Browsing by Author "Li, B"

Now showing 1 - 6 of 6

Cross-Sectional International Survey to Determine the Educational Interests of Spanish-Speaking Latin American Radiation Oncologists
(American Society of Clinical Oncology, 2021) Mailhot Vega, BJ; De La Mata, DJ; Amendola, BJ; Li, B; Poitevin, AJ; Sarria, G; Sole, SJ; Sher, DJJ; Hardenbergh, P
PURPOSE. With the existing oncology disparities in Latin America, physician expertise has been cited as a possible contributor to inferior oncologic outcomes in some cancers. As two-dimensional radiotherapy rapidly evolved to intensity-modulated radiation therapy in Latin America, adequate contouring education is an actionable target to improving physician knowledge and clinical outcomes. Yet, topics of interest to Latin American radiation oncologists are underreported. We assessed Latin American interest in a virtual platform for case discussion and identified the educational topics of most interest to them. MATERIALS AND METHODS. A Spanish-language online survey was designed by a team of Latin American educators. The questions assessed professional nationality, desire for an online educational platform for case presentation, career length, and topics of interest. Educational topics included head and neck (H&N), CNS, GI, lung, gynecologic, breast, and pediatric cancers, lymphoma, sarcoma, stereotactic body radiotherapy (SBRT), brachytherapy, and medical physics. RESULTS. One hundred thirty-three surveys were included for analysis. Overall, 127 respondents (98%) affirmed interest in participating in a virtual platform for case discussion and treatment advances. The most popular educational themes were H&N cancers (24%), SBRT (14%), and CNS cancers (13%). Of countries with > 10 respondents, the most popular educational topic remained H&N cancers for Argentina, Chile, and Mexico, but the most popular topic among Peruvian respondents was CNS cancer (27%). CONCLUSION. With international collaboration and a large sample size, we present the first survey results describing Latin American radiation oncology educational interests. Participants were overwhelmingly interested in a virtual platform, and most were specifically interested in H&N cancer education. These results can be used for focused didactic preparation in Latin America. Future efforts should expand on improving representation and outreach among Central American radiation oncologists.
Exploring the Cost of Radiation Therapy Delivery for Locally Advanced Cervical Cancer in a Public and a Private Center in Latin America Using Time-Driven Activity-Based Costing
(Elsevier Inc., 2023) Li, B; Hirata, E; Trejo, JM; Garcia, B; Chang, B; Malhotra, S; Ning, M; Sarria, GJ
In low- and middle-income countries (LMICs), 85% of cervical cancer diagnoses and 88% of cervical cancer deaths occur annually.1,2 The majority of presentations (with reports up to 75%)3 are locally advanced (International Federation of Gynecology and Obstetrics stages IB2 and IIBIVA) where combination external beam radiation therapy (EBRT) followed by brachytherapy is indicated for curative treatment.4 Despite large bodies of evidence that radiation therapy (RT) is effective for treating cancer, a shortage of economic investment limits its availability and contributes to global shortages.5,6 RT is generally described as a costeffective treatment, but only limited data exists about the institutional cost of combination RT in LMICs.7 Understanding treatment costs is critical for cancer capacity planning efforts, particularly in regions where radiation oncology is less understood or newly developing.
