• To see if treatment with radiation from 153 Sm-EDTMP and a stem cell transplant will control breast cancer that has spread to the bone. [ Time Frame: 3 Years ] [ Designated as safety issue: No ]
  

• The side effects of the study drug will also be studied. [ Time Frame: 3 Years ] [ Designated as safety issue: Yes ]
  

Inclusion Criteria:

1. Stage IV breast cancer metastatic to bone and/or bone marrow only.
2. Age between 18 and 65 years.
3. ECOG performance score of 0, 1
4. Subjects with breast tumors with hormone receptor positive disease (ER+/PR+, ER+/PR-, or ER-/PR+) must have failed at least one hormonal-based therapy for bone only disease.
5. Subjects with breast tumors with hormone receptor negative disease must have failed at least one anthracycline and/or taxane-based therapy for bone only disease.
6. Subject must have a minimum of 2x10^6 un-manipulated CD34+ cells/kg cryopreserved and available as a source of stem cells for autologous transplant.
7. WBC >/= 3.5 x10^9/L, Hb >/= 10 g/dL, platelets >/= 100 x10^9/L.
8. Adequate pulmonary function defined as FEV1, FVC and DLCO (corrected for hemoglobin) >/= 50% of predicted.
9. Adequate cardiac function as evidenced by left ventricular ejection fraction (LVEF) of >/= 45%.
10. Serum total bilirubin < 2x ULN, and ALT/SGPT < 3x ULN
11. Creatinine clearance of >/= 75 mL/min for subjects up to 50 years of age, and adjusted for age by a 10% decrease per decade for subjects of more than 50 years of age.
12. Ability to understand the study and provide informed consent.

Exclusion Criteria:

1. Any metastatic disease or history of metastatic disease other than skeletal metastases
2. Impending fracture, spinal cord compression, and/or potentially unstable compression fracture of vertebral body with possibility of cord compression.
3. Previous strontium-89 or samarium-153 treatment for any skeletal involvement.
4. Cumulative external beam radiation to > 20% of marrow volume or > 40 Gy to any single region of the spinal cord.
5. Prior radiation to the bladder or kidney, defined as radiation portals that directly include any volume of either kidney and/or the bladder.
6. Life expectancy severely limited by concomitant illness (less than 6 months).
7. Prior nephrectomy.
8. History of hemorrhagic cystitis obstructive uropathy or hydronephrosis.
9. Uncontrolled arrhythmia or symptomatic cardiac disease.
10. Current gross hematuria in UA in the absence of vaginal bleeding.
11. Potential inability to have bladder catheter placed.
12. Evidence of HIV-seropositivity.
13. Use of bisphosphonates within 30 days preceding enrollment.
14. Use of any chemotherapy for breast cancer within 3 weeks preceding enrollment.
15. Use of any investigational agent within 30 days preceding enrollment.
16. Pregnant or lactating women.
17. Other current or prior malignancy except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer.
18. Myelodysplastic syndrome.
19. Subject weight of more than 125 kg.