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H W Chin

Publications and source records attributed to H W Chin.

At least 37 records · Page 2Linked to original sources

Age at treatment and long-term performance results in medulloblastoma.

Medulloblastoma is highly radioresponsive, and recent treatment results have improved greatly since the introduction of megavoltage machine in 1960s. There is increasing evidence for the potential cure of medulloblastoma if properly treated in its early stages. The curable group represents approximately 75% of diagnosed patients. Long-term treatment effects were examined in this study. The study reveals age-dependent late effects in learning ability; the patients less than 4-years-old at treatment had major learning problems; patients of 5 to 7 years old performed at satisfactory-to-low passing levels in school work; patients older than 8 years old had no major intellectual impairment. Short stature was common when growth potential was present at the time of therapy, but endocrine tests were generally negative. These observations indicate special educational requirement needs, especially for children treated at a young age.

Adolescent↗

Cerebellar glioblastoma in childhood.

Cerebellar glioblastoma multiforme in childhood is extremely rare. Only ten such cases have been reported to date. Although treatment results are reported to be extremely poor, complete tumor clearance was achieved in a patient treated with superfractionated radiotherapy. She received high dose postoperative radiotherapy using a three times per day technique and is disease-free for more than three years posttherapy. This suggests that improved tumor response can be obtained by high dose postoperative radiotherapy using a modified fractionation technique.

Adolescent↗

Intracerebral neutron brachytherapy for hemispheric glioblastoma multiforme. A pilot study.

The University of Kentucky Brain Tumor Study and Research Group has developed a new treatment protocol of interstitial brain brachytherapy using Californium-252 neutron source implantation in 1980. Only patients with malignant gliomas were eligible for this pilot study. Nine patients entered the Phase I trial of the protocol study between November 1980 and October 1981. According to the design of the protocol, all patients who had a verified histologic diagnosis of glioblastoma multiforme underwent postoperative intracerebral Cf-252 neutron source implantation, followed by 6 000 cGy of external photon beam irradiation. The purpose of this pilot study was to test the feasibility of interstitial Cf-252 neutron source implantation and only one implant afterloading applicator was used for brachytherapy. The implant applicator was placed in the center of tumor and the procedure was performed under CT guidance. In the assessment of the procedure, Karnofsky functional performance status, intellectual status, neurological examination, CT scans, and complications were used. All patients tolerated the procedure well and no serious complications were encountered. Despite the quality of these early treatments, there was some evidence of short-term benefit in duration of survival of the patients. We believe that further technical improvement to achieve an adequate isodose distribution to cover the tumor volume might result in longer duration improvement in survival.

Aged↗

CT and MR for brain tumor implant therapy using CF-252 neutrons.

Magnetic resonance (MR) imaging of the brain allows very effective localization of tumor in brain, visualization of brain reaction to tumor, peritumoral edema, as well as destruction of normal anatomy and spread of tumor. MR readily imaged the brain in multiple views allowing three dimensional (3D) evaluation and more precise localization of tumor in the depths of the brain. It also assessed the extent of tumor infiltration away from the primary site. In an ongoing study of Cf-252 neutron brachytherapy of hemispheric malignant gliomas of the brain, we have found that the extent of tumor and the planning of the placement of multiple applicators in the brain for implant therapy was facilitated by both CT and MR scanning, but MR allowed better 3D localization, assessment of response and follow-up of tumor response. MR gave additional and different types of information about the tumor than CT scanning based upon proton distribution which greatly aided planning of tumor implant therapy and understanding of patterns of tumor response and recurrence after therapy.

Adult↗

Implantation of brain tumors with Cf-252. Use of computed tomography and magnetic resonance imaging to guide insertion and evaluate response.

Magnetic resonance imaging (MR) was evaluated as a guide to planning and follow-up of Cf-252 neutron brachytherapy in 8 patients with malignant glioma of the cerebral hemispheres. A combination of sagittal, transverse, and coronal views allowed three-dimensional assessment of the dimensions and extent of tumor; by comparison, CT scans delineated the tumor less sharply, multiple views were not routinely obtained, and the reconstructed sagittal images were inadequate. Both techniques were complementary in enabling accurate tumor localization as well as separating enhanced zones from central avascular regions and tumor from edema. However, MR images provided more detail than serial CT scans, making MR the preferred method of follow-up.

Brachytherapy↗

Intracranial ependymomas and ependymoblastomas.

