulmonary disease may be exacerbated by bleomycin and radiation therapy. EVA, as given in this study (in three cycles), was insufficient chemotherapy for patients who had disease in areas outside the radiation fields (occult 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.

The value of gallium imaging after therapy for Hodgkin's disease

BACKGROUND

Although it is used widely, the value of gallium imaging in managing Hodgkin's disease remains unclear.

METHODS

A retrospective review of gallium imaging and treatment outcome in 60 patients with Hodgkin's disease treated between January 1990 and July 1995 was conducted. The minimum follow-up was 1 year.

RESULTS

Based on gallium imaging, 46 patients were in complete remission (CR) after initial treatment, 10 were in partial remission (PR), and 4 had persistent or progressive disease (NR). Ten of 29 patients (34%) with gallium CR after chemotherapy subsequently recurred, compared with no recurrences in 17 patients receiving initial radiotherapy or combined chemoradiation. Eight of ten patients received further therapy after gallium PR, and nine patients remained disease free at last follow-up. Survival did not differ in patients achieving a gallium CR or PR.

CONCLUSIONS

Gallium-67 imaging may help confirm the presence of active Hodgkin's disease, but was unreliable in defining disease remission after chemotherapy in this study population. Patients with a gallium PR may still have a good prognosis after additional therapy.

Increased risk of breast cancer in splenectomized patients undergoing radiation therapy for Hodgkin's disease

PURPOSE

Second malignancies have been reported among patients who were treated by radiation therapy or chemotherapy alone or in combination. Studies have implied an increased risk of breast cancer in women who received radiotherapy as part of their treatment for Hodgkin's disease. This review was performed to determine if there is an association between splenectomy and subsequent breast cancer.

METHODS AND MATERIALS

One hundred and thirty-six female patients with histologically proven Hodgkin's disease were seen in the Division of Radiation Oncology between 1962 and 1985. All patients received mantle or mediastinal irradiation as part of their therapy. The risk of breast cancer was assessed and multiple linear regression analysis was performed on the following variables: patient age, stage, dose and extent of radiation field, time after completing radiation therapy, splenectomy, and chemotherapy.

RESULTS

Breast cancer was observed in 11 of 74 splenectomized patients and in none of 62 patients not splenectomized. The mean follow-up was 13 years in splenectomized patients and 16 years, 7 months in nonsplenectomized patients. Nine patients developed invasive breast cancer and two developed ductal carcinoma in situ. Splenectomy was the only variable independently associated with an increased risk of breast cancer (p < 0.005) in multiple linear regression analysis; age, latency, and splenectomy considered together were also associated with an increased risk of breast cancer (p < 0.01).

CONCLUSION

Our data show an increased risk of breast cancer in splenectomized patients who had treatment for Hodgkin's disease. A multiinstitutional survey may better define the influence of splenectomy relative to developing breast cancer in patients treated for Hodgkin's disease. The risk of breast cancer should be considered when recommending staging laparotomy, and we recommend close follow-up examination including routine mammograms for female patients successfully treated for Hodgkin's disease.

Surface dose for tangentially incident photon beams in the presence of air gap and air cavity

Dose to a surface parallel to an incident photon beam has been investigated in the presence of air gaps and air cavities. Measurements have been made in an acrylic phantom with a parallel plate chamber. Photon beams of Co 60, 4-MV, 6-MV, and 15-MV X-rays have been investigated. The results of our measurements show that in the case of air gaps, the dose reduction to a tangential surface is considerable. On the other hand, the dose reduction is 2% or less in the case of air cavity for volumes encountered in clinical situations.

Secondary hypertension due to renin secreting tumor: a case report

We report a 20-year-old female with severe hypertension, hypokalemia, hyperaldosteronism and elevated level of plasma renin activity (PRA). The clinical diagnosis of renin secreting tumor of left kidney was made before surgery by the lateralization of plasma renin activity via selective renal venous blood sampling and CT scan of kidney. Prompt normalization of blood pressure and decrease of PRA and aldosterone levels were found after surgical removal of the tumor. The pathological findings showed a juxtaglomerular cell tumor.

