Improving accessibility to radiotherapy services in Cali, Colombia: cross-sectional equity analyses using open data and big data travel times from 2020.

In this study, we evaluated and forecasted the cumulative opportunities for residents to access radiotherapy services in Cali, Colombia, while accounting for traffic congestion, using a new people-centred methodology with an equity focus. Furthermore, we identified 1-2 optimal locations where new services would maximise accessibility. We utilised open data and publicly available big data. Cali is one of South America's cities most impacted by traffic congestion. METHODOLOGY: Using a people-centred approach, we tested a web-based digital platform developed through an iterative participatory design. The platform integrates open data, including the location of radiotherapy services, the disaggregated sociodemographic microdata for the population and places of residence, and big data for travel times from Google Distance Matrix API. We used genetic algorithms to identify optimal locations for new services. We predicted accessibility cumulative opportunities (ACO) for traffic ranging from peak congestion to free-flow conditions with hourly assessments for 6-12 July 2020 and 23-29 November 2020. The interactive digital platform is openly available. PRIMARY AND SECONDARY OUTCOMES: We present descriptive statistics and population distribution heatmaps based on 20-min accessibility cumulative opportunities (ACO) isochrones for car journeys. There is no set national or international standard for these travel time thresholds. Most key informants found the 20-min threshold reasonable. These isochrones connect the population-weighted centroid of the traffic analysis zone at the place of residence to the corresponding zone of the radiotherapy service with the shortest travel time under varying traffic conditions ranging from free-flow to peak-traffic congestion levels. Additionally, we conducted a time-series bivariate analysis to assess geographical accessibility based on economic stratum. We identify 1-2 optimal locations where new services would maximize the 20-min ACO during peak-traffic congestion. RESULTS: Traffic congestion significantly diminished accessibility to radiotherapy services, particularly affecting vulnerable populations. For instance, urban 20-min ACO by car dropped from 91% of Cali's urban population within a 20-min journey to the service during free-flow traffic to 31% during peak traffic for the week of 6-12 July 2020. Percentages represent the population within a 20-min journey by car from their residence to a radiotherapy service. Specific ethnic groups, individuals with lower educational attainment, and residents on the outskirts of Cali experienced disproportionate effects, with accessibility decreasing to 11% during peak traffic compared to 81% during free-flow traffic for low-income households. We predict that strategically adding sufficient services in 1-2 locations in eastern Cali would notably enhance accessibility and reduce inequities. The recommended locations for new services remained consistent in both of our measurements.These findings underscore the significance of prioritising equity and comprehensive care in healthcare accessibility. They also offer a practical approach to optimising service locations to mitigate disparities. Expanding this approach to encompass other transportation modes, services, and cities, or updating measurements, is feasible and affordable. The new approach and data are particularly relevant for planning authorities and urban development actors.

[The quality and safety approach in radiotherapy : an added value for the patient]. / La démarche qualité et sécurité en radiothérapie : une plus-value pour le patient.

Radiation therapy is the use of radiation to treat cancer cells while preserving healthy tissue. More than half of cancer patients will receive radiation therapy at some point during their treatment. The implementation of a Quality Management System (QMS) in radiotherapy departments guarantees high quality care and optimal safety for patients. The QMS is a set of policies, procedures and processes aimed at ensuring effective management of the quality of treatments. It is crucial for planning, implementing, monitoring and continuously improving the care of radiotherapy patients. The benefits of the QMS for patients are multiple. It provides high quality support through specific protocols and deadlines. The security of processing is reinforced by the continuous training of personnel, the monitoring of incidents and the analysis of errors. Developing a culture of safety and continuous improvement also helps to minimize risk. In conclusion, the implementation of a QMS in radiotherapy departments guarantees quality care, secure and adapted to the individual needs of patients. This improves patient satisfaction while reducing the risk of errors.

