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Biomedical subjects

H W Chin

Publications and source records attributed to H W Chin.

At least 19 recordsLinked to original sources
PubMed2001

Palliative radiotherapy for synchronous bilateral lung cancers.

Scant information is available about the outcomes of patients with synchronous bilateral lung cancers (SBLC) treated with radiation. We report on 32 patients with SBLC who were treated for palliation by external beam irradiation during a 19-year period. The overall median survival was 7 months; 20 individuals (63%) survived at least 6 months. Among the evaluable patients, the complete/partial subjective and objective response rates were 100% and 60%, respectively. Survival was not significantly influenced by the total dose applied. Radiotherapy is effective for palliation of symptoms associated with SBLC. However, the dismal prognosis of SBLC managed by nonradical radiotherapy alone warrants investigation of treatment using curative doses of radiotherapy or chemotherapy with radiotherapy.

Adult↗
PubMed1996

The hepatoprotective effects of Taiwan folk medicine ham-hong-chho in rats.

Bidens pilosa L. var minor (Blume) Sherff, B. pilosa L. and B. chilensis DC (compositae), commonly known as "Ham-hong-chho" in Taiwan, have been traditionally used for medicinal purposes. To clarify and compare the hepatoprotective effects of these three plants, we evaluated their potential effectiveness on CCl4- and acetaminophen-induced acute hepatic lesions in rats. The results indicated that the increase in SGOT and SGPT activities caused by CCl4 (3.0 ml/kg, s.c.) and acetaminophen administration (600 mg/kg, i.p.) could be significantly reduced by treating with the extracts of all the three kinds of "Ham-hong-chho" and the extract of B. chilensis exhibited the greatest hepatoprotective effects. These phenomena were also confirmed by histological observation. Liver damage induced by CCl4 and acetaminophen was markedly improved in the extract of B. chilensis treated groups, while groups treated with the extracts of B. pilosa var minor and B. pilosa demonstrated only moderate protective effects. The pharmacological and pathological effects of these three crude groups were compared with Bupleurum chinense, which has been reported previously as a treatment criteria in the CCl4 model, and with silymarin as a standard reference medicine in the acetaminophen model. The results suggest that B. pilosa var minor, B. pilosa and B. chilensis can protect liver injuries from various hepatotoxins and have potential as broad spectrum antihepatic agents.

Animals↗
PubMed1995

Screening bone scintigraphy in the staging of locally advanced head and neck cancer.

A retrospective determination of the yield from screening bone scintigraphy in detecting bone metastasis when used for disease staging of 93 asymptomatic patients with locally extensive head and neck cancer was undertaken. The bone scintigraphy findings were correlated with observations from other radioimaging studies done within 1 month of head and neck cancer diagnosis. Bone scintigraphy did not reveal a single case of bone metastasis outside the head and neck region. On the other hand, 3 cases (8%) of resectable and 2 cases (5%) of non-resectable bone metastasis located within the head and neck area were observed among the 40 patients with abnormal bone scintigraphy. Old rib fracture or degenerative disease was responsible for the increased radionuclide uptake in bony areas below the clavicle in less than half of the remaining 35 cases. We conclude that the routine use of bone scintigraphy for disease staging in asymptomatic patients with locally advanced head and neck cancer is not warranted because the positive yield is low.

Adult↗
PubMed1994

Spinal epidural compression in head and neck cancer. Report of five cases.

Patients with newly diagnosed head and neck cancer (HNC) during a 13-year period were retrospectively studied for the development of spinal epidural compression (SEC). Of the 759 patients studied, 5 developed epidural compression (1%), 4 of whom were relatively young. SEC occurred simultaneously with HNC in 2 patients and long after the diagnosis of HNC in 3 individuals. There was no observed tendency to involve a particular segment of the spine. Local control of HNC following definitive treatment along with regained ability to walk after palliative radiotherapy in a patient was associated with long-term survival. Recommendations are made for aggressive treatment of SEC to achieve a satisfactory outcome.

Adult↗
PubMed1993

Wrist fractures.

The various types of wrist fractures are described. Keeping in mind the anatomy and biomechanics of the wrist assists in the detection of these injuries. The clinical and radiographic findings are discussed and the various associated injuries that may go undiscovered without maintaining a high index of suspicion.

Carpal Bones↗
PubMed1993

Ligamentous wrist injuries.

