Correlations Between Radiation Dose in Bone Marrow and Hematological Toxicity in Patients With Cervical Cancer: A Comparison of 3DCRT, IMRT, and RapidARC.

Objective: To comparatively evaluate the hematological toxicity (HT) associated with 3 concurrent chemoradiotherapies that are routinely used to treat cervical cancer, including 3-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiation therapy (IMRT), and RapidARC and to establish a new normal tissue complication probability model of bone marrow (BM) to predict HT in cervical cancer patients undergoing concurrent chemoradiotherapy.

Methods: Patients with cervical cancer (N = 100) who received concurrent cisplatin and whole-pelvic radiotherapy were enrolled in this study. Dosimetric parameters (including V10, V20, V30, and V40 and mean doses to the pelvic bone) and HT were analyzed.

Results: The V20, V30, and V40 and mean doses to the BM were lower in the IMRT and RapidARC groups than in the 3DCRT group, and the RapidARC group had higher V10 and V40 and mean values than the IMRT group. The V20, V30, and V40 and the mean dose to the pelvic bone were positively correlated with HT. Generalized linear normal tissue complication probability models of white blood cell (WBC) and absolute neutrophil cell (ANC) nadirs and BM V20 were established as follows: WBC nadir = 3.382 - 4.056 • V20 + 0.295 • baseline of WBC (adjusted R = 0.246, F = 15.847) and ANC nadir = 2.438 - 2.780 • V20 + 0.233 • baseline of ANC (adjusted R = 0.236, F = 16.282).

Conclusions: This study suggests that IMRT results in milder hematological toxicity than either 3DCRT or RapidARC. Dosimetric parameters were associated with the incidence of HT in cervical cancer patients who received concurrent chemoradiotherapies.