Global Access to Radiotherapy Services: Have We Made Progress During the Past Decade?

Irradiated tumour cell-derived microparticles upregulate MHC-I expression in cancer cells via DNA double-strand break repair pathway

Radiotherapy (RT) is used for over 50 % of cancer patients and can promote adaptive immunity against tumour antigens. However, the underlying mechanisms remain unclear. Here, we discovered that RT induces the release of irradiated tumour cell-derived microparticles (RT-MPs), which significantly upregulate MHC-I expression on the membranes of non-irradiated cells, enhancing the recognition and killing of these cells by T cells. Mechanistically, RT-MPs induce DNA double-strand breaks (DSB) in tumour cells, activating the ATM/ATR/CHK1-mediated DNA repair signalling pathway, and upregulating MHC-I expression. Inhibition of ATM/ATR/CHK1 reversed RT-MP-induced upregulation of MHC-I. Furthermore, phosphorylation of STAT1/3 following the activation of ATM/ATR/CHK1 is indispensable for the DSB-dependent upregulation of MHC-I. Therefore, our findings reveal the role of RT-MP-induced DSBs and the subsequent DNA repair signalling pathway in MHC-I expression and provide mechanistic insights into the regulation of MHC-I expression after DSBs.

Intra-operative extracorporeal irradiation of tumour-invaded craniotomy bone flap in meningioma: a case series

BACKGROUND

Extracorporeal irradiation of tumorous calvaria (EITC) can be performed to restore function and form of the skull after resection of bone-invasive meningioma. We sought to examine the rate of tumour recurrence and other selected outcomes in patients undergoing meningioma resection and EITC.

METHODS

Retrospective single-centre study of adult patients undergoing meningioma resection and EITC between January 2015 and November 2022 at a tertiary neurosurgical centre. Patient demographics, surgery data, tumour data, use of adjuvant therapy, surgical complications, and tumour recurrences were collected.

RESULTS

Eighteen patients with 11 (61%) CNS WHO grade 1, 6 (33%) grade 2, and 1 (6%) grade 3 meningiomas were included. Median follow-up was 42 months (range 3-88). Five (28%) patients had a recurrence, but none were associated with the bone flap. Two (11%) wound infections requiring explant surgery occurred. Six (33%) patients required a further operation. Two operations were for recurrences, one was for infection, one was a washout and wound exploration but no evidence of infection was found, one patient requested the removal of a small titanium implant, and one patient required a ventriculoperitoneal shunt for a persistent CSF collection. There were no cases of bone flap resorption and cosmetic outcome was not routinely recorded.

CONCLUSION

EITC is feasible and fast to perform with good outcomes and cost-effectiveness compared to other reconstructive methods. We observed similar recurrence rates and lower infection rates requiring explant compared to the largest series of cranioplasty in meningioma. Cosmetic outcome is universally under-reported and should be reported in future studies.

FLASH radiotherapy: A new milestone in the field of cancer radiotherapy

Radiotherapy plays a pivotal role in the control and eradication of tumors, but it can also induce radiation injury to surrounding normal tissues while targeting tumor cells. In recent years, FLASH-Radiotherapy (FLASH-RT) has emerged as a cutting-edge research focus in the field of radiation therapy. By delivering high radiation doses to the treatment target in an ultra-short time, FLASH-RT produces the FLASH effect, which reduces the toxicity to normal tissues while achieving comparable tumor control efficacy to conventional radiotherapy. This review provides a brief overview of the development history of FLASH-RT and its impact on tumor control. Additionally, it focuses on introducing the protective effects and molecular mechanisms of this technology on various normal tissues, as well as exploring its synergistic effects when combined with other tumor therapies. Importantly, this review discusses the challenges faced in translating FLASH-RT into clinical practice and outlines its promising future applications.

Invisible cancers: Seeing, knowing, enacting and proving cancers in Haiti

In Haiti, pathological confirmation of a cancer diagnosis is often delayed or impossible, imaging is expensive and imperfect, and many tests are unavailable. Physicians frequently struggle to establish cancers at a level of certainty required by "evidence based" standards, delaying definitive diagnosis and rendering some cancers permanently "suspected." I use 22 months of participant observation at the two largest cancer treatment programs in Haiti, as well as throughout Haiti's fragmented healthcare system, to look closely at processes of diagnosis and management of suspected 'cancers' which may never fully come to be. I argue that as global oncology becomes increasingly standardized, local practices are forced into alignment with a global knowledge basis that governs the knowability/unknowability of cancer. Using three case studies drawn from this work, I examine relationships among visibility, power, expertise and the replication of inequity through the governance of knowledge production. Finally, I examine the implications of these processes for cancer care in the global south.

Current and projected gaps in the availability of radiotherapy in the Asia-Pacific region: a country income-group analysis

BACKGROUND

Cancer incidence and mortality is increasing rapidly worldwide, with a higher cancer burden observed in the Asia-Pacific region than in other regions. To date, evidence-based modelling of radiotherapy demand has been based on stage data from high-income countries (HIC) that do not account for the later stage at presentation seen in many low-income and middle-income countries (LMICs). We aimed to estimate the current and projected demand and supply in megavoltage radiotherapy machines in the Asia-Pacific region, using a national income-group adjusted model.

METHODS

Novel LMIC radiotherapy demand and outcome models were created by adjusting previously developed models that used HIC cancer staging data. These models were applied to the cancer case mix (ie, the incidence of each different cancer) in each LMIC in the Asia-Pacific region to estimate the current and projected optimal radiotherapy utilisation rate (ie, the proportion of cancer cases that would require radiotherapy on the basis of guideline recommendations), and to estimate the number of megavoltage machines needed in each country to meet this demand. Information on the number of megavoltage machines available in each country was retrieved from the Directory of Radiotherapy Centres. Gaps were determined by comparing the projected number of megavoltage machines needed with the number of machines available in each region. Megavoltage machine numbers, local control, and overall survival benefits were compared with previous data from 2012 and projected data for 2040.

FINDINGS

57 countries within the Asia-Pacific region were included in the analysis with 9·48 million new cases of cancer in 2020, an increase of 2·66 million from 2012. Local control was 7·42% and overall survival was 3·05%. Across the Asia-Pacific overall, the current optimal radiotherapy utilisation rate is 49·10%, which means that 4·66 million people will need radiotherapy in 2020, an increase of 1·38 million (42%) from 2012. The number of megavoltage machines increased by 1261 (31%) between 2012 and 2020, but the demand for these machines increased by 3584 (42%). The Asia-Pacific region only has 43·9% of the megavoltage machines needed to meet demand, ranging from 9·9-40·5% in LMICs compared with 67·9% in HICs. 12 000 additional megavoltage machines will be needed to meet the projected demand for 2040.

INTERPRETATION

The difference between supply and demand with regard to megavoltage machine availability has continued to widen in LMICs over the past decade and is projected to worsen by 2040. The data from this study can be used to provide evidence for the need to incorporate radiotherapy in national cancer control plans and to inform governments and policy makers within the Asia-Pacific region regarding the urgent need for investment in this sector.

FUNDING

The Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology for Asia and the Pacific (RCA) Regional Office (RCARP03).

Antecedents of patient health engagement in the radiotherapy service (evidence from Indonesia)

Background

Private radiotherapy (RT) facilities in emerging countries are growing with cancer incidence. Private healthcare providers must provide better care based on patient perspectives to reach more patients.

Aim

This study investigated the relationship between antecedents of patient health engagement (PHE) with revisit intention (RVI) and intent to recommend (ITR) in private RT facilities.

Setting

The survey was conducted in a private hospital with a RT service in Central Java province, Indonesia.