Radiotherapy for nasolacrimal tract epithelial cancer

PURPOSE

Tumors of the lacrimal sac are rare and have traditionally been treated surgically. We investigated the use of irradiation for treatment.

METHODS AND MATERIALS

Three consecutive patients with primary epithelial cancer of the nasolacrimal apparatus were treated with irradiation. A tumor dose of 52-66 Gy was delivered with conventional fractionation to fields limited to the primary site and immediately surrounding tissues.

RESULTS

Local tumor control was achieved in all three patients. Two patients subsequently developed metastatic cervical adenopathy; both were controlled with irradiation to the neck. One of these two died of distant metastases. Two patients are alive and well at 13 years and at 26 months.

CONCLUSION

We conclude that epithelial lacrimal sac tumors are controllable by radiation therapy and with a good cosmetic result. Poorly differentiated lesions require elective cervical nodal irradiation.

Early extramedullary relapse of acute myelogenous leukemia in bilateral breasts: a case report

We report a case of a 19-year-old female with acute myelogenous leukemia successfully treated with daunorubicin and Ara-c. Eight months after complete remission, palpable breast masses developed bilaterally. Biopsy and fine needle aspiration of the right mass showed cluster of leukemic cells indicative of extramedullary leukemic relapse. One month after biopsy, the patient's bone marrow showed presence of 90% blast cells. Palpable breast mass may be an early sign of relapse of acute myelogenous leukemia.

Stage II seminoma: results of postorchiectomy irradiation

One hundred forty patients with testicular seminoma were treated at the State University of New York Health Science Center at Syracuse between 1966 and 1985. Disease was classified as stage II in 32 patients (23%): stage IIA in 21 patients and stage IIB in 11 patients. All patients underwent irradiation below the diaphragm after a radical orchiectomy, and 28 underwent planned mediastinal and supraclavicular irradiation. The median follow-up was 8 1/2 years; 24 of 32 patients have been followed up for more than 5 years. Twenty-eight patients remain alive and well; four patients died of intercurrent disease. Two patients developed a recurrent seminoma in the mediastinum; a variant lymphangiographic pattern was shown in these patients, and they were cured. A third patient developed a non-seminomatous "recurrence" in the ipsilateral, unirradiated, inguinal nodes and is well after chemotherapy.

External beam radiotherapy for carcinoma of the prostate

Five hundred nineteen patients with prostate cancer were seen in the Radiation Oncology Division of the State University of New York (SUNY) Health Science Center, Syracuse, New York, between 1969 and 1981. The results for the 239 patients treated with radical intent are reported here. All patients received 60 to 70 Gy to the prostate with megavoltage beam irradiation; 142 with a small field (10 X 10 cm) 360 degrees rotational technique for Stage A, B, or C disease and 69 with a four-field pelvic brick technique (followed by a boost to the prostate) for Stage A through C and D1 disease. Twenty-eight patients were treated postoperatively for residual disease after radical prostatectomy or for recurrent tumor. The minimum follow-up time was 5 years. Actuarial 5-year and 7-year survival rates for Stage A (n = 34), B (n = 100), C (n = 63), and D1 (n = 14) were 91% and 76%, 86% and 75%, 67% and 40%, and 46% and 36%, respectively. The corresponding 5-year and 7-year relapse-free survival rates were 72% and 65%, 77% and 60%, 46% and 28%, and 38% and 25%. The local tumor control rates at 5 years were 91%, 85%, 77%, and 62% for Stage A, B, C, and D1, respectively. In our experience, there was no significant difference in relapse-free survival rates for patients who underwent transurethral resection (TURP) versus those who did not (67% versus 78% for Stage B [P greater than 0.25] and 38% versus 47% for Stage C [P greater than 0.25], respectively). Also there was no significant difference in relapse-free survival rates between large and small field techniques (64% versus 77% for Stage B [P greater than 0.25] and 56% versus 41% for Stage C [P greater than 0.25], respectively). The 5-year and 7-year actuarial survival rates were 90% and 71%, respectively, for the 15 patients with residual tumor and 58% and 33%, respectively, for the 13 patients treated for postprostatectomy recurrence. Severe complications were documented in only nine patients (3.7%) and mild to moderate complications in 53 patients (22%). Larger fields did not cause a higher rate of complications, although small fields were tolerated better than large fields; the significant acute reaction rate was 27% for large field techniques versus 11% for small field techniques (P greater than 0.01). These results confirm that external beam irradiation is an effective treatment for prostate cancer.

