Tumor lysis syndrome following hemi-body irradiation for metastatic breast cancer

Tumor lysis syndrome (TLS) is a rare serious acute complication of cancertherapy, reported mainly following chemotherapy in patients with large tumorload and chemosensitive disease. These are mainly patients with non-Hodgkin'slymphoma, leukemia and rarely in solid tumors. It is less frequently describedafter radiotherapy for lymphoid and hematological malignancies. TLS followingradiotherapy for solid tumors is a very rare complication. In thisreport/review we describe a seventy-three-year-old male patient withprogressive metastatic carcinoma of the breast to the lungs, liver and bone.He was referred for radiotherapy because of generalized bony pains. Thepatient was planned for sequential hemi-body irradiation starting with themore symptomatic upper half body. After premedication, he was given 8.5 Gy tothe mid point at the maximum chest separation with anterior lung attenuatorlimiting uncorrected lung dose to 6.15 Gy. A further 3.5 Gy electron boost tothe fungating breast tumor was given to the 100%.Forty-eight hours after irradiation he developed hyperkalemia,hyperphosphatemia, hyperuricemia, hypocalcemia and renal failure. Theseclinical and biochemical changes are typical of tumor lysis syndrome (TLS).Despite hydration, and treating the hyperuricemia, the patient developed comaand died eight days after irradiation.The prophylaxis and management of TLS and in high-risk patients aredescribed to avoid this frequently fatal complication.