The population benefit of evidence-based radiotherapy: 5-Year local control and overall survival benefits

Volume de-escalation in radiation therapy: state of the art and new perspectives

PURPOSE

New RT techniques and data emerging from follow-up for several tumor sites suggest that treatment volume de-escalation may permit to minimize therapy-related side effects and/or obtain better clinical outcomes. Here, we summarize the main evidence about volume de-escalation in RT.

METHOD

The relevant literature from PubMed was reviewed in this article. The ClinicalTrials.gov database was searched for clinical trials related to the specific topic.

RESULTS

In Lymphoma, large-volume techniques (extended- and involved-field RT) are being successfully replaced by involved-site RT and involved-node RT. In head and neck carcinoma, spare a part of elective neck is controversial. In early breast cancer, partial breast irradiation has been established as a treatment option in low-risk patients. In pancreatic cancer stereotactic body radiotherapy may be used to dose escalation. Stereotactic radiosurgery should be the treatment choice for patients with oligometastatic brain disease and a life expectancy of more than 3 months, and it should be considered an alternative to WBRT for patients with multiple brain metastases.

CONCLUSION

Further clinical trials are necessary to improve the identification of suitable patient cohorts and the extent of possible volume de-escalation that does not compromise tumor control.

Radiotherapy underutilisation and its impact on local control and survival in New South Wales, Australia

BACKGROUND AND PURPOSE

This study aimed to identify the actual radiotherapy utilisation rate (A-RUR) in New South Wales (NSW) Australia for 2009-2011 and compare that to the published evidence-based optimal radiotherapy utilisation rate (O-RUR) and to previously reported A-RUR in NSW in 2004-2006. It also aimed to estimate the effect of underutilisation on 5-year local control (LC) and overall survival (OS) and identify factors that predict for underutilisation.

MATERIALS AND METHODS

All cases of registered cancer diagnosed in NSW between 2009 and 2011 were identified from the NSW Central Cancer Registry and linked with data from all radiotherapy departments. The A-RUR was calculated and compared with O-RURs for all cancers. The difference for each indication was used to estimate 5-year OS and LC shortfall. Univariate and multivariate analyses were performed to identify factors that correlated with reduced radiotherapy utilisation.

RESULTS

110,645 cancer cases were identified. 25% received radiotherapy within one year of diagnosis compared to an estimated optimal rate of 45%. This has marginally improved from previously reported rate of 22% in NSW in 2004-2006. We estimated that 5-year OS and LC were compromised in 1162 and 5062 patients respectively. Factors that predicted for underuse of radiotherapy were older age, male gender, lower socioeconomic status, increasing distance to nearest radiotherapy centre and localised disease.

CONCLUSION

The identified deficit in radiotherapy use has a significant negative impact on patient outcomes. Strategies to overcome such shortfalls need to be developed to improve radiotherapy use and patient outcomes.

What is multidisciplinary cancer care like in practice? a protocol for a mixed-method study to characterise ambulatory oncology services in the Australian public sector

INTRODUCTION

An understanding of the real-world provision of oncology outpatient services can help maintain service quality in the face of escalating demand and tight budgets, by informing the design of interventions that improve the effectiveness or efficiency of provision. The aims of this study are threefold. First, to develop an understanding of cancer services in outpatient clinics by characterising the organisation and practice of multidisciplinary care (MDC). Second, to explore the key areas of: (a) clinical decision-making and (b) engagement with patients' supportive needs. Third, to identify barriers to, and facilitators of, the delivery of quality care in these settings.

METHODS AND ANALYSIS

A suite of mixed-methods studies will be implemented at six hospitals providing cancer outpatient clinics, with a staged roll-out. In Stage One, we will examine policies, use unstructured observations and undertake interviews with key health professionals to characterise the organisation and delivery of MDC. In Stage Two, observations of practice will continue, to deepen our understanding, and to inform two focused studies. The first will explore decision-making practices and the second will examine how staff engage with patients' needs; both studies involve interviews, to complement observation. As part of the study of supportive care, we will examine the implications of an introduction of patient-reported measures (PRMs) into care, adding surveys to interviews before and after PRMs roll-out. Data analysis will account for site-specific and cross-site issues using an adapted Qualitative Rapid Appraisal, Rigorous Analysis approach. Quantitative data from clinician surveys will be statistically analysed and triangulated with the related qualitative study findings.

