Dosimetric analysis and acute toxicity comparison of bone marrow sparing intensity-modulated radiation therapy versus three-dimensional conformal therapy with concurrent chemotherapy for the treatment of cervical carcinoma: A prospective single institutional study

Background: The aim of the study was to compare the dosimetry and acute toxicities of bone marrow sparing intensity-modulated radiation therapy (BMS-IMRT) and three-dimensional conformal radiation techniques (3DCRT) in locally advanced cervical cancer. Materials and Methods: This is a hospital-based prospective randomized study and histologically proven locally advanced cervical carcinoma patients were selected for the analysis. A total of thirty patients were equally allocated in the two treatment arms: BMS-IMRT and 3DCRT. External beam radiation therapy was delivered to a dose of 50 Gy/25 followed by high dose rate brachytherapy along with concurrent chemotherapy. The target volumes and the organs at risks were delineated. The BM comprised pelvic BM (PBM); lumbosacral BM (LSBM); ilium BM (IBM) and Ischium, Pubis and Pelvic femora together constituting lower PBM (LPBM). Results: BMS-IMRT was superior to the 3DCRT arm in reducing the dose to the PBM, small bowel, rectum, and bladder. On comparison of the BM dose volume histogram, the P value was significant (BMS IMRT vs. 3DCRT) in the higher dose range (30 and 40 Gy) for the IBM, LPBM, and whole pelvis BM. However, the difference in the low-dose irradiation (10 and 20 Gy) region was not significant. Furthermore, in the LSBM region, BMS IMRT was superior at all dose levels with no significant P value. Acute toxicities were higher in the 3DCRT arm. Conclusion: Thus, BMS-IMRT resulted in significant reduction of dose to the PBM. This can help in reducing the hematologic toxicities associated with pelvic radiation. (author)