Phosphorus-32-colloidal chromic phosphate: treatment of choice for malignant pericardial effusion. A 68-yr-old male with agnogenic myeloid metaplasia was given phosphorus-32-colloidal chromic phosphate intrapericardially for the treatment of malignant pericardial effusion. Technetium-99m-sulfur colloid was used to verify catheter placement and to visualize distribution within the pericardium. Estimated dosimetry for this mode of therapy is presented, and it is suggested that pericardial administration of phosphorus-32-colloidal chromic phosphate is the treatment of choice for malignant pericardial effusion. 