Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We present preliminary findings on the effectiveness of panretinal photocoagulation in preventing neovascular glaucoma in eyes with radiation-induced ocular ischemia. Our study group consisted of 20 patients who developed radiation-induced ocular ischemia following cobalt-60 plaque radiotherapy for a choroidal or ciliary body melanoma. Eleven of the 20 patients were treated by panretinal photocoagulation shortly after the diagnosis of ocular ischemia, but nine patients were left untreated. In this non-randomized study, the rate of development of neovascular glaucoma was significantly lower (p = 0.024) for the 11 photocoagulated patients than for the nine who were left untreated.
 ...
PMID:Panretinal photocoagulation for radiation-induced ocular ischemia. 365 14

A 59-year-old woman had a sectorial pigmented iris tumor in her right eye and was found to have secondary glaucoma unresponsive to medical therapy. Gonioscopy revealed a satellite tumor in the inferior chamber angle, which we suspected to be a ciliary body melanoma. Subsequently, both lesions were removed completely by superior total and inferior partial iridocyclectomy. Histologic examination disclosed a spindle cell nevus with surface plaque associated with a borderline epithelioid cell nevus. This case is an example of unexpected clinical findings that may be encountered in any iris melanocytic lesion, benign or malignant, and the consequent problems of diagnosis and management.
 ...
PMID:Implantation growth of an iris melanocytic lesion simulating a ciliary body melanoma. 365 18

Ophthalmic plaque radiotherapy has been demonstrated to be a useful alternative to enucleation in the treatment of small choroidal melanomas. The prognosis for tumours larger than 8 mm in height, however, continues to be poor. Treatment complications limit the radiation dose which may be delivered to these larger tumours. Hyperthermia has been shown to enhance the effectiveness of radiotherapy for many tumours, particularly malignant melanoma. The use of hyperthermia in conjunction with plaque radiotherapy may improve local tumour control for larger choroidal melanomas, allowing patients to maintain useful vision. We have developed an instrument which enables the combination of localized current field hyperthermia with radiotherapy using an episcleral plaque. The system is simple and inexpensive. We have measured temperature distributions in tissue-like phantoms, in excised bovine eyes, and in vivo in normal rabbits. In each of the cases studied, temperature varied by less than 1 degree C within 3 mm of, and across the concave surface of the plaque. At distances greater than 3 mm, the temperature gradient was approximately -0.3 degree C per millimetre.
 ...
PMID:A 500 KHz localized current field hyperthermia system for use with ophthalmic plaque radiotherapy. 368 Oct 42

To determine the prognostic value of the regression rate of choroidal melanomas after cobalt-60 plaque radiotherapy, the authors performed a multivariate analysis on 159 patients treated with a cobalt plaque during the interval from 1976 through 1980. Thirty-three of the 159 patients had died as of the survey date; 29 of metastatic melanoma and 4 of other causes. Multivariate Cox proportional hazards modeling identified a two-term regression incorporating maximal basal tumor diameter at treatment and tumor thickness at 12 months posttreatment as the best model (P less than 0.005 for both parameters) for predicting length of tumor-free survival. These results are consistent with the hypothesis that rapid regression of a choroidal melanoma after cobalt-60 plaque radiotherapy is an unfavorable prognostic sign for prolonged metastasis-free survival.
 ...
PMID:Post-irradiation regression of choroidal melanomas as a risk factor for death from metastatic disease. 368 35

We reviewed the records of 17 patients with posterior uveal malignant melanoma who had been followed for at least 3 months prior to cobalt plaque radiotherapy and whose tumor had been documented to enlarge in thickness during that interval. We evaluated the relationship between the rates of pretreatment tumor enlargement and post-treatment tumor shrinkage using linear regression analysis. We found that the rate of postirradiation tumor shrinkage correlated strongly with the rate of preirradiation tumor enlargement regardless of whether the pretreatment rate of growth was slow, intermediate or rapid. We speculate that the more rapidly regressing tumors were more mitotically active than their more slowly regressing counterparts. If true, the survival rate of patients whose posterior uveal malignant melanomas regress rapidly following radiation therapy may prove to be worse than that of patients whose tumors regress slowly.
 ...
PMID:Regression of posterior uveal malignant melanomas after cobalt plaque radiotherapy. 375 85