Ethanol enhancement of isoproterenol-stimulated melatonin and cyclic AMP release from cultured pineal glands

Norepinephrine stimulates the synthesis of melatonin in the pineal gland. The action of norepinephrine is believed to be mediated primarily by beta adrenergic receptors, and involves activation of adenylate cyclase. Ethanol, 25 to 50 mM, added to cultured pineal glands in vitro, enhanced isoproterenol-induced stimulation of cyclic AMP and melatonin production. The action of ethanol was observed only at doses of isoproterenol that produced a submaximal effect, and ethanol alone had no effect on cyclic AMP or melatonin release. Butanol, at a concentration of 2 mM, was as effective as 50 mM ethanol in increasing isoproterenol-stimulated cyclic AMP and melatonin release, indicating that the response to alcohols was not due simply to changes in osmolarity, and may reflect a hydrophobic interaction of the alcohols with the cell membrane. The effects of ethanol on pineal cyclic AMP and melatonin release were reversible after a 15-min preincubation, but not after a 2-hr preincubation, suggesting that, over a long incubation period, ethanol may sensitize the pineal beta adrenergic receptor-coupled adenylate cyclase system to isoproterenol. The findings in this study are consistent with earlier work showing that ethanol increases cerebral cortical beta adrenergic receptor-coupled adenylate cyclase activity, and demonstrate that the effect of ethanol on the receptor-effector system can result in an endocrinological response.

One-step preparation of competent Escherichia coli: transformation and storage of bacterial cells in the same solution

We have developed a simple, one-step procedure for the preparation of competent Escherichia coli that uses a transformation and storage solution [TSS; 1 x TSS is LB broth containing 10% (wt/vol) polyethylene glycol, 5% (vol/vol) dimethyl sulfoxide, and 50 mM Mg2+ at pH 6.5]. Cells are mixed with an equal volume of ice-cold 2 x TSS and are immediately ready for use. Genetic transformation is equally simple: plasmid DNA is added and the cells are incubated for 5-60 min at 4 degrees C. A heat pulse is not necessary and the incubation time at 4 degrees C is not crucial, so there are no critical timing steps in the transformation procedure. Transformed bacteria are grown and selected by standard methods. Thus, this procedure eliminates the centrifugation, washing, and long-term incubation steps of current methods. Although cells taken early in the growth cycle (OD600 0.3-0.4) yield the highest transformation efficiencies (10(7)-10(8) transformants per micrograms of plasmid DNA), cells harvested at other stages in the growth cycle (including stationary phase) are capable of undergoing transformation (10(5)-10(7) transformants per micrograms of DNA). For long-term storage of competent cells, bacteria can be frozen in TSS without addition of other components. Our procedure represents a simple and convenient method for the preparation, transformation, and storage of competent bacterial cells.

Effect of Precursors on Growth and Alkaloid Production in Chinchona ledgeriana Leaf-Shoot Organ Cultures

The alkaloid contents of the serially propagated CINCHONA LEDGERIANA leaf-shoot organ cultures that were fed with various precursors, were compared to the control cultures that were grown in Murashige and Skoog's medium supplemented with 5 mg/l benzyladenine. the average total alkaloid content of the 8-week-old leaf-shoot cultures increased approximately 66% with tryptopnan; 42% with secologanin; 5% with strictosidine-type, and decreased 10% with methoxystrictosidine-type alkaloid intermediates. The radioactive precursors: L-[3'- (14)C]-tryptophan was incorporated into cinchonidine (0.04%), cinchonine (0.01%), quinidine (0.01%), and quinine (0.08%); [5- (14)C]-10-strictosidine-HCl was incorporated into cinchonidine (0.01%), cinchonine (0.003%), quinidine (0.003%), and quinine (0.005%); and [5- (14)C]-10-methoxystrictosidine.HCl was incorporated equally (0.01%) into quinidine and quinine.

