Targeting Education as a Barrier to Implement Hypofractionation: Results of a Country-Wide Training Program.

Introduction: Access to radiation therapy in low- and middle-income countries (LMICs) could be improved with modern hypofractionated radiation therapy schedules, although their adoption remains limited. We aimed to evaluate perceptions regarding hypofractionation and the effect of a dedicated curriculum in an LMIC. Methods and Materials: We developed a pilot e-learning hypofractionation curriculum focused on breast, prostate, rectal cancer, and high-grade glioma in Colombia. International educators taught 13 weekly, 90-minute sessions. Participants completed pre- and postcurriculum questionnaires regarding hypofractionation attitudes, 1 to 5 Likert-scale self-confidence, and practices for 12 clinical scenarios. Physicians' responses were categorically scored "1" (for hypofractionation or ultrahypofractionation) or "0" (for conventional fractionation). We used the paired t test to measure pre- versus postcurriculum differences in self-confidence and the McNemar test to detect differences in hypofractionation selection. Results: Across 19 cities in Colombia, 147 clinicians enrolled: 61 radiation oncologists, 6 radiation oncology residents, 59 medical physicists, 18 physics residents, and 3 other staff. Among physicians, education was the greatest barrier to select hypofractionation, common in ultrahypofractionation for prostate (77.6%) and breast cancer (74.6%) and less common for moderate hypofractionation of prostate (61.2%) and breast cancer (52.2%). Additional perceived barriers included unfamiliarity with clinic protocols (7%-22%), clinical experience (5%-15%), personal preference (3%-16%), and lack of technology (3%-20%), with variation across different clinical settings. After the curriculum, paired (n = 38) physicians' selection of hypofractionation increased across all disease sites (mean aggregate score 6.2/12 vs 8.2/12, P <.001). Self-confidence among paired clinicians (n = 87) increased for prostate ultrahypofractionation (+0.45), rectal ultrahypofractionation (+0.43), breast hypofractionation (+0.38), and prostate hypofractionation (+0.23) (P ≤ .03). Conclusions: In an LMIC with a bundled payment system, lack of education and training was a perceived barrier for implementation of hypofractionation and ultrahypofractionation. A targeted e-learning hypofractionation curriculum increased participant confidence and selection of hypofractionated schedules.

Leveling Up the Access to Radiation Therapy in Latin America: Economic Analysis of Investment, Equity, and Inclusion Opportunities Up to 2030.

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.

Estimation of the Need for Radiation Therapy Services According to the Incidence of Cancer in Colombia to 2035.

PURPOSE: To estimate the supply and demand of current and future radiation therapy services by 2035 for Colombia. METHODS AND MATERIALS: The present study was performed by surveying different radiation therapy services identified in Colombia through the Colombian Association of Radiation Oncology. The demand was estimated based on incident cases and published information on the use of radiation therapy by type of cancer. Future demand was estimated under the assumption that incidence rates do not change and therefore the change in the number of cases is due to the change in the age structure of the Colombian population. Sensitivity analyses were conducted on the percentage of radiation therapy use by type of cancer. A Monte Carlo simulation was carried out to estimate the distribution of cases requiring radiation therapy, the amount of equipment, and the number of staff needed for care with the use of this technology. RESULTS: In total, Colombia has 69 linear accelerators, 2 radiosurgery equipment, 30 high-dose-rate brachytherapy pieces of equipment, 124 radiation therapy oncologists (113 working, 9 not working, and 2 not informed), and 275 radiation therapy technologists as of June 2020. It was estimated that to meet the current cancer burden the country would need a total of 162 radiation therapy oncologists, 121 medical physicists, and 323 radiation therapy technologists and to increase the number of radiation therapy technologists, radiation therapy oncologists, and medical physicists to 491, 246, and 184, respectively, to meet the disease burden by 2035 (73,684-88,743 cases per year). CONCLUSIONS: In Colombia it is estimated that there is a deficit of human resources and technology for radiation therapy; therefore, there is need to investment resources from the public and private sectors to provide timely and quality care to cancer patients requiring this treatment.

High-dose-rate brachytherapy delivered in two fractions as monotherapy for low-risk prostate cancer.

