Radiation Therapy Physics Quality Assurance and Management Practices in Low- and Middle-Income Countries: An Initial Pilot Survey in Six Countries and Validation Through a Site Visit

Purpose

Our purpose was to assess physics quality assurance (QA) practices in less resourced radiation therapy (RT) centers to improve quality of care.

Methods and Materials

A preliminary study was conducted in 2020 of 13 select RT centers in 6 countries, and in 2021, our team conducted onsite visits to all the RT centers in Ghana, one of the countries from the initial survey. The RT centers included 1 private and 2 public institutions (denoted as Public-1 and Public-2). Follow-up surveys were sent to 17 medical physicists from the site visit. Questions centered on the topics of equipment, institutional practice, physics quality assurance, management, and safety practices. Qualitative and descriptive methods were used for data analysis. Questions regarding operational challenges (machine downtime, patient-related issues, power outages, and staffing) were asked on a 5-point Likert scale.

Results

The preliminary survey from 2020 had a 92% response rate. One key result showed that for RT centers in lower gross national income per capita countries there was a direct correlation between QA needs and the gross national income per capita of the country. The needs identified included film/array detectors, independent dose calculation software, calibration of ion chambers, diodes, thermoluminiscence diodes (TLDs), phantoms for verification, Treatment Planning System (TPS) test phantoms, imaging test phantoms and film dosimeters, education, and training. For the post survey after the site visit in 2021, we received a 100% response rate. The private and the Public-1 institutions each have computed tomography simulators located in their RT center. The average daily patient external beam workload for each clinic on a linear accelerator was: private = 25, Public-1 = 55, Public-2 = 40. The Co-60 workload was: Public-1 = 45, Public-2 = 25 (there was no Co-60 at the private hospital). Public-1 and -2 lacked the equipment necessary to conform to best practices in Task Group reports (TG) 142 and 198. Public-2 reported significant operational challenges. Notably, Public-1 and -2 have peer review chart rounds, which are attended by clinical oncologists, medical physicists, physicians, and physics trainees. All 17 physicists who responded to the post site visit survey indicated they had a system of documenting, tracking, and trending patient-related safety incidents, but only 1 physicist reported using International Atomic Energy Agency Safety in Radiation Oncology.

Conclusions

The preliminary study showed a direct correlation between QA needs and the development index of a country, and the follow-up survey examines operational and physics QA practices in the RT clinics in Ghana, one of the initial countries surveyed. This will form the basis of a planned continent-wide survey in Africa intended to spotlight QA practices in low- and middle-income countries, the challenges faced, and lessons learned to help understand the gaps and needs to support local physics QA and management programs. Audits during the site visit show education and training remain the most important needs in operating successful QA programs.

Heterogeneity in head and neck cancer incidence among black populations from Africa, the Caribbean and the USA: Analysis of cancer registry data by the AC3

BACKGROUND

Africa and the Caribbean are projected to have greater increases in Head and neck cancer (HNC) burden in comparison to North America and Europe. The knowledge needed to reinforce prevention in these populations is limited. We compared for the first time, incidence rates of HNC in black populations from African, the Caribbean and USA.

METHODS

Annual age-standardized incidence rates (IR) and 95% confidence intervals (95%CI) per 100,000 were calculated for 2013-2015 using population-based cancer registry data for 14,911 HNC cases from the Caribbean (Barbados, Guadeloupe, Trinidad & Tobago, N = 443), Africa (Kenya, Nigeria, N = 772) and the United States (SEER, Florida, N = 13,696). We compared rates by sub-sites and sex among countries using data from registries with high quality and completeness.

RESULTS

In 2013-2015, compared to other countries, HNC incidence was highest among SEER states (IR: 18.2, 95%CI = 17.6-18.8) among men, and highest in Kenya (IR: 7.5, 95%CI = 6.3-8.7) among women. Nasopharyngeal cancer IR was higher in Kenya for men (IR: 3.1, 95%CI = 2.5-3.7) and women (IR: 1.5, 95%CI = 1.0-1.9). Female oral cavity cancer was also notably higher in Kenya (IR = 3.9, 95%CI = 3.0-4.9). Blacks from SEER states had higher incidence of laryngeal cancer (IR: 5.5, 95%CI = 5.2-5.8) compared to other countries and even Florida blacks (IR: 4.4, 95%CI = 3.9-5.0).

CONCLUSION

We found heterogeneity in IRs for HNC among these diverse black populations; notably, Kenya which had distinctively higher incidence of nasopharyngeal and female oral cavity cancer. Targeted etiological investigations are warranted considering the low consumption of tobacco and alcohol among Kenyan women. Overall, our findings suggest that behavioral and environmental factors are more important determinants of HNC than race.