Methods

A quantitative, cross-sectional design with a purposive sampling method was used. Patient questionnaire survey modified from validated self-administered radiotherapy experience (RTEQ) and PHE questionnaire were used to collect data. Partial least squares-structural equation modelling was used to analyse the data.

Results

In this study, 173 respondents consented to participate, which demonstrated that seven of the eight experience antecedents of PHE measured by reliable and valid RTEQ and were significantly related to PHE (p-value <0.05). At the same time, the degree of PHE has a significant relationship with RVI and ITR (p-value <0.05).

Conclusion

Patient informational needs elements from the patient experience, followed by situational repose, were shown to have a prominent relation to PHE. The management of private RT facilities needs to focus more on these elements to encourage PHE to establish hospital performance.

Contribution

The findings denote that six elements of RTEQ relate to PHE and further hospital outcomes. Hospital management could utilise this approach to improve the quality of care in RT facilities, specifically in private hospitals in emerging countries.

Evaluating the effect of low-density inhomogeneities: A comparative study of lithium fluoride detectors, radiochromic films, and collapsed cone algorithm in 6 MV photon beams

In recent years, there has been significant advancement in the development of physical simulators for dose evaluation. Many dosimetric studies employ solid materials, equivalent to human tissues, to evaluate dose distribution. This study aims to evaluate the effectiveness of inhomogeneity correction carried out by the Monaco/Elekta radiotherapy planning software. To achieve this goal, a physical simulator was created using cork boards to simulate lung tissue and solid water to represent other tissues. This simulator was combined with a dosimetric system that utilized lithium fluoride thermoluminescent detectors - RADOS MTS-N (LiF:Mg,Ti). The thermoluminescent detectors were positioned at various depths using a precisely drilled 2.0 mm thick acrylic plate, and they were placed at predefined positions. The irradiation of the simulator was conducted using an Elekta Synergy® Platform accelerator, employing a 6 MV photon beam with a field size of 15 × 15 cm2 and a source-surface distance (SSD) of 97.5 cm. A radiation dose of 200 cGy was applied for this study. In addition to the dosimetric assessment using thermoluminescent detectors, GAFCHROMIC™ EBT-3 Dosimetry Films were utilized to evaluate the dose at the same measurement points. The dose distribution data measured with the detectors were compared with the values provided by the planning system (TPS) and the inhomogeneity correction was verified. The results support the hypothesis that there is a lack of precision in the analytical simulations performed by the TPS, particularly in cases involving dose distribution at interfaces with varying densities.

Systematic Review and Meta-analysis of the Association Between Radiation Therapy Treatment Volume and Patient Outcomes

PURPOSE

Evidence of a volume-outcome association in cancer surgery has shaped the centralization of cancer services; however, it is unknown whether a similar association exists for radiation therapy. The objective of this study was to determine the association between radiation therapy treatment volume and patient outcomes.

METHODS AND MATERIALS

This systematic review and meta-analysis included studies that compared outcomes of patients who underwent definitive radiation therapy at high-volume radiation therapy facilities (HVRFs) versus low-volume facilities (LVRFs). The systematic review used Ovid MEDLINE and Embase. For the meta-analysis, a random effects model was used. Absolute effects and hazard ratios (HRs) were used to compare patient outcomes.

RESULTS

The search identified 20 studies assessing the association between radiation therapy volume and patient outcomes. Seven of the studies looked at head and neck cancers (HNCs). The remaining studies covered cervical (4), prostate (4), bladder (3), lung (2), anal (2), esophageal (1), brain (2), liver (1), and pancreatic cancer (1). The meta-analysis demonstrated that HVRFs were associated with a lower chance of death compared with LVRFs (pooled HR, 0.90; 95% CI, 0.87- 0.94). HNCs had the strongest evidence of a volume-outcome association for both nasopharyngeal cancer (pooled HR, 0.74; 95% CI, 0.62-0.89) and nonnasopharyngeal HNC subsites (pooled HR, 0.80; 95% CI, 0.75-0.84), followed by prostate cancer (pooled HR, 0.92; 95% CI, 0.86-0.98). The remaining cancer types showed weak evidence of an association. The results also demonstrate that some centers defined as HVRFs are undertaking very few procedures per annum (<5 radiation therapy cases per year).

CONCLUSIONS

An association between radiation therapy treatment volume and patient outcomes exists for most cancer types. Centralization of radiation therapy services should be considered for cancer types with the strongest volume-outcome association, but the effect on equitable access to services needs to be explicitly considered.

Chronic inflammatory effects of in vivo irradiation of the murine heart on endothelial cells mimic mechanisms involved in atherosclerosis

PURPOSE

Radiotherapy is a major pillar in the treatment of solid tumors including breast cancer. However, epidemiological studies have revealed an increase in cardiac diseases approximately a decade after exposure of the thorax to ionizing irradiation, which might be related to vascular inflammation. Therefore, chronic inflammatory effects were examined in primary heart and lung endothelial cells (ECs) of mice after local heart irradiation.

METHODS

Long-lasting effects on primary ECs of the heart and lung were studied 20-50 weeks after local irradiation of the heart of mice (8 and 16 Gy) in vivo by multiparameter flow cytometry using antibodies directed against cell surface markers related to proliferation, stemness, lipid metabolism, and inflammation, and compared to those induced by occlusion of the left anterior descending coronary artery.

RESULTS

In vivo irradiation of the complete heart caused long-lasting persistent upregulation of inflammatory (HCAM, ICAM‑1, VCAM-1), proliferation (CD105), and lipid (CD36) markers on primary heart ECs and an upregulation of ICAM‑1 and VCAM‑1 on primary ECs of the partially irradiated lung lobe. An artificially induced heart infarction induces similar effects with respect to inflammatory markers, albeit in a shorter time period.

CONCLUSION

The long-lasting upregulation of prominent inflammatory markers on primary heart and lung ECs suggests that local heart irradiation induces chronic inflammation in the microvasculature of the heart and partially irradiated lung that leads to cardiac injury which might be related to altered lipid metabolism in the heart.

The American Brachytherapy Society and Indian Brachytherapy Society consensus statement for the establishment of high-dose-rate brachytherapy programs for gynecological malignancies in low- and middle-income countries

PURPOSE

The global cervical cancer burden is disproportionately high in low- and middle-income countries (LMICs), and outcomes can be governed by the accessibility of appropriate screening and treatment. High-dose-rate (HDR) brachytherapy plays a central role in cervical cancer treatment, improving local control and overall survival. The American Brachytherapy Society (ABS) and Indian Brachytherapy Society (IBS) collaborated to provide this succinct consensus statement guiding the establishment of brachytherapy programs for gynecological malignancies in resource-limited settings.

METHODS AND MATERIALS

ABS and IBS members with expertise in brachytherapy formulated this consensus statement based on their collective clinical experience in LMICs with varying levels of resources.

RESULTS

The ABS and IBS strongly encourage the establishment of HDR brachytherapy programs for the treatment of gynecological malignancies. With the consideration of resource variability in LMICs, we present 15 minimum component requirements for the establishment of such programs. Guidance on these components, including discussion of what is considered to be essential and what is considered to be optimal, is provided.

CONCLUSIONS

This ABS/IBS consensus statement can guide the successful and safe establishment of HDR brachytherapy programs for gynecological malignancies in LMICs with varying levels of resources.

Development and implementation barriers of a new patient-reported measure: The Radiation therapy-related Inconvenience Questionnaire (RIQ)

INTRODUCTION

Radiation therapy (RT) can benefit approximately 50% of cancer patients and contribute to 40% of all cancer cures, yet its utilisation in cancer is low globally. Several factors contribute to this including perceived inconvenience related to accessing and utilising RT. To quantitatively assess the latter, a new tool - the Radiation therapy-related Inconvenience Questionnaire (RIQ) - was developed. This study aimed to pre-test the RIQ and explore barriers and facilitators to implementing it in routine clinical practice and clinical trials.

