Cobalt Machines Research Articles

Effect of ionizing radiation on the shear bond strength of two different adhesive systems in primary teeth. in-vitro study

BackgroundRadiotherapy is a treatment modality used for head and neck cancer patients. It has a negative influence on bonding strength of adhesives. Little information is available about the effect of radiotherapy on bonding strength of adhesives in primary teeth. Therefore, this in vitro study aimed to detect the best adhesive system and ideal time to apply restorations in primary irradiated teeth regarding adhesive shear bond strength.MethodsDentin samples from primary teeth were randomly assigned to four groups based on restoration application time and radiation exposure, (G1: control, G2: preradiation, G3: 24 h postradiation, and G4: 6 months postradiation) with 20 samples per group. These groups were further divided into 2 subgroups according to the adhesive system used, with 10 samples per subgroup. (1) 3M™ Single Bond Universal Adhesive (SB), (2) 3M AdperSingle Bond 2 (AS). Samples were exposed to gamma radiation from a cobalt-60 machine. One shot of 60 Gy of radiation was delivered. Then samples were subjected to a shear bond strength test. The load was applied until failure and the maximum load was recorded. Numerical data are presented as mean and standard deviation values, then distributed according to Shapiro–Wilk test or Levene's test and analyzed via two-way ANOVA. The significance level was set at p < 0.05 for all tests. Statistical analysis was performed with R statistical analysis software version 4.4.1 for Windows (Team RC, R: A language and environment for statistical computing. R foundation for statistical computing, 2023).ResultsCompared with the AS subgroup, the SB subgroup presented significantly greater values (p < 0.001). For SB, there was no significant difference among the G1 and G4 groups (p > 0.001). However, there was a significant difference between G1, G2, and G3 (p < 0.001, P = 0.025, P = 0.265 ns respectively), and G3 presented the lowest values. For AS, there was no significant difference between groups G1 and G4 (p = < 0.001). Compared with the other groups, G3 presented a significant difference (p = 0.265 ns) and the lowest results.ConclusionRestorations performed 24 h after radiation had lower bond strength than those performed six months after radiation. Regardless of the adhesive system used, SB performed better than AS in terms of the shear bond strength.

Challenges and Considerations in Transitioning from Cobalt-60 to Linear Accelerators for Radiotherapy in LMICs Healthcare Settings: A Case Study of Nepal.

Nepal's move from Cobalt-60 machines to modern linear accelerators in radiation therapy presents significant challenges. Infrastructure limitations demand substantial investments for facility upgrades, particularly in retrofitting existing cobalt-60 bunkers and ensuring stable power supplies. The scarcity of skilled personnel underscores the need for comprehensive education initiatives and international collaborations. Regulatory compliance requires the establishment of robust frameworks, emphasizing the urgency of an independent regulatory authority. Collaborations with international institutions offer expertise and resources crucial for capacity building. Financial constraints necessitate innovative financing models to mitigate procurement and maintenance costs. Unforeseen circumstances, exemplified by the Covid-19 pandemic, highlight the importance of adaptability in implementation strategies. Despite challenges, Nepal's transition signifies an opportunity to enhance cancer care, emphasizing the need for a tailored, multidimensional approach addressing infrastructure, workforce, regulatory, financial, and collaborative aspects.

Setting up a new radiation therapy centre in Malawi: Opportunities and challenges

Radiotherapy (RT) is one of the three pillars of cancer treatment (with surgery and systemic therapies) and has proven to be a cost–effective modality for curative and palliative treatment. In low and middle-income countries, access to RT treatment is limited posing many challenges to patients and caregivers. Many patients living in low and middle-income countries (LMICs) such as Malawi spend enormous sums of money to be treated abroad, through Government schemes, or, more commonly, go without treatment. This paper reviews the progress of the Malawi Government in establishing the first dedicated cancer treatment center with RT facilities at Kamuzu Central Hospital in Lilongwe. Malawi is expected to have a fully functional dedicated RT centre towards the end of 2024 equipped with one cobalt machine, two linear accelerators (LINAC), and a high dose rate (HDR) Brachytherapy unit. More cancer patients will have access to RT services locally, resulting in the Government saving on the foreign currency required to treat patients out of the country. While there has been great progress towards establishment of services in Malawi, careful and strategic planning is needed for the sustainability of required resources to avoid long-term disruption of treatments.