Nineteen cases of intracranial ependymal tumors were reviewed to examine the prognostic factors influencing survival of the patients with this disease. The two most important predictive factors in relation to survival status were a histologic grade of tumors and a presence of hydrocephalus. The clinicopathological correlation in this study has supported the view of two distinct ependymal tumors; more curable ependymomas and highly malignant ependymoblastomas .

Adolescent↗

Early response and long-term results in the radiotherapy of childhood medulloblastoma.

Outcome results of 23 patients with childhood medulloblastomas were analyzed in relation to radiation technique and survival. No failures were noted when radiation dose of 5 400 rad was used; whereas none survived in the sub-group treated with less than 4 000 rad. The prognosis in the very young age group, less than three years old, was worse compared to the older child with a tendency to advanced disease at presentation. Quality of life in all survivors was satisfactory and long-term sequelae were surprisingly minimal in all aspects of physical, mental, and intellectual developments. Vertebral growth disturbance and short stature were the major late sequellae of successful radiotherapy.

Cerebellar Neoplasms↗

The role of radiation treatment in craniopharyngioma.

The long natural course of craniopharyngioma and short-term follow-up period in many reports make comparison of various treatment results difficult. Some patients may enjoy virtually symptom-free lives despite known recurrence. Some patients with recurrence may have a good response to retreatment. Such unpredictable behavior and treatment responses have led to considerable disparity in clinical reports concerning the best treatment method. Treatments using surgery alone and/or low dose postoperative radiation treatment could prolong survival time, but may not prevent recurrence leading to ultimate failure. High dose postoperative radiotherapy following radical surgery should be an ideal approach in dealing with this tumor.

Adolescent↗

Adult intraventricular craniopharyngioma.

A case of craniopharyngioma with unusual location confined within the third ventricle is reported. The 56 years old adult presented with symptoms and signs of increased intracranial pressure. There were no characteristic findings of craniopharyngioma in X-ray examinations, but computed tomography scan showed a mass lesion in the third ventricle. Literature survey revealed nine cases of craniopharyngioma developed solely within the third ventricle.

Cerebral Ventricle Neoplasms↗

Intracranial ependymoma: results of radiotherapy at the University of Kentucky.

Sixteen patients with intracranial ependymoma received radiation treatment at the Department of Radiation Medicine, University of Kentucky, between 1962 and 1974. The majority of intracranial tumors occurred in children and had an infratentorial location; most adult tumors were supratentorial and adults had a greater tendency for high-grade malignant tumors. The overall five-year survival rate was 37% with 50% failure within three years. Survival appeared to be closely related to grade of tumor. Therefore, tumors were classified as ependymoma (well-differentiated) or ependymoblastoma (anaplastic, poorly differentiated). Five-year survival rate in patients with ependymoma tumors was 71% and with ependymoblastoma 11%. The data and a literature review indicate that radical radiotherapy of the ependymoma produces good patient survival; the ependymoblastoma is not adequately controlled with radical radiotherapy alone an adjuvant therapy may be necessary.

Adolescent↗

Prognostic factors in medulloblastoma.

Clinical data on 30 patients with cerebellar medulloblastoma treated at this institution were analyzed. This review presents data on the clinical features, natural history of disease, and prognostic factors, as well as survival. Patients were treated uniformly using similar methods and tumor doses. The two important factors were use of optimum techniques and dosage of radiotherapy, and extent of the disease. The development of hydrocephalus had significant bearing on the prognosis, and there was a correlation between survival and clinical evidence of hydrocephalus.

Adolescent↗

Interstitial 252Cf neutron therapy for glioblastoma multiforme.

252Cf brachytherapy has been combined with whole brain photon beam therapy to 6000 rads in 5-7 weeks. In early phase I studies, all patients selected for study tolerated the procedure and the subsequent photon beam therapy. All showed improvement in performance status and decreased tumor size by CT scan evaluation, but it became clear that these tumors are of large size and bulk, produce marked adjacent brain edema, and require individualized implant therapy as well as high-dose external beam irradiation if response is to occur.

Brachytherapy↗

Work in progress: 252Cf neutron brachytherapy for hemispheric malignant glioma.

It has been shown that 252Cf neutron brachytherapy of hemispheric malignant glioma can be readily carried out and may be combined with external, whole brain photon beam therapy of 6,000 rad (60 Gy) administered over a five-week to seven-week period. The ten patients who were studied tolerated both procedures well. There was improvement in performance status, and a decrease in tumor size was observed upon computed tomographic scanning.

Aged↗