Low-dose P32 therapy in essential thrombocythemia

Area of Science:

• Hematology
• Nuclear Medicine

Background:

• Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by elevated platelet counts.
• Medically refractory ET poses a significant risk for thrombotic events, including venous thrombosis.
• Phosphorus-32 (32P) sodium phosphate is a historically used treatment for ET but carries risks of myelosuppression.

Observation:

• An 85-year-old woman with medically refractory ET and venous thrombosis was treated with phosphorus-32 sodium phosphate.
• She received two low-dose intravenous administrations: 3 mCi and later 3.5 mCi, approximately half the standard dose.
• The patient experienced no adverse hematologic complications during or after treatment.

Findings:

• Both low-dose phosphorus-32 sodium phosphate treatments were effective in reducing the patient's platelet count.
• The conservative dosing strategy successfully managed ET and prevented further thrombotic events.
• The treatment avoided significant hematologic toxicity, such as severe myelosuppression.

Implications:

• Conservative dosing of phosphorus-32 sodium phosphate may be a viable therapeutic option for select elderly patients with essential thrombocythemia.
• This approach could offer an alternative to standard doses, potentially mitigating the risk of hematologic complications.
• Further investigation into low-dose 32P therapy could refine treatment protocols for myeloproliferative neoplasms.