Samarium Sm 153 Lexidronam Pentasodium and 3-Dimensional Conformal Radiation Therapy or Intensity-Modulated Radiation Therapy in Treating Patients With Rising Prostate-Specific Antigen Levels After Radical Prostatectomy for Prostate Cancer

OBJECTIVES:

Primary

- To assess the effectiveness of samarium Sm 153 lexidronam pentasodium (as determined by
a 30% decline in the PSA level within 12 weeks) followed by either three-dimensional
conformal radiation therapy or intensity-modulated radiation therapy in patients with
rising prostate-specific antigen levels (PSA) after radical prostatectomy prostate
cancer.

Secondary

- To assess the proportion of patients completing protocol treatment.

- To evaluate hematological toxicity at 12 weeks.

- To evaluate samarium Sm 153 lexidronam pentasodium-related adverse events at 12 weeks.

- To evaluate the "acute" and "late" radiation therapy-related events having occurred up
to 24 weeks from the end of radiation therapy.

- To compare the freedom from progression rate at 2 years to that predicted by the Kattan
Nomograms.

OUTLINE: Patients receive samarium Sm 153 lexidronam pentasodium (SM) IV on day 1. Patients
are closely monitored for prostate-specific antigen (PSA) level and SM-associated toxicity
for 12 weeks. After the 12 weeks, patients undergo either intensity-modulated radiation
therapy or 3-dimensional conformal radiation therapy 5 days a week for 7-8 weeks. Patients
may receive hormonal therapy (after radiation therapy) at the discretion of their physician.

Treatment continues in the absence of disease progression (defined as a PSA doubling time
less than 3 months), severe thrombocytopenia (defined as a platelet count of 25,000
cells/mm³ or less), or unacceptable toxicity.

After completion of study treatment, patients are followed up at 3 months, 6 months, and 12
months, every 6 months for 2 years, and then annually thereafter.

DISEASE CHARACTERISTICS:

Inclusion criteria:

- Histologically proven diagnosis of prostate cancer progressing after prior radical
prostatectomy as indicated by one of the following:

- Postoperative prostate-specific antigen (PSA) rising above 1.0 ng/mL

- Postoperative PSA rising above 0.2 ng/mL with a surgical tumor Gleason score of
9 or 10

- Postoperative PSA rising above 0.2 ng/ml with nodal disease

- Stage II-IV disease (T2 -T4, N0-N1)

- No distant metastases based on the following minimum diagnostic work up:

- History or physical examination within the past 8 weeks

- Bone scan negative for bone metastases within the past 4 months

- Abdominal imaging negative for metastases within the past 6 months

Exclusion criteria:

- Biopsy evidence of M1 disease

- Presence of neuroendocrine features in any prostate cancer specimen

PATIENT CHARACTERISTICS:

Inclusion criteria:

- Zubrod Performance Status 0-1

- Absolute neutrophil count (ANC) ≥ 1,800 cells/mm³

- Platelet count ≥ 100,000 cells/mm³

- Hemoglobin ≥ 8.0 g/dL (transfusion or other intervention to achieve Hgb ≥ 8.0 g/dl is
permitted)

Exclusion criteria:

- Prior invasive malignancy (except nonmelanoma skin cancer) unless disease free for a
minimum of 3 years

- Severe, active comorbidity, defined as follows:

- Unstable angina and/or congestive heart failure requiring hospitalization within
the last 6 months

- Transmural myocardial infarction within the last 6 months

- Acute bacterial or fungal infection requiring intravenous antibiotics at the
time of registration

- Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects
(laboratory tests for liver function and coagulation parameters, however, are
not required for entry into this protocol)

- Renal failure (laboratory tests for renal function, however, are not required
for entry into this protocol)

- AIDS based upon current Centers for Disease Control (CDC) definition (HIV
testing is not required)

PRIOR CONCURRENT THERAPY:

- No prior systemic chemotherapy for the study cancer

- Prior chemotherapy for a different cancer is permitted

- No hormonal therapy initiated within the last 3 months

- No prior radiotherapy to the pelvic region that would result in overlap of
radiotherapy fields