Air-fluid level in axillary vein simulating abscess

Demonstration of an air-fluid level in the body wall on a computed tomography examination usually suggests the presence of an abscess or a postoperative fluid collection. However, the small amount of air that frequently is injected during intravenous contrast administration may result in a similar computed tomography appearance.

Atypical distribution of Pneumocystis carinii infiltrates during radiation therapy

Bilateral peripheral pulmonary infiltrates caused by Pneumocystis carinii developed in a patient undergoing mediastinal irradiation after chemotherapy for Hodgkin disease. The paramediastinal part of the lung included within the treatment port remained clear during the 2 1/2 weeks of radiation therapy. The distribution of the pneumocystis infiltrates was altered by the radiation, producing a pattern that is the "radiographic negative" of typical post-radiation therapy paramediastinal fibrosis.

Effects of Age and Growth Regulators on Growth and Alkaloid Production in Cinchona ledgeriana Leaf-Shoot Organ Cultures

CINCHONA LEDGERIANA Moens et Trimen leaf-shoot organ cultures established and maintained on Murashige and Skoog's medium containing benzyladenine (BA 5 mg/l) were used to study the effects of age and growth regulators on alkaloid production. The total and individual alkaloid content of the leaf-shoot organ cultures increased with age and resembled closely that of the 1-year-old plant which favored quinine production. The 32-week-old tissue cultures contained the same amount of alkaloid as that of the 1-year-old plant (350 mg%). Quinine production was favored by the presence of benzyladenine (5 mg/l), gibberellic acid (5 mg/l) and/or shoots. Quinidine production was high in the presence of indole-3-acetic acid (5 mg/l), the absence of benzyladenine, and/or the presence of roots. High concentrations of abscisic acid and mefluidide inhibited growth and alkaloid production.

Controversy in the management of optic nerve glioma

The records of 16 patients with optic nerve glioma treated between 1961 and 1984 were reviewed. All patients except two had extension of tumor beyond the chiasm to the hypothalamus, adjacent brain and/or along the posterior optic tract. Eleven of 16 cases were biopsy-proven, two patients had craniotomy and visual inspection but no biopsy was performed, and in two cases the biopsy was not diagnostic. Fourteen patients received radiation therapy, usually consisting of 50 Gy in 5 weeks (range 40-56 Gy), one patient was treated surgically and one with chemotherapy. With a follow-up of 1 to 20 years, 7 of the 14 patients irradiated are alive, three patients are dead of disease at 3, 6 and 9 years post-treatment, three were lost to follow-up at 1, 8, and 8 years, and one is dead of intercurrent disease at 5.5 years. Overall vision was improved in five patients and stable in seven following treatment. In two patients, vision could not be evaluated because of young age at presentation. Four patients had recurrences. One was retreated with 30 Gy in 3 weeks and shows no evidence of disease at 20 years. The three other patients died of their disease. There is controversy over the best treatment for these patients. Based on these results and a review of the literature, the authors recommendation is to irradiate tumors with extension beyond the chiasm at the time of presentation rather than waiting for increasing symptoms because function that is lost may not always be recovered. Chemotherapy needs to be further investigated but holds promise, especially for the younger children.

