PV QA 1 - Poster Viewing Q&A 1
SU_6_2055 - Dosimetric Predictors of Acute Hematologic Toxicity Due to Intensity-Modulated Pelvic Radiation Therapy With Concurrent Chemotherapy for Chinese Rectal and Cervical Cancer Patients
Sunday, October 21
1:15 PM - 2:45 PM
Location: Innovation Hub, Exhibit Hall 3
Dosimetric Predictors of Acute Hematologic Toxicity Due to Intensity-Modulated Pelvic Radiation Therapy With Concurrent Chemotherapy for Chinese Rectal and Cervical Cancer Patients
Y. Yang1, W. Li2, J. Qian1, J. Zhang1, Y. Shen1, and Y. Tian1; 1Department of Radiotherapy & Oncology, The Second Affiliated Hospital of Soochow University; Institute of Radiotherapy & Oncology, Soochow University; Suzhou Key Laboratory for Radiation Oncology, Suzhou, China, 2Department of Medical Oncology, Yueyang Guangji Hospital, Yueyang, China
Purpose/Objective(s): Hematologic toxicity is a major common side effect after chemoradiotherapy in pelvic cancer patients. Here, we investigate the clinical and dosimetric factors associated with acute hematologic toxicity in Chinese rectal and cervical cancer patients treated with pelvic intensity-modulated radiotherapy with concurrent chemotherapy.
Materials/Methods: We retrospectively analyzed 167 patients receiving concurrent chemoradiotherapy or pelvic radiotherapy alone. The volume of pelvic bone marrow receiving 5 Gy, 10 Gy, 20 Gy, 30 Gy, 40 Gy, and 50 Gy and the patient baseline clinical characteristics were calculated. The χ2 test and univariate and multiple logistic regression analyses were used to evaluate associations between the dosimetric parameters and grade ≥ 2 acute hematologic toxicity.
Results: One hundred and fifty-seven patients were eligible for analysis, and of these patients, 105 (66.9%) had grade ≥ 2 acute HT. Patients treated with chemoradiotherapy with pelvic bone marrow V10 ≥90%, V20 ≥75%, V30 ≥59.2%, and V40 ≥37% had higher rates of grade ≥ 2 hematologic toxicity than those with pelvic bone marrow V10 < 90%, V20 < 75%, V30 < 59.2%, and V40 < 37% (85.2% vs. 60.4%, P = 0.004; 78.9% vs. 58.1%, P = 0.027; 83.3% vs. 60.8%, P = 0.010; 82.3% vs. 60.0%, P = 0.011; respectively). Multiple logistic regression analysis showed that increased pelvic bone marrow V10 and pelvic bone marrow V40 were associated with increased grade 2 or worse hematologic toxicity for patients treated with chemoradiotherapy (odds ratio, 4.07; 95% confidence interval, 1.38–11.96; P = 0.011; odds ratio, 3.41; 95% confidence interval, 1.20-9.69; P = 0.022; respectively).
Conclusion: Increased pelvic bone marrow V10 and V40 were associated with hematologic toxicity in cervical and rectal cancer patients undergoing concurrent chemoradiotherapy. We suggest that pelvic bone marrow should be routinely considered to be an at-risk organ in rectal and cervical cancer patients treated with pelvic radiotherapy.
Author Disclosure: Y. Yang: None. W. Li: None. J. Zhang: None.