PURPOSE: High-dose-rate (HDR) brachytherapy has been accepted as an effective and safe method to treat prostate cancer. The aim of this study was to describe acute toxicity following HDR brachytherapy to the prostate, and to examine the association between dosimetric parameters and urinary toxicity in low-risk prostate cancer patients. MATERIAL AND METHODS: Patients with low-risk prostate cancer were given HDR brachytherapy as monotherapy in two 12.5 Gy fractions. Planning objectives for the planning target volume (PTV) were V100% ≥ 90% and V150% ≤ 35%. Planning objectives for organs at risk were V75% ≤ 1 cc for the bladder, rectum and perineum, and V125% ≤ 1 cc for the urethra. Toxicity was assessed three months after treatment using the Common Terminology Criteria for Adverse Events. RESULTS: Seventy-three patients were included in the analysis. Thirty-three patients (45%) reported having any type of toxicity in the three months following HDR brachytherapy. Most toxicity cases (26%) were grade 1 urinary toxicity. Mean coverage index was 0.89 and mean V100 was 88.85. Doses administered to the urethra were associated with urinary toxicity. Patients who received more than 111.3% of the prescribed dose in 1 cc of the urethra were four times more likely to have urinary toxicity compared to patients receiving less than 111.3% (OR = 4.71, 95% CI: 1.43-15.6; p = 0.011). CONCLUSIONS: High-dose-rate brachytherapy administered as monotherapy for prostate cancer proved to be a safe alternative treatment for patients with low-risk prostate cancer. Urinary toxicity was associated with the dose administered to 1 cc and 0.1 cc of the urethra and was remarkably inferior to the reported toxicity in similar studies.

Fusión de imágenes y protección de hipocampo para el tratamiento de metástasis cerebrales con radioterapia / Image fusion and hippocampus protection in radiotherapy treatment of brain metastases

Las imágenes de simulación obtenidas mediante TAC son actualmente el estándar para uso en los sistemas de planificación de haces externos empleados en los tratamientos de radioterapia. Sin embargo, una de las limitaciones es su bajo contraste y poca especificidad para la identificación y caracterización de lesiones tumorales y algunas estructuras a nivel de sistema nervioso central. Los nuevos algoritmos implementados en los sistemas de planificación de radioterapia permiten realizar la fusión de imágenes de RM con TAC de simulación, definir y proteger estructuras como el hipocampo, buscando administrar dosis bajas en esta zona, lograr mayores dosis a los volúmenes tumorales y disminuir los efectos secundarios derivados de tratamientos holoencefálicos con radioterapia. En este artículo se presentan las imágenes correspondientes a esta técnica de tratamiento.

CT simulation images are the current standard in external beam radiotherapy planning systems. However, the limitations of images obtained from CT scanning include their low contrast and low specificity in the identification and characterization of tumor lesions and some central nervous system structures. The new algorithms implemented in radiotherapy planning systems allow image fusion to be performed using MRI images and CT simulation images. It also allows structures like the hippocampus to be defined and protected, by administering lower Radiosurgery; doses to this area and higher doses to the tumor volume, thus decreasing side effects arising from whole brain radiotherapy treatment. Images corresponding to this treatment technique are presented in this article.

Displacements of fiducial markers in patients with prostate cancer treated with image guided radiotherapy: A single-institution descriptive study.

AIM: To describe daily displacements when using fiducial markers as surrogates for the target volume in patients with prostate cancer treated with IGRT. BACKGROUND: The higher grade of conformity achieved with the use of modern radiation technologies in prostate cancer can increase the risk of geographical miss; therefore, an associated protocol of IGRT is recommended. MATERIALS AND METHODS: A single-institution, retrospective, consecutive study was designed. 128 prostate cancer patients treated with daily on-line IGRT based on 2D kV orthogonal images were included. Daily displacement of the fiducial markers was considered as the difference between the position of the patient when using skin tattoos and the position after being relocated using fiducial markers. Measures of central tendency and dispersion were used to describe fiducial displacements. RESULTS: The implant itself took a mean time of 15 min. We did not detect any complications derived from the implant. 4296 sets of orthogonal images were identified, 128 sets of images corresponding to treatment initiation were excluded; 91 (2.1%) sets of images were excluded from the analysis after having identified that these images contained extreme outlier values. If IGRT had not been performed 25%, 10% or 5% of the treatments would have had displacements superior to 4, 7 or 9 mm respectively in any axis. CONCLUSIONS: Image guidance is required when using highly conformal techniques; otherwise, at least 10% of daily treatments could have significant displacements. IGRT based on fiducial markers, with 2D kV orthogonal images is a convenient and fast method for performing image guidance.

IMRT, RapidArc® and conformal radiotherapy in the treatment of tumours of the anal canal.

