Po02

Purpose Definitive radiotherapy (RT) for locally advanced cervical cancer in the US includes external beam radiotherapy (EBRT) with brachytherapy (BT). Although there are ABS guidelines for BT dose/fractionation regimens, there is limited data on actual usage. Our project aims to provide a contemporary assessment of cervical cancer BT boost modality and dose/fractionation regimens in the US, and their associations with patient/facility characteristics and impact by COVID-19 pandemic. Materials and Methods We utilized the 2020 National Cancer Database (NCDB). Starting in 2018, additional “phases” of radiation treatment, such as boost treatments, were required to be reported by Commission on Cancer (CoC)-accredited facilities. Inclusion criteria included cervical cancer patients diagnosed in 2018-2020 who received definitive RT defined as EBRT and BT in a total of 2 phases with the total number of BT fractions <10 as per ABS guideline, without surgery in the same CoC facility. Patient characteristics, RT modality, and dose/fractionation regimen were examined using frequencies and proportions. The number of fractions for BT (1-9) was collapsed into 3 levels: 1-3, 4, and 5-9 fractions. The associations of patient characteristics and treatment facility with fractionation regimen were evaluated separately using univariate multinomial logistic regression. Statistical analysis was performed using SAS. Results The cohort includes 961 patients. In 2018, 2019, and 2020, 257 patients (26.7%), 341 patients (35.5%), and 363 patients (37.8%) were diagnosed, respectively. Other than 39 patients (4.1%) whose BT is not otherwise specified, the remainder received HDR or LDR BT (922 patients; 95.9%) and is further analyzed. More patients received HDR than LDR BT (98.2% vs 1.8%; p<0.0001) and intracavitary than interstitial BT (91.0% vs 9.0%; p<0.0001). Table 1 shows the dose/fractionation regimen for HDR BT, with common regimens including 6Gy x 5 fractions, 7Gy x 4 fractions, and 5Gy x 3 fractions. Spanish or Hispanic origin (yes vs no), primary payer at diagnosis (insured vs not), and facility type (academic/research program vs not) significantly affected fractionation regimen delivery. For a patient with non-Spanish or Hispanic origin, the odds of her receiving >4 fractions vs <4 fractions were about twice of that of a patient with Spanish or Hispanic origin (OR=2.12, 95% CI=1.34-3.36, p=0.0014). For an insured patient, the odds of her receiving >4 fractions vs <4 fractions were about twice of that of an uninsured patient (OR=2.21, 95% CI=1.13-4.33, p=0.0201). For a patient receiving treatment in a non-academic/research program, the odds of her receiving >4 fractions vs 4 fractions were about twice of that of a patient receiving in an academic or research facility (OR=2.35, 95% CI=1.48-3.72, p=0.0003). Conclusions The study provides a contemporary assessment of cervical cancer BT boost modality and dose/fractionation regimens in the US, finding that the number of patients treated with definitive EBRT with BT was not significantly impacted by COVID-19 pandemic. Patients who are non-Hispanic, insured, or at a non-academic/research facility were more likely to receive >4 fractions than their counterparts. Definitive radiotherapy (RT) for locally advanced cervical cancer in the US includes external beam radiotherapy (EBRT) with brachytherapy (BT). Although there are ABS guidelines for BT dose/fractionation regimens, there is limited data on actual usage. Our project aims to provide a contemporary assessment of cervical cancer BT boost modality and dose/fractionation regimens in the US, and their associations with patient/facility characteristics and impact by COVID-19 pandemic. We utilized the 2020 National Cancer Database (NCDB). Starting in 2018, additional “phases” of radiation treatment, such as boost treatments, were required to be reported by Commission on Cancer (CoC)-accredited facilities. Inclusion criteria included cervical cancer patients diagnosed in 2018-2020 who received definitive RT defined as EBRT and BT in a total of 2 phases with the total number of BT fractions <10 as per ABS guideline, without surgery in the same CoC facility. Patient characteristics, RT modality, and dose/fractionation regimen were examined using frequencies and proportions. The number of fractions for BT (1-9) was collapsed into 3 levels: 1-3, 4, and 5-9 fractions. The associations of patient characteristics and treatment facility with fractionation regimen were evaluated separately using univariate multinomial logistic regression. Statistical analysis was performed using SAS. The cohort includes 961 patients. In 2018, 2019, and 2020, 257 patients (26.7%), 341 patients (35.5%), and 363 patients (37.8%) were diagnosed, respectively. Other than 39 patients (4.1%) whose BT is not otherwise specified, the remainder received HDR or LDR BT (922 patients; 95.9%) and is further analyzed. More patients received HDR than LDR BT (98.2% vs 1.8%; p<0.0001) and intracavitary than interstitial BT (91.0% vs 9.0%; p<0.0001). Table 1 shows the dose/fractionation regimen for HDR BT, with common regimens including 6Gy x 5 fractions, 7Gy x 4 fractions, and 5Gy x 3 fractions. Spanish or Hispanic origin (yes vs no), primary payer at diagnosis (insured vs not), and facility type (academic/research program vs not) significantly affected fractionation regimen delivery. For a patient with non-Spanish or Hispanic origin, the odds of her receiving >4 fractions vs <4 fractions were about twice of that of a patient with Spanish or Hispanic origin (OR=2.12, 95% CI=1.34-3.36, p=0.0014). For an insured patient, the odds of her receiving >4 fractions vs <4 fractions were about twice of that of an uninsured patient (OR=2.21, 95% CI=1.13-4.33, p=0.0201). For a patient receiving treatment in a non-academic/research program, the odds of her receiving >4 fractions vs 4 fractions were about twice of that of a patient receiving in an academic or research facility (OR=2.35, 95% CI=1.48-3.72, p=0.0003). The study provides a contemporary assessment of cervical cancer BT boost modality and dose/fractionation regimens in the US, finding that the number of patients treated with definitive EBRT with BT was not significantly impacted by COVID-19 pandemic. Patients who are non-Hispanic, insured, or at a non-academic/research facility were more likely to receive >4 fractions than their counterparts.