METHODS

Semi-structured cognitive interviews were conducted with patients undertaking RT, recruited via three hospitals to examine content validity, acceptability, and comprehensibility of the RIQ. Interviews identified inconsistencies, relevance, and clarity of items. Semi-structured interviews with healthcare professionals involved in the delivery of care to individuals undertaking RT explored barriers and facilitators to routine usage. Thematic analysis was used to identify themes.

RESULTS

Patients (N = 15) identified problems in content, instructions, layout, length, and response options; consequently, 25 items were revised and eight removed, resulting in a final 29-item questionnaire. Clinicians identified staff- and patient-specific barriers to implementing RIQ in clinical practice. Perceived facilitators included the following: (a) workplace factors, (b) mode of administration, and (c) imparting knowledge.

CONCLUSION

This study demonstrated acceptability and comprehensibility of the 29-item RIQ amongst cancer patients undertaking RT and treating clinicians. The next phase will evaluate the RIQ's measurement properties in a larger clinical study. The barriers and facilitators identified can guide future implementation of RIQ in clinical practice and clinical trials.

Lipid Polyunsaturated Fatty Acid Chains in Mouse Kidneys Were Increased within 5 min of a Single High Dose Whole Body Irradiation

To understand the ultra-early reaction of normal organ lipids during irradiation, we investigated the response of lipids, including polyunsaturated fatty acid (PUFA) chains, which are particularly susceptible to damage by ROS, in mice's kidneys, lungs, brains, and livers within 5 min of single high-dose irradiation. In this study, we set up three groups of C56BL/6 male mice and conducted whole-body irradiation with 0 Gy, 10 Gy, and 20 Gy single doses. Kidney, lung, brain, and liver tissues were collected within 5 min of irradiation. PUFA-targeted and whole lipidomic analyses were conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that PUFA chains of kidney phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TG) significantly increased within 5 min of 10 Gy and 20 Gy irradiation. The main components of increased PUFA chains in PC and PE were C18:2, C20:4, and C22:6, and in TG the main component was C18:2. The kidney lipidomes also showed significant changes from the perspective of lipid species, mainly dominated by an increase in PC, PE, TG, and signal lipids, while lipidomes of the lung, brain, and liver were slightly changed. Our results revealed that acute PUFA chains increase and other lipidomic changes in the kidney upon whole-body irradiation within 5 min of irradiation. The significantly increased lipids also showed a consistent preference for possessing PUFA chains. The lipidomic changes varied from organ to organ, which indicates that the response upon irradiation within a short time is tissue-specific.

Nano X Image Guidance in radiation therapy: feasibility study protocol for cone beam computed tomography imaging with gravity-induced motion

BACKGROUND

This paper describes the protocol for the Nano X Image Guidance (Nano X IG) trial, a single-institution, clinical imaging study. The Nano X is a prototype fixed-beam radiotherapy system developed to investigate the feasibility of a low-cost, compact radiotherapy system to increase global access to radiation therapy. This study aims to assess the feasibility of volumetric image guidance with cone beam computed tomography (CBCT) acquired during horizontal patient rotation on the Nano X radiotherapy system.

METHODS

In the Nano X IG study, we will determine whether radiotherapy image guidance can be performed with the Nano X radiotherapy system where the patient is horizontally rotated while scan projections are acquired. We will acquire both conventional CBCT scans and Nano X CBCT scans for 30 patients aged 18 and above and receiving radiotherapy for head/neck or upper abdomen cancers. For each patient, a panel of experts will assess the image quality of Nano X CBCT scans against conventional CBCT scans. Each patient will receive two Nano X CBCT scans to determine the image quality reproducibility, the extent and reproducibility of patient motion and assess patient tolerance.

DISCUSSION

Fixed-beam radiotherapy systems have the potential to help ease the current shortfall and increase global access to radiotherapy treatment. Advances in image guidance could facilitate fixed-beam radiotherapy using horizontal patient rotation. The efficacy of this radiotherapy approach is dependent on our ability to image and adapt to motion due to rotation and for patients to tolerate rotation during treatment.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04488224. Registered on 27 July 2020.

In Response to Precision Medicine: Current Subcellular Targeting Strategies for Cancer Therapy

Emerging as a potent anticancer treatment, subcellular targeted cancer therapy has drawn increasing attention, bringing great opportunities for clinical application. Here, two targeting strategies for four main subcellular organelles (mitochondria, lysosome, endoplasmic reticulum, and nucleus), including molecule- and nanomaterial (inorganic nanoparticles, micelles, organic polymers, and others)-based targeted delivery or therapeutic strategies, are summarized. Phototherapy, chemotherapy, radiotherapy, immunotherapy, and "all-in-one" combination therapy are among the strategies covered in detail. Such materials are constructed based on the specific properties and relevant mechanisms of organelles, enabling the elimination of tumors by inducing dysfunction in the corresponding organelles or destroying specific structures. The challenges faced by organelle-targeting cancer therapies are also summarized. Looking forward, a paradigm for organelle-targeting therapy with enhanced therapeutic efficacy compared to current clinical approaches is envisioned.

Palliative care on the radiation oncology ward-improvements in clinical care through interdisciplinary ward rounds

INTRODUCTION

Palliative care is essential for patients with terminal diseases and aims at effective symptom control. This may stand in opposition to radiation treatment as an oncological treatment modality. The hereby presented work demonstrates the successful integration of a palliative care service in the radiation oncology ward.

METHODS

Since 2015, 1018 patients were seen by the palliative care service on the radiation oncology ward and have been analyzed in this single center study. To assess teaching efficacy of the consultation service, a survey was conducted among 15 radiation oncology residents.

RESULTS

Cooperation between the two departments proved to be efficient with rising patient numbers. Palliative care was able to guide appropriate postdischarge care with the number of patients dying on the radiation oncology ward decreasing significantly (p = 0.009). The main topics for consultation were pain medication (92.3%), organization of postdischarge care (92.3%), and psycho-oncological support (84.6%). Most residents had a positive image of the palliative care service and consented on adjectives like "enriching", "empathic", "collegial", "professionally founded", and a "low threshold for consultation". All participants agreed that cooperation deepened their knowledge on palliative care.

CONCLUSION

A synergistic cooperation between a palliative care consultation service and a radiation oncology department addresses patient symptoms on an individual level. It confers advanced knowledge on palliative care which is essential for resident education and patient treatment.

Measuring Global Inequity in Radiation Therapy: Resource Deficits in Low- and Middle-Income Countries Without Radiation Therapy Facilities

Purpose

Although radiation therapy (RT) is an effective and inexpensive pillar of multidisciplinary cancer care, access to RT facilities remains highly inequitable globally. Numerous studies have documented this resource gap, yet many countries continue facing their raging cancer epidemics ill-equipped. In this study, we present an estimation of resource deficits in low- and middle-income countries (LMICs) without any RT facilities at all.

Methods and Materials

This study builds on publicly available data on country classification, population, cancer incidence, and RT requirements provided by the World Bank Group, the World Health Organization, and the International Atomic Energy Agency. Leveraging these data, we developed a capacity-planning model to estimate the current deficit of fundamental RT resources for LMICs with more than 1 million inhabitants and no active RT facilities.

