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