Positron Emission Tomography Using Fluorothymidine F 18 in Finding Recurrent Disease in Patients With Gliomas

DISEASE CHARACTERISTICS:

* Radiological or established histological diagnosis of glioma

  * WHO grade 2-4 disease
* Presence of a new or enlarging enhancing lesion on gadolinium-enhanced MRI after prior radiotherapy

  * Differentiation of recurrent tumor from radiation necrosis is not possible
* No clinically significant signs of uncal herniation, including any of the following:

  * Acute pupillary enlargement
  * Rapidly developing (i.e., over hours) motor changes
  * Rapidly decreasing level of consciousness

PATIENT CHARACTERISTICS:

* Platelet count ≥ 75,000/mm\^3
* WBC ≥ 3,000/mm\^3
* Gamma-glutamyl-transferase ≤ 5 times upper limit of normal (ULN)
* Absolute neutrophil count ≥ 1,500/mm\^3
* Hemoglobin ≥ 10 g/dL
* SGOT and SGPT ≤ 2 times ULN
* Alkaline phosphatase ≤ 2 times ULN
* Lactic dehydrogenase ≤ 2 times ULN
* Direct and total bilirubin normal
* Amylase normal
* Haptoglobin normal
* Serum electrolytes normal
* CBC with platelets normal
* PT, PTT normal
* BUN and creatinine normal
* Not pregnant or lactating
* Urinalysis normal
* Negative pregnancy test
* Female patients must be postmenopausal for ≥ 1 year or surgically sterile, or on 1 of the following methods of birth control for ≥ 1 month: IUD, oral contraceptives, Depo-Provera, or Norplant

  * These criteria can be waived at the discretion of the investigator if the patient's intracranial tumor is considered life threatening and the 1-month wait required is not in the best interest of the patient
* No known allergic or hypersensitivity reactions to previously administered radiopharmaceuticals
* No known HIV positivity
* Not requiring monitored anesthesia for positron emission tomography scanning

PRIOR CONCURRENT THERAPY:

* Concurrent biopsy or neurosurgical procedure for diagnostic and/or therapeutic purposes for this cancer allowed
* Concurrent surgery for this cancer allowed