Operational Ontology for Radiation Oncology (OORO): A Professional Society-Based, Multi-Stakeholder Consensus Driven Informatics Standard Supporting Clinical and Research Use of Real-World Data

PURPOSE/OBJECTIVE(S)

There is a critical need for large-scale, multi-institutional "real-world" data to evaluate patient, diagnosis and treatment factors affecting oncology patient outcomes. However, lack of data standardization undermines the potential for automated learning from the vast amount of information routinely archived in electronic health records (EHRs), Radiation Oncology Information Systems and other cancer care databases. As next step to promote data standardization beyond the American Association of Physicists in Medicine (AAPM)'s TG-263 guidance for radiotherapy (RT) nomenclature, the AAPM's Big Data Subcommittee (BDSC) has led an international RT professional society collaboration to develop the Operational Ontology for Radiation Oncology (OORO).

MATERIALS/METHODS

Initiated July 2019 to explore issues that typically compromise formation of large inter- and intra- institutional databases from EHRs, the AAPM's BDSC membership includes representatives from the AAPM, American Society of Radiation Oncology (ASTRO), Canadian Organization of Medical Physicists (COMP), Canadian Association of Radiation Oncology (CARO), European Society of Therapeutic Radiation Oncology (ESTRO) and clinical trials experts from NRG Oncology. Multiple external stakeholders were engaged, including government agencies, vendors and RT community members through the iterative and consensus-driven approach to OORO development.

RESULTS

The OORO includes 42 key elements, 359 attributes, 144 value sets, and 155 relationships, ranked for priority of implementation based on clinical significance, likelihood of availability in EHRs, or ability to modify routine clinical processes to permit aggregation. The initial version of OORO includes many disease-site independent concepts common for all cancer patients and a smaller set specific for prostate cancer. The OORO development methodology is currently being applied/adapted to include additional disease site-specific concepts beginning with head and neck cancers.

CONCLUSION

The first of its kind in radiation oncology, the OORO is a professional society-based, multi-stakeholder, consensus driven informatics standard. The iterative and collaborative approach to ontology development and refinement aims to ensure that OORO serves as a « living » guidance document, facilitating incremental expansion of data elements over time, as disease site-specific standards are set and RT concepts evolve. Supporting construction of comprehensive "real-world" datasets and application of advanced analytic techniques, including artificial intelligence (AI), OORO holds the potential to revolutionize patient management and improve outcomes.

National Cancer Institute support for targeted alpha-emitter therapy

BACKGROUND

Radiopharmaceutical targeted therapy (RPT) has been studied for decades; however, recent clinical trials demonstrating efficacy have helped renewed interest in the modality.

METHODS

This article reviews National Cancer Institute (NCI)'s support of RPT through communication via workshops and interest groups, through funding extramural programs in academia and small business, and through intramural research, including preclinical and clinical studies.

RESULTS

NCI has co-organized workshops and organized interest groups on RPT and RPT dosimetry to encourage the community and facilitate rigorous preclinical and clinical studies. NCI has been supporting RPT research through various mechanisms. Research has been funded through peer-reviewed NCI Research and Program Grants (RPG) and NCI Small Business Innovation Research (SBIR) Development Center, which funds small business-initiated projects, some of which have led to clinical trials. The NCI Cancer Therapy Evaluation Program (CTEP)'s Radiopharmaceutical Development Initiative supports RPT in NCI-funded clinical trials, including Imaging and Radiation Oncology Core (IROC) expertise in imaging QA and dosimetry procedures. Preclinical targeted a-emitter therapy (TAT) research at the NCI's intramural program is ongoing, building on foundational work dating back to the 1980s. Ongoing "bench-to-bedside" efforts leverage the unique infrastructure of the National Institutes of Health's (NIH) Clinical Center.

CONCLUSION

Given the great potential of RPT, our goal is to continue to encourage its development that will generate the high-quality evidence needed to bring this multidisciplinary treatment to patients.

