The relation between absorbed dose by quantitative SPECT at radioisotope therapy and clinical course in the patients with thyroid carcinoma and malignant pheochromocytoma
- Tokyo Women`s Medical College, Tokyo (Japan); and others
Treatment with {sup 131}I is widely used in endocrinology for metastatic tumors from thyroid cancer and malignant pheochromocytoma, but the accurate measurement of absorbed dose of Na {sup 131}I or {sup 131}I MIBG to tumors is difficult. The purpose of this study is to present the results of dosimetry of tumors by SPECT and outcome of treated patients who were followed over 4 years. The study population included five men and 18 women, with ages ranging from 19 to 71 years. Patients were selected only in the cases with functioning metastasis of thyroid cancer of pheochromocytoma and treated with Na {sup 131}I or {sup 131}I MIBG between April 1982 and June 1989. Uptake of 45 lesions was estimated serially using a SPECT system following administration of treatment dose. The {sup 131}I standard source used in the phantom was also analyzed daily and absorbed dose was calculated based on MIRD equation. Outcome of 9 patients with metastasis from thyroid cancer and 1 patient with malignant pheochromocytoma were evaluated as good and their total absorbed dose was over 94Gy with 1.2-4.0 days of effective half life. The mean absorbed dose per 3.7GBq of administered radioisotope was about six times higher in the patients with metastatic carcinoma who responded to therapy than in those who did not. The present study demonstrated that calculation of absorbed dose with SPECT at therapy is great dosimetric value in the assessment of radioisotope therapy.
- OSTI ID:
- 197896
- Report Number(s):
- CONF-940605-; ISSN 0161-5505; TRN: 95:007029-0019
- Journal Information:
- Journal of Nuclear Medicine, Vol. 35, Issue Suppl.5; Conference: 41. annual meeting of the Society of Nuclear Medicine, Orlando, FL (United States), 5-8 Jun 1994; Other Information: PBD: May 1994
- Country of Publication:
- United States
- Language:
- English
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