La radiothérapie consiste à utiliser des radiations pour traiter les cellules cancéreuses, tout en préservant les tissus sains. Plus de la moitié des patients atteints de cancer recevront une radiothérapie à un moment donné de leur traitement. La mise en place d'un Système de Management Qualité (SMQ) dans les services de radiothérapie garantit des soins de haute qualité et une sécurité optimale pour les patients. Le SMQ est un ensemble de politiques, procédures et processus visant à assurer la gestion efficace de la qualité des traitements. Il est crucial pour planifier, implémenter, contrôler et améliorer continuellement la prise en charge des patients en radiothérapie. Les avantages du SMQ sont multiples. Il assure une prise en charge de haute qualité grâce à des protocoles et des délais spécifiques. La sécurité des traitements est renforcée par la formation continue du personnel, la surveillance des incidents et l'analyse des erreurs. Le développement d'une culture de sécurité et d'amélioration continue contribue également à minimiser les risques. En conclusion, la mise en place d'un SMQ dans les services de radiothérapie garantit des traitements de qualité, sécurisés et adaptés aux besoins individuels des patients. Cette approche améliore la satisfaction des patients, tout en réduisant les risques d'erreurs.

Gynecologic radiation therapy in low and middle income countries during the COVID-19 pandemic.

The COVID-19 pandemic has forever affected healthcare and posed an incredible challenge to our society to care for our sick. Patients with cancer were found early on to have higher rates of complications with COVID-19. Radiation therapy is an integral part of treatment for many types of gynecologic cancer and adaptation on its utilization during the pandemic varied across the globe. In this review, we detail certain guidelines for the use of radiation in gynecologic cancers during the pandemic as well as real world accounts of how different countries adapted to these guidelines or created their own based on individualized resources, staffing, government restrictions, and societal norms. Critically, this review demonstrates the breadth of fractionation schemes and technologies used when resources were limited but highlights the importance of long term follow-up for many of our patients during this time.

Liver function after combined selective internal radiation therapy or sorafenib monotherapy in advanced hepatocellular carcinoma.

BACKGROUND & AIMS: SORAMIC is a previously published randomised controlled trial assessing survival in patients with advanced hepatocellular carcinoma who received sorafenib with or without selective internal radiation therapy (SIRT). Based on the per-protocol (PP) population, we assessed whether the outcome of patients receiving SIRT+sorafenib vs. sorafenib alone was affected by adverse effects of SIRT on liver function. METHODS: The PP population consisted of 109 (SIRT+sorafenib) vs. 173 patients (sorafenib alone). Comparisons were made between subgroups who achieved a significant survival benefit or trend towards improved survival with SIRT and the inverse group without a survival benefit: <65 years-old vs. ≥65 years-old, Child-Pugh 5 vs. 6, no transarterial chemoembolisation (TACE) vs. prior TACE, no cirrhosis vs. cirrhosis, non-alcohol- vs. alcohol-related aetiology. The albumin-bilirubin (ALBI) score was used to monitor liver function over time during follow-up. RESULTS: ALBI scores increased in all patient groups during follow-up. In the PP population, ALBI score increases were higher in the SIRT+sorafenib than the sorafenib arm (p = 0.0021 month 4, p <0.0001 from month 6). SIRT+sorafenib conferred a survival benefit compared to sorafenib alone in patients aged <65 years-old, those without cirrhosis, those with Child-Pugh 5, and those who had not received TACE. A higher increase in ALBI score was observed in the inverse subgroups in whom survival was not improved by adding SIRT (age ≥65 years-old, p <0.05; cirrhosis, p = 0.07; Child-Pugh 6, p <0.05; prior TACE, p = 0.08). CONCLUSION: SIRT frequently has a negative, often subclinical, effect on liver function in patients with hepatocellular carcinoma, which may impair prognosis after treatment. Careful patient selection for SIRT as well as prevention of clinical and subclinical liver damage by selective treatments, high tumour uptake ratio, and medical prophylaxis could translate into better efficacy. CLINICAL TRIAL NUMBER: EudraCT 2009-012576-27, NCT01126645 LAY SUMMARY: This study of treatments in patients with hepatocellular carcinoma found that selective internal radiation therapy (SIRT) has an adverse effect on liver function that may affect patient outcomes. Patients should be carefully selected before they undergo SIRT and the treatment technique should be optimised for maximum protection of non-target liver parenchyma.