Experimental study of dosimetric properties of thermoluminescent powder TLD-100

The creation of a scientifically substantiated quality assurance system for dosimetry and the optimization of medical exposure of the population of Ukraine during diagnostic and therapeutic procedures (and the possibility of dosimetric control and monitoring of emergency situations) falls within the field of the application of ionizing radiation sources (IRs). Trends in modern medicine in most countries, including Ukraine, prove a continued increase in the share of medical exposure. The main requirements and recommendations for the use of IRs for medical purposes while ensuring the radiation safety requirements for patients are provided in the documents of such International Organizations as the International Commission on Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA), the World Health Organization (WHO) and the European Commission (EC).&#x0D; One of the key factors to ensure the quality of radiation therapy is metrological and dosimetric support. To enhance the effectiveness of radiation treatment and reduce the number of complications in the future, it is necessary to irradiate the local target within the patient’s body with a dose error of no more than 5%. Control of the radiation output of the therapeutic device, i.e., the calibration of the therapeutic beam used in the treatment process, is an essential element of radiation therapy.&#x0D; Radiation protection programmes are based on checking the accuracy of the calibration of remote radiotherapy devices using thermoluminescent dosimeters (TLDs) – small plastic capsules filled with thermoluminescent powder that are sent by post to radiology centres for exposure to a specific dose in a water phantom.&#x0D; Radiation therapy in Ukraine is primarily conducted using cobalt machines, X-ray therapy devices and linear accelerators.&#x0D; The results of the study include the examination of the dependency of measurement results on various exposure parameters using the automatic reader PCL-3, the determination of dosimetric characteristics of the thermoluminescent powder TLD-100, and the development of a calibration method for thermoluminescent dosimeters under standard irradiation conditions on a remote gamma therapy device.&#x0D; Therefore, the accuracy of beam calibration using TLD dosimeters has been studied, which will enable to timely detect errors in clinical dosimetry and reduce the number of cases of radiation-related complications for patients during their treatment.

Biochemical analysis of saliva in head and neck cancer patients receiving definitive chemoradiotherapy.

Radiation therapy leads to salivary gland damage that causes xerostomia, the standard radiation-induced complication during radiotherapy that affects the quality of life in head and neck cancer patients. This study was conducted at a tertiary cancer institute in Punjab state to analyze the influence of radiation therapy on various parameters and substances of saliva. Sixty head and neck cancer patients who underwent conventional radiotherapy on a Cobalt machine were included. Saliva was collected in both stimulated and unstimulated states. Stimulated whole saliva was collected by applying two to three drops of citric acid solution (2%) over the dorsum of the tongue bilaterally at 30-s intervals for 2 min. Biochemical changes in the whole saliva were evaluated by biochemical methods at baseline, completion of therapy, and 3 and 6 months post-radiotherapy completion. The lowest concentration of proteins was seen after the therapy in unstimulated and stimulated saliva. Salivary protein levels showed a rising trend toward baseline in 3- and 6-month posttherapy samples. The peak value (0.4 mg/dl) was reached in the stimulated saliva after therapy. Salivary amylase did not show a consistent concentration graph. The salivary concentrations of sodium, potassium, and chloride showed peak values after radiotherapy. The lowest salivary pH was obtained at completion of therapy, both in unstimulated and stimulated saliva. After 3 months of chemoradiotherapy, the saliva reached a pH value of 8.3, whereas 6-month posttherapy sample showed a pH value of 8.4 in both unstimulated and stimulated saliva. At the completion of chemoradiotherapy, the total salivary protein, albumin, and inorganic components (calcium, magnesium, phosphorus) showed a downward trend from the baseline values due to the damage caused to the acinar part of the salivary gland by radiotherapy. The rise in salivary electrolytes' concentrations is attributed to the fact that even though there is loss of absorptive property of the tubular portion of the salivary gland, it retains its secretory property. Saliva becomes thick, scarce, tenacious, and acidic during the period of chemoradiotherapy.