ETHICS AND DISSEMINATION

Ethical approval was granted by South Eastern Sydney Local Health District Human Research Ethics Committee (no. 18/207). Findings will be shared with participating hospitals and widely disseminated through publications and presentations.

Access to radiotherapy and its association with cancer outcomes in a high-income country: Addressing the inequity in Canada

BACKGROUND AND PURPOSE

Canada is a high-income country with universal healthcare. In international comparisons, its overall level of access to radiotherapy appears sufficient. However, challenges exist due to Canada's large geographic area and small population density. The association between access and cancer outcomes nationally has not yet been described.

MATERIALS AND METHODS

We quantified geographic accessibility for 2012 using the linear distance from each Canadian health region centroid to the nearest radiotherapy center. We used geospatial analytic techniques to detect clusters of age-standardized all-cancer mortality-to-incidence ratios (MIRs) across health regions, from 2010-2012. Global ordinary least squares (OLS) and geographically-weighted regression (GWR) were conducted to examine relationships between distance and MIR, adjusting for sociodemographic factors.

RESULTS

Median distance from health region centroid to nearest radiotherapy center was 101.73 km (range 1.14-2095.12). One cluster of worse outcomes (MIR range 0.45-0.88) involved most of northern Canada, with a second cluster of better outcomes (MIR range 0.40-0.41) in southern British Columbia. In both regression models, regions with longer distance to radiotherapy center (ß = 0.0001), increased smoking (ß = 0.002), and poorer food security (ß = -0.003) were significantly associated with worse outcomes (OLS R² = 0.70, GWR R² = 0.74). Distance remained independently associated with MIR for lung and colorectal cancer subgroups, but not breast and prostate.

CONCLUSIONS

A clear north-south discordance in cancer outcomes exists in Canada, with poorer outcomes in the north, while radiotherapy centers are concentrated along the south. Increased distance to radiotherapy, along with other sociodemographic and health-system factors, are associated with poorer cancer outcomes. Our study could be replicated, particularly in other high-income countries, to help identify national patterns and regional disparities in access and outcomes.

Cellular and Genetic Determinants of the Sensitivity of Cancer to α-Particle Irradiation

Targeted α-particle-emitting radionuclides have great potential for the treatment of a broad range of cancers at different stages of progression. A platform that accurately measures cancer cellular sensitivity to α-particle irradiation could guide and accelerate clinical translation. Here, we performed high-content profiling of cellular survival following exposure to α-particles emitted from radium-223 (²²³Ra) using 28 genetically diverse human tumor cell lines. Significant variation in cellular sensitivity across tumor cells was observed. ²²³Ra was significantly more potent than sparsely ionizing irradiation, with a median relative biological effectiveness of 10.4 (IQR: 8.4-14.3). Cells that are the most resistant to γ radiation, such as Nrf2 gain-of-function mutant cells, were sensitive to α-particles. Combining these profiling results with genetic features, we identified several somatic copy-number alterations, gene mutations, and the basal expression of gene sets that correlated with radiation survival. Activating mutations in PIK3CA, a frequent event in cancer, decreased sensitivity to ²²³Ra. The identification of cellular and genetic determinants of sensitivity to ²²³Ra may guide the clinical incorporation of targeted α-particle emitters in the treatment of several cancer types. SIGNIFICANCE: These findings address limitations in the preclinical guidance and prediction of radionuclide tumor sensitivity by identifying intrinsic cellular and genetic determinants of cancer cell survival following exposure to α-particle irradiation.See related commentary by Sgouros, p. 5479.

Patient Recruitment in Radiation Therapy Research: An Evaluation of Local Challenges

INTRODUCTION

Locally-initiated research studies in radiation therapy (RT) aim to substantiate clinical processes and are an effective approach to gather evidence for advances in patient care, new techniques, and protocols. The aim of this study was to retrospectively quantify recruitment challenges at a radiation oncology network (RON).

METHODS

Five locally initiated studies were included for analysis through the criteria of being undertaken within 2001-2017, initiated through local research teams, and having recruitment records available. Data extraction from each study included duration, aims, patient activities, recruitment strategy, target number of participants, and number of participants who were recruited/not recruited and who withdrew from the study. Reasons for nonregistration and withdrawal were recorded if available. Two studies are presented as case studies.

