Bone marrow recovery following use of systemic (153)Sm-lexidronam and (89)Sr-chloride for bone pain palliation after myelosuppressive therapy.
OBJECTIVE
Using plasma flt3 ((FMS (Friend murine strain))-like tyrosine kinase 3)-ligand cytokine (FL) as a biomarker, the purpose of this study was to determine whether patients receiving palliative radionuclide treatment following chemotherapy experienced enhanced myelosuppression.


METHODS
A total of 48 patients with solid tumors who failed multi-agent chemotherapy were investigated; they previously received 1-3 cycles of combination chemotherapy over 4-10 months. Patients were divided into four cohorts including 10 patients with early stage solid tumors prior to chemotherapy induction (naive group), 10 patients with (non-metastatic) malignancy actively undergoing chemotherapy without radionuclide follow-up (chemotherapy-alone group), 13 patients who underwent standard (1.0 mCi/kg) dose (153)Sm ((153)samarium)-lexidronam therapy following chemotherapy ((153)Sm group), and 15 patients who underwent standard (4 mCi) dose (89)Sr ((89)strontium)-chloride therapy following chemotherapy ((89)Sr group). Plasma FL was measured using a quantitative sandwich enzyme immunoassay and CBC (complete blood count), measuring WBC (white blood cell) and PLT (platelet), was performed.


RESULTS
Plasma FL concentration demonstrated a gradual decrease after chemotherapy. In patients who received (153)Sm within two weeks of completing chemotherapy, there is a distinguishable spike in FL concentration at approximately three weeks after dose administration, which precedes a decrease in WBC and PLT counts. On the other hand, a spike in FL levels in patients who received (89)Sr therapy is noted at approximately 10 weeks (p < 0.034).


CONCLUSIONS
Increases in FL concentration associated with (153)Sm-lexidronam therapy following combination chemotherapy occurred earlier and returned to control levels more rapidly than did those in patients similarly treated with (89)Sr. These differences might be associated with the shorter decay half-life and lower particle emission energies of (153)Sm.
Department of Radiology, Rebecca and John Moores UCSD Comprehensive Cancer Center, University of California, San Diego, USA.
Frank J
FJ
Papatheofanis
Mohammad M
MM
Najib
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001853:Bone Marrow / Q000503:physiopathology* / Q000528:radiation effects*; D001842:Bone and Bones / Q000473:pathology*; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008565:Membrane Proteins / Q000097:blood; D008875:Middle Aged; D009942:Organometallic Compounds / Q000627:therapeutic use*; D009943:Organophosphorus Compounds / Q000627:therapeutic use*; D010146:Pain / Q000097:blood / Q000532:radiotherapy*; D010166:Palliative Care / Q000379:methods*; D010976:Platelet Count; D013324:Strontium / Q000627:therapeutic use*
D015415:Biomarkers; D008565:Membrane Proteins; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; C084881:flt3 ligand protein; C061972:samarium Sm-153 lexidronam; C025700:strontium chloride; D013324:Strontium