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

RATIONALE: Giving samarium Sm 153 lexidronam pentasodium and 3-dimensional (3-D) conformal radiation therapy or intensity-modulated radiation therapy may keep prostate cancer from growing in patients with rising prostate-specific antigen (PSA) levels after radical prostatectomy for prostate cancer.

PURPOSE: This phase II trial is studying how well samarium Sm 153 lexidronam pentasodium and 3-D conformal radiation therapy or intensity-modulated radiation therapy work in treating patients with rising PSA 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.

Eligibility Criteria:
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