Results

There were 23 LMICs with a population of more than 1 million inhabitants and without any active RT facilities, 78% of which were located in sub-Saharan Africa. The aggregate population of these countries was 197.3 million people. The largest countries without RT facilities were Afghanistan and Malawi, with a population of 38.0 million and 18.6 million inhabitants, respectively. Estimated cancer incidence for all countries under study totaled at 134,783 new cases per year, 84,239 (62.5%) of which would have required RT. There was an aggregate deficit of 188 megavoltage machines and 85 brachytherapy afterloaders, along with simulation equipment and human capital in the magnitude of approximately 3363 trained radiation oncology staff.

Conclusions

Hundreds of thousands of patients with cancer in LMICs continue to live in countries without access to RT in their own country. This extreme form of global health inequity requires urgent and decisive action, the success of which depends on the integration of international and local efforts.

Driving quality improvement through better data: The story of New Zealand's radiation oncology collection

Aotearoa/New Zealand is one of the first nations in the world to develop a comprehensive, high-quality collection of radiation therapy data (the Radiation Oncology Collection, ROC) that is able to report on treatment delivery by health region, patient demographics and service provider. This has been guided by radiation therapy leaders, who have been instrumental in overseeing the establishment of clear and robust data definitions, a centralised database and outputs delivered via an online tool. In this paper, we detail the development of the ROC, provide examples of variation in practice identified from the ROC and how these changed over time, then consider the ramifications of the ROC in the wider context of cancer care quality improvement. In addition to a review of relevant literature, primary data were sourced from the ROC on radiation therapy provided nationally in New Zealand between 2017 and 2020. The total intervention rate, number of fractions and doses are reported for select cancers by way of examples of national variation in practice. Results from the ROC have highlighted areas of treatment variation and have prompted increased uptake of hypofractionation for curative prostate and breast cancer treatment and for palliation of bone metastases. Future development of the ROC will increase its use for quality improvement and ultimately link to a real time cancer services database.

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.

Predictors of treatment refusal in patients with colorectal cancer: A systematic review

This systematic review was conducted to investigate predictors of treatment refusal in colorectal cancer (CRC) patients. An understanding of these predictors would inform statistical models for the identification of high-risk patients who might benefit from interventions that seek to improve treatment compliance. We performed a search of PubMed and Scopus to identify potentially relevant studies on predictors of treatment refusal in CRC patients that were published between January 1, 2000 and December 31, 2021. We screened manuscripts using predefined eligibility criteria. Information on study design, study location, patient characteristics, treatments, rates and predictors of treatment refusal, and the impact of treatment refusal on mortality or survival were collected from eligible studies. Study quality was assessed using the Newcastle-Ottawa score. The overall findings of the review process were summarized using descriptive statistics and a narrative synthesis. A total of 13 studies were included in this review. Ten studies reported on refusal of CRC surgery, refusal rate: 0.25%-3.26%; three studies reported on chemotherapy refusal (one of which reported on both surgery and chemotherapy refusal), refusal rate: 7.8%-41.5%; and one study reported on refusal of any cancer treatment, refusal rate: 8.7%. The bulk of the published literature confirmed the harmful association between treatment refusal and poor survival outcomes in CRC patients. Frequently cited predictors of treatment refusal included patient demographic characteristics (age, race, gender), clinical characteristics (disease stage, comorbidity), and factors that impact access to cancer care services (healthcare insurance, facility level). Potentially high rates of treatment refusal pose a challenge to CRC control. This review has identified several factors which must be considered when attempting to reduce treatment refusal in CRC patients. Furthermore, these factors should be tested as components of predictive risk models for this important outcome.

Socioeconomic Impact of Cancer in Latin America and The Caribbean

The incidence of cancer in Latin America and the Caribbean (LAC) is increasing yearly and is expected to reach 2.4 million new cases by 2040, with a more pronounced effect in Central America and South America. In addition, cancer is already the most frequent cause of premature death for most countries in LAC, and the second cause of death independent of country socioeconomic status, clearly demonstrating that the cancer burden in LAC should be addressed now rather than considered as an issue to be dealt with in the future. LAC countries performed in a mid-range zone in terms of income and mortality-to-incidence ratio compared to other countries globally. The LAC continent has, in general, a median income per capita and a median availability of radiotherapy (RDT) machines per capita. Patients that have private health coverage are more likely to receive preventive care such as pap smears and mammography in many countries of the LAC. The human development index was negatively related to mortality from oral cancer in the LAC countries with medium and low Human Development Index (HDI). Cancer treatment adverse events can negatively affect survivors' workability compromising their return to work after diagnosis. In conclusion, the cancer burden can be a major public health issue with a considerable socioeconomic impact in LAC countries. It is demonstrated in several studies that unequal access to optimal care is frequent in LAC and that health insurance type may impact patients' diagnosis and outcome.

Radiotherapy prioritization in 143 national cancer control plans: Correlation with radiotherapy machine availability, geography and income level

BACKGROUND

In 2015, the Global Task Force on Radiotherapy for Cancer Control (GTFRCC) called for 80% of National Cancer Control Plans (NCCP) to include radiotherapy by 2020. As part of the ongoing ESTRO Global Impact of Radiotherapy in Oncology (GIRO) project, we assessed whether inclusion of radiotherapy in NCCPs correlates with radiotherapy machine availability, national income, and geographic region.

METHODS

A previously validated checklist was used to determine whether radiotherapy was included in each country's NCCP. We applied the CCORE optimal radiotherapy utilisation model to the GLOBOCAN 2020 data to estimate the demand for radiotherapy and compared this to the International Atomic Energy Agency (IAEA) Directory of Radiotherapy Centres (DIRAC) supply data, stratifying by income level and world region. World regions were defined according to the IAEA.

FINDINGS

Complete data (including GLOBOCAN 2020, DIRAC and NCCP) was available for 143 countries. Over half (55%, n = 79) included a radiotherapy-specific checklist item within the plan. Countries which included radiotherapy services planning in their NCCP had a higher median number of machines (1.68 vs 0.75 machines/1000 patients needing radiotherapy, p < 0.001). There was significant regional and income-level heterogeneity in the inclusion of radiotherapy-related items in NCCPs. Low-income and Asia-Pacific countries were least likely to include radiation oncology services planning in their NCCP (p = 0.06 and p = 0.003, respectively). Few countries in the Asia-Pacific (18.6%) had a plan to develop or maintain radiation services, compared to 57% of countries in Europe.

INTERPRETATION

Only 55% of current NCCPs included any information regarding radiotherapy, below the GTFRCC's target of 80%. Prioritisation of radiotherapy in NCCPs was correlated with radiotherapy machine availability. There was regional and income-level heterogeneity regarding the inclusion of specific radiotherapy checklist items in the NCCPs. Ongoing efforts are needed to promote the inclusion of radiotherapy in future iterations of NCCPs in order to improve global access to radiation treatment.

FUNDING

No direct funding was used in this research.

Radiobiological Aspects of FLASH Radiotherapy

Radiotherapy (RT) is one of the primary treatment modalities for cancer patients. The clinical use of RT requires a balance to be struck between tumor effect and the risk of toxicity. Sparing normal tissue is the cornerstone of reducing toxicity. Advances in physical targeting and dose-shaping technology have helped to achieve this. FLASH RT is a promising, novel treatment technique that seeks to exploit a potential normal tissue-sparing effect of ultra-high dose rate irradiation. A significant body of in vitro and in vivo data has highlighted a decrease in acute and late radiation toxicities, while preserving the radiation effect in tumor cells. The underlying biological mechanisms of FLASH RT, however, remain unclear. Three main mechanisms have been hypothesized to account for this differential FLASH RT effect between the tumor and healthy tissue: the oxygen depletion, the DNA damage, and the immune-mediated hypothesis. These hypotheses and molecular mechanisms have been evaluated both in vitro and in vivo. Furthermore, the effect of ultra-high dose rate radiation with extremely short delivery times on the dynamic tumor microenvironment involving circulating blood cells and immune cells in humans is essentially unknown. Therefore, while there is great interest in FLASH RT as a means of targeting tumors with the promise of an increased therapeutic ratio, evidence of a generalized FLASH effect in humans and data to show that FLASH in humans is safe and at least effective against tumors as standard photon RT is currently lacking. FLASH RT needs further preclinical investigation and well-designed in-human studies before it can be introduced into clinical practice.