Co-treatment with Ginsenoside 20(S)-Rg3 and Curcumin increases Radiosensitivity of MDA-MB-231 Cancer Cell Line.

Background: Breast cancer is the second most common cancer in women worldwide. Developing drugs increase the radiosensitivity effect of tumoral tissue, while protecting normal tissues has gained much attention. Ginsenoside Rg3, one of the active components of ginseng, has been shown to possess various pharmacological effects and antiproliferation activity on cancer cell lines. In this study, we assessed the anti-cancer effect of co-treatment with ginsenoside 20(S)-Rg3 and curcumin on MDA-MB-231 breast cancer cells with and without radiotherapy. Methods: MTT assay was applied using different concentrations of ginsenoside 20(S)-Rg3 (0, 10, 80, 150 µmol/l) and curcumin (0, 10, 30, 50, 90 µg/mL). The inhibitory effect of co-treatment with these herbal drugs with and without 4 Gy radiotherapy on the MDA-MB-231 cell line was examined. Flow cytometry was applied to measure the effect of co-treatment of the drugs on radiation-induced apoptosis. The data were analyzed using ANOVA and Kruskal-Wallis tests. P values<0.05 were considered statistically significant. Results: The results of the MTT assay showed that ginsenoside 20(S)-Rg3 and curcumin had an inhibitory effect on the MDA-MB-231 cell line in a concentration-dependent manner. Ginsenoside 20(S)-Rg3 and curcumin inhibited tumor cell development and proliferation at concentrations of 80 µmol/L and 30 µg/mL, respectively, with 50% cell viability (P=0.018, P=0.01, respectively) at 48 hour incubation time. Conclusion: Ginsenoside 20(S)-Rg3 and curcumin inhibited MDA-MB-231 cell growth in a dose- and time-dependent manner and increased the radiosensitivity of cancer cells. These herbal drugs can be considered as a radiosensitizer in radiotherapy.

Radiation techniques in aggressive pituitary tumours and carcinomas.

Defining the role of radiation techniques in treatment of aggressive pituitary tumours and carcinomas is a difficult task: indeed, studies reported in the literature on this topic can probably be counted on the fingers of one hand. To try to better define these roles, it is thus necessary to extrapolate based on anti-secretory and anti-tumor efficacy reported in studies on non-selected pituitary tumours, regardless of their pathological status and intrinsic aggressiveness. Generally, radiation techniques are delivered as part of a multimodal treatment, usually with the primary aim of controlling tumor volume. Side-effects need to be divided into short and long-term, also depending on the overall prognosis of the tumour, since hypopituitarism will likely appear in the majority of patients, extra-pituitary side-effects, which have been reported after a significant delay after the procedure, can only be considered in patients with less aggressive pituitary tumours. In this review, we will first detail the different modalities of radiation techniques and the inherent limits of each technique depending on the volume and the localization of the tumour. We will then discuss the anti-tumour and anti-secretory efficacy of radiation techniques in aggressive pituitary tumors, either as a single treatment or as part of a multimodal treatment. Finally we will discuss the technique-specific side-effects.

Multidisciplinary management of acromegaly: A consensus.

The 13th Acromegaly Consensus Conference was held in November 2019 in Fort Lauderdale, Florida, and comprised acromegaly experts including endocrinologists and neurosurgeons who considered optimal approaches for multidisciplinary acromegaly management. Focused discussions reviewed techniques, results, and side effects of surgery, radiotherapy, and medical therapy, and how advances in technology and novel techniques have changed the way these modalities are used alone or in combination. Effects of treatment on patient outcomes were considered, along with strategies for optimizing and personalizing therapeutic approaches. Expert consensus recommendations emphasize how best to implement available treatment options as part of a multidisciplinary approach at Pituitary Tumor Centers of Excellence.

Anal Squamous Cell Carcinoma: Radiation Therapy Alone Must Be Avoided.

