Acute Haematological Variations in Patients Receiving Radiotherapy and its Correlation with Volume of the Bone Marrow and Radiation Dose

: Purpose: Radiation treatment of all malignancies inevitably includes certain percentage of bone marrow in the site and volume of irradiation. The purpose is to study the magnitude of radiation induced early haematological toxicity in relation to the total dose and volume of the marrow in the field of irradiation. Materials & Methods: A Prospective analysis was done in 60 patients treated with telecobalt. Haemoglobin, WBC and platelet counts were done before starting treatment and then weekly till the completion of treatment. The volume of bone marrow in the radiation fields was also recorded. Results: The haemoglobin percentage change between baseline and 5 th week was 5.19%(p=0.026) and7.35% (p=0.049) in <5%, 5-20% &>20% of bone marrow irradiated respectively. The percentage of change between baseline and 5 th week total WBC count was 23.79% (p=0.000), 35.53% (p=0.006) and 27.90% (p=0.000) in <5%, 5-20% &>20% of bone marrow irradiated respectively. The percentage change in platelets between baseline and 5 th week of 22.14%, 24.66% & 24.80% in patients with <5%, 5-20% and >20% of bone marrow irradiated respectively (overall p=0.000). Conclusion: The percentage of active bone marrow in the field of irradiation, dose per fraction and the total dose received are the best parameters for the study of haematological variations in patients being treated with radiotherapy. There is significant Haematological variations with decreasing trend in relation to volume of bone marrow irradiated and radiation dose.