Digital transfer in radiation oncology education for medical students-single-center data and systemic review of the literature

PURPOSE

Modern medical education demands innovative, competence-orientated concepts. The forced digital transfer of teaching due to the coronavirus pandemic also affected radiation oncology (RO). The following analysis investigates whether the attractivity of RO teaching at our faculty could be maintained during the pandemic and which possibilities exist to involve students (in active learning). The latter aspect is further elaborated on a broader scale by a systemic review of the literature on competence-orientated digital education.

METHODS

Evaluation results and participation rates of clinical lectures in radiation oncology (RO) were analyzed between the winter semester 2018/2019 and the summer semester 2021. A systemic review of the literature on digital education in RO for medical students was conducted.

RESULTS

Concerning evaluation results, a significant improvement for the 7th and 9th semesters was observed in comparison between the pre-pandemic and pandemic semesters (p = 0.046 and p = 0.05, respectively). Overall participation rates did not differ. However, the number of students attending > 75% of classes in the respective semester increased significantly between the pre-pandemic and pandemic period (median values: 38 vs. 79%, p = 0.046; 44 vs. 73%, p = 0.05; 45 vs. 64%, p = 0.05; 41 vs. 77%, p = 0.05; 41 vs. 71%, p = 0.05, for the 6th to 10th semester, respectively).

CONCLUSION

The analysis demonstrates the possibility of efficient digital transfer of a core curriculum in RO to the digital era, with a more continuous participation of students. This transfer may enable amelioration of teaching quality and the introduction of innovative and interactive concepts in accordance with the literature.

High-specificity protection against radiation-induced bone loss by a pulsed electromagnetic field

Radiotherapy increases tumor cure and survival rates; however, radiotherapy-induced bone damage remains a common issue for which effective countermeasures are lacking, especially considering tumor recurrence risks. We report a high-specificity protection technique based on noninvasive electromagnetic field (EMF). A unique pulsed-burst EMF (PEMF) at 15 Hz and 2 mT induces notable Ca²⁺ oscillations with robust Ca²⁺ spikes in osteoblasts in contrast to other waveforms. This waveform parameter substantially inhibits radiotherapy-induced bone loss by specifically modulating osteoblasts without affecting other bone cell types or tumor cells. Mechanistically, primary cilia are identified as major PEMF sensors in osteoblasts, and the differentiated ciliary expression dominates distinct PEMF sensitivity between osteoblasts and tumor cells. PEMF-induced unique Ca²⁺ oscillations depend on interactions between ciliary polycystins-1/2 and endoplasmic reticulum, which activates the Ras/MAPK/AP-1 axis and subsequent DNA repair Ku70 transcription. Our study introduces a previously unidentified method against radiation-induced bone damage in a noninvasive, cost-effective, and highly specific manner.

Access to Radiation Therapy: From Local to Global and Equality to Equity

The discipline of radiation oncology is the most resource-intensive component of comprehensive cancer care because of significant initial investments required for machines, the requirement of dedicated construction, a multifaceted workforce, and recurring maintenance costs. This review focuses on the challenges associated with accessible and affordable radiation therapy (RT) across the globe and the possible solutions to improve the current scenario. Most common cancers globally, including breast, prostate, head and neck, and cervical cancers, have a RT utilization rate of > 50%. The estimated annual incidence of cancer is 19,292,789 for 2020, with > 70% occurring in low-income countries and low-middle–income countries. There are approximately 14,000 teletherapy machines globally. However, the distribution of these machines is distinctly nonuniform, with low-income countries and low-middle–income countries having access to < 10% of the global teletherapy machines. The Directory of Radiotherapy Centres enlists 3,318 brachytherapy facilities. Most countries with a high incidence of cervical cancer have a deficit in brachytherapy facilities, although formal estimates for the same are not available. The deficit in simulators, radiation oncologists, and medical physicists is even more challenging to quantify; however, the inequitable distribution is indisputable. Measures to ensure equitable access to RT include identifying problems specific to region/country, adopting indigenous technology, encouraging public-private partnership, relaxing custom duties on RT equipment, global/cross-country collaboration, and quality human resources training. Innovative research focusing on the most prevalent cancers aiming to make RT utilization more cost-effective while maintaining efficacy will further bridge the gap.

Improving global access to Radiotherapy: The current scenario and the road ahead

Modern Radiotherapy Technology: Obstacles and Opportunities to Access in Low- and Middle-Income Countries

Low- and middle-income countries (LMICs) have a large burden of cancer with differential population needs and outcomes compared to high-income countries. Access to radiotherapy, especially modern technology, is a major challenge. Modern radiotherapy has been demonstrated with better utility in overall cancer outcomes. We deliberate various challenges and opportunities unique to LMICs' set up for access to modern radiotherapy technology in the light of discussions and deliberations made during the recently concluded annual meeting of Tata Memorial Centre, India. We take examples available from various LMICs in this direction in our manuscript.

[Probiotics' Ameliorating Effect on Side Effects of Cancer Treatment: Reflections and Prospects]

Surgical resection, radiotherapy, chemotherapy, and immunotherapy are the main therapies for cancers. These cancer therapies all prolong patient survival, but also bring multiple side effects. Gut microbiota participates in almost all the physiological and biochemical processes of the host, playing a key role in human health and diseases. As an exogenous intervention, probiotics can prevent diseases and enhance immunity. Their anti-cancer ability and ameliorative effect have received increasing recognition. Herein, we reported the latest findings on gut microbiota and cancer pathogenesis, focusing on the application of probiotics in reducing the side effects caused by cancer therapies and hoping to provide supportive references for the clinical use of probiotics in cancer treatment.

Global disparities in access to cancer care

Despite the significant advances made in our understanding of cancer and how to treat it over the last hundred years, there are wide global disparities in access to cancer care and in who gets to benefit from cutting-edge cancer research.

Treatment of cervical cancer: overcoming challenges in access to brachytherapy

INTRODUCTION

Brachytherapy is an essential component of the cervical cancer treatment paradigm as it contributes to improved clinical outcomes and overall survival. Yet brachytherapy remains globally underutilized, with disparities in access at both national and international levels.

AREAS COVERED

The review explores current brachytherapy utilization practices and efforts being undertaken to address barriers to implementation in low-, middle-, and high-income countries, and how these efforts are projected to impact future brachytherapy access. The content presented is based on a review of published literature and the authors' collective clinical experiences.

EXPERT OPINION

There exists a tremendous opportunity to expand access to essential brachytherapy services for women with cervical cancer. Many national and international brachytherapy efforts exist; yet it remains imperative that such focused efforts continue to grow and provide further access to this critical treatment modality for women in need worldwide.

The state of gynecologic radiation therapy in low- and middle-income countries

A disproportionate burden of gynecologic malignancies occurs in low- and middle-income countries. Radiation therapy is an integral component of treatment for gynecologic malignancies both from a curative (locally advanced cervical cancer) and palliative (bleeding cervical or pelvic mass) standpoint. Critical to understanding how better to serve patients in this regard is understanding both the extent of disease epidemiology and the radiotherapy infrastructure to treat these diseases. In this review, we explore various geographic regions and how they address a unique set of challenges specific to the peoples and culture of the region. We identify common threads across regions, including sparse distribution of radiation equipment, geographic access, and specialized training. We also highlight examples of success in the use of telemedicine and cross-cultural partnerships to help bolster access to training to ensure increased access to adequate and appropriate treatment of gynecologic malignancies.