BACKGROUND: Anal squamous cell carcinoma (ASCC) is the most common histological subtype of anal cancer. Rates have been observed to increase in recent years. Combined chemoradiotherapy (CCRT) is currently the gold standard of treatment. The aim of this study is to assess ASCC prevalence, treatment trends, and overall survival (OS) in the United States. METHODS: Patients diagnosed with stage I-IV ASCC were identified from the National Cancer Database from 2004 to 2015. The primary outcome was 5-year OS, which was analyzed using Kaplan-Meier survival curves, log-rank test, and Cox proportional hazards models. RESULTS: 34,613 cases were included (stage I: 21.45%; II: 41.00%; III: 31.62%; IV: 5.94%), with an increasing trend in prevalence. CCRT was the most used treatment. Multimodal treatment, combining surgery with CCRT, offered the best OS rates for stage I, II, and IV cancers (I: 84.87%; II: 75.12%; IV: 33.08%), comparable with survival of stage III patients treated with CCRT (III: 61.14%). Radiation alone had the worse OS rates, and on adjusted analysis, radiation treatment alone had the greatest risk of mortality (I: hazard ratio, 2.01; 95% confidence interval, 1.14-3.54; P = 0.016; II: 2.05, 1.44-2.93, P < 0.001; IV: 1.99, 0.99-4.02, P = 0.054). CONCLUSIONS: ASCC has increased in prevalence, notably in stage III and IV disease. Although CCRT is the most commonly used treatment type for all stages of ASCC, multimodal treatment offers better OS in stages I, II, and IV. Treatment with radiation alone offers the worst OS no matter the stage and should no longer be used as a solitary treatment modality.

50 Years of the IAEA/WHO postal dose audit programme for radiotherapy: what can we learn from 13756 results?

Background: The IAEA/WHO postal dose audit programme has been operating since 1969 with the aim of improving the accuracy and consistency of dosimetry in radiotherapy in low-income and middle-income countries world-wide. This study summarises the 50 years' experience of audits and explores the quality of reference dosimetry in participating radiotherapy centres throughout the years.Material and methods: During the IAEA/WHO postal audits the dose determined from the mailed dosimeter is compared with that stated by the participant. Agreement to within ±5% is regarded acceptable whilst deviations outside ±5% limits trigger follow-up actions. Of particular interest in this study was the dependence of clinical dosimetry quality on factors related to the centre infrastructure and expertise in dosimetry of its staff.Results: The IAEA/WHO dose audit programme noted great increase in the overall percentage of acceptable results from about 50% in its early years to 99% at present, although there is some variability of results amongst participating countries. Whereas results for younger radiotherapy machines show the agreement rate between the measured and the stated doses well above 90%, for those over 20 years old the rate dropped to <80%. Linac dosimetry was always better than 60Co dosimetry and multi-machine centres generally performed better than single machine centres equipped with cobalt alone. Second and subsequent participation in audits showed higher quality dosimetry than the first participation. The implementation of modern dosimetry protocols resulted in more accurate dosimetry than the use of the older protocols.Conclusions: Over the 50 years that the IAEA has accumulated dosimetry audit data, practices in radiotherapy centres have significantly improved. Higher quality dosimetry confirmed in audits is generally associated with better infrastructure and adequate dosimetry expertise of medical physicists in participating centres.

Efficiency and safety increases after the implementation of a multi-institutional automated plan check tool at our institution.

PURPOSE: The plan check tool (PCT) is the result of a multi-institutional collaboration to jointly develop a flexible automated plan checking framework designed with the versatility to be shared across collaborating facilities while supporting the individual differences between practices. We analyze the effect that PCT has had on the efficiency and effectiveness of initial chart checks at our institution. METHODS AND MATERIALS: Data on errors identified during initial chart checks were acquired during two time periods: before the introduction of PCT in the clinic (6/24/2015 to 7/31/2015, 187 checks) and post-clinical release (4/14/2016 to 5/2/2016, 186 checks). During each time period, human plan checkers were asked to record all issues that they either manually detected or that were detected by PCT as well as the amount of time, less breaks, or interruptions, it took to check each plan. RESULTS: After the clinical release of PCT, there was a statistically significant decrease in the number of issues recorded by the human plan checkers both related to checks explicitly performed by PCT (13 vs 50, P < 0.001) and in issues identified overall (127 vs 200, P < 0.001). The mean and medium time for a plan check decreased by 20%. CONCLUSIONS: The use of a multi-institutional, configurable, automated plan checking tool has resulted in both substantial gains in efficiency and moving error detection to earlier points in the planning process, decreasing their likelihood that they reach the patient. The sizeable startup effort needed to create this tool from scratch was mitigated by the sharing, and subsequent co-development, of software code from a peer institution.

