Correlation between changes of pelvic bone marrow fat content and hematological toxicity in concurrent chemoradiotherapy for cervical cancer

Abstract

Objectives To quantify the pelvic bone marrow (PBM) fat content changes receiving different radiation doses of concurrent chemoradiotherapy for cervical cancer and to determine association with peripheral blood cell counts. Methods The data of 54 patients were prospectively collected. Patients underwent MRI iterative decomposition of water and fat with echo asymmetrical and least squares estimation (IDEAL IQ) scanning at RT-Pre, RT mid-point, RT end, and six months. The changes in proton density fat fraction (PDFF%) at 5–10 Gy, 10–15 Gy, 15–20 Gy, 20–30 Gy, 30–40 Gy, 40–50 Gy, and > 50 Gy doses were analyzed. Spearman’s rank correlations were performed between peripheral blood cell counts versus the differences in PDFF% at different dose gradients before and after treatment. Results The lymphocytes (ALC) nadirs appeared at the midpoint of radiotherapy, which was only 27.6% of RT-Pre; the white blood cells (WBC), neutrophils (ANC), and platelets (PLT) nadirs appeared at the end of radiotherapy which was 52.4%, 65.1%, and 69.3% of RT-Pre, respectively. At RT mid-point and RT-end, PDFF% increased by 46.8% and 58.5%, respectively. Six months after radiotherapy, PDFF% decreased by 4.71% under 5–30 Gy compared to RT-end, while it still increased by 55.95% compared to RT-Pre. There was a significant positive correlation between PDFF% and ANC nadirs at 5–10 Gy (r = 0.62, P = 0.006), and correlation was observed between PDFF% and ALC nadirs at 5–10 Gy (r = 0.554, P = 0.017). Conclusion MRI IDEAL IQ imaging is a non-invasive approach to evaluate and track the changes of PBM fat content with concurrent chemoradiotherapy for cervical cancer. The limitation of low-dose bone marrow irradiation volume in cervical cancer concurrent chemoradiotherapy should be paid more attention to.

Functional MRI radiomics-based assessment of pelvic bone marrow changes after concurrent chemoradiotherapy for cervical cancer

“…Quantitative MRI of the fat fraction has been shown to be sensitive to changes in bone marrow fat content. The use of IDEAL IQ to identify active bone marrow for RT planning in patients undergoing pelvic CCRT can reduce the risk of HT [ 13 ]. Our previous study, which used the MR IDEAL IQ sequence to examine changes in PBM fat content during cervical cancer CCRT, discovered that PBM fat content increased with accumulated radiation dose.…”

Dosimetric evaluation of bone marrow sparing in proton radiotherapy for cervical cancer guided by MR functional imaging

“…In another study, we reported that IDEAL IQ FatFrac imaging could be used to measure PBM fat content changes during concurrent chemoradiotherapy. The fat content of PBM increased with the increase in radiotherapy dose, especially in the PBM region close to the target region receiving high-dose irradiation (the fat fraction increased from 48.5% to 74.2%), and the change was significantly related to the HT [ 11 ]. Liang et al [ 18 ] used the FatFrac image to contour the PBM for the IMRT-BMS plan design, which can reduce the incidence of G3 + HT from 47 to 30%.…”

“…Low-dose irradiation of 10–20 Gy to PBM is the primary cause of HT [ 8 – 10 ]. In our previous study, we found a significant positive correlation between fat content changes in the 5–10 Gy irradiated PBM region and the nadir of lymphocytes and neutrophils during chemoradiotherapy [ 11 ]. A meta-analysis showed that bone marrow sparing (BMS) techniques could effectively reduce the bone marrow dose and the incidence of grade 2 or 3 HT by approximately 70% [ 12 ].…”

“…The accurate localization and sparing of ABM can reduce HT and improve tolerance to chemotherapy and survival rates [ 14 , 15 ]. Magnetic resonance (MR) FatFrac imaging can be used to quantitatively analyze the fat content of the BM and can reflect the fat content changes in PBM during cervical cancer radiotherapy [ 11 ]. MR functional imaging provides a feasible method for ABM segmentation.…”

Is it time for bone marrow sparing radiation therapy to be standard of care in cervical cancer?

“…Quantitative magnetic resonance imaging (MRI) or functional imaging studies with either single-photon emission computed tomography (SPECT) or 18 F-fluorodeoxyglucose (FDG) or 18 Ffluorothymidine positron emission tomography/computed tomography (PET/CT) have demonstrated that hematopoietically active red BM can be distinguished from inactive yellow marrow composed primarily of fat. [10][11][12][13][14][15] With SPECT imaging, 99 mTc sulfur colloid is sequestered by macrophages in the BM thereby identifying areas of active (red) BM. PET radiotracers identify metabolically active cells within the BM.…”