RESULTS

Included studies were diverse in patient population and study aim and included patient immobilization (lung and breast cancer), evaluation of radiation-induced esophagitis, documentation of anatomical and dosimetric changes in patients with head and neck cancer, and education (breast cancer). The exclusion of non-English-speaking patients, which is significant for the RON, which covers a wide cultural and linguistic diversity, was an important limiting factor, along with RT patients' disinterest in participation.

DISCUSSION

Challenges experienced in the evaluated RON studies are similar to non-RT clinical trials and included difficulties with patients interacting with study protocol, health practitioners' influence, and patient-related inclusion issues.

CONCLUSION

The resulting database provides a foundation for continued monitoring and documentation of study recruitment practice, which could elicit positive effects on planning and implementation of future patient recruitment strategies in RT locally initiated studies.

Human Error Bowtie Analysis to Enhance Patient Safety in Radiation Oncology

PURPOSE

Ensuring safety within RT is of paramount importance. To further support and augment patient safety efforts, the purpose of this research was to test and refine a robust methodology for analyzing human errors that defeat individual controls within RT quality assurance (QA) programs.

METHODS

The method proposed for performing Bowtie Analysis (BTA) was based on training and recommendations from practitioners in the field of Human Factors and Ergonomics practice. Multidisciplinary meetings to iteratively develop BTA focused on incorrect site setup instructions was conducted.

RESULTS

From November 2015 to February 2017, we had 12 reported incidents related to site setup notes that could have led to site setup errors. Based on this data, we conducted five BTA analyses related to incorrect site setup instructions. None of the individual controls within our QA program designed to check for potential errors with site setup instructions met the level of robustness to be classified as key safeguards or barriers.

CONCLUSIONS

The relatively low number of incidents causing patient harm has led us to typically assume that we have sufficient and effective controls in place to prevent serious human errors from leading to severe patient consequences. Based on our BTA, we question how well we truly understand the details of our individual controls. To meet the level of safety achieved by high reliability organizations (HROs), we need to better ensure that our controls are as reliable and robust as we assume.

Estimating the cost of radiotherapy for 5-year local control and overall survival benefit

BACKGROUND AND PURPOSE

Escalating health care costs have led to greater efforts directed at measuring the cost and benefits of medical treatments. The aim of this study was to estimate the costs of 5-year local control and overall survival benefits of radiotherapy for the cancer population in Australia.

MATERIALS AND METHODS

The local control and overall survival benefits of radiotherapy at 5-years and optimal number of fractions per course have been estimated for 26 tumour sites for which radiotherapy is indicated. For this study, a hybrid approach that merges features from activity based costing (ABC) and relative value units costing (RVU) were used to provide cost estimates. ABC methodology was used to allocate costs to all radiotherapy activities associated with each patient's treatment course, while the RVUs represent the cost of each radiotherapy activity relative to the average cost of all activities and were used to achieve a weighted cost allocation. A patient's journey for the financial year was constructed by consolidating all the radiotherapy activities and their associated costs, and the average cost per activity (fraction) was determined. The cost of radiotherapy per 5-year overall survival and local control was then estimated.

RESULTS

The estimated population 5-year local control and overall survival benefits of radiotherapy for all cancer were 23% and 6%, respectively. The optimal number of fractions per treatment course if guidelines were followed was 19.4 fractions. The average cost per fraction for all cancer was AU$276. The estimated cost of radiotherapy was AU$23,585 per 5-year local control and AU$86,480 per 5-year overall survival (equivalent to 5 life years) for all cancer.

CONCLUSION

The cost of AU$86,480 per 5-year overall survival would translate to AU$17,296 1-year overall survival. Therefore, the cost of radiotherapy is inexpensive if delivered optimally. Policy implications from this study include knowledge about cost to deliver radiotherapy to allow one to quantify the expected benefit at a population level.

Safety and efficacy of combined radiotherapy, immunotherapy and targeted agents in elderly patients: A literature review

PURPOSE

Aim of the present review is to assess present data about the use of the association of Radiotherapy (RT) and targeted therapy/immunotherapy (TT/IT) in elderly people.

