Treatment Of Choroidal Melanoma Research Articles

Orbital extension of Choroidal and ciliary body melanomas.

In a review of 432 choroidal and ciliary body melanomas, histopathologic evidence of orbital extension was found in 45 cases (10.4 percent). The occurrence of orbital extension was influenced mainly by the cell type (P less than .05) and by the size of the choroidal mass (P less than .001). Local orbital recurrence occurred in 23 percent of cases with evidence of extrascleral extension. Survival rates were independent of cell type, pigmentation, and size and shape of the extension. Patients treated by exenteration had significantly better prognosis than nontreated patients or patients treated by chemotherapy, radiotherapy, or local excision (P equals .0002). Early exentration is the best treatment for choroidal melanomas with orbital extension.

Clinical experience and expectation with protons and heavy ions

The experience in fractionated radiation therapy using proton beams from the 160 MV Harvard cyclotron on 23 patients is described. Advantages for the proton beam are expected to lie entirely with the dose distribution patterns which are qualitatively different from those obtainable with photon beam techniques. Treatment is discussed in terms of complexity of compensation for tissue heterogeneity and patients are placed into three categories. I: no heterodense structure within the beam path; II: one or two large and heterodense structures of simple configuration; III: multiple and/or complex density heterogeneities within the beam path. Treatment results seem almost certain to he improved for selected sites which would be in Treatment Category I. We are confident that improved results can be obtained for certain of the Category II problems. Additional work must be completed before much in the way of a sensible prediction can be made for patients whose treatment problems would he in Category III. The largest experience to date is the treatment of choroidal melanoma. Because of the high precision of dose delivery and uniformity of dose distribution achieved we are confident that after an appropriate dose level has been selected that good results will he obtained on a regular basis for this group of tumors. General problems of particle therapy are discussed and details of treatment of several illustrative cases are presented.