Counteracting Radio-Resistance Using the Optimization of Radiotherapy.

Radiotherapy is an essential component of cancer therapy and remains one of the most (cost-) effective treatment options available [...].

Nanoparticle-Based Radiosensitization.

Radiotherapy is a highly multidisciplinary field with respect to its foundations of research and development, and in its clinical utility [...].

COVID-19 pandemic: Implications for radionuclide therapy in Nuclear Medicine departments.

The global COVID-19 health and economic crisis has forced people to adopt challenging rules of social distancing and self-isolation. Health care staff has been advised to change working routines to keep themselves and their patients safe. Radionuclide therapy has had an increasing role in clinical practice. Most therapeutic radionuclide procedures have applications in oncology. Cancer patients are an especially fragile and vulnerable population with higher risk due to co morbidities and immunosuppression. COVID-19 is another risk that must be considered in treatment planning. Therapeutic, prophylactic, and supportive interventions may require changes for these patients. The most common radionuclide therapies involve patients with differentiated thyroid cancer (DTC) who need radioiodine therapy (RAI), patients with neuroendocrine tumours (NETs) who need peptide receptor radionuclide therapy (PRRT), patients with hepatocellular carcinoma (HCC) who need therapy with radiolabelled microspheres, and patients with prostate cancer and bone metastasis who need radionuclide palliative therapy. If infected, cancer patients could be at a higher risk for serious COVID-19 disease. Treatment decisions for thyroid cancer and NETs are challenging in this environment. Any decision to postpone therapy must be carefully considered, balancing risks and benefits. A risk of worsened prognosis due to delayed or suboptimal cancer treatment must be weighed against the risk of severe COVID-19 illness.

Nuclear Medicine and Oncology in the COVID-19 pandemic era.

The coronavirus disease 2019 (COVID-19) global pandemic poses a significant challenge to the national health systems. Not only China, the first country that experienced the health crisis since last December, but the rest of the world, is facing an unprecedented global health crisis, the most serious crisis in a century, with social and economic impact. However, the most important impact of the new pandemic is the human impact. Till 4th of June 2020, coronavirus SARS-CoV-2, causing COVID-19 disease, has infected more than 65000.000 people and has been responsible for more than 386000 deaths globally. The first priority of public health authorities is to contain and mitigate the spread and infection rate of the coronavirus SARS-CoV-2, distributing the number of infections over time and, if possible, reduce the incidence of the disease (COVID-19) it causes. A critical task for health systems confronted with the spread of the coronavirus is to protect the health of all citizens, so this requires that both diagnosis/testing and appropriate care should be readily available, affordable, and provided in a safe environment. The health care systems of many developed countries failed to demonstrate a satisfactory response to the increased demand for acute care hospital beds, ventilators, emergency services, diagnostics tests, support equipment for their COVID-19 patients, availability of essential medicines, protective equipment for their staff etc. Nuclear Medicine (NM) departments and their staff, in spite of the fact that not being in the front line of the pandemic response, have experienced a dramatic alteration in their daily clinical activity, trying to adapt their clinical routine to the new environment. There are several issued guidance from national and international organizations, trying to help to cope with suspected or verified COVID-19 patients. Patients with cancer are thought to be more susceptible and have higher morbidity and mortality rates from COVID-19 than the general population. In the current article, our aim is to present measures, guidance and thoughts that should be considered for the cancer patients.

Clinical and dosimetric considerations for Y90: recommendations from an international multidisciplinary working group.

