ABSTRACT
BACKGROUND@#Radiotherapy (RT) to the chest or other large areas of the body may cause bone marrow suppression, resulting in anemia and other changes in blood cell counts.@*OBJECTIVE@#To compare the postRT hemoglobin levels between patients who underwent forward planned intensitymodulated radiotherapy (FPIMRT) and those who underwent threedimensional conformal radiotherapy (3DCRT).@*DESIGN@#Retrospective cohort study@*SETTING@#Department of Radiological and Imaging Sciences, Southern Philippines Medical Center, Davao City, from October 2018 to March 2019.@*PARTICIPANTS@#94 women with invasive ductal carcinoma, aged 29 to 75 years, who received at least 28 fractions (with or without boost dose) of either 3DCRT or FPIMRT.@*MAIN OUTCOME MEASURES@#Mean hemoglobin counts and anemia within 4 weeks postRT.@*MAIN RESULTS@#Of the 94 women, 62 (65.96%) underwent 3DCRT, and 32 (34.04%) underwent FPIMRT. The proportion of patients with leftsided tumors was significantly higher in the FPIMRT group than in the 3DCRT group. The baseline hemoglobin levels (12.60 ± 1.04 g/dL for 3DCRT vs 12.49 ± 0.80 g/dL for FPIMRT; p=0.5994) and the mean changes in hemoglobin count from baseline (0.11 ± 0.72 g/dL for 3DCRT vs 0.18 ± 0.67 g/dL for FPIMRT; p=0.6707) were both comparable between the two groups. The proportions of patients with anemia within four weeks postRT were also comparable between the two groups (13/62, 20.97% for 3DCRT vs 8/32, 25.00% for FPIMRT; p=0.6565). Leftsided tumors were significantly associated with postRT anemia (unadjusted OR 2.87; 95% CI 1.00 to 8.22; p=0.0498), even after controlling for type of RT technique (adjusted OR 3.15; 95% CI 1.01 to 9.87; p=0.0484).@*CONCLUSION@#After RT, the mean hemoglobin levels of patients with breast cancer who underwent 3DCRT were comparable with those of patients who underwent IMRT. The type of RT technique was not significantly associated with the occurrence of postRT anemia in these patients.