The wrist is one of the most complex joints of the body. Wrist injuries are quite common, yet improper diagnosis of ligamentous injuries as simply 'sprains' often occurs. Understanding the functional anatomy and mechanics of the wrist is extremely important in appreciating the spectrum of injuries that occur there. A review of the analysis and detection of potential injuries is provided.

Humans↗
PubMed1993

Primary non-Hodgkin's lymphoma of the central nervous system.

In the past few years, non-Hodgkin's lymphoma of the central nervous system has been the object of increasing attention because of the recent rise in its incidence. Part of this increase can clearly be attributed to the AIDS epidemic. This tumor responds unsatisfactorily to the traditional treatments. Various studies to determine the most effective treatment modality have yielded inconclusive results. A concise review of non-Hodgkin's lymphoma of the central nervous system is presented along with a case study of cerebellar non-Hodgkin's lymphoma.

Aged↗
PubMed1992

Treatment options in high-grade brain tumors: brain brachytherapy.

The extremely poor prognosis of high-grade brain tumors (glioblastoma multiforme and anaplastic astrocytomas) has been well documented in the literature. Almost 90% of patients die within 18 months after therapy, most commonly because of local persistence of the tumor, which may be controlled if a sufficient amount of irradiation can be delivered. Currently, postoperative radiation therapy offers the best median survival rate. However, the response to external-beam radiation therapy has reached a plateau because of the intolerance of healthy brain tissue to excessive irradiation. To treat these tumors, brachytherapy (interstitial implantation of radioactive sources) can be used with debulking surgery. This therapy is becoming an effective alternative to conventional external-beam radiation therapy, since it allows a higher dose to be delivered to the tumor bed without damaging the surrounding healthy brain tissue. With continual refinements of the technique, brachytherapy, performed by a skilled brachytherapy team, offers an opportunity to improve patient survival.

Astrocytoma↗
PubMed1992

Positron emission tomography and its role in the evaluation of brain tumors.

Positron emission tomography (PET) is a newly evolving, biological method for quantitative imaging of regional function and metabolism within various organs of the living human body. Whereas existing conventional tomographic imaging modalities--CT and MRI--provide only anatomical information, positron emission tomography provides quantifiable information about organ metabolism and function. Brain tumors are the disease entities for which positron emission tomography is most widely applied. PET has the great potential for providing clinically important information about disease processes. PET has not only had a major impact on the diagnostic role of radiology in brain tumors, but also has potential role for therapeutic application to brain brachytherapy.

Brain Neoplasms↗
PubMed1991

Standardization of dosimetry chart checks.

This paper reports on a standardized report form that can be used to analyze dose error rates from radiation therapy. An error classification scheme of Types 1 to 5 was developed to indicate increasing severity of errors. Type 1 (charting errors) and Type 3 (daily dose errors) were the most prominent types. Dosimetry errors were reduced by using the results of the reports to correct operating procedures. Type 1 error rates decreased from 17% initially to an average of 3.9%. An average error rate of 1.7% for Type 3 dose errors was found to be consistent with normal operation. Use of the report form is useful in documenting and correcting errors and as a reporting record for use in a quality assurance program.

Forms and Records Control↗
PubMed1991

Technical application of stereotactic irradiation in malignant brain tumors.

This study reports the technical application of stereotactic interstitial brachytherapy for malignant gliomas in two groups of patients. Group I consisted of 2 patients who had undergone previous debulking brain surgery; group II were 3 patients who were not candidates for craniotomy because their tumors were surgically inaccessible. The stereotactic implantation technique in group I was somewhat complicated due to the irregular shape of the residual tumor masses. Sophisticated pre-implantation planning was necessary for adequate coverage of the entire tumor volume. In this series, inoperable tumors were also successfully implanted with excellent results.

Brachytherapy↗
PubMed1991

Endobronchial adenoid cystic carcinoma.

A case of endobronchial adenoid cystic carcinoma of the lung is presented. This is probably the first report of endobronchial brachytherapy being applied for recurrent adenoid cystic carcinoma of the lung with a good response. We found that endobronchial implantation therapy is very useful in the control of endobronchial adenoid cystic carcinoma. In addition, a clinical history and options for treatment are briefly discussed.

Aged↗
PubMed1991

Modern therapeutic approach for high grade astrocytoma: intracranial Ir-192 brachytherapy.