The Styryl Benzoic Acid Derivative DC10 Potentiates Radiotherapy by Targeting the xCT-Glutathione Axis

Metastatic tumors with moderate radiosensitivity account for most cancer-related deaths, highlighting the limitations of current radiotherapy regimens. The xCT-inhibitor sulfasalazine (SAS) sensitizes cancer cells to radiotherapy by blocking cystine uptake via the xCT membrane antiporter, and thereby glutathione (GSH) synthesis protecting against radiation-induced oxidative stress. The expression of xCT in multiple tumor types implies it as a target generic to cancer rather than confined to few subtypes. However, SAS has limited clinical potential as a radiosensitizer due to side effects and low bioavailability. Using SAS as a starting point, we previously developed synthetic xCT-inhibitors through scaffold hopping and structure optimization aided by structure-activity relationship analysis (SAR). Notably, the compound DC10 exhibited inhibition of GSH synthesis. In this study, we validated DC10 as a radiosensitizer in the xCT-expressing cancer cell lines A172, A375 and MCF7, and mice harboring melanoma xenografts. After DC10 treatment, we measured 14C-cystine uptake in the cancer cells using liquid scintillation counting, and intracellular GSH levels and reactive oxygen species (ROS) using luminescence assays. We performed immunoblotting of H2AX and ATM to assess DNA damage after treatment with DC10 and radiotherapy. We then assessed the effect of adding DC10 to radiation upon cancer cell colony formation. Blood samples from mice treated with DC10 underwent biochemical analysis to assess toxicity. Finally, mice with A375 melanomas in the flank, received DC10 and radiotherapy in combination, as monotherapies or no treatment. Notably, DC10 reduced cystine uptake and GSH synthesis and increased ROS levels in a dose-dependent manner. Furthermore, DC10 interacted synergistically with radiation to increase DNA damage and reduce tumor cell colony formation. Mice receiving DC10 were clinically unaffected, whereas blood samples analysis to assess bone marrow suppression, liver or kidney toxicity revealed no significant differences between treated mice and untreated controls. Importantly, DC10 potentiated the anti-tumor efficacy of radiation in mice with melanoma xenografts. We conclude that DC10 is well tolerated and acts as a radiosensitizer by inhibiting cystine uptake, leading to GSH depletion and increased oxidative stress. Our findings demonstrate the feasibility of using synthetic xCT-inhibitors to overcome radioresistance.

Theranostic near-infrared-IIb emitting nanoprobes for promoting immunogenic radiotherapy and abscopal effects against cancer metastasis

Radiotherapy is an important therapeutic strategy for cancer treatment through direct damage to cancer cells and augmentation of antitumor immune responses. However, the efficacy of radiotherapy is limited by hypoxia-mediated radioresistance and immunosuppression in tumor microenvironment. Here, we construct a stabilized theranostic nanoprobe based on quantum dots emitting in the near-infrared IIb (NIR-IIb, 1,500-1,700 nm) window modified by catalase, arginine-glycine-aspartate peptides and poly(ethylene glycol). We demonstrate that the nanoprobes effectively aggregate in the tumor site to locate the tumor region, thereby realizing precision radiotherapy with few side-effects. In addition, nanoprobes relieve intratumoral hypoxia and reduce the tumor infiltration of immunosuppressive cells. Moreover, the nanoprobes promote the immunogenic cell death of cancer cells to trigger the activation of dendritic cells and enhance T cell-mediated antitumor immunity to inhibit tumor metastasis. Collectively, the nanoprobe-mediated immunogenic radiotherapy can boost the abscopal effect to inhibit tumor metastasis and prolong survival.

Gut Microbiota-Derived l-Histidine/Imidazole Propionate Axis Fights against the Radiation-Induced Cardiopulmonary Injury

Radiation-induced cardiopulmonary injuries are the most common and intractable side effects that are entwined with radiotherapy for thorax cancers. However, the therapeutic options for such complications have yielded disappointing results in clinical applications. Here, we reported that gut microbiota-derived l-Histidine and its secondary metabolite imidazole propionate (ImP) fought against radiation-induced cardiopulmonary injury in an entiric flora-dependent manner in mouse models. Local chest irradiation decreased the level of l-Histidine in fecal pellets, which was increased following fecal microbiota transplantation. l-Histidine replenishment via an oral route retarded the pathological process of lung and heart tissues and improved lung respiratory and heart systolic function following radiation exposure. l-Histidine preserved the gut bacterial taxonomic proportions shifted by total chest irradiation but failed to perform radioprotection in gut microbiota-deleted mice. ImP, the downstream metabolite of l-Histidine, accumulated in peripheral blood and lung tissues following l-Histidine replenishment and protected against radiation-induced lung and heart toxicity. Orally gavaged ImP could not enter into the circulatory system in mice through an antibiotic cocktail treatment. Importantly, ImP inhibited pyroptosis to nudge lung cell proliferation after radiation challenge. Together, our findings pave a novel method of protection against cardiopulmonary complications intertwined with radiotherapy in pre-clinical settings and underpin the idea that gut microbiota-produced l-Histidine and ImP are promising radioprotective agents.

50 years of radiotherapy research: Evolution, trends and lessons for the future

Rapid and relentless technological advances in an ever-more globalized world have shaped the field of radiation oncology in which we practise today. These developments have drastically modified the habitus¹ of health professionals and researchers at an individual and organisational level. In this article we present an analysis of trends in radiation oncology research over the last half a century. To do so, the data from >350,000 scientific publications pertaining to a yearly search of the PubMed database with the keywords cancer radiotherapy was analysed. This analysis revealed that, over the years, radiotherapy research output has declined relative to alternative cancer therapies, representing 64% in 1970 it decreased to 31% in 2019. Also, the pace of research has significantly accelerated with, in the last 15 years, a doubling in the number of articles published by the 10% most productive researchers. Researchers are also facing stronger competition today with a proportion of first authors that will never get to publish as a last author increasing steadily from 58% in 1970 to 84% in 2000. Additionally, radiotherapy research output is extremely unequally distributed in the world, with Africa and South America contributing to ∼3% of radiotherapy articles in 2019 while representing 23% of the world's population. This disparity, reflecting economic situations and radiotherapy capabilities, has a knock-on effect for the provision of routine clinical treatment. Since research activity is inherent to delivery of high quality clinical care, this contributes to the global inequity of radiotherapy services. Learning from these trends is crucial for the future not only of radiation oncology research but also for effective and equitable cancer care.

The Modernization of Radiation Therapy Services in Cambodia: A Model of International Collaboration

PURPOSE

Cambodia is a Southeast Asian low-middle-income country with a population of >15 million. In 2020, Cambodia was estimated to have 18,375 new diagnoses of cancer and 12,638 deaths attributable to cancer. Cambodia was estimated to have a deficit of 16 megavoltage machines in 2012. Cambodia's radiation therapy services have suffered through the tumultuous events of the country's history, with intermittent services until the last decade. In recent years, Cambodia has undergone rapid economic growth and, with this, the development of its first comprehensive cancer center, the National Cancer Centre (NCC).

