Inclusion Criteria:

1. Patients with histologically proven small cell carcinoma of the bladder, or elsewhere
along the urothelium, which is locally advanced or metastatic (i.e. > or = cT3b, > or
= pT3b, N+, or M+) at the time of presentation or cystectomy who have been treated
with chemotherapy.

2. Patients must have had a response to chemotherapy, which the investigator feels is
likely to resulting systemic control of the cancer. In most instances, this would
reflect a major response (i.e. > or = 90% reduction of tumor), though a lower
percentage may be acceptable if the investigator feels the residual reflects another
component, such as transitional cell carcinoma (TCC). Dr Arlene Siefker-Radtke will
serve as the final arbiter when questions regarding response arise.

3. Since small cell tumors of the bladder are often associated with other variant
histology including TCC and adenocarcinoma, the presence of variant histology will be
allowed.

4. Patients must be > or = 18 years of age.

5. Patients may be on other trials (either here at M.D. Anderson Cancer Center or at an
outside institution) as long as the other eligibility criteria are met.

6. Patients must not have any evidence of progressive disease at the time of study
entry.

7. Patients must have an MRI or CT of the head showing no CNS metastases within 6 weeks
of study entry.

8. Patients must have adequate physiologic reserves as evidenced by: a) Zubrod
Performance Status (PS) of < or = 2; b) Adequate bone marrow reserves as evidenced by
ANC > 1000, and platelet count > 100,000. Supranormal values judged to be of benign
or inconsequential etiology will be acceptable.

9. Patients must be enrolled within 6 months of completing chemotherapy or after surgery
of the primary site. Any acute/subacute > or = grade 3 toxicities from the
chemotherapy must be resolved to < or = grade 2 at the time of study entry. It is
suggested that patients undergo prophylactic cranial irradiation as a soon as they
have recovered from chemotherapy or surgery, at a minimum of 2 weeks, and up to 6
months following chemotherapy or surgery.

Exclusion Criteria:

1. Patients with CNS metastasis at presentation will not be eligible.

2. History of TIA or stroke within 6 months of study entry.

3. Prior cranial irradiation.

4. Pregnant women will not be eligible; women of childbearing potential must have a
negative pregnancy test before starting therapy.