ACUTE TOXIC EFFECTS OF OCULAR SURFACE AND ADNEXA INDUCED BY EXTERNAL BEAM RADIOTHERAPY IN HEAD AND NECK CANCER PATIENTS

Head and neck cancers (HNC) are one of the commonest cancers in India. The primary treatment modality of these patients is either radiotherapy (RT) alone or combined surgical and radio/chemotherapy approach. RT of HNC leads to various acute and chronic ophthalmic complications. After approval from institutional ethics committee we conducted a prospective cohort study for a period of 3 months at a tertiary care center to find the incidence of various acute ophthalmic complications of radiotherapy in these patients specifically dry eye disease (DED) and also to correlate these findings with the total radiation dose (TRD). We recruited 40 patients "of HNC" undergoing. external beam radiotherapy by cobalt-60 machine. Patients were selected based on inclusion and exclusion criteria. Radiation records of all patients were noted. Patients were evaluated prior to start of RT and then at 1 week, 4 weeks and 12 weeks post RT. All underwent a thorough clinical history and complete ophthalmological examination including Ocular surface disease index (OSDI) questionnaire, visual acuity, anterior segment, angle and posterior segment examination, a complete dry eye work up including Schirmer test, tear meniscus height, tear break up time, corneal fluorescein staining &amp; grading at each visit. Data was analysed using percentage and microsoft excel. Of the 40 patients; 24 (60%) were male and 16 (40%) were female (ratio1.5:1) and the median age of patients was 56 years with an age range of 35 to 63 years. Various acute complications found in our study were redness, madarosis, tylosis, limbal ischemia and dry eye disease (18 patients; 45%). We also found a strong positive correlation of DED with TRD. (r= 0.87)

Three-week hypofractionated radiotherapy in early glottic cancer – a single institution retrospective study

BackgroundRadiotherapy is a standard treatment option for early glottic carcinoma (stage I and II) with a fraction size of 2–2.2 Gy over 5–7 weeks. This study evaluates the outcome and prognostic factors of a 3-week hypofractionated treatment in early glottic malignancy.Materials and MethodsThe case records of 329 eligible patients with stage I and II glottic carcinoma recorded at the institution from 2003 to 2008 were retrospectively analysed. All patients were treated in a Cobalt-60 machine to a dose of 52.5 Gy in 15 fractions (3.5 Gy/fraction) over 3 weeks.ResultsEighty-three percent had stage I disease. The local control rate at 5 years was 91.9%. On univariate analysis, stage I and II patients without subglottic extension had better local control. Disease extension to the subglottis fared poorly on multivariate analysis. After salvage treatment, the 5-year disease-free survival rate was 96.1% and the functional larynx preservation rate was 94.9% for stage I and 83.9% for stage II. The rate of severe complications was 2.1%.ConclusionComparable results with low morbidity are achievable with a 3-week hypofractionation in early glottic cancers and it offers better patient convenience.HighlightsIn early glottic cancer, hypofractionated radiation provides excellent local control.Subglottic extension is a poor prognostic factor.5-year disease-free survival rate of 96.1%.5-year functional larynx preservation rate of 94.9%.Severe complication rate of 2.1%.

DECOMMISSIONING OF TELETHERAPY MACHINE AND TRANSPORT OF DECAYED TELETHERAPY SOURCE

Radioactive Cobalt-60 teletherapy machines find a prominent place in radiation therapy departments in India. The first teletherapy cobalt machine in SMS hospital (Picker Advance Tele Cobalt (ATC) C/9) was installed in 1995. The initial activity of the cobalt source was 333 TBq (9000 Ci).In March 2019, the source output became lesser than 50 cGy/hr at normal treatment distance (NTD) of 80cm which is clinically not acceptable for patient treatment because of increase in treatment time. The decommissioning of the machine was considered due to ageing of machine and vendor was not providing services anymore. This present study describes radiation safety aspect of the planning of decommissioning of teletherapy machine and transport of the decayed Cobalt-60 source for disposal and personnel dose measurements during the procedure. Decommissioning of the cobalt machine began with preparation of a plan and its submission for approval by competent national authority. Radiation survey of the source head was performed before the source transfer operation by AERB certified decommissioning engineers. Then decayed source was unloaded in shielded container (flask Sl No 112) and was kept in another outer container (type B (U) package). It transported for disposal to BRIT, Kota on receipt of transport permission fromAERB.A radiation survey was done in a matrix format of the all sides of this package.To measure the personnel doses, pocket dosimeter, TLD badge and OSLDs were used. The maximum dose received by the engineers was .03mSv. Maximum radiation level at 1 m from the external surface of the package was found 0.83mR/hr. The development of the new concepts and practices in the field of the decommissioning includes the preparation and approval of a decommissioning plan, the actual decommissioning operations as well the safe management of the waste arising from the decommissioning process. Such plans need to be developed for each facility with radiation sources.