METHODS AND MATERIALS

Planning for NCC began in the early 2000s, with the aim to provide comprehensive care, including modern radiation therapy services, to the public. Funding for the center was supplied primarily by the Cambodian government, assisted by donations from partners including the International Atomic Energy Agency. Training collaborations were formed with international partners, including the Asia-Pacific Radiation Oncology Special Interest Group (APROSIG) of the Royal Australian and New Zealand College of Radiologists and the Asia-Pacific Special Interest Group (APSIG) of the Australasian College of Physical Scientists and Engineers in Medicine.

RESULTS

The main model of APROSIG/APSIG collaboration has been in-country training, including the posting of an Australian medical physicist and radiation therapist in Phnom Penh for a year's duration to oversee a safe and sustainable start to the radiation therapy program. The first linear accelerator patient was treated at NCC in March 2018 and the first brachytherapy patient in September 2018. Since that time, the department has treated to capacity, with very little machine downtime. NCC provides comprehensive cancer services including medical oncology, pediatric oncology, hematology, palliative care, surgical oncology, and nuclear medicine. Several challenges to expanding radiation therapy services currently exist, including human resources and cultural stigma.

CONCLUSION

Despite many decades of tragedy and suffering, Cambodia serves as an example of successful implementation of modern radiation therapy in a low- and middle-income country. The keys to success have included local champions, support of the Ministry of Health, and willingness to embrace collaboration. The pandemic brings yet another challenge to cancer control in Cambodia, and novel training platforms are being explored.

Contemporary radiotherapy: present and future

Oncology care is increasingly a multidisciplinary endeavour, and radiation therapy continues to have a key role across the disease spectrum in nearly every cancer. However, the field of radiation oncology is still one of the most poorly understood of the cancer disciplines. In this Review, we attempt to summarise and contextualise developments within the field of radiation oncology for the non-radiation oncologist. We discuss advancements in treatment technologies and imaging, followed by an overview of the interplay with advancements in systemic therapy and surgical techniques. Finally, we review new frontiers in radiation oncology, including advances within the metastatic disease continuum, reirradiation, and emerging types of radiation therapy.

Late Sequelae of Radiotherapy

BACKGROUND

Approximately half of all patients with tumors need radiotherapy. Long-term survivors may suffer from late sequelae of the treatment. The existing radiotherapeutic techniques are being refined so that radiation can be applied more precisely, with the goal of limiting the radiation exposure of normal tissue and reducing late sequelae.

METHODS

This review is based on the findings of a selective search in PubMed for publications on late sequelae of conventional percutaneous radiotherapy, January 2000 to May 2020. Late sequelae affecting the central nervous system, lungs, and heart and the development of second tumors are presented, and radiobiological mechanisms and the relevant technical and conceptual considerations are discussed.

RESULTS

The current standard of treatment involves the use of linear accelerators, intensity-modulated radiotherapy (IMRT), image-guided and respiratory-gated radiotherapy, and the integration of positron emission tomography combined with computed tomography (PET-CT) in radiation treatment planning. Cardiotoxicity has been reduced with regard to the risk of coronary heart disease after radiotherapy for Hodgkin's lymphoma (hazard ratio [HR] 0.44 [0.23; 0.85]). It was also found that the rate of radiation- induced pneumonitis dropped from 7.9% with conformal treatment to 3.5% with IMRT in a phase III lung cancer trial. It is hoped that neurocognitive functional impairment will be reduced by hippocampal avoidance in modern treatment planning: an initial phase III trial yielded a hazard ratio of 0.74 [0.58; 0.94]. It is estimated that 8% of second solid tumors in adults are induced by radiotherapy (3 additional tumors per 1000 patients at 10 years).

CONCLUSION

Special challenges for research in this field arise from the long latency of radiation sequelae and the need for largescale, well-documented patient collectives in order to discern dose-effect relationships, and take account of cofactors, when the overall number of events is small. It is hoped that further technical and conceptual advances will be made in the areas of adaptive radiotherapy, proton and heavy-ion therapy, and personalized therapy.

Implementation of 3D conformal radiotherapy technology at the National Cancer Centre Mongolia: A successful Asia-Pacific collaborative initiative

INTRODUCTION

Mongolia has a population of 3.3 million and is classified by the WHO as a lower middle-income country. Cancer is now a major public health issue and one of the leading causes of mortality. Within the framework of an existing national cancer control plan, the National Cancer Centre of Mongolia (NCCM) aimed to implement 3D conformal radiation planning and linac-based treatment delivery.

METHODS

In 2018, an opportunity arose for collaboration between the Mongolia Society for Radiation Oncology (MOSTRO), the National Cancer Centre Mongolia (NCCM), the Asia-Pacific Radiation Oncology Special Interest Group (APROSIG) of the Royal Australian and New Zealand College of Radiologists (RANZCR) and the Asia-Pacific Special Interest Group (APSIG) of the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) and radiation therapists (RTTs) from a range of Australian centres. We describe here the results to date of this collaboration.

RESULTS

Despite a number of significant technical and practical barriers, successful linac commissioning was achieved in 2019. Key factors for success included a leadership receptive to change management, stable bureaucracy and health systems, as well as a synchronised effort, regional cooperation and mentorship.

CONCLUSION

Future directions for ongoing collaborative efforts include a continued focus on education, practical training in radiotherapy planning and delivery and postgraduate education initiatives. Radiotherapy safety and quality assurance remain an ongoing priority, particularly as technological advances are sequentially implemented.

Equity should know no borders: The role of Australasian radiation oncologists in supporting radiation oncology services in low- and middle-income countries in the Asia-Pacific

The rapid rise in cancer incidence within the world's poorest nations highlights the need for equitable access to evidence-based cancer care. It has been previously demonstrated that radiotherapy is a cost-effective and necessary tool in cancer treatment. However, globally there is a growing divide between demand and supply of radiotherapy services. In low- and middle-income countries, this resource gap is particularly problematic. By region, the Asia-Pacific has been demonstrated to have the highest absolute deficit in radiotherapy services. Radiation oncologists in Australia and New Zealand are geographically well positioned to assist departments within the Asia-Pacific to help to reduce these inequities. The Asia-Pacific Radiation Oncology Special Interest Group (APROSIG) aims to support oncology professionals in the Asia-Pacific to develop safe and sustainable cancer services. Members have already contributed to multiple projects throughout the region, supported by grants and departmental funding. However, the backbone of support comes from volunteers sharing their time and expertise. The Australasian oncological community has the skills and knowledge to help not only those within our borders but also beyond. Such efforts provide the potential to develop valuable clinical, educational, research and leadership experiences whilst establishing networking opportunities throughout the most populated regions of the world. More options for growth and work in global health must be investigated, encouraging future trainees to consider a role within the global cancer community. Without prompt and continued action, the resource deficit is likely to grow and the inequity in accessing radiotherapy and other cancer services further magnified.

Australia and New Zealand's responsibilities in improving oncology services in the Asia-Pacific: A call to action

AIM

To review the expected increasing demand for cancer services among low and middle-income countries (LMICs) in the Asia-Pacific (APAC), and to describe ways in which Australia and New Zealand (ANZ) can provide support to improve cancer outcomes in our region.

METHODS

We first review the current and projected incidence of cancer within the APAC between 2018 and 2040, and the estimated demand for chemotherapy, radiotherapy and surgery. We then explore potential ways in which ANZ can increase regional collaborations to improve cancer outcomes.

RESULTS

We identify 6 ways that ANZ can collaborate with LMICs to improve cancer care in the APAC through the ANZ Regional Oncology Collaboration Strategy: Increasing education and institutional collaborations in the APAC region through in-country training, twinning partnerships, observerships and formalised training programs in order to increase cancer care quality and capacity. Promoting and assisting in the establishment and maintenance of population-based cancer registries in LMICs. Increasing research capacity in LMICs through collaboration and promoting high quality global oncology research within ANZ. Engaging and training Australian and New Zealand clinicians in global oncology, increasing awareness of this important career path, and increasing health policy engagement. Increasing web-based endeavours through virtual tumour boards, web-based advocacy platforms and web-based teaching programs. Continuing to leverage for funding through professional bodies, government, industry, not-for-profit organisations and local hospital funds.

