Inclusion Criteria

Patients must meet all of the following inclusion criteria:

1. Males or females who are >12 months of age

2. Have a diagnosis of neuroblastoma either by (a) histologic verification of
neuroblastoma and/or (b) demonstration of tumor cells in the bone marrow with
increased urinary catecholamine metabolites

3. Have high-risk neuroblastoma with relapsed/refractory disease at any time.

4. MIBG avid disease demonstrated by 131I or 123I -MIBG uptake into tumor at ≥ one site
within 28 days prior to study treatment and no intervention/therapy between the time
of the MIBG scan and study treatment.

5. To be eligible to receive at least one therapeutic dose, patients must have adequate
banked autologous stem cells defined as:

PBSC: A minimum of 2.0 x 106 viable CD34+ cells/kg (purged or unpurged) (see Section
10.4.15)

6. Prior Therapy:

1. Patients must have fully recovered from the acute toxic effects of all prior
chemotherapy, immunotherapy, or radiotherapy prior to entering this study. There
is no limitation on the number of prior chemotherapeutic regimens that the
patient may have received.

2. The last dose of all local palliative radiation must be ≥ 14 days prior to the
first therapeutic dose of Ultratrace iobenguane I 131. Any lesion treated with
local palliative radiation during this period can not be included in the
baseline target lesion evaluation.

3. The last dose of all local palliative radiation to more than 25% of marrow
containing bones must be ≥ 28 days prior to the first therapeutic dose of
Ultratrace iobenguane I 131. A minimum of 3 months is required following prior
large field radiation therapy (i.e. craniospinal therapy, total lung, > 50%
marrow space). Note: Radiation therapy of focal skull-based bony metastatic
disease (only) is not considered craniospinal therapy.

4. The last dose of any myelosuppressive or biologic (e.g., isotretinoin [also
known as cis-retinoic acid, or Accutane®]) therapy must be at least 14 days
before the administration of the first therapeutic dose of Ultratrace iobenguane
I 131 on this protocol.

5. The last dose of immunotherapy must be at least 28 days prior to the first
therapeutic dose of Ultratrace iobenguane I 131.

6. All cytokines or hematopoietic growth factors must be discontinued for a minimum
of 7 days prior to the first therapeutic dose of Ultratrace iobenguane I 131or
14 days prior to the first therapeutic dose of Ultratrace iobenguane I 131for
long-acting colony stimulating factors.

7. Prior treatment with 131I-MIBG therapy must be ≥12 months prior to the first
therapeutic dose of Ultratrace iobenguane I 131.

8. Administration of Neuroblastoma therapeutic investigational medication or
devices must be ≥30 days prior to dosimetry dose.

9. Prior autologous stem cell infusion must be ≥2 months prior to study entry.
The patient must have recovered from all toxicities

7. Adequate Organ Function:

1. Adequate bone marrow function requirements, including patients
post-myeloablative therapy or tumor involvement of bone marrow

2. Adequate renal, hepatic, cardiac, lung and thyroid function

Exclusion Criteria:

Patients will be excluded if any of the following conditions are observed:

1. Pregnant, or lactating females with the intent to breast feed. Females of
child-bearing potential must have a negative serum pregnancy test prior to therapy.
Males and females of reproductive age and childbearing potential must use effective
contraception defined as abstinence or use of IUD, oral contraceptive, barrier and
spermicide, or hormonal implant for the duration of their participation. Sexually
active female patients using oral contraception will be required to use a second form
of barrier birth control. All patients will be required to use effective
contraception for 60 days following the last therapeutic dose of Ultratrace
iobenguane I 131.

2. Have disease of any major organ system that would compromise their ability to
withstand therapy.

3. Receiving hemodialysis or have a renal obstruction, which would effect the urinary
excretion of MIBG.

4. Is platelet transfusion dependent

5. Status post-allogeneic hematopoietic stem cell transplant.

6. Concomitant use of medications that inhibit uptake of Ultratrace iobenguane I 131.

7. Have a known allergy to iobenguane, iodine or SSKI.

8. If patients and/or families who are physically and psychologically unable to
cooperate with the radiation safety isolation or imaging requirements (sedation or
general anesthesia permitted).

9. Administered prior chemotherapy within 30 days of study entry or have active
malignancy (other than neuroblastoma) requiring additional treatment.

10. Any other condition, that in the opinion of the investigator, may compromise the
safety or compliance of the subject or would preclude the subject from successful
completion of the study.

11. Patient unable to receive at least one 15 mCi/kg dose per dosimetry findings.