Hematologic changes associated with half-body irradiation in dogs with lymphoma.
BACKGROUND
Reports describe the technique and efficacy of half-body irradiation (HBI) of dogs with lymphoma, but few describe the distinctive toxicoses associated with the combination of HBI and chemotherapy.


OBJECTIVE
HBI would transiently affect myelocytic and erythroid variables as assessed by serial analysis of complete blood counts.


METHODS
Twenty-nine dogs with lymphoma treated with HBI during 2002 and 2003.


METHODS
A retrospective study of medical records of 29 dogs was performed. Two HBI protocols were used, resulting in delivery of either 6 Gy or 8 Gy to each half of the body, 1 month apart. Dogs received chemotherapy before, during, or after irradiation, or at multiple times. Serial hematology was available for all dogs. Data were analyzed between collection periods by analysis of variance (ANOVA) RESULTS: The mean granulocyte count significantly (P < .01) decreased from 10,017 cells/microL (data range 3,001-20,170 cells/ microL) before the first radiation treatment to 3,250 cells/microL (820-4,400 cells/microL) at week 5 (P < .01). Three weeks after this nadir, the mean increased to 10,150 cells/microL (900-26,700 cells/microL). The hematocrit did not change (36-38%). Thrombocytopenia (<100,000/microL) occurred in 10 dogs. Two dogs died because of complications associated with thrombocytopenia. No significant difference in toxicity was found between the 6 Gy and 8 Gy group.


CONCLUSIONS
HBI was myelosuppressive but effects were short term and resolved in 22 of 24 dogs. Further studies are needed to elucidate the safety and role of HBI in the treatment of dogs with lymphoma.
Axiak
Sandra M
SM
Gulf Coast Veterinary Specialists, 111 West Loop South, Suite 150, Houston, TX 77027, USA.
Carreras
Janet K
JK
Hahn
Kevin A
KA
Endicott
Melissa M
MM
Parshley
Dorothy E
DE
King
Glen K
GK
D000704:Analysis of Variance; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D004283:Dog Diseases / Q000097:blood* / Q000188:drug therapy / Q000532:radiotherapy; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects / Q000627:therapeutic use; D008223:Lymphoma / Q000097:blood / Q000188:drug therapy / Q000532:radiotherapy / Q000662:veterinary*; D008297:Male; D009367:Neoplasm Staging / Q000662:veterinary; D012189:Retrospective Studies; D013921:Thrombocytopenia / Q000139:chemically induced / Q000453:epidemiology / Q000662:veterinary; D013997:Time Factors; D016896:Treatment Outcome
D000970:Antineoplastic Agents