PURPOSE: To compare dosimetric results of the use of RapidArc® with simultaneous integrated boost, sliding window intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost, and conformal radiotherapy with sequential boost in the management of anal canal cancer. METHODS: Two patients with squamous cell cancer of the anal canal with compromised inguinal nodes were included. The simulation was performed in the supine position with a customized Vac-Lok™ immobilizer. Treatment volumes and organs at risk were defined in accordance with international recommendations. Dosimetric comparisons were made in the target volume by means of tumour conformity, coverage, and homogeneity indexes; in healthy organs, integral doses were compared. RESULTS: A similar planning target volume coverage was achieved with the three techniques. The two IMRT techniques demonstrated benefits in doses received by healthy organs compared to the conformal radiotherapy. RapidArc® showed reduction in the execution time and monitor units required for treatment compared with sliding window IMRT. CONCLUSIONS: The IMRT showed coverage and tumour conformity indexes similar to those of conformal radiotherapy with better dosimetric results in the organs at risk, which should translate into a better toxicity profile. RapidArc® demonstrated benefits over the sliding window IMRT, which makes treatment more comfortable for the patient with less uncertainty about intrafraction motion and a reduced potential for radiation-induced tumours.

Intensity modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) in a patient with left breast cancer and pectus excavatum.

INTRODUCTION: Pectus excavatum is a frequent anomaly. It represents a challenge for adjuvant radiotherapy in the conservative treatment of breast cancer. Primary objective of this study is to compare dosimetric outcomes, normal tissue complication probability (NTCP), and integral dose using four radiation techniques. Secondary objective is to describe acute toxicity and setup errors. METHODS AND MATERIALS: A 57-year-old female patient with an inner quadrant, left breast, ductal carcinoma in situ, was identified. Whole breast was prescribed with 50 Gy in 25 fractions. Boost planning target volume (PTV) was prescribed with 60 Gy in 30 fractions for sequential boost (SB) plans or 57.5 Gy in 25 fractions in the simultaneous integrated boost (SIB) plan. All plans were normalized to deliver 47.5 Gy to 95 % of the breast PTV. Daily image-guided radiotherapy (IGRT) was performed. Setup deviations were described. RESULTS: Constraints were not accomplished for heart when using intensity modulated radiotherapy (IMRT) + SB or conformal radiotherapy with three photon fields and SB. Left lung constraint was not achieved by any of the techniques in comparison. IMRT + SIB and conformal photons and electrons + SB plan were closer to the objective. Integral doses were lower with IMRT for heart and ipsilateral lung; however, it were higher for contralateral breast and lung. Coverage and tumoral conformity indexes were similar for all techniques in comparison. Greater inhomogeneity was observed with the photons and electrons + SB. IMRT + SIB treatment was administered daily with grade I skin toxicity. The highest setup error was observed in Y direction. CONCLUSION: Planning target volume coverage was similar with the four techniques. Homogeneity was superior with both IMRT plans. A good balance between dose constraints for organs at risk, PTV coverage, homogeneity, and NTCP was observed with IMRT + SIB. The documented daily setup error justifies the use of online IGRT.

Supervivencia en pacientes con cáncer de mama temprano tratadas con cirugía conservadora asociada a radioterapia en el Instituto Nacional de Cancerología / Survival in patients with early breast cancer treated with conservative surgery and radiotherapy at the National Cancer Institute of Colombia

Objetivo: Evaluar los resultados de pacientes con cáncer temprano de mama tratadas con cirugía conservadora y teleterapia en el servicio de radioterapia entre 2003 y 2004. Métodos: Serie de casos secuencial retrospectiva. Se realizó un análisis descriptivo aplicando medidas resumen y métodos de supervivencia. Resultados: Se incluyó a 75 pacientes con cáncer de mama temprano tratadas con cirugía conservadora asociada a teleterapia. La supervivencia global a 5 años fue del 92,9%; la supervivencia libre de recaída locorregional, del 88,4%; y la supervivencia libre de enfermedad, del 79,8%. La mayoría de las pacientes eran mayores de 50 años, posmenopáusicas, con tumores moderadamente diferenciados, de tipo ductal infiltrante y expresión de receptores hormonales. La mayoría de ellas no recibieron neoadyuvancia, y fueron tratadas con un vaciamiento axilar de más de 10 ganglios, márgenes de resección mayores a 1 cm y adyuvancia con quimioterapia y hormonoterapia. Pocas pacientes recibieron manejo radioterápico supraclavicular; la mayoría recibieron sobreimpresión. Dentro de los factores pronósticos se encontraron los receptores hormonales y la razón ganglionar. Conclusión: El cáncer de mama es la primera causa de incidencia y la segunda causa de mortalidad por cáncer entre las mujeres colombianas. La cirugía conservadora de mama asociada a radioterapia es el estándar actual de tratamiento en pacientes con cáncer temprano. Aunque las cifras de supervivencia global y libre de enfermedad son similares a las reportadas, la supervivencia libre de recaída locorregional resulta inferior. Se recomienda considerar los receptores como factor pronóstico para recaída locorregional y garantizar márgenes de sección libres de compromiso tumoral.

