A prospective dosimetric and clinical comparison of acute hematological toxicities in three-dimensional conformal radiation therapy and intensity modulated radiation therapy with concurrent chemotherapy in carcinoma cervix.

ABSTRACT

BACKGROUND AND OBJECTIVES: Acute hematological toxicities are an important cause of morbidity in patients receiving concurrent chemoradiation to pelvis in carcinoma cervix. The objective of this study was to evaluate the role of intensity-modulated radiotherapy (IMRT) in reducing the dose to the bone marrow as compared with three-dimensional conformal radiotherapy (3DCRT) and hence its impact on reducing the acute hematological toxicities. MATERIALS AND METHODS: Eleven consecutive patients treated with IMRT and 12 patients treated with 3DCRT to the whole pelvis along with concurrent chemotherapy were selected. Bone marrow was delineated. V10 Gy, V20 Gy, V95%, and Dmean of bone marrow were recorded. Weekly blood counts were recorded and graded as per Common Terminology Criteria version 4.0 for all the patients. RESULTS: The dose to the bone marrow V20 Gy was 206.78 ± 57.10 cc (75%) and 251.70 ± 40.45 cc (91%) for IMRT and 3DCRT, respectively (P = 0.04) and V95% was 23.30 ± 8.34% and 46.76 ± 6.71% for IMRT and 3DCRT, respectively (P = 0.001). The grade of toxicities during each week did not show the difference in either arm. However, the total count and Neutrophil counts during the 2nd week showed statistical significance between IMRT and 3DCRT. CONCLUSION: IMRT significantly reduces the dose to the bone marrow as compared to 3DCRT. The reduction of the dose did not translate into a decrease in acute hematological toxicities. Concurrent platinum-based chemotherapy is the probable cause for the hematological toxicities.