Monte Carlo calculations of radiation dosimetry using MORSE code are performed for 125I and 60Co point sources in a cylindrical head phantom that simulates the geometry of eye plaque therapy for choroidal melanoma. We obtain the dose variation in the eye at submillimeter intervals over distances as close as 1 mm and up to 2.5 cm from the source. The calculations for 125I are performed for the phantom media of water, protein, and a homogenized protein-water mixture simulating the composition of the eye. Relative dose functions for 125I for these phantom media are fitted to second-degree polynomials. Agreement is found with published results. The relative dose function for 60Co at eye position in the water head phantom is fitted to a third-degree polynomial and compared with that for 60Co at the center of a large water sphere. A boundary effect due to the head phantom-air interface on the dose distribution for 60Co is demonstrated. The dose falloff with distance is faster for the eye geometry compared with the bulk geometry. We also show that the relative dose distributions within the tumor are comparable for 125I and 60Co by comparing their relative dose functions. This result is consistent with the success of clinical trials of large melanoma treatments with 125I plaques.
 ...
PMID:Monte Carlo dosimetry for 125I and 60Co in eye plaque therapy. 378 96

Confirmation of iodine-125 plaque position was determined with a modified fiberoptic light pipe that directed light at right angles to the long axis of the fiberoptic pipe. While the examiner observed the interior of the eye with indirect ophthalmoscopy, the point source of light from the fiberoptic light pipe was moved along the margins of the episcleral plaque. The position of the plaque relative to the location of the underlying melanoma could then be verified by transillumination.
 ...
PMID:A technique for accurate placement of episcleral iodine-125 plaques. 379 90

Low-energy radiation sources, such as iodine-125, are suitable for treating choroidal melanoma because of their physical characteristics. Iodine-125 emits x-rays and gamma-rays between 27 and 35 keV. Gold plaques can direct radiation toward the tumor and minimize radiation to normal ocular structures. Effective treatment requires the cooperation of the ophthalmologist, radiotherapist, and radiation physicist. The preparation of the radioactive plaque and methods for its accurate surgical placement are detailed.
 ...
PMID:New techniques for iodine-125 radiotherapy of intraocular tumors. 382 64

Parameters derived from computer analysis of digital radio-frequency (rf) ultrasound scan data of untreated uveal malignant melanomas were examined for correlations with tumor regression following cobalt-60 plaque. Parameters included tumor height, normalized power spectrum and acoustic tissue type (ATT). Acoustic tissue type was based upon discriminant analysis of tumor power spectra, with spectra of tumors of known pathology serving as a model. Results showed ATT to be correlated with tumor regression during the first 18 months following treatment. Tumors with ATT associated with spindle cell malignant melanoma showed over twice the percentage reduction in height as those with ATT associated with mixed/epithelioid melanomas. Pre-treatment height was only weakly correlated with regression. Additionally, significant spectral changes were observed following treatment. Ultrasonic spectrum analysis thus provides a noninvasive tool for classification, prediction and monitoring of tumor response to cobalt-60 plaque.
 ...
PMID:Regression of uveal malignant melanomas following cobalt-60 plaque. Correlates between acoustic spectrum analysis and tumor regression. 390 Nov 66

Over the past 15 years 140 patients with choroidal melanoma have been treated by local surgical resection of the tumour. The method appears worth considering for tumours up to 15 mm in diameter not involving more than one-third of the ciliary body. Sixty percent of patients retained useful vision and 25% good vision. Eighty-two percent retained a cosmetically satisfactory eye. The total tumour-related mortality in this group of patients was 9%, almost all of the 12 patients dying having had tumours larger than would now be recommended for local resection. The five-year survival rate among patients undergoing local resection was 84%. Low-energy long-exposure laser has been used to treat a small number of choroidal tumours. The technique appears useful for tumours up to 10 mm in diameter and not more than 3 mm in thickness. Ruthenium plaque therapy has also been used in some cases and appears a suitable method of treatment for tumours up to 10 mm in diameter and not more than 6 mm in thickness. The options for conservative management of choroidal tumours are greater with small tumours than with large ones except in only eyes, tumours of over 15 mm in diameter are best treated with enucleation. The long-term survival after all forms of conservative management has not yet been established. At present the use of controversial techniques such as local resection should be restricted to a few centres so that adequate statistical evaluation of the method may be made.
 ...
PMID:Alternatives to enucleation in the management of choroidal melanoma. 396 76


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>