In three patients, comparison was possible of the tumor resolution produced by the barotherapy technique with the resolution produced when similar dosage was given in air to a regional metastasis later appearing. Definite local recurrence of tumor within the treated volume was confirmed in only a few cases. The use of antibiotics, conticosteroids, and triiodothyronine did not infiuence progression.
Delayed necroses appeared commonly five months after completing treatment in those cases treated with high doses who developed the most intense mucous membrane reactions even though healing was almost complete 2 to 3 months after treatment. Tumor resolution with the various dosage schemes employed was very satisfactory and often dramatic.
#Disadvantages of using cobalt 60 skin#
Skin reactions, on the other hand, seemed to parallel the dosage received on the skin and not to be aggravated by oxygenation effects. Animal lab studies lended suppont to this conclusion. Experience with similar large doses delivered in air, compared with those used with barotherapy, suggests that dose for dose the mucosal reactions were more intense with barotherapy. The higher doses in oxygen showed mucosal reactions similar to those seen nt the site of a radon implant producing 6000 to 7000-rad tumor doses in 5 to 7 days but of course involved much larger volumes of tissue. The reduced dosage was well tolerated, being no worse than that expected when conventional techniques were used to deliver 6000 to 6500-rad tumor doses in 5 to 6 weeks with 4-Mev x rays. Reduction of the dose to 3 x 1000-rad maximum tumor dose did not significantly alter the sequelae and more recently a maximum tumor dose of 3 x 800 rad was used. Immediate tumor resolution was good but severe radiation reactions required reduction of the dosagn first used. Cases treated during the more » first 10 months are reported in relation to their status from 2 months after treatment. Each patient received general anesthesia, bilateral myringotomy, and pressurization of oxygen to 45 lb/in./sup 2/ gauge pressure in a pressure vessel. Results are reported for 110 cases of locally advanced malignant tumors in various sites that have received treatment combining oxygen barotherapy with 4-Mev x-ray therapy, delivering three large fractions of x-ray dosage in a total time of 21 days. = ,Īttempts were made to develop a radiotherapy technique to increase the sensitivity of various types of tumors by exposing the patient to oxygen at high pressure in a specially constructed chamber while undergoing high-voltage x-ray treatment. Favorable results are described in patients with urinary bladder tumors administered l50- to 200-rad daily doses, for a total of 6000 to 8000 rads over 6 to 8 weeks. Various technical problems of Co/sup 60/ therapy are discussed, including precise localization of the tumor, calculation of dosage, use of filters to evenly distribute radiation and prevent hot spots, immobilization and positioning of the patient, and direct dosimetry for affirmation of calculated dosage. Some tumors at limited skin depth, such as in the larynx, are not amenable to Co/sup 60/ therapy because of the high exit dose. As a disadvantage, possibility of injury to adjacent organs is greater with Co/ sup 60/ therapy, since skin reactions, indicative of overdosage with x-ray therapy, may be absent. The advantages of Co/sup 60/ therapy over conventional x-ray therapy, stemming from the fact that in the lst instance energy absorption within the tissues is by the Compton effect and in the 2nd case by the photoelectric effect, are: (1) increased skin tolerance, (2) reduced bone absorption, (3) increase in depth dose, (4) diminished radiation sickness, and (5) simplicity of operation.
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