The TheraSphere Global Dosimetry Steering Committee was formed in 2017 by BTG International to review existing data and address gaps in knowledge related to dosimetry. This committee is comprised of health care providers with diverse areas of expertise and perspectives on radiation dosimetry. The goal of these recommendations is to optimize glass microspheres radiation therapy for hepatocellular carcinoma while accounting for variables including disease presentation, tumour vascularity, liver function, and curative/palliative intent. The recommendations aim to unify glass microsphere users behind standardized dosimetry methodology that is simple, reproducible and supported by clinical data, with the overarching goal of improving clinical outcomes and advancing the knowledge of dosimetry.

Reduced inter-observer and intra-observer delineation variation in esophageal cancer radiotherapy by use of fiducial markers.

Objective: Delineation variation of esophageal tumors remains a large source of geometric uncertainty. In the present study, we investigated the inter- and intra-observer variation in esophageal gross tumor volume (GTV) delineation and the impact of endoscopically implanted fiducial markers on these variations. Material/Methods: Ten esophageal cancer patients with at least two markers endoscopically implanted at the cranial and caudal tumor borders and visible on the planning computed tomography (pCT) were included in this study. Five dedicated gastrointestinal radiation oncologists independently delineated GTVs on the pCT without markers and with markers. The GTV was first delineated on pCTs where markers were digitally removed and next on the original pCT with markers. Both delineation series were executed twice to determine intra-observer variation. For both the inter- and intra-observer analyses, the generalized conformity index (CIgen), and the standard deviation (SD) of the distances between delineated surfaces (i.e., overall, longitudinal, and radial SDs) were calculated. Linear mixed-effect models were used to compare the without and with markers series (α = 0.05). Results: Both the inter- and intra-observer CIgen were significantly larger in the series with markers than in the series without markers (p < .001). For the series without markers vs. with markers, the inter-observer overall SD, longitudinal SD, and radial SD was 0.63 cm vs. 0.22 cm, 1.44 cm vs. 0.42 cm, and 0.26 cm vs. 0.18 cm, respectively (p < .05); moreover, the intra-observer overall SD, longitudinal SD, and radial SD was 0.45 cm vs. 0.26 cm, 1.10 cm vs. 0.41 cm, and 0.22 cm vs. 0.15 cm, respectively (p < .05). Conclusion: The presence of markers at the cranial and caudal tumor borders significantly reduced both inter- and intra-observer GTV delineation variation, especially in the longitudinal direction. Our results endorse the use of markers in GTV delineation for esophageal cancer patients.

When Can We Avoid Postmastectomy Radiation Following Primary Systemic Therapy?

PURPOSE OF REVIEW: Postmastectomy radiation therapy (PMRT) has been shown to reduce the risk of locoregional recurrences (LRR) and of distant metastases (DM) and to improve breast cancer-specific survival (BCSS) as well as overall survival (OS) in patients with locally advanced breast cancer who are considered high risk because of large tumors (> 5 cm) and/or presence of axillary lymph node involvement. RECENT FINDINGS: Controversy is still ongoing with respect to the indication of PMRT in the case of earlier stage invasive tumors in the presence of risk factors including young age, premenopausal status, presence of lymphovascular invasion (LVI), high tumor grade, or tumor size 2-5 cm. Simultaneously, the evolution of our understanding of breast cancer biology has led us to better identify patients for whom the administration of systemic treatment prior to surgery reduces tumor load, not only in the case of locally advanced tumors but also for earlier stages, namely in the case of unfavorable molecular subtypes. The role of PMRT in the context of these patients treated with primary systemic therapy (PST), especially after a good tumor response, is under evaluation by various studies. This review identifies factors that may permit PMRT omission in a selected group of patients after PST.

What do radiation therapists know about health literacy and the strategies to improve it for patients? A qualitative study.

