Longitudinal Changes in Active Bone Marrow for Cervical Cancer Patients Treated With Concurrent Chemoradiotherapy

Publication date: Available online 29 November 2016
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Sonal S. Noticewala, Nan Li, Casey W. Williamson, Carl K. Hoh, Hanjie Shen, Michael T. McHale, Cheryl C. Saenz, John Einck, Steven Plaxe, Florin Vaida, Catheryn M. Yashar, Loren K. Mell
Purpose/Objective(s)To quantify longitudinal changes in active bone marrow (ABM) distributions within unirradiated (extra-pelvic) and irradiated (pelvic) bone marrow (BM) in cervical cancer patients treated with concurrent chemoradiotherapy (CRT).Materials/MethodsWe sampled 39 cervical cancer patients treated with CRT, of which 25 were treated with concurrent cisplatin (40 mg/m²) and 14 were treated with cisplatin (40 mg/m²)/ gemcitabine (50-125 mg/m²) (C/G). Patients underwent ¹⁸F-FDG-PET/CT imaging at baseline and 1.5-6.0 months post-treatment. ABM was defined as the subvolume of bone with standardized uptake value (SUV) above the mean SUV of the total bone. The primary aim was to measure the compensatory response, defined as the change in the log of the ratio of extra-pelvic vs. pelvic ABM percent from baseline to post-treatment. We also quantified the change in the proportion of ABM and mean SUV in pelvic and extra-pelvic BM using a two-sided paired t-test.ResultsWe observed a significant increase in the overall extra-pelvic compensatory response following CRT (0.381; 95% CI: 0.312, 0.449), and separately in patients treated with cisplatin (0.429; 95% CI: 0.340, 0.517) and C/G (0.294; 95% CI: 0.186, 0.402). We observed a trend toward higher compensatory response in patients treated with cisplatin compared to C/G (p=0.057). Pelvic ABM percentage was reduced after CRT both in patients receiving cisplatin (p<0.001) and C/G (p<0.001), while extra-pelvic ABM percentage was increased in patients receiving cisplatin (p<0.001) and C/G (p<0.001). The mean SUV in pelvic structures was lower after CRT with both cisplatin (p<0.001) and C/G (p<0.001). The mean SUV appeared lower in extra-pelvic structures after CRT in patients treated with C/G (p=0.076), but not with cisplatin (p=0.942). We also observed that older age and more intense chemotherapy regimens were correlated with a decreased compensatory response on multivariable analysis. In patient's treated with C/G, mean pelvic bone marrow dose was found to be negatively correlated with the compensatory response.ConclusionPatients have differing subacute compensatory responses after CRT, owing to variable recovery in unirradiated marrow. Intensive chemotherapy regimens appear to decrease the extra-pelvic compensatory response, which may lead to increased hematologic toxicity.



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