Typical Administered Doses for 32P Compounds

32P Na phosphate for treatment of polycythemia vera

1. IV injection of 3-4 mCi for initial treatment, which adequately treats 50% of patients.

2. Of 50% requiring 2nd injection, 35% are successfully treated. Remainder are refractory to treatment and may require 3rd or 4th dose.

3. Median survival time for untreated patients after time of diagnosis is 1.5 yr. After treatment with 32P Na phosphate, interval is increased to 12 yr.

4. 11% incidence of leukemia in successfully treated patients.

Controversy

Is 11% incidence of leukemia a result of injection of 32P Na phosphate or is P. Vera a preleukemogenic condition whose natural course is development of leukemia?

The increased risk of leukemia is probably partially attributable to both causes.

Radiation dosimetry following IV injection of 4 mCi of 32P Na phosphate.

organ absorbed dose (rads)
skeleton  240
liver  24
spleen 29
gonads  4
whole body  40

32P chromic phosphate colloid for palliation of malignant effusions

1. Intracavitary injection: 10 mCi in 250 ml saline

2. >90% of patients respond => significantly decreased frequency of "tapping" required to remove fluid.

3. Rarely need to retreat patient.

4. Palliative, not curative.

5. Approved drug, <$1000 per treatment