CONCLUSION

We propose the creation of an Australian and New Zealand Interest Group to provide formalised and sustained collaboration between researchers, clinicians and stakeholders.

Regional collaboration to improve quality of radiation therapy in Asia

In Asia, several challenges hinder the delivery of high-quality cancer treatment, especially radiation therapy (RT). Many Asian countries face large-scale shortage of RT centres and treatment machines. Additionally, there is also a significant technological gap, with many RT centres in Asia still using outdated technology. There is an urgent need to improve radiation treatment quality in Asia. The Federation of Asian Organizations for Radiation Oncology (FARO) was set up to foster regional collaboration, which we believe can help to identify and solve some of these issues collectively. This report describes the background and rationale of starting FARO, and puts forth some of the early achievements of the group, including fact-finding and educational activities. Finally, we discuss future possibilities, including strategic proposals that may benefit the RT community and our patients in Asia.

Essential oncology nursing care along the cancer continuum

Oncology nurses are at the heart of tackling the increasing global burden of cancer. Their contribution is unique because of the scale and the diversity of care roles and responsibilities in cancer care. In this Series paper, to celebrate the International Year of the Nurse and Midwife, we highlight the contribution and impact of oncology nurses along the cancer care continuum. Delivering people-centred integrated care and optimal communication are essential components of oncology nursing care, which are often played down. More oncology nurses using, doing, and leading research will further show the key nursing impact on care as part of a team. The oncology nurse influence in saving lives through prevention and early detection of cancer is noteworthy. Supportive care, the central pillar of oncology nursing, enables and empowers people to self-manage where possible. Globally, oncology nurses make a great positive difference to cancer care worldwide; their crucial contribution throughout the continuum of care warrants the inclusion and promotion of nursing in every country's cancer strategy. 2020 is the year of the nurse: let us take this learning to the future.

Beam data modeling of linear accelerators (linacs) through machine learning and its potential applications in fast and robust linac commissioning and quality assurance

BACKGROUND AND PURPOSE

To propose a novel machine learning-based method for reliable and accurate modeling of linac beam data applicable to the processes of linac commissioning and QA.

MATERIALS AND METHODS

We hypothesize that the beam data is a function of inherent linac features and percentage depth doses (PDDs) and profiles of different field sizes are correlated with each other. The correlation is formulated as a multivariable regression problem using a machine learning framework. Varian TrueBeam beam data sets (n = 43) acquired from multiple institutions were used to evaluate the framework. The data sets included PDDs and profiles across different energies and field sizes. A multivariate regression model was trained for prediction of beam specific PDDs and profiles of different field sizes using a 10 × 10 cm² field as input.

RESULTS

Predictions of PDDs were achieved with a mean absolute percent relative error (%RE) of 0.19-0.35% across the different beam energies investigated. The maximum mean absolute %RE was 0.93%. For profile prediction, the mean absolute %RE was 0.66-0.93% with a maximum absolute %RE of 3.76%. The largest uncertainties in the PDD and profile predictions were found at the build-up region and at the field penumbra, respectively. The prediction accuracy increased with the number of training sets up to around 20 training sets.

CONCLUSIONS

Through this novel machine learning-based method we have shown accurate and reproducible generation of beam data for linac commissioning for routine radiation therapy. This method has the potential to simplify the linac commissioning procedure, save time and manpower while increasing the accuracy of the commissioning process.

Increased local tumor control through nanoparticle-mediated, radiation-triggered release of nitrite, an important precursor for reactive nitrogen species

The efficacy of dose-enhancing gold nanoparticles (AuNPs) is negatively impacted by low tumor uptake, low cell membrane penetration, limited diffusion distance, and short lifetime of radiation-induced secondary particles. To overcome these limitations, we have developed a novel AuNP system capable of radiation-triggered release of nitrite, a precursor of reactive nitrogen species, and report here on the in vivo characterization of this system. AuNPs were functionalized through PEGylation, cell-penetrating peptides (CPP; AuNP@CPP), and nitroimidazole (nIm; AuNP@nIm-CPP). Mice with subcutaneous 4T1 tumors received either AuNP@nIm-CPP or AuNP@CPP intraperitoneally. Tumor and normal tissue uptake were evaluated 24 h post AuNP administration. A separate cohort of mice was injected and irradiated to a single-fraction dose of 18 Gy in a 225 kVp small animal irradiator 24 h post NP administration. The mice were followed for two weeks to evaluate tumor response. The mean physical and hydrodynamic size of both NP systems were 5 and 13 nm, respectively. NP nIm-loading of 1 wt% was determined. Tumor accumulation of AuNP@nIm-CPP was significantly lower than that of AuNP@CPP (0.2% vs 1.2%, respectively). In contrast, AuNP@nIm-CPP showed higher accumulation compared to AuNP@CPP in liver (16.5% vs 6.6%, respectively) and spleen (10.8% vs 3.1%, respectively). With respect to tumor response, no differential response was found between non-irradiated mice receiving either saline or AuNP@nIm-CPP alone. The combination of AuNP@CPP+ radiation showed no differential response from radiation alone. In contrast, a significant delay in tumor regrowth was observed in mice receiving AuNP@nIm-CPP+ radiation compared to radiation alone. AuNP functionalized with both CPP and nIm exhibited an order of magnitude less tumor accumulation compared to the NP system without nIm yet resulted in a significantly higher therapeutic response. Our data suggest that by improving the biokinetics of AuNP@nIm-CPP, this novel NP system could be a promising radiosensitizer for enhanced therapeutic response following radiation therapy.

Radiotherapy waiting time in Northern Nigeria: experience from a resource-limited setting

Background

Access and availability of radiotherapy treatment is limited in most low- and middle-income countries, which leads to long waiting times and poor clinical outcomes. The aim of our study is to determine the magnitude of waiting times for radiotherapy in a resource-limited setting.

Methods

This is a retrospective cohort study of patients with the five most commonly treated cancers managed with radiotherapy between 2010 and 2014. Data includes diagnosis, patients’ demographics and treatment provided. The waiting time was categorised into intervals (1) between diagnosis and first radiation consultation (2) First consultation to radiotherapy treatment (3) Decision-to-treat to treatment and (4) Diagnosis to treatment.

Results

A total of 258 cases were involved, including cervical (50%; 129/258), breast (27.5%; 71/258), nasopharynx (12.8%; 33/258), colorectal (5%; 13/258) and prostate cancers (4.7%; 12/258). Mean age was 48 (±12.9) years. Treatment with radical intent comprised 67% (178/258) of cases, while 33% (80/258) had palliative treatment. The median time from diagnosis to first radiation consultation was 40 (IQR 17–157.75) days for all the patients, with prostate cancer having the longest time – 305 days (IQR 41–393.8). The median time between the first radiation oncology consultations and first radiotherapy treatment was 130.5 (IQR 14–211.5) days; cervical cancer patients waited a median of 139 (IQR 13–195.5) days. The median time between diagnosis and first radiotherapy for breast cancer patients was 329 (IQR 207–464) days, compared to 213 (IQR 101.5–353.5) days for all the patients.

Conclusion

The study shows that waiting time for radiotherapy in Nigeria was generally longer than what is recommended internationally. This reflects the need to improve access to radiotherapy in order to improve cancer treatment outcomes in resource-limited settings.