Bladder carcinoma. Experience with radical and preoperative radiotherapy in 421 patients

Four hundred twenty-one patients with bladder carcinoma were treated with radical intent between 1968 and 1981: 356 were treated with irradiation alone with megavoltage tumor doses of 60-66 Gy delivered over a period of 6 to 7 weeks. Actuarial 5- and 10-year survival was 66% and 58% for Stage A (58 patients), 42% and 35% for Stage B1 (62 patients), 35% and 28% for Stage B2 (120 patients), and 23% and 19% for Stage C (75 patients), respectively. Five-year survival after salvage cystectomy (47 patients) was 51% from the time of surgery, with 4 operative mortalities and a major complication rate of 30%. Sixty-five patients were entered into an integrated preradical cystectomy irradiation program. Fifty-three patients in stages B2-C-D1 received high-dose preoperative radiotherapy (40-50 Gy) before a planned, delayed radical cystectomy. The actuarial 5-year survival was 66% for 65 patients, and 64% for the 53 patients in the high-dose precystectomy program; major complications were encountered in 34% and there were 2 mortalities. Five-year actuarial survival for Stage B2-C was 30% but fell to 24% when patients with salvage cystectomy were excluded. Distant metastasis was found in 30% of patients in Stage B2-C-D1, and also in the high-dose precystectomy program patients. Two-thirds of patients with distant metastasis in the radiation alone group were never considered for salvage cystectomy as they had distant metastasis alone, persistent disease with metastasis within 6 months after initiation of irradiation, or local recurrence and distant metastasis simultaneously. Early local recurrence may be salvaged in 50% to 60% of patients without a significant increase in mortality or major complications. Accordingly, a program of radical irradiation with salvage cystectomy may avoid loss of the bladder in 45% of patients in Stage B2-C-D1 without compromising overall survival.

Thyrotoxic thyroiditis after radiotherapy for Hodgkin's disease

Exposure of the thyroid gland to ionizing radiation has been associated with a variety of abnormalities. Among these are tardive hypothyroidism and an increased risk of developing thyroid nodules and cancer. Although acute thyroiditis has been known to complicate radioactive iodine 131 therapy, it has rarely been associated with external beam irradiation. Thyrotoxic painless thyroiditis developed in two patients after mantle-field irradiation for Hodgkin's disease.

Effects of ethanol, temperature, and endogenous regulatory factors on the characteristics of striatal opiate receptors

Ethanol can alter the affinity of mouse striatal opiate receptors for their ligands, and the present studies were aimed at determining the importance of the receptor microenvironment for this effect of ethanol. Changing the temperature of the binding assay, and thus altering the properties of neuronal membrane lipids, resulted in changes in the observed affinity of striatal binding sites for dihydromorphine (DHM), but not for D-Ala2, D-Leu5-enkephalin (ENK). The changes in temperature also differentially altered the response of the two binding sites to ethanol. Two other factors that regulate opiate receptor affinity, Na+ and GTP, also affected the response to ethanol. High concentrations of ethanol were more effective at decreasing receptor affinity for both DHM and ENK when the binding assays were performed in the presence of GTP or Na+. In addition, at 37 degrees C and in the presence of GTP or Na+, DHM binding, but not ENK binding, was significantly inhibited by a low, physiologically attainable concentration of ethanol. Our results suggest that the response of opiate receptors to ethanol is influenced by the microenvironment of the receptors, including the physical state of the membrane lipids and/or by the nature of the interactions of receptors with "coupling proteins" within the membrane. The differential responses of mu and delta receptors to temperature and to ethanol suggest that these receptors reside in specific membrane environments. Under physiological conditions, several different factors may contribute to a selective action of ethanol on particular subtypes of opiate receptors.

Local excision and radiotherapy for cancer of the oral tongue. A preliminary report

A group of 18 patients with squamous cell carcinoma of the mid one-third of the tongue was treated by local resection and planned postoperative radiotherapy between 1976 and 1980. Tumors 0.5 cm or greater in thickness were included; no patients had cervical adenopathy. Six were categorized as T1, 10 as T2 and two as T3. In eight patients, histologic review showed tumor extension at or near the resection margin, despite a tumor-free margin at frozen section, while in 10 patients the margins were clear. Local tumor control was achieved in 16 patients (89%). Two failures were evident within 3 months after completion of treatment. The relatively short follow-up of such a small series limits the conclusions from this preliminary study, but the excellent results thus far merit further study.

