Dosimetric comparison between bone marrow-sparing intensity-modulated radiotherapy and conventional intensity-modulated radiotherapy for cervical cancer

Objective To compare bone marrow-sparing intensity-modulated radiotherapy (BMS-IMRT) with conventional intensity-modulated radiotherapy (IMRT) without considering pelvic bone marrow (PBM) as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods BMS-IM-RT and IMRT planning were separately designed in a cohort of 10 patients with cervical cancer after hysterec-tomy. The prescribed dose was 95% planning target volume receiving 45 Gy/25 f. A commercially available TPS with convolution/superposition (CS) algorithm was used for dose calculation. Plans were compared ac-cording to dose-volume histogram (DVH) analysis in terms of PTV homogeneity (HI), conformity index (CI) as well as dose and volume parameters of organ at risks (OARs). Results BMS-IMRT was better than IMRT in terms of CI, but inferior to the latter for HI. When compared with IMRT, V_5, V_(10), V_(20), V_(30) and V_(40) of PBM in BMS-IMRT were reduced by 1.81% ,8.61% ,31.81% ,29.50% and 28.29%, respec-tively. No statistically significant differences were found between BMS-IMRT and IMRT for dose distritutions of the small bowel, bladder or rectum. Conclusions For patients with cervical cancer after hysterectomy, BMS-IMRT can reduce the PBM volume irradiated by low dose, which may reduce acute hematologic toxici-ties. Key words: Cervical neoplasms/radiotherapy;  Radiotherapy,intensity-modulated ;  Dosimetry