Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed primary soft tissue sarcoma of the retroperitoneum or pelvis
(e.g., iliac fossa)

- The following histologies are eligible:

- Alveolar soft part sarcoma

- Anaplastic sarcoma

- Angiosarcoma

- Atypical lipomatous tumor (low-grade liposarcoma)

- Clear cell sarcoma

- Epithelioid sarcoma

- Fibrosarcoma

- Leiomyosarcoma

- Liposarcoma (all subtypes)

- Malignant fibrous histiocytoma

- Malignant peripheral nerve sheath tumor

- Myxofibrosarcoma

- Neurofibrosarcoma

- Spindle cell sarcoma

- Synovial sarcoma

- Unclassified sarcoma

- The following histologies are not eligible:

- Rhabdomyosarcoma

- Extraosseous Ewing's sarcoma

- Primitive neuroectodermal tumor

- Osteosarcoma

- Chondrosarcoma

- Aggressive fibromatosis (desmoid tumor)

- Gastrointestinal stromal tumor

- Sarcomatoid carcinoma

- Hemangiopericytoma

- Retroperitoneal sarcomas located predominantly in the retroperitoneum extending
across the inguinal ligament into the abdominal wall are allowed provided that ≥ 90%
of the tumor volume is located within the retroperitoneal space

- No bowel obstruction OR history of previous bowel obstruction attributed to
retroperitoneal tumor

- Primary non-visceral retroperitoneal masses consistent with sarcoma allowed provided
diagnoses of carcinoma, melanoma, and lymphoma are excluded by immunohistochemistry

- Measurable gross disease by abdominopelvic CT scan (with IV and oral contrast) or MRI
(with IV contrast)

- Patients must have undergone radiotherapy consultation within the past 30 days to
confirm the feasibility of preoperative external-beam radiotherapy

- Patients must have undergone surgical consultation within the past 30 days to confirm
and document the feasibility of macroscopically complete resection

- No prior macroscopically incomplete (R2) resection (i.e., partial debulking or
subtotal tumor resection with gross residual disease)

- No pelvic sarcoma extending through the sciatic notch

- No clinical or radiographic evidence of probable metastatic disease

- Equivocal pulmonary or liver lesion allowed provided the likelihood of
metastatic disease is small

- No sarcoma arising from bone or any retroperitoneal viscus (except the kidney)

- No sarcoma extending across the diaphragm into the thorax

- No recurrent retroperitoneal tumor

- No multifocal disease

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-1 OR

- Zubrod 0-1

Life expectancy

- Not specified

Hematopoietic

- WBC ≥ 2,500/mm^3

- Platelet count ≥ 80,000/mm^3

Hepatic

- Bilirubin ≤ 1.5 times upper limit of normal (ULN)

- AST ≤ 2.5 times ULN

- Albumin normal* NOTE: *Higher levels allowed

Renal

- Creatinine normal

- BUN normal

- Functional kidney confirmed by intravenous pyelogram and/or differential renal
isotope scan

Other

- Not pregnant

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 3 months after study
participation

- No other malignancy within the past 5 years (except effectively treated basal cell or
squamous cell skin cancer) unless patient was curatively treated AND is at low risk
for recurrence

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- No concurrent chemotherapy for primary tumor

Endocrine therapy

- Not specified

Radiotherapy

- No prior abdominal or pelvic irradiation

- No concurrent intraoperative or postoperative radiotherapy for primary tumor

Surgery

- See Disease Characteristics