External-beam irradiation of carcinoma of the penis

Twenty-four patients with biopsy-proved squamous-cell carcinoma of the penis underwent external-beam radiation therapy between 1966 and 1980. Fifteen were treated for the primary tumor and 9 for metastatic inguinal lymphadenopathy; no patient received prophylactic nodal irradiation. Doses ranged from 4,500 rad (45 Gy)/15 fractions/3 wk. to 6,400 rad (64 Gy)/32 fractions/6 1/2 wk. Seven out of 9 tumors in stage I, 2/3 in stage II, and 1/3 in stage IV were controlled for three years. Control of fixed, inoperable groin nodes was poor, and none of these patients survived beyond 1 1/2 years.

Dose enhancement in bone in electron beam therapy

This study investigated dose to bone tissue in electron beam therapy. Measurements were made using films and thermoluminescent dosimeters in a polystyrene phantom containing bone inhomogeneity for 15-MeV, 12-MeV, and 9-MeV electron beams. An increase in dose of approximately 18%, 12%, and 11%, for the three electron energies respectively, relative to the dose in polystyrene, was found for bone material having an electron density (relative to water) of 1.73. Measurements were also made using films for 15- and 9-MeV electrons in a phantom with a mandibular bone and teeth. A dose enhancement in bone of approximately 10% and 7%, respectively, for the two energies was found in the phantom where the electron density of bone was about 1.60. These results suggest that injury to bone is possible in those clinical situations where high doses of electrons are used for therapy.

The changing role of external-beam irradiation in the management of malignant tumors of the major salivary glands

Postoperative irradiation reduces the local recurrence rate for malignant salivary gland tumors. Less extensive surgery followed by immediate radiotherapy is possible without decreasing local control; moreover, cosmetic appearance and physiological function are preserved. Local tumor control was achieved in 16 out of 17 patients without gross tumor using a dose of 6,000 rad/6 wk. Combined photon and electron beams give better cosmetic and functional results than either modality alone. Irradiation with greater than or equal to 7,000 rad should be employed in unresectable cases and may effect tumor control.

Treatment results of combined high-dose preoperative radiotherapy and surgery for oropharyngeal cancer

Fifty eight patients receiving planned high-dose preoperative radiotherapy followed by en bloc oro-mandibular-cervical resection for oropharyngeal cancer were reviewed. These patients received continued close observation and care from both the Otolaryngology and Radiotherapy services. In light of the ongoing controversy of preoperative vs. postoperative radiotherapy, we present our data demonstrating the value of preoperative radiation. An overall tumor control rate of 66% was achieved, with an adjusted survival rate of 62%. This was not only for early lesions, but also in patients having advanced (T3, T4) tumor and/or nodal disease (N1-4). These figures are somewhat higher than expected from the literature. A review and discussion of the surgical complications are also presented.

Carcinoma of the anterior tongue

We have reviewed 126 patients with squamous cell carcinoma of the anterior tongue. Our experience suggests that carcinoma of the anterior tongue is a highly aggressive disease. It is no less aggressive and dangerous than carcinoma of the posterior tongue. The clinically negative neck is a problem. Many clinical stage I and II cancers are, in fact, stage III when analyzed by the pathologist. This difficulty in clinical staging results in a significant management problem when stage III carcinomas are treated as stage I and stage II disease. Management, if it is to cure, must be aggressive. An adequate, wide surgical resection will control early carcinoma of the anterior tongue. Advanced cancers of the anterior tongue, clinical stages III and IV, should be widely excised; the cervical lymph nodes on the side of the primary lesion must be treated by surgery and radiation therapy. Treatment of the opposite side of the neck is indicated based on a high rate of metastases to contralateral lymph nodes in this series. Those patients treated with irradiation who had recurrence did so predominantly at the primary site of disease. Patients treated surgically tended to have recurrence in the regional cervical lymphatics.