Tumor lysis syndrome following hemi-body irradiation for metastatic breastcancer

Tumor lysis syndrome (TLS) is a rare serious acute complication of cancer t herapy, reported mainly following chemotherapy in patients with large tumor load and chemosensitive disease. These are mainly patients with non-Hodgki n's lymphoma, leukemia and rarely in solid tumors. It is less frequently de scribed after radiotherapy for lymphoid and hematological malignancies. TLS following radiotherapy for solid tumors is a very rare complication. In th is report/review we describe a seventy-three-year-old male patient with pro gressive metastatic carcinoma of the breast to the lungs, liver and bone. H e was referred for radiotherapy because of generalized bony pains. The pati ent was planned for sequential hemi-body irradiation starting with the more symptomatic upper half body. After premedication, he was given 8.5 Gy to t he mid point at the maximum chest separation with anterior lung attenuator limiting uncorrected lung dose to 6.15 Gy. A further 3.5 Gy electron boost to the fungating breast tumor was given to the 100%. Forty-eight hours after irradiation he developed hyperkalemia, hyperphospha temia, hyperuricemia, hypocalcemia and renal failure. These clinical and bi ochemical changes are typical of tumor lysis syndrome (TLS). Despite hydrat ion, and treating the hyperuricemia, the patient developed coma and died ei ght days after irradiation. The prophylaxis and management of TLS and in high-risk patients are describ ed to avoid this frequently fatal complication.