Radiation Sensitizers, Fractionation Schedules, and Future Clinical Trials

Historical assumptions concerning the optimal fractionation schedules for women with breast cancer are being challenged by the early results of randomised clinical trials. Multiple small fractions of 2.0 Gy or less are optimal for squamous cell carcinomas, which are clearly less sensitive to fraction size than the surrounding dose-limiting normal tissues. Breast cancer may be different in showing comparable sensitivity to fraction size as the healthy tissues of the breast and underlying ribcage. If this is confirmed, it means that fewer, larger fractions confer the same benefit as standard 2.0 Gy schedules, provided appropriate downward corrections are made to the total dose. The approach also lends itself to tests of acceleration, shorter treatment times being of obvious interest to patients and possibly of therapeutic benefit in their own right.

Download Full-text

Clinical trials of radiation sensitizers in Head and neck cancer

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/0360-3016(81)90204-2 ◽

1981 ◽

Vol 7 (12) ◽

pp. 1739-1740 ◽

Cited By ~ 2

Author(s):

Andrew R. Harwood(C)

Keyword(s):

Clinical Trials ◽

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Radiation Sensitizers

Download Full-text

Localization of Gallium-67 in Peritoneal Cells by Electron Microscopic Autoradiography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072460 ◽

1973 ◽

Vol 31 ◽

pp. 404-405

Author(s):

D. C. Swartzendruber ◽

Norma L. Idoyaga-Vargas

Keyword(s):

Clinical Trials ◽

Soft Tissue ◽

Tumor Tissue ◽

Soft Tissue Tumors ◽

Clinical Usefulness ◽

Electron Microscopic ◽

Normal Cells ◽

Electron Microscopic Autoradiography ◽

Peritoneal Cells ◽

Gallium 67

The radionuclide gallium-67 (67Ga) localizes preferentially but not specifically in many human and experimental soft-tissue tumors. Because of this localization, 67Ga is used in clinical trials to detect humar. cancers by external scintiscanning methods. However, the fact that 67Ga does not localize specifically in tumors requires for its eventual clinical usefulness a fuller understanding of the mechanisms that control its deposition in both malignant and normal cells. We have previously reported that 67Ga localizes in lysosomal-like bodies, notably, although not exclusively, in macrophages of the spocytaneous AKR thymoma. Further studies on the uptake of 67Ga by macrophages are needed to determine whether there are factors related to malignancy that might alter the localization of 67Ga in these cells and thus provide clues to discovering the mechanism of 67Ga localization in tumor tissue.

Download Full-text