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Title: Californium-252 radiotherapy sources for interstitial afterloading

Conference ·
OSTI ID:7354078

Californium-252 neutron sources for interstitial afterloading were developed to investigate the value of this radionuclide in cancer therapy. Californium-252 seed assemblies contain essentially point sources of /sup 252/Cf permanently sealed on 1-cm centers within a flexible plastic tube. The seed assemblies are fabricated with remotely operated, specially designed machines. The fabrication process involves the production of a Pt-10 percent Ir-clad wire with a /sup 252/Cf/sub 2/O/sub 3/-Pd cermet core. The wire is swaged and drawn to size, cut to length, and welded in a Pt-10 percent Ir capsule 0.8 mm in diameter and 6 mm long. Each seed capsule contains approximately 0.5 microgram of /sup 252/Cf. Because the effective half-life of /sup 252/Cf is 2.6 years, the seed assemblies are not disposable and must be reused until their activities have decreased to unsuitable levels. The flexible plastic components must therefore have sufficient resistance to radiation damage to survive the neutron-plus-gamma radiation from /sup 252/Cf. On the basis of accelerated irradiation tests with a large /sup 252/Cf source, a recently developed fluoropolymer, ''Tefzel'' (trademark of E. I. du Pont de Nemours and Company) has adequate radiation resistance for this application. Californium-252 seed assembly systems are loaned by the United States Energy Research and Development Administration for clinical investigations under a protocol of the Radiation Therapy Oncology Group, U.S. National Cancer Institute.

Research Organization:
Du Pont de Nemours (E.I.) and Co., Aiken, S.C. (USA). Savannah River Lab.
DOE Contract Number:
AT(07-2)-1
OSTI ID:
7354078
Report Number(s):
DP-MS-75-106; CONF-760436-3; TRN: 76-014278
Resource Relation:
Conference: International symposium on californium-252 utilization, Paris, France, 26 Apr 1976
Country of Publication:
United States
Language:
English