Validation of Leaf Design Characteristics of an Add-on Automated Multi Leaf Collimator for Telecobalt Therapy Machine.

Background: In developing countries like India, cobalt-60 machines still find their applicability, considering the cost and maintenance issues. With a view to deliver conformal treatment plans using teletherapy machines, an automated Multi-Leaf Collimator (MLC) was developed for the existing machines as a retrofit attachment to the collimator assembly without any modifications to the unit. Objective: This study aims to investigate the radiation characteristics of leaf designs incorporated in two add-on prototype MLC systems with respect to the shape of leaf projected at the isocenter plane and the isodose distribution around the target. Besides, the dosimetric characteristics of prototype MLC with divergent leaf design are validated through simulation and experimental measurements.Material and Methods: In this experimental study, two add-on prototype MLC systems were designed and fabricated. The characteristic measurements of leaf designs incorporated in both the prototypes were carried out using Gafchromic films (GAF) and compared with Monte Carlo (MC) simulations. For divergent leaf design, beam profiles were obtained using Monte Carlo simulations which are complemented with the results obtained from measurements of radiochromic films and ionization chamber (IC) profiler. Dosimetric characteristics like radiation field width and beam penumbra were evaluated.Results: The Monte Carlo simulated data are in agreement with experimental data from IC profiler as well as from Radiochromic films. The results of this study are well within acceptable tolerance limits. Conclusion: The prototype MLC system designed for existing telecobalt machines supports its clinical applicability for conformal therapy to better manage treatment in rural areas, which can provide superior cost effective treatments.

Assessment of Breast Cancer Management in Sub-Saharan Africa.

PURPOSETo document progress and bottlenecks in breast cancer management in sub-Saharan Africa, subsequent to a 2013 pilot survey conducted through the African Organization for Research and Treatment in Cancer (AORTIC) network.METHODSAn anonymous survey of breast cancer management was conducted in 2018 among AORTIC members. Results concerning respondent specialty, access to tumor boards, treatment accessibility, diagnostic services, and factors influencing treatment outcomes were compared with the 2013 findings.RESULTSThirty-seven respondents from 30 facilities in 21 sub-Saharan Africa countries responded. The majority (92%) were clinical oncologists. Radiotherapy facilities were available in 70% of facilities. Seventy-eight percent of these had linear accelerators, and 42% had cobalt60 machines. Eighty percent of facilities had multidisciplinary tumor boards. Immunohistochemistry was routinely performed in 74% of facilities, computed tomography scan in 90%, bone scan in 16%, and positron emission tomography scans in 5%. Anthracyclines, taxanes, tamoxifen, letrozole, anastrozole, and zoledronic acid were available in the majority; trastuzumab, fertility, and genetic counseling were available in 66%, 58%, and 16%, respectively. There were a 50% increase in oncologist respondents over 2013 and a > 50% increase in radiotherapy facilities, particularly linear accelerators. Availability of trastuzumab, aromatase inhibitors, and taxanes increased. Immunohistochemistry capacity remained the same, whereas facilities harvesting at least 10 axillary lymph nodes increased. Bone scan facilities decreased. Responses suggested improved diagnostic services, systemic therapies, and radiotherapy. Sociocultural and economic barriers, system delays, and advanced stage at presentation remain.CONCLUSIONClinicians in sub-Saharan Africa have basic tools to improve breast cancer outcomes, recording positive strides in domains such as radiotherapy and systemic therapy. Socioeconomic and cultural barriers and system delays persist. Workforce expansion must be prioritized to improve quality of care to improve outcomes.

