Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of primary gastrointestinal and/or retroperitoneal sarcoma

- Scheduled to undergo ≥ 3000 cGy or ≥ 3 weeks of external beam radiation to the
abdomen

- Radiotherapy fields to extend between T11 and L3, and of a size ≥ 100 cm^2

- No brain metastases

PATIENT CHARACTERISTICS:

- ECOG performance status 0-2

- Negative pregnancy test

- Not pregnant or nursing

- Fertile patients must use effective contraception

- Able to complete questionnaire(s) alone or with assistance

- Willing to return to NCCTG enrolling institution for follow-up

- Able to reliably take oral medication (for purposes of rescue medication)

- No hypersensitivity to palonosetron hydrochloride or other selective 5-HT3 receptor
antagonists

- No comorbid systemic illness or other severe concurrent disease that, in the judgment
of the investigator, would make the patient inappropriate for study entry or
interfere significantly with the proper assessment of safety and toxicity of the
prescribed regimens

- No nausea ≤ 48 hours prior to study enrollment

- No history of dystonic reactions to prochlorperazine or haloperidol or related agents

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- More than 7 days since prior agents known to have significant effects on emesis,
including the following:

- Ondansetron

- Sedating antihistamines

- Antipsychotics

- Cannabinoids

- Corticosteroids

- Metoclopramide

- Narcotic analgesics

- Benzodiazepines

- More than 7 days since prior chemotherapy other than fluorouracil or capecitabine
used as a radiosensitizer

- More than 7 days since of prior cetuximab

- More than 7 days since prior and no concurrent oral steroids

- No prior palonosetron hydrochloride