Prognosis of high-grade astrocytoma has been extremely disappointing and the median survival of patients with this tumor is less than 10 months at best. The most common cause of failure is local persistence of the tumor. Many neuro-oncologists have now turned to an alternative therapeutic approach involving brain brachytherapy (interstitial implantation) for the treatment of high-grade astrocytomas because in this manner a higher dose can be delivered to the tumor bed without excessively irradiating the surrounding normal brain tissue. Brachytherapy has shown some evidence of superior results in survival of malignant astrocytomas if properly performed by a qualified brachytherapy team. The objective of this report is to discuss the rationale and technique of brachytherapy in the management of high-grade astrocytoma as well as future prospects concerning this particular treatment modality.

Brachytherapy↗
PubMed1991

Application of positron emission tomography to neurological oncology.

PET has a promising role in neuroradiology for accurate diagnosis and prognostication of malignant tumors as well as differential diagnosis of radiation necrosis and recurrent tumors. Particularly, PET has proven its ability to accurately differentiate radiation necrosis from recurrent brain tumor. Active tumors have accelerated glycolysis, and a remarkable accumulation of FDG radiotracer in high grade brain tumors is evident on PET images. Tumor metabolism also proportionally increases with increasing pathologic grades of brain tumor, and accelerated tumor metabolism indicates a poor prognosis for the tumor.

Adult↗
PubMed1990

Accelerated fractionation radiotherapy for hospitalized glioblastoma multiforme patients with poor prognostic factors.

The standard 6 week course of post-operative radiotherapy for glioblastoma multiforme (astrocytoma grade IV) is lengthy, considering the poor prognosis. The standard schedule is especially unsuitable for hospitalized patients and for those with poor prognostic factors (such as old age and poor performance status) since their survival is particularly short. In order to improve the survival-treatment time ratio, we entered a total of 14 hospitalized patients with glioblastoma multiforme (GBM) and poor prognostic factors (mean age 62, mean KPS 57%) into a Phase I trial of accelerated fractionation (AF) external beam radiotherapy. A total tumor dose of 5400-5500 cGy was given in 3 weeks: 4300-4500 cGy whole brain using 100 cGy tid fractions on weekdays plus a 900-1200 cGy boost using single daily fractions of 150-200 cGy on weekends. Only one patient entered did not complete therapy, due to the development of pulmonary embolism resulting in death. Mean survival for all 14 patients from the time of surgical diagnosis was 30.4 weeks. The schedule was well tolerated and resulted in a substantial decrease in treatment time compared to conventional fractionation in these patients. AF schedules should continue to be explored since they may be more appropriate than conventional fractionation schedules for GBM patients with poor prognostic factors, particularly when hospitalized.

Aged↗
PubMed1990

Primary lymphoma of bone.

Primary lymphoma of bone is a rare clinical entity that accounts for less than one per cent of all non-Hodgkin's lymphomas. Although they occasionally present as a solitary lesion in bone, lymphoma involving bone is a manifestation of disseminated disease in many instances. All patients initially found to have a solitary lymphoma of bone need to be thoroughly investigated for systemic disease because more than half of the patients presenting with initially solitary bone lesions are found to have systemic disease involving lymph nodes and/or other organs. Choice of therapeutic management is based on the stage of disease. Stage I-E primary lymphoma of bone can be controlled in 70-90% of cases using local radiation therapy alone if adequate radiation doses are used. Patients with advanced disease should be treated with combination chemotherapy in addition to local radiotherapy. Loeffler et al reported long-term survival results of 90% 8-year actuarial overall survival rate for children with primary lymphoma of bone who received combined therapy with radiation and chemotherapy (adriamycin, prednisone and oncovin). The actuarial lymphoma-free survival rate was 100% at eight years. Regardless of stage of the disease, radiation treatment to the primary tumor appears to be critical for adequate local control of disease as well as rapid symptomatic relief.

Adult↗
PubMed1986

A clinical study with brain brachytherapy for malignant gliomas.

A clinical trial with neutron brachytherapy for malignant glioma is now in progress at the University of Kentucky Medical Center. In the initial three year period, 32 patients entered the study. There were 24 males and eight females, and the peak incidence was seen in the seventh decade. All patients underwent surgical resection of tumor followed by Cf-252 implantation and external radiotherapy. The implantation procedure was well tolerated by the patients and demonstrated a short-term benefit in survival of patients who were able to complete planned radiotherapy. Older patients had less tolerance to radiotherapy. The evaluation of the beneficial effects of Cf-252 brachytherapy will require patients who are able to tolerate the whole course of therapy.

Adult↗