Radiotherapy in the Caribbean: a spotlight on the human resource and equipment challenges among CARICOM nations

BACKGROUND

There is limited data on access to radiotherapy services for CARICOM nations.

METHODS

This was a descriptive mixed-methods observational study which used data collected via survey from staff working in Radiation Oncology in 14 CARICOM countries. Benchmark recommendations from the International Atomic Energy Agency were compared to existing numbers. The Directory of Radiotherapy Centers, World Bank, and Global Cancer Observatory databases were all accessed to provide information on radiotherapy machines in the region, population statistics, and cancer incidence data respectively. Both population and cancer incidence-based analyses were undertaken to facilitate an exhaustive review.

RESULTS

Radiotherapy machines were present in only 50% of the countries. Brachytherapy services were performed in only six countries (42.9%). There were a total of 15 external beam machines, 22 radiation oncologists, 22 medical physicists, and 60 radiation therapists across all nations. Utilizing patient-based data, the requirement for machines, radiation oncologists, medical physicists, and radiation therapists was 40, 66, 44, and 106, respectively. Only four (28.6%) countries had sufficient radiation oncologists. Five (35.7%) countries had enough medical physicists and radiation therapists. Utilizing population-based data, the necessary number of machines, radiation oncologists, and medical physicists was 105, 186, and 96 respectively. Only one county (7.1%) had an adequate number of radiation oncologists. The number of medical physicists was sufficient in just three countries (21.4%). There were no International Atomic Energy Agency population guidelines for assessing radiation therapists. A lower economic index was associated with a larger patient/population to machine ratio. Consequentially, Haiti had the most significant challenge with staffing and equipment requirements, when compared to all other countries, regardless of the evaluative criteria. Depending on the mode of assessment, Haiti's individual needs accounted for 37.5% (patient-based) to 59.0% (population-based) of required machines, 40.1% (patient-based) to 59.7% (population-based) of needed radiation oncologists, 38.6% (patient-based) to 58.3% (population-based) of medical physicists, and 42.5% (patient-based) of radiation therapists.

CONCLUSION

There are severe deficiencies in radiotherapy services among CARICOM nations. Regardless of the method of comparative analysis, the current allocation of equipment and staffing scarcely meets 50% of regional requirements.

Investigation of triple negative breast cancer rates in women diagnosed with breast cancer in Trinidad and Tobago

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Background: According to the WHO/PAHO, Trinidad and Tobago (T&T) has the 2nd highest breast cancer mortality rate in the Caribbean region. In T&T, citizens of African descent make up about 36.8% of the T&T population, with 24.8% being of East Indian ancestry, and 32.4% identifying as having mixed heritage. In the United States, it has been showed that African American women, despite being diagnosed less often, have an earlier onset of breast cancer with less favorable clinical outcomes. One of the factors studied has been the higher frequency of triple negative breast cancer (TNBC) in African American women particularly when these patients are diagnosed at a younger age. Notably, a large proportion of breast cancer cases in T&T appear to occur at a young age, with nearly 36% of them being diagnosed under the age of 50. However, breast cancer tumor phenotypes have not been well studied. Therefore, we sought to investigate the distribution of tumor hormone receptor markers in the T&T breast cancer population. Methods: At the National Radiotherapy Center, T&T’s main oncology unit, we investigated breast cancer patients born in T&T using paper chart reviews. We collected information about their demographics, personal breast cancer diagnosis, tumor hormone receptor status and germline genetic testing results. Results: So far, we reviewed 90 patient charts, and in our sample, 33.3% (30/90) had TNBC. This is higher than the rates in the US where TNBC accounts for 10-20% of breast cancer patients, and of those TNBC cases, 10.6% have BRCA 1 or BRCA 2 mutations. In our T&T sample, of those with TNBC, 23.3% (7/30) had a HBOC mutation (5 BRCA, 1 TP53 and 1 PTEN). Average diagnosis age of TNBC cases reported in our sample was 45.7 years. In our sample, 52.2% (47/90) identified as having African ancestry, 37.8% (34/90) identified as having East Indian ancestry and 10% (9/90) identified as Mixed. Of the patients with TNBC, 63.3% (19/30) were of African ancestry, 30.0% (9/30) were of East Indian ancestry and 6.7% (2/30) identified as Mixed. Conclusions: Therefore, our sample results suggest that there is a significant portion of the breast cancer cases being TNBC in the T&T population, particularly in citizens with African ancestry. As we continue to finalize the incoming data, we hope to draw associations between tumor pathology, clinical presentation and genetic profiles. However, these initial results demonstrate the need to study tumor pathology within the T&T population, as this could lead to improved clinical and screening guidelines specific to T&T citizens.