External Beam Radiotherapy in Western Africa: 1969–2019

AimsWe describe the absolute and per capita numbers of megavoltage radiotherapy machines (MVMs) in Western Africa from 1969 to 2019. Materials and methodsWestern Africa was defined in accordance with the United Nations' delineation and inclusive of 16 countries. A literature search for publications detailing the number of cobalt-60 machines (COs) and linear accelerators (LINACs) in radiotherapy centres was carried out. Population data from the World Bank Group and crude cancer rates from the International Agency for Research on Cancer were used to calculate ratios of million persons per MVM and MVMs per 1000 cancer cases. ResultsThe numbers of MVMs in Western Africa in 1969, 1979, 1989, 1999 and 2009 were zero, two, three, six and nine, respectively. In 2019 there were 22 MVMs distributed across Ghana (five), Côte d’Ivoire (two), Mali (one), Mauritania (two), Nigeria (nine) and Senegal (three). Nine countries (56.3%) had no history of external beam radiotherapy (EBRT). The largest increase in absolute EBRT capacity occurred from 2017 to 2019, during which 13 MVMs were commissioned. The largest decrease in EBRT capacity occurred from 2015 to 2017, during which four LINACs and three COs were rendered non-operational. The ratio of million persons per MVM improved from 67.0 in 1979 to 17.8 in 2019. As of 2019, there was 0.09 MVM per 1000 cancer cases. ConclusionsWestern African nations have experienced an increase in the absolute number of MVMs and per capita radiotherapy capacity during the last 50 years, especially in the last decade. As non-functional LINACs contributed to a temporary decline in the EBRT infrastructure, dual use of CO/LINAC technologies may act to promote the availability of EBRT treatment in centres with capacity for multiple MVMs.

Access of Patients With Lung Cancer to High Technology Radiation Therapy in Brazil.

PURPOSELung cancer is a global health problem, with more than 220,000 new cases and 150,000 deaths per year in the United States. Likewise, in Brazil, lung cancer is the most lethal cancer with 30,200 new cases expected in 2020. Regarding treatment types, radiation therapy (RT) represents an important approach, since 60%-70% of the patients will receive this modality of treatment during the course of their disease. However, access to RT remains challenging because of the socioeconomic inequalities in the Brazilian population, where approximately 100,000 patients/year die without access to RT. This work provides an overview on the availability of high technology RT in Brazil.METHODSA retrospective study was performed using the Brazilian Radiotherapy Census, local public and private databases, and the current literature published in 2019.RESULTSThe Brazilian radiotherapy network relies on approximately 363 linear accelerators and 20 cobalt machines that remain operational. Most of these machines are installed at public health facilities. Regarding high technology, intensity-modulated RT is available in 53.7% (n = 130) and volumetric modulated arc therapy in 28.5% (n = 69) of the institutions, although only 19.8% (n = 48) of those facilities are capable of performing image-guided RT using cone beam computed tomography. Considering only the public health care system, the scenario is more restricted, with 40.1% (n = 65) of the institutions offering intensity-modulated RT, 21% (n = 34) volumetric modulated arc therapy, and 14.8% (n = 24) using cone beam computed tomography. Because of these scare resources, only 16% of Radiation Departments offer stereotactic body RT.CONCLUSIONBrazil still needs to improve and provide high and safer RT technologies to patients with lung cancer across all Brazilian regions to attend the population needs and obtain better patient outcomes.

“A comparative study using conventional concomitant chemoradiotherapy (using cisplatin-based chemotherapy) with accelerated (six fractions a week) chemoradiotherapy in inoperable or nonresectable locally advanced non-small cell lung cancers:” A prospective randomized trial

