Potential Advantages of Bone Marrow Sparing IMRT in Cancer Cervix: A Dosimetric Evaluation XC01-XC05
Dr. Sunil Choudhary,
Associate Professor, Department of Radiotherapy and Radiation Medicine Institue of Medical Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India.
Introduction: Concurrent Chemoradiation (CRT) is the standard of care for locally advanced cervical cancer patients. Addition of chemotherapy to pelvic radiotherapy augments Haematological Toxicity (HT). Whether reducing the radiation dose to Bone Marrow (BM) will diminish HT is yet not clear.
Aim: The purpose of the present study was to analyse the feasibility of Bone Marrow Sparing (BMS) in cervical cancer patients using Intensity Modulated Radiotherapy (IMRT).
Materials and Methods: Computed Tomography (CT) images of 10 consecutive biopsy-proven invasive cervical cancer patients were used. All patients were treated using Intensity Modulated Radiotherapy (IMRT) without bone marrow sparing (normal-IMRT). BMS-IMRT plans were generated for this study and Dose-Volume Histogram (DVH) parameters were then compared with normal-IMRT plans.
Results: The mean values of the Planning Target Volume (PTV) V95 and V97 were lower and were statistically significant (p=0.016 and 0.019 respectively) in BMS-IMRT when compared to normal-IMRT, however, PTV coverage was not compromised in any BMS-IMRT plan. There was no statistically significant difference in the mean values of rectum V30, V40, bowel V35, V40, V45, and femoral head V35. However, the mean values of rectum V50, bladder V40, V45, and V50 were statistically lower in the case of BMS-IMRT. When compared to normal-IMRT the mean values of Pelvic Bone Marrow (PBM) V10, V20, V30, V40 were lower and found to be statistically significant in BMS-IMRT.
Conclusion: The BMS-IMRT spares the PBM without compromising the target volume and at the same time spares bladder and rectum more effectively.