African-Caribbean Cancer Consortium Scientific and Training Conference 2017

The sixth International African-Caribbean Cancer Consortium (AC3) Conference was held 6-9 October 2017 in Miami, Florida, U.S.A. The conference was open to all researchers, trainees, clinical and public health professionals, and community members, and served as an international hub for the United States, the Caribbean, and Africa. Sessions included AC3 collaboration meetings, cancer surveillance and research skills training workshops, and a community cancer prevention conference.

Differential vaginal wall dosing in high-dose rate brachytherapy for endometrial cancer: The potential for superior coverage of at-risk areas while preserving organs at risk—An analysis of simulated data

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Background: The treatment of curable endometrial cancer (EC)involves surgery with adjuvant radiotherapy. Histology of EC is a major determining factor for intracavitary brachytherapy (ICRT) treatment volume in early stage EC. Many guidelines recommend ICRT treatment of an extended volume up to the whole length of the vaginal stump (VS) for cases of high risk histologies (HRH) wherein a differential dosing of proximal and distal VS has the potential to achieve targeted therapeutic doses to at risk areas without compromise to critical structures.We present a simulated novel way to treat the VS by ICRT in cases of EC with HRH. Analysis of the simulated and approved plans allow us to compare the doses to organs at risk (OAR’s). Methods: Seventy-five cases from July 2017-August 2018 were reviewed and twenty-five (25) met the criteria for inclusion in this study. All these cases received External Beam Radiation Therapy (EBRT) dose of 50.4Gy/28. The ICRT simulation CT data-set was subsequently used to generate the study plan which was then compared to the actual treatment plan. In order to treat the whole VS but spare OARs a club-shaped design was proposed. This technique involved treating the upper 1/3 with a prescription point at 0.5cm lateral to the applicator surface and the lower 2/3 with a prescription point at the applicator surface. The length of the VS was defined from the tip of the applicator to 2cm superior to the introitus. The D2cc values for the contoured bladder and rectum were extracted from the treatment plan and used along with the D2cc values from the EBRT treatment to calculate OAR EQD2. QUANTEC Constraints used were (ICRU 83): EQD2 bladder: 90Gy; EQD2 rectum: 75Gy. Once calculated, the results were analyzed and the percent deviation between the proposed plan and the constraints as well as the approved plan were determined. Results: Twelve (12) of twenty-five (25) cases were HRH cases. The club-shaped design to treat the whole VS didn't further compromise the OAR (EQD2: 22% below constraints) or the rectum (EQD2: 1% below constraints). There was only a 2% difference between the final constraints in both treatment techniques. Conclusions: This technique to treat the full VS length can be used without adversely affecting OAR toxicities with superior coverage to at risk areas while maintaining dose constraints to OAR. Results, however, are limited by the small sample size.

Investigation of HBOC germline mutations in women diagnosed with breast cancer in Trinidad and Tobago

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Background: Trinidad and Tobago (T&T) is the southern-most Caribbean island, and according to the WHO/PAHO, it has the 2nd highest breast cancer mortality rate in the region. Notably, a large proportion of breast cancer cases in T&T occur at a young age; with nearly 36% of them being diagnosed under the age of 50. There is a known association between a younger age at diagnosis and Hereditary Breast and Ovarian Cancer syndrome (HBOC). Yet, the prevalence of HBOC mutations remains unknown in T&T, as genetic counseling and testing services are extremely limited in the region. Therefore, we sought to determine the prevalence and spectrum of HBOC mutations in T&T. Methods: At the National Radiotherapy Center, T&T’s main oncology unit, female breast cancer patients, who met NCCN criteria for further genetic counseling and testing were recruited through chart reviews. After pre-test counseling, enrolled subjects had a detailed interview about their personal breast cancer diagnosis and family history. A saliva sample was collected using an Oragene kit, and analyzed by Color Genomics Inc. for 30 genes associated with hereditary cancers. Finalized results were returned to patients by genetic counselors from Color Genomics. Results: A total of 118 female patients who met NCCN guidelines for HBOC testing received genetic testing. A majority were 50 years of age or younger (69/118, 59%). The cohort was ethnically diverse: 34% African, 15% Asian, 48% multiple ethnicity, and 3% other/unknown. A pathogenic or likely pathogenic variant (positive result) was identified in 21.2% of the cohort (25/118) - most commonly identified in the BRCA1 gene (13/25, 52%), followed by BRCA2 (5/25, 20%), PTEN (2/25, 8%), BRIP1 (1/25, 4%), CHEK2 (1/25, 4%), MSH6 (1/25, 4%), PALB2 (1/25, 4%), and RAD51C (1/25, 4%). Conclusions: We found a strikingly high HBOC germline mutation prevalence rate of 21.2% among a cohort of female breast cancer patients meeting NCCN criteria for HBOC testing in T&T. Given the growing implications of germline HBOC mutations for breast cancer treatment and prevention, our results demonstrate an urgent need for funding, as well as the development of robust genetic counseling and testing services in T&T.