Context: The conventional concomitant chemoradiotherapy (CCRT) is the standard treatment for locally advanced non-small cell lung cancer. Accelerated CCRT results in shortening of overall treatment time which can contribute in controlling accelerated tumor repopulation. The increase in tumor control probability (TCP) can be expected with no or little effect on late normal tissue injury for a given total dose. Aim: The aim of this study was to compare the disease response, toxicity profile, quality of life (QoL), and overall survival in accelerated versus conventional CCRT. Subjects and Methods: Total 42 patients were randomized into two groups – study group (n = 21): Accelerated CCRT, radiation was given as 6 fractions per week (60 Gy/5 weeks/30#) with injection cisplatin 20 mg/m2 intravenous (iv) days 1–5 and days 29–33 + injection etoposide 50 mg/m2 iv days 1–5 and days 29–33 and control group (n = 21): Conventional CCRT, radiation was given as 5 fractions per week (60 Gy/6 weeks/30#) along with the same chemotherapy. External beam radiation therapy was delivered by cobalt-60 machines. Results: The overall response rate (complete and partial response) for all patients was 66.6%. In the control group, it was 66.2%, and in the study group, it was 66.6%. Grade ≥II pulmonary, hematological, and esophageal toxicities were seen in 57%, 43%, and 24% in patients of the control group and 53%, 53%, and 33% in the study group, respectively. In QoL analysis, maximum improvement was noted for hemoptysis, arm/shoulder pain, dyspnea, and chest pain in both the groups. Statistical Analysis Used: The data were analyzed by Student's t-test and Chi-square test. P

"Christie Regimen" palliative radiotherapy in advanced head-and-neck cancer: A single-center experience.

Relevance of aggressive treatment in advanced head neck squamous cell cancers(HNSCC) is debatable in view of expected poor outcome. Long treatment duration only adds up to the cost of treatment without any improvements in outcomes. To assess the outcomes of hypofractionated "Christie" palliative radiotherapy regimen in advanced HNSCC. Patients of advanced HNSCC registered from June 2015 to June 2019 were treated by parallel pair field technique on Cobalt60 machine (Theatron 780E) to total dose of 50 Gray/16 fractions over 3.2 weeks. Toxicity was scored using Radiation Therapy Oncology Group (RTOG) criteria and response was evaluated as per WHO criteria. Records of 110 patients of HNSCC with mean age of 56.19 years were analysed. Evaluation at 4-8 weeks after radiotherapy resulted in a complete response (CR) in 19.1%, partial response (PR) in 32.7%, stable disease (SD) in 29.1% and progressive disease (PD) in 3.6%, while 15.5% patients did not report for post treatment evaluation. Median progression free survival was 9.52 months (95% CI 5.9 - 13.1 months). The median overall survival was 12.7 ± 2.2 months (95% CI 8.2 - 17.2). Median time to progression after completion of radiotherapy was 84 days. Grade IV dermatitis and mucositis was encountered in 2.7% and 1.8% cases respectively, requiring hospitalization. Christie regimen for advanced HNSCC is a clinically viable option with acceptable outcomes in a resource constrained setting.

PO-1779: The feasibility study of MLC-based IMRT treatment planning on a Cobalt-60 machine

PO-1779: The feasibility study of MLC-based IMRT treatment planning on a Cobalt-60 machine

Individual dose overload on the rectal mucosa during the postoperative radiation therapy in uterine cancer patients based on the in vivo dosimetry data

The article is devoted to the quality control of the radiation therapy in uterine cancer patients. The treatment of such patients includes surgery and postoperative course of radiation therapy. The purpose of adjuvant course of radiation therapy is to damage the subclinical tumor foci. During the radiation therapy, it is impossible to avoid the radiation overload on the adjacent organs. The search and utilization of methods that quantify the dose overload on critical organs — rectal mucosa, during the adjuvant course of radiation therapy are highly relevant, especially in comparison to the estimated radiation therapy planning data. In our study the postoperative course of radiotherapy was performed in 110 uterine cancer patients stage I–II by the cobalt machine (60Co) ROCUS-AM or linear accelerator Clinac-600C. In vivo dosimetry was performed in order to evaluate the variation of the actual dose overload after the first irradiation session and in the middle of the adjuvant course (after achieving the dose level of 20 Gy). While performing radiation therapy by ROCUS-AM (60Co) during the first measurement, the single absorbed dose to the rectal mucosa in all 50 (100 %) patients was less than planned, and the range of the single absorbed dose was from 1.69 Gy (min) to 1.89 Gy (max), which was fixed as the deviation from the planned dose from ‒15.26 to ‒5.50 %, and the median of the relative deviation from the planned dose was ‒12.76 %. While conducting the radiation therapy by the Clinac-600C, the range of the single absorbed dose at the first session was 1.56‒2.19 Gy (min-max), which have made the deviation from the planned dose from ‒21.5 to 9.66 %, and the median relative deviation from the planned dose was ‒0.88 %. Thus, in vivo dosimetry data indicates on significant differences between the planned and measured absorbed doses to the rectal mucosa. The presence of intra- and interindividual variability of in vivo dosimetry results during the radiation treatment showed the necessity of development of new approaches to the topometric preparation of uterine cancer patients, who are scheduled for the postoperative course of radiation therapy