Leveling Up the Access to Radiation Therapy in Latin America: Economic Analysis of Investment, Equity, and Inclusion Opportunities Up to 2030
(Elsevier Inc., 2023) Sarria, GR; Martinez, DA; Li, B; Castillo, RD; Salgado, A; Pinillos, L; Felix, A; Bobadilla, I; Ferraris, G; Castilho, M; Carmona, J; Leon, B; Aviles, L; Ricagni, L; Isa, N; Flores, C; Giordano, FA; Zubizarreta, EH; Polo, A; Sarria, GJ
Purpose: Latin America faces a shortage in radiation therapy (RT) units and qualified personnel for timely and high-quality treatment of patients with cancer. Investing in equitable and inclusive access to RT over the next decade would prevent thousands of deaths. Measuring the investment gap and payoff is necessary for stakeholder discussions and capacity planning efforts. Methods and Materials: Data were collected from the International Atomic Energy Agency's Directory of Radiotherapy Centers, industry stakeholders, and individual surveys sent to national scientific societies. Nationwide data on available devices and personnel were compiled. The 10 most common cancers in 2020 with RT indication and their respective incidence rates were considered for gap calculations. The gross 2-year financial return on investment was calculated based on an average monthly salary across Latin America. A 10-year cost projection was calculated according to the estimated population dynamics for the period until 2030. Results: Eleven countries were included in the study, accounting for 557,213,447 people in 2020 and 561 RT facilities. Approximately 1,065,684 new cancer cases were diagnosed, and a mean density of 768,469 (standard deviation ±392,778) people per available unit was found. By projecting the currently available treatment fractions to determine those required in 2030, it was found that 62.3% and 130.8% increases in external beam RT and brachytherapy units are needed from the baseline, respectively. An overall regional investment of approximately United States (US) $349,650,480 in 2020 would have covered the existing demand. An investment of US $872,889,949 will be necessary by 2030, with the expectation of a 2-year posttreatment gross return on investment of more than US $2.1 billion from patients treated in 2030 only. Conclusions: Investment in RT services is lagging in Latin America in terms of the population's needs. An accelerated outlay could save additional lives during the next decade, create a self-sustaining system, and reduce region-wide inequities in cancer care access. Cash flow analyses are warranted to tailor precise national-level intervention strategies.
Longitudinal Remote SBRT/SRS Training in Latin America: A Prospective Cohort Study
(Frontiers Media S.A., 2022) Sarria, GR; Timmerman, R; Hermansen, M; Malhotra, S; Chang, B; Carter, R; Martinez, DA; Sarria, GJ; Giordano, FA; Chetty, IJ; Roa, D; Li, B
Background: Continuing medical education in stereotactic technology are scarcely accessible in developing countries. We report the results of upscaling a longitudinal telehealth training course on stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS), after successfully developing a pilot course in Latin America. Methods: Longitudinal training on SBRT and SRS was provided to radiation oncology practitioners in Peru and Colombia at no cost. The program included sixteen weekly 1-hour live conferencing sessions with interactive didactics and a cloud-based platform for case-based learning. Participant-reported confidence was measured in 16 SBRT/SRS practical domains, based on a 1-to-5 Likert scale. Pre- and post-curriculum exams were required for participation credit. Knowledge-baseline, pre- and post-curriculum surveys, overall and single professional-group confidence changes, and exam results were assessed. Results: One hundred and seventy-three radiotherapy professionals participated. An average of 56 (SD ±18) attendees per session were registered. Fifty (29.7%) participants completed the pre- and post-curriculum surveys, of which 30% were radiation oncologists (RO), 26% radiation therapists (RTT), 20% residents, 18% medical physicists and 6% neurosurgeons. Significant improvements were found across all 16 domains with overall mean +0.55 (SD ±0.17, p<0.001) Likert-scale points. Significant improvements in individual competences were most common among medical physicists, RTT and residents. Pre- and post-curriculum exams yielded a mean 16.15/30 (53.8 ± 20.3%) and 23.6/30 (78.7 ± 19.3%) correct answers (p<0.001). Conclusion: Longitudinal telehealth training is an effective method for improving confidence and knowledge on SBRT/SRS amongst professionals. Remote continuing medical education should be widely adopted in lower-middle income countries.