PURPOSE: Low health literacy leads to poor knowledge and understanding of health information, delayed diagnosis, lower use of preventative medicines/health services, increased likelihood of hospitalisation, and increased patient anxiety. Effective communication facilitates patient understanding and helps patients to manage the adverse side-effects associated with treatment. It is not yet known whether radiation therapists in Ireland tailor their communication to match a patient's health literacy level. The purpose of this research was to investigate radiation therapists' knowledge and awareness of health literacy and perceptions of their role in supporting patients with low health literacy. METHODS: Semi-structured interviews were conducted with sixteen radiation therapists working in four radiotherapy departments in Ireland. Data were analysed using the framework approach. RESULTS: Through discussions with participants, it was apparent that radiation therapists had limited knowledge of the concept of health literacy. Common themes arose from the interviews with four key themes identified: 1. Strategies used to identify patients' health literacy 2. Perceived effect of low health literacy 3. Obstacles faced when addressing low health literacy 4. Recommendations to support lower health literacy groups CONCLUSION: Currently, radiation therapists show some knowledge and awareness of health literacy, but an increased awareness of the prevalence of low health literacy and a structured approach to supporting patients would allow radiation therapists to more effectively communicate with patients, thus improving their treatment experience and reducing the risk of adverse outcomes.

Applying radiation protection and safety in radiotherapy.

Radiotherapy is one of the primary treatment options in cancer management. Modern radiotherapy includes complex processes requiring many different kinds of expertise. Among them, knowledge and skills are needed in clinical oncology, radiobiology, radiotherapy planning and simulation, dose measurement and calculation, radiation safety and medical physics. Radiation oncologists should assume the full and final responsibility for treatment, follow-up and supportive care of the patient. For all these activities, radiation oncologist should coordinate and collaborate with a team including different professionals: nurses, radiographers (RTT), clinical engineers, information system experts, taking advantage in particular of the dosimetry expertise of the medical physicist. Radiation therapy is widely recognized to be one of the safest areas of modern medicine, and errors are very rare. However, radiation protection recommendations developed at national level should comply with the EURATOM Directive 2013/59. This paper describes several contemporary and emerging concerns related to radioprotection in radiation therapy including quality and safety in external beam radiotherapy and brachytherapy, foetal dose, secondary malignancies, and the safety issues related to the new techniques and treatment strategies.

The importance in diagnosing patients with conflicting observational data for post surgery radioiodinated ablation of thyroid remnants.

OBJECTIVE: There is a special group of patients, according to 2015 American Thyroid Association guidelines. This group is defined as "the patients with conflicting observational data for post-surgery radioiodine ablation (COD for PSRIA)". For this special group of patients RIA is applied after a thorough reassessment of histopathological, clinical and biochemical features, including thyroglobulin (Tg). However, there is no consensus on what is the suitable cut-off value for the radioiodine ablation (RIA) decision or for therapy prediction. Moreover, is also unclear which Tg parameters should be used for these purposes. If we can determine useful and practical cut-off values for excellent response (ER) and non-structural incomplete response (non-SIR) response categories, this will facilitate our therapy response prediction before RIA and may allow us to categorize the group of "COD for PSRIA" based on a higher risk of recurrence/relapse or disease specific mortality rates according to serum thyroglobulin (Tg). This categorization may also enable us to plan the follow-up frequency of patients more scientifically. Consequently, it may provide the more efficient use of medical facility and healthcare system resources. SUBJECTS AND METHODS: Two hundred forty-nine patients (out of 577 examined) with "COD for PSRIA" were included in this study. Firstly, patients with indeterminate, biochemical incomplete and structural incomplete responses were considered as the non-ER group and compared to the ER group. Secondly, patients with excellent, indeterminate, and biochemically incomplete responses were considered as the non-SIR group and compared to the SIR group. The data were evaluated by MedCalc Statistical Software version 18.9. RESULTS: The cut-off value for ER patients was calculated as ≤6.57ng/mL. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 67.9%, 75.4%, 55.6% and 83.8%, respectively. The cut-off value for non-SIR patients was calculated as ≤12.7ng/mL. Sensitivity, specificity, PPV and NPV were 78.5%, 91.7%, 35.5% and 98.6%, respectively. CONCLUSION: If a patient has ≤6.57ng/mL pre-ablative Tg, follow-up intervals of patients with "COD for PSRIA" may be extended due to lower recurrence/relapse rates. However, if a patient has >12.7ng/mL pre-ablative Tg, these patients should be followed-up more frequently in order to determine SIR earlier. This approach may enable more efficient use of medical facility and healthcare system resources and a more scientific planning of their follow-up treatment. This approach seems to have the potential to contribute significantly to cost-effectiveness.