Establishing Comprehensive Cancer Care in Cambodia

Abstract Radiotherapy and cancer care did not exist at all during the civil wars in Cambodia, and of course, the cancer care was not a priority soon after the wars until 2003 when a Cobalt-60 machine was in full operation at the Khmer Soviet Friendship Hospital. However, this was still just the beginning of re-establishing cancer treatments for Cambodians. Due to the economic growth and the expansion of the middle-class in the past two decades, more people have access to provincial and national hospitals for the diagnosis of cancer, although the standard of facilities is not the same as in high-income countries. More medical specialties have also emerged in response to demands. These factors and others have finally resulted in the planning of the national cancer center project at the Calmette Hospital in Cambodia. The government, the World Health Organization, the International Atomic Energy Agency and multiple international partners have collaboratively worked to achieve the goals. The presentation will highlight the most essential milestones to realize some of the goals as of today, the challenges and the prospects of the project.

Challenges of Building and Sustaining Radiation Therapy Capacity in Low-Resource Settings: A Case of the Breakdown of Cobalt 60 Teletherapy in Uganda and Lessons Learned

Background and context: The use of radiotherapy in developing countries is slowly gaining momentum but the gains are accompanied by some pitfalls. The breakdown of a teletherapy (cobalt 60) machine in Uganda is an example of the challenges to be considered while expanding access to treatment. It was a major test for the country and the Uganda Cancer Institute the agency of government responsible for provision of cancer services. It attracted a national and international outcry. This unprecedented response was based on the importance a seemingly old equipment in Kampala was playing in the entire region (Kenya, Tanzania, Rwanda, Burundi, Democratic Republic of Congo and southern Sudan). However, the manner in which the crisis was handled demonstrated clearly how to turn a misfortune into an opportunity given the many lessons learnt. Aim: In this paper we aim to highlight how the breakdown of the equipment triggered a major crisis and the response to the crisis resulting in the restoration of services within a reasonable time frame. We also want to show the long-term service modernization and expansion drive this has triggered within Uganda and the entire region. Strategy/Tactics: The restoration process comprised planning, decommissioning, renovation, security and safety systems, procurement of new machine, installation and commissioning. As this was ongoing there was the need for care provision for patient in need. Concurrently undertaken was public reassurance through building confidence and trust in the capacity for speedy restoration of services. Program/Policy process: All these steps were taken collaboratively within country, region and internationally. In the region there was support from the Aga Khan University Hospital Nairobi and internationally, technical support from the IAEA. Outcomes: Service has been fully restored, a new teletherapy cobalt machines installed and commissioned. The machine has modern capabilities compared with the previous. So far more than 200 patients have been treated. The numbers of patients are steadily increasing hence the government has embarked on modernization and expansion of the radiotherapy services in the country. What was learned: The breakdown of Uganda's radiotherapy machines has provided lessons that are important for handling health system operational crisis which may occur as we try to build complex delivery systems. It provided lessons that are important in the drive for expansion of radiotherapy services in developing countries. In particular that benefit of investments in modern equipment transcends national boundaries. Secondly how to limit potential impact of major crisis through regional and international collaboration. Further that the needs of patients is central in crisis management. Finally need to consider pooling infrastructure investments in tackling NCD's such as the East Africa's centre of excellence for skills and tertiary education project of the East African community.