Objective: To evaluate the results of patients with early breast cancer treated with conservative surgery and teletherapy in the Department of Radiotherapy at the National Cancer Institute (NCI) between 2003 and 2004. Methods: Research was based upon a retrospective sequential case study. Descriptive analysis included the application of summarized measurement and survival methods. Results: Seventy-five patients with early breast cancer treated with conservative surgery in combination with teletherapy were included in the study. Overall survival at five years was 92.9%, loco-regional relapse free survival was 88.4%, and disease free survival was 79.8%. Most patients were over 50, postmenopausal, with moderately differentiated tumors of infiltrating ductal carcinoma and hormone receptor expression. The majority did not receive neoadjuvant therapy, had axilliary dissection on more than 10 lymph nodes with resection margins greater than one centimeter and adjuvant chemo and radiotherapy. A few patients underwent the majority received overpressing. Hormone receptors and the nodal region were included among prognostic factors. Conclusion: Although the overall survival and disease free rates were similar to those reported elsewhere; loco-regional relapse free survival turned out to be lower. We recommend considering receptors as loco-regional prognosisfactors and that tumor-free margin sections be assured in surgery.

Supervivencia en pacientes con cáncer de mama localmente avanzado tratadas con radioterapia posterior a mastectomía en el Instituto Nacional de Cancerología / Locally advance breast cancer survival after radiotherapy following mastectomy at the National Cancer Institute of Colombia

Objetivo: evaluar los resultados del manejo de pacientes con cáncer localmente avanzado de mama tratadas con mastectomía y teleterapia en el servicio de radioterapia del Instituto Nacional de Cancerología entre los años 2003 y 2004. Métodos: serie de casos secuencial retrospectiva. Se emplearon frecuencias, medidas de tendencia central y de dispersión. Se hizo un análisis de supervivencia libre de recaída locorregional, libre de enfermedad y global aplicando el método de Kaplan-Meyer y la regresión de Cox. Resultados: se identificaron 174 pacientes en su mayoría con tumores ductales, con compromiso ganglionar y expresión de receptores hormonales. El tratamiento se realizó con quimioterapia, seguida de mastectomía, vaciamiento axilar, quimioterapia, radioterapia y hormonoterapia adyuvante en la mayoría de casos. La supervivencia libre de recaída locorregional a cinco años fue de 88.,8%, la supervivencia libre de enfermedad fue de 63,3% y la supervivencia global fue de 84,4%. Conclusión: los datos de supervivencia libre de recaída locorregional son similares a los reportados en la literatura. La reconstrucción mamaria se asoció con un aumento en el peligro de recaída locorregional. La razón ganglionar fue un factor pronóstico relevante para supervivencia global, libre de enfermedad y libre de recaída local y regional, mientras que el grado tumoral fue un factor pronóstico relevante en supervivencia global y libre de enfermedad.

Objective: To evaluate survival after treatment with mastectomy and teletherapy for locally advance breast cancer at the National Cancer Institute of Colombia. Methods: A case serie analysis was conducted. Frequencies and measures of central tendency were applied. Locoregional relapse free survival, disease free survival and overall survival were determined with Kaplan-Meyer and Cox regression analyses. Results: 174 patiens were included. Most of the patients corresponded to ductal tumors with positive axillary nodes and hormone receptors. The treatment was neoadjuvant chemotherapy, mastectomy, axillary nodes resection, radiotherapy, and adjuvant hormone therapy. The 5-years locoregional relapse free survival was 88.8%, disease free survival was 63.3%, and overall survival 84.4%. Conclusions: The results are similar to previous reports. Breast reconstruction was associated with a greater chance of locoregional relapse. The node rate is a relevant predictor for overall survival, disease free survival, and locoregional relapse free survival, and tumor grade for the former two.