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Biomedical subjects

C Crowell

Publications and source records attributed to C Crowell.

5 recordsLinked to original sources

Potential improvement of three dimension treatment planning and proton therapy in the outcome of maxillary sinus cancer.

Carcinomas arising in the maxillary sinus are challenging technical problems for radiotherapists due to the complexity of the regional anatomy and the close relations of the tumor to dose-limiting critical structures (eyes, optic nerves, optic chiasm, and brain stem). This study shows that an improvement in the dose distribution can be achieved with the use of three dimensional treatment planning and a combination of x-ray and proton beam arrangements. Although tumor coverage was identical when comparing dose distributions of X rays alone to X rays plus proton beam boost, the critical structures received less dose in the X rays plus proton beam plan. Because a superior dose distribution should yield an improved local control and reduced morbidity, a benefit in survival could be expected.

Carcinoma, Squamous Cell

Fractionated proton radiation therapy of cranial and intracranial tumors.

Since 1973 fractionated proton radiation therapy has been used in the treatment of malignant disease. Protons have favorable physical characteristics that yield dose distributions superior to those of photons in certain clinical situations. As of December 31, 1987, 1,678 patients had been treated. Of these, 110 had chordomas or low-grade chondrosarcomas of the base of skull. The first 68 patients have a minimum follow-up of 17 months. The median dose was 69 Cobalt Gray Equivalent (CGE). (CGE is the dose in proton Gray multiplied by 1.1, which is the relative biological effectiveness for protons relative to 60Cobalt.) The actuarial 5-year local control rate is 82%, and the disease-free survival rate is 76%. Thirteen patients with meningiomas have been treated, following subtotal resection. The median dose was 59.4 CGE. With a median follow-up of 26 months, no patient has had tumor progression. In addition, nine patients with gliomas and 12 with craniopharyngiomas have been treated.

Adolescent