Radiotherapy Facilities, Equipment, and Staffing in Brazil: A Survey by the Brazilian Society of Radiation Oncology

Background: The rising incidences in cancer, together with the population aging have increased the demand for radiotherapy (RT) services in Brazil. Currently, Brazil faces a dearth of RT and solutions to provide a more universal care to cancer is a hot topic in this country. Aim: To evaluate the current status of RT department, staffing, and techniques in Brazil for 2017 following the launch of the National Cancer Program and the EXPANDE program. Methods: The Brazilian Society for Radiation Oncology (SBRT), sent detailed, online-based survey to heads of departments of all Brazilian RT centers (public and private), located in the 27 states in 2017. The survey included questions related to personnel, equipment, type of the center, and % of patients treated (private exclusive (≥ 90% of the treatments focused the private system) or public exclusive (≥ 90% of the treatments focused the public system) or mixed). Respondents were asked to provide average data from the last 5 year. For final analysis we grouped the states per region north, northeast (NE), central-west (C), southeast (SE) and south. A descriptive analysis was performed. Results: A total of 142 responses from 212 sent surveys (67% response rate) were received from 23 states. The total number of the departments and median functioning years per federative region was: 7 departments and 8 years in the north; 27 and 13 years in the NE; 7 and 11.5 years in the central; 27 and 17 years in the south; and 72 and 20 years in the SE region, respectively. The rate of radiation oncologist, physicist, nurse and dosimetrist per department was 3.0, 2.0, 1.7, 0.2 (north), 3.2, 2.4, 1.6, 0.7 (NE), 2.5, 1.7, 1.0, 0.3 (central), 3.4, 2.6, 1.6, 0.7 (south) and 3.9, 2.8, 1.6, 0.9 (SE), respectively. High dose rate brachytherapy was offered by 70% of the departments in the north, 55% in the NE, 30% in the central, 40% in the SE and 37% in the south region, respectively. Ninety-five percent of the department had at least one linear accelerator and only 5% had exclusively cobalt machines. The minority of the centers offered intensity modulated RT (36%) and image-guided RT (42%). 3D-conformal was the technique offered by 87% of the departments and 18% of them still treat patients with 2D technique. Overall, 30% of the departments provide services to the public health system exclusively, 1% to the private sector only and 69% of the department to both private and public. Conclusion: Important heterogeneity in the number of departments and professionals involved within RT services among Brazilian regions was found. Most departments were found to be in operation &gt; 10+ years, indicating the need for recent hardware and software update and/or maintenance. 3D-conformal is the most common offered technique and mixed approach (public and private partnership) is the most common model of business in the country.

Feasibility of 2D‑conformal radiotherapy for pancreatic carcinoma

The purpose of the present study was to propose an optimized 2D technique (2D-conformal) for radiotherapy (RT) of pancreatic cancer (CaP). This technique is based on double simulation which resolves the problems of radiographic image distortion. Five patients with locally advanced CaP were identified and enrolled. Treatment planning was simulated in 3 different ways: Two dimensional-standard (2D-SRT), 2D-conformal (2D-CRT), and three dimensional-conformal (3D-CRT) techniques for 10 MV LINAC. Simulation for a cobalt machine was also performed using only the 2D techniques. 2D-SRT technique was planned with fields definition based on anatomical landmarks (bone and duodenum). 3D-CRT was planned with standard virtual simulation technique, and 3D dose evaluation and optimization. 2D-CRT technique was based on manual information transfer from a diagnostic CT-scan to simulation radiograms. To eliminate the X-ray image distortion, a double simulation was employed and the profile of the GTV was delineated on radiographs bearing the simulator isocenter into the target center. Concerning target irradiation of either LINAC (10 MV) or cobalt source, the PTV constraints (ICRU 62) were met in all patients (Dmin >95%, Dmax <107%) with all techniques (2D-SRT, 3D-CRT, 2D-CRT). For organs at risk irradiation, in terms of Dmax to both duodenum and spinal cord, similar results were recorded with all techniques using the LINAC (10 MV). Liver and kidneys Dmean gradually improved from 2D-SRT to 2D-CRT and 3D-CRT. The 2D-CRT compared to 2D-SRT technique, halved the average dose to the liver and reduced to about 1/3 the average dose to the kidneys. With the cobalt source, using the 2D-CRT produced a reduction of Dmean to the kidneys (median from 30.7 to 16.9%) and liver (median from 33.4 to 22.3%) compared to 2D-SRT. This analysis showed better planning results in RT treatment of CaP while using a 2D-CRT compared to 2D-SRT technique and therefore presents an example for optimized 2D RT use.