Relationships between tumor size and curablity for uniformly targeted therapy with beta-emitting radionuclides

Journal Article · Sun Oct 01 00:00:00 EDT 1995 · Journal of Nuclear Medicine

OSTI ID:478321

O`Donoghue, J A; Bardies, M; Wheldon, T E ^[1]

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1. Univ. of Glasgow (United Kingdom)

Targeted radionuclide therapy is a new form of radiotherapy that differs in some important respects from external beam irradiation. One of the most important differences is due to the finite range of ionizing beta particles emitted as a result of radionuclide disintegration. The effects of particle range have important implications for the curability of tumors. We used a mathematical model to examine tumor curability and its relationship to tumor size for 22 beta-emitting radionuclides that may have therapeutic potential. The model assumed a uniform distribution of radionuclide throughout. For targeted radionuclide therapy, the relationship between tumor curability and tumor size is different from that for conventional external beam radiotherapy. With targeted radionuclides, there is an optimal tumor size for cure. Tumors smaller than the optimal size are less vulnerable to irradiation from radionuclides because a substantial proportion of the disintegration energy escapes and is deposited outside the tumor volume. We found an optimal tumor size for radiocurability by each of the 22 radionuclides considered. Optimal cure diameters range from less than 1 mm for short-range emitters such as {sup 199}Au and {sup 33}P to several centimeters for long-range emitters such as {sup 90}Y and {sup 188}Re. The energy emitted per disintegration may be used to predict optimal cure size for uniform distributions of radionuclide. 17 refs., 8 figs., 3 tabs.

• OSTI ID: 478321
• Journal Information: Journal of Nuclear Medicine, Vol. 36, Issue 10; Other Information: PBD: Oct 1995
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
NEOPLASMS
SIZE
RADIOTHERAPY
EVALUATION
OPTIMIZATION
BETA DECAY RADIOISOTOPES
RADIONUCLIDE KINETICS
RADIATION DOSES
MATHEMATICAL MODELS
DOSE RATES
TUMOR CELLS
RADIOSENSITIVITY
CELL PROLIFERATION
BETA PARTICLES
FRACTIONATED IRRADIATION
DOSIMETRY