DESIGN

PubMed database was searched for English literature published up to December 2017 using the keywords "radiotherapy" combined with "bevacizumab", "cetuximab", "trastuzumab", "erlotinib", "gefitinib", "sorafenib", "sunitinib", "vismodegib", "sonidegib", "ipilimumab", "pembrolizumab", "nivolumab". Studies performing RT and TT/IT in people aged >65-years were evaluated focusing on safety, toxicity and efficacy. Studies eligible for inclusion were: case reports, retrospective/prospective studies in which RT and new drugs were used concomitantly or sequentially, focusing on elderly sub-group.

RESULTS

The systematic search identified 626 records. After exclusion of duplicates, full-text review, cross-referencing and paper that did not respect the inclusion criteria, 81 studies were included in this review. In elderly patients the combination of RT with cetuximab or bevacizumab seems feasible but with higher reported side effects. Patients' age should not limit the association of trastuzumab and RT in HER2 positive breast cancer. The concurrent administration of TKIs and RT appears to be feasible and effective. Regarding the Immune Check Point inhibitors and RT, tolerance seems similar among older and younger people but definitive data are lacking. Instead, the association of RT and vismodegib/sonidegib remains investigational.

CONCLUSION

TT/IT in association of RT seems to be safe, but in elderly patients data concerning safety and toxicity are limited. Specific clinical trials on this population are encouraged.

Evaluation of Italian radiotherapy research from 1985 to 2005: preliminary analysis

AIM

The difficulty in conducting meaningful clinical research is a multifactorial issue, involving political, financial and cultural problems, which can lead to unexpected negative long-term consequences, in terms of knowledge advancement and impact on patient care. The aims of the present review were to evaluate the publications of Italian radiotherapy (RT) groups during a 20-year period and to verify whether research is still appealing to young radiation oncologists (ROs) in Italy.

METHODS

PubMed database was searched for English-language articles published by Italian groups from January 1985 to December 2005. Analyzed variables were: publication/year, kind of study, geographical area and age of the first author.

RESULTS

The systematic review identified 3291 articles: 1207 papers fulfilled the inclusion criteria. The number of Italian published papers increased during the examined period. Retrospective analyses, prospective phase I-II trials and literature reviews were 44, 20 and 14.5% of all published manuscripts, respectively. Randomized trials showed a mild increase from 2000 to 2005, but their absolute number remained low respect to other types of studies (4%). Northern Italy produced the very most of Italian research papers (58.7%). The age of the first/second author was evaluated on 716 papers: In more than 50% of cases, the first author was younger than 40.

CONCLUSION

Despite a general gradual improvement, RT clinical research suffers in Italy (as elsewhere) from insufficient funding, with a negative impact on evidence production. It is worth noting that clinical research is still appealing and accessible to junior Italian RO.

Number of radiotherapy treatment machines in the population and cancer mortality: an ecological study

Objectives

The aim of this study was to assess the association between the number of radiotherapy treatment machines (RTMs) in the population and incidence-adjusted cancer mortality.

Methods

Data on cancer incidence and mortality were obtained from the GLOBOCAN project (only high-quality data, C3, or higher according to GLOBOCAN quality label), information on the number of RTMs from the Directory of Radiotherapy Centers database, and remaining data from the World Bank and World Health Organization database. We used linear regression models to assess the associations between RTM per 10,000,000 inhabitants (logarithmized) and the log-transformed mortality/incidence ratio. Models were adjusted for public health variables. To assess the bias due to unobserved confounders, mortality from leukemia was considered as a negative control. Here radiotherapy treatment is less frequently applied, but a common set of confounders is shared with cancer types where radiotherapy plays a stronger role, enabling us to estimate the bias due to confounding of unmeasured parameters. To assess an exposure–effect size relationship, estimated cancer type-specific estimates were related to the proportion of subjects receiving radiotherapy.

Results

We found an inverse linear relationship between RTM in the population and the cancer mortality to incidence ratio for prostate cancer (14.1% per doubling of RTM; 95% CI: 0.1%–26.1%), female breast cancer (12.3%; 95% CI: 2.7%–20.9%), and lung cancer in women (11.2%; 95% CI: 4.3%–17.6%). There was no evidence for bias due to unobserved confounders after covariate adjustment. For women, an exposure-effect size relationship was found (P=0.02).

Conclusion

In this ecological study, we found evidence that the population density of RTM is related to cancer mortality independently of other public health parameters.