Laboratory tumor lysis syndrome: abnormality in two or more of the following, occurring within three days before or seven days after chemotherapy.

• • uric acid  ≥ 0,476 mmol/l or 25% increase

• • potassium ≥ 6 mmol/l or 25% increase

• • phosphate ≥ 1,45 mmol/l or 25% increase

• • calcium ≤ 1,75 mmol/l or 25% decrease

Clinical tumor lysis syndrome: laboratory tumor lysis syndrome plus one or more of the following:

• • increased serum creatinine (1.5 times upper limit of normal)

• • cardiac arrhythmia or sudden death

• • seizure