Low-dose radiotherapy to the lungs using an interventional radiology C-arm fluoroscope: Monte Carlo treatment planning and dose measurements in a postmortem subject
(Institute of Physics, 2022) Leon, S; Paucar, O; Correa, N; Glassell, M; Gonzales, A; Olguin, E; Shankar, A; Moskvin, V; Schwarz, B; Alva-Sanchez, M; Moyses, H; Hamrick, B; Sarria, GR; Li, B; Tajima, T; Necas, A; Guzman, C; Challco, R; Montoya, M; Meza, Z; Zapata, M; Gonzales, A; Marquina, J; Quispe, K; Chavez, T; Castilla, L; Moscoso, J; Ramirez, J; Marquez ,F; Neira, R; Vilca, W; Mendez, J; Hernandez, J; Roa, D
Objective. The goal of this study was to use Monte Carlo (MC) simulations and measurements to investigate the dosimetric suitability of an interventional radiology (IR) c-arm fluoroscope to deliver low-dose radiotherapy to the lungs. Approach. A previously-validated MC model of an IR fluoroscope was used to calculate the dose distributions in a COVID-19-infected patient, 20 non-infected patients of varying sizes, and a postmortem subject. Dose distributions for PA, AP/PA, 3-field and 4-field treatments irradiating 95% of the lungs to a 0.5 Gy dose were calculated. An algorithm was created to calculate skin entrance dose as a function of patient thickness for treatment planning purposes. Treatments were experimentally validated in a postmortem subject by using implanted dosimeters to capture organ doses. Main results. Mean doses to the left/right lungs for the COVID-19 CT data were 1.2/1.3 Gy, 0.8/0.9 Gy, 0.8/0.8 Gy and 0.6/0.6 Gy for the PA, AP/PA, 3-field, and 4-field configurations, respectively. Skin dose toxicity was the highest probability for the PA and lowest for the 4-field configuration. Dose to the heart slightly exceeded the ICRP tolerance
Monte Carlo simulations and phantom validation of low-dose radiotherapy to the lungs using an interventional radiology C-arm fluoroscope
(Associazione Italiana di Fisica Medica, 2022) Roa, D; Leon, S; Paucar, O; Gonzales, A; Schwarz, B; Olguin, E; Moskvin, V; Alva-Sanchez, M; Glassell, M; Correa, N; Moyses, H; Shankar, A; Hamrick, B; Sarria, GR; Li, B; Tajima, T; Necas, A; Guzman, C; Challco, R; Montoya, M; Meza, Z; Zapata, M; Marquez, F; Neira, R; Vilca, W; Mendez, J; Hernandez, J
Purpose: To use MC simulations and phantom measurements to investigate the dosimetry of a kilovoltage x-ray beam from an IR fluoroscope to deliver low-dose (0.3–1.0 Gy) radiotherapy to the lungs. Materials and Methods: PENELOPE was used to model a 125 kV, 5.94 mm Al HVL x-ray beam produced by a fluoroscope. The model was validated through depth-dose, in-plane/cross-plane profiles and absorbed dose at 2.5-, 5.1-, 10.2- and 15.2-cm depths against the measured beam in an acrylic phantom. CT images of an anthropomorphic phantom thorax/lungs were used to simulate 0.5 Gy dose distributions for PA, AP/PA, 3-field and 4-field treatments. DVHs were generated to assess the dose to the lungs and nearby organs. Gafchromic film was used to measure doses in the phantom exposed to PA and 4-field treatments, and compared to the MC simulations. Results: Depth-dose and profile results were within 3.2% and 7.8% of the MC data uncertainty, respectively, while dose gamma analysis ranged from 0.7 to 1.0. Mean dose to the lungs were 1.1-, 0.8-, 0.9-, and 0.8- Gy for the PA, AP/PA, 3-field, and 4-field after isodose normalization to cover ∼ 95% of each lung volume. Skin dose toxicity was highest for the PA and lowest for the 4-field, and both arrangements successfully delivered the treatment on the phantom. However, the dose distribution for the PA was highly non-uniform and produced skin doses up to 4 Gy. The dose distribution for the 4-field produced a uniform 0.6 Gy dose throughout the lungs, with a maximum dose of 0.73 Gy. The average percent difference between experimental and Monte Carlo values were −0.1% (range −3% to +4%) for the PA treatment and 0.3% (range −10.3% to +15.2%) for the 4-field treatment. Conclusion: A 125 kV x-ray beam from an IR fluoroscope delivered through two or more fields can deliver an effective low-dose radiotherapy treatment to the lungs. The 4-field arrangement not only provides an effective treatment, but also significant dose sparing to healthy organs, including skin, compared to the PA treatment. Use of fluoroscopy appears to be a viable alternative to megavoltage radiation therapy equipment for delivering low-dose radiotherapy to the lungs.