● Cancer and Bone Pain
● Therapeutic Approaches to Palliation of Bone Pain
● Radionuclide Therapy: Palliative, not Curative
● Internal Radiation Dosimetry

Radiopharmaceuticals approved by the Food and Drug Administration

⁸⁹Sr strontium chloride
¹⁵³Sm-EDTMP
³²P-Na phosphate

Typical Injected Dose:

4 mCi of ⁸⁹Sr strontium chloride
1 mCi/kg of ¹⁵³Sm-EDTMP (maximum 100 mCi)
4 mCi/kg of ³²P-Na phosphate

 

Physical Characteristics of 89Sr and 153Sm and 32P

General information

● Sr-89 is a bone localizing calcium analog with distribution very similar to 99mTc-MDP
● Sm-153 EDTMP is a bone localizing phosphate analog with a distribution very similar to that of 99mTc-MDP
● Ratio of metastatic lesions to normal bone = 5:1
● Ratio of metastatic lesions to marrow = 10:1
● Retention of 89Sr and 153Sm in metastases is significantly longer than in bone
● No reported adverse reactions
● 30-50% of patients have measurable decrease in WBC and platelets
● Recovery begins at about 6 weeks
● Flare phenomenon (increased pain for a few days early in the course of treatment) is often prognostic indicator of successful treatment
● 80% Response rate overall for both drugs
● Sm has a gamma ray usable for imaging
● Sm has a more rapid onset of relief than Sr-89, but a shorter mean duration of effect than Sr-89
● Up to 80% patients experience relief- onset of effect at 10 to 20 days for Sm-153 and 15-25 days for Sr-89
● 20% of prostate Ca patients become pain free
● Average duration of effect is up to 6 mo
● Range of relief was between 4 and 12 mo
● Greater success with prostate cancer than breast cancer
● Retreatment no sooner than 90 days (if a minimal effect has been obtained, retreatment at 30-45 days may be indicated)
● Osteosarcoma outcome questionable- usually not beneficial

Radionuclide Therapy: Clinical Outcomes

● 80% response divided into 3 groups, based on pain and medication diaries
● moderate response: morphine moving down to codeine
● marked response: morphine moving down to advil
● dramatic response: morphine moving down to no drugs