National Cancer Institute Workshop on Proton Therapy for Children: Considerations Regarding Brainstem Injury

PURPOSE

Proton therapy can allow for superior avoidance of normal tissues. A widespread consensus has been reached that proton therapy should be used for patients with curable pediatric brain tumor to avoid critical central nervous system structures. Brainstem necrosis is a potentially devastating, but rare, complication of radiation. Recent reports of brainstem necrosis after proton therapy have raised concerns over the potential biological differences among radiation modalities. We have summarized findings from the National Cancer Institute Workshop on Proton Therapy for Children convened in May 2016 to examine brainstem injury.

METHODS AND MATERIALS

Twenty-seven physicians, physicists, and researchers from 17 institutions with expertise met to discuss this issue. The definition of brainstem injury, imaging of this entity, clinical experience with photons and photons, and potential biological differences among these radiation modalities were thoroughly discussed and reviewed. The 3 largest US pediatric proton therapy centers collectively summarized the incidence of symptomatic brainstem injury and physics details (planning, dosimetry, delivery) for 671 children with focal posterior fossa tumors treated with protons from 2006 to 2016.

RESULTS

The average rate of symptomatic brainstem toxicity from the 3 largest US pediatric proton centers was 2.38%. The actuarial rate of grade ≥2 brainstem toxicity was successfully reduced from 12.7% to 0% at 1 center after adopting modified radiation guidelines. Guidelines for treatment planning and current consensus brainstem constraints for proton therapy are presented. The current knowledge regarding linear energy transfer (LET) and its relationship to relative biological effectiveness (RBE) are defined. We review the current state of LET-based planning.

CONCLUSIONS

Brainstem injury is a rare complication of radiation therapy for both photons and protons. Substantial dosimetric data have been collected for brainstem injury after proton therapy, and established guidelines to allow for safe delivery of proton radiation have been defined. Increased capability exists to incorporate LET optimization; however, further research is needed to fully explore the capabilities of LET- and RBE-based planning.

The Future of Global Radiation Oncology As Part of Accurate, Precision Cancer Medicine

Background: When global health and cancer care are discussed, it is usually in the context of underserved communities, inadequate resources, standards of care below that in the developed world, loss of talented individuals to upper-income countries and the inability to recruit and retain a robust regional workforce. While such conditions may now exist, they are by no means “guaranteed” to be so in the future. Aim: To consider a visionary future for the radiation sciences to encourage investment by individuals in their careers and countries in their cancer care resources such that the current resource-limited facilities will be on the leading edge of accurate, precision radiation medicine. Such a change in perspective can greatly impact recruiting and retaining expertise. Methods: As part of building a visionary strategic plan for radiation oncology and the radiation sciences for the next few decades, a personal opinion paper was prepared by authors from the US National Cancer Institute, Conseil Européen pour la Recherche Nucléaire (CERN)/European Organization for Nuclear Research and the International Conference on Translational Research in Radio-Oncology/Physics for Health in Europe. Considering the critical role for global involvement in the future of radiation sciences, the paper provides a path forward via “win-win” sustainable partnerships formed by current resource-limited and resource-rich countries, as envisioned by the International Cancer Expert Corps ( www.iceccancer.org ). Results: The manuscript “ Accurate, precision radiation medicine: a meta-strategy for impacting cancer care, global health, nuclear policy, and mitigating radiation injury from necessary medical use, space exploration and potential terrorism” is in press. A figure (the Radiation Rotary) illustrates that there are a number of crossroads facing the radiation sciences best addressed as part of a rotary. Four sets of issues are illustrated: 1) cancer care with radiation therapy as both technology and biology, 2) global collaboration in technology development ranging from improved linear accelerators for resource-challenged environments to particle therapy for highly specialized uses, 3) nuclear policy, from energy to the potential for nuclear terrorism and conflagration, and 4) mitigating radiation injury including enabling long-term space exploration, helping reduce the fear of radiation and producing drugs to mitigate radiation injury. Conclusion: Many of these technology, research and development issues must involve LMICs. This is in addition to understanding the differences between upper- and lower-income regions in cancer biology and the environment, including infectious etiologies, diet and the microbiome. The talent and capability of radiation oncologists and related professionals within LMICs are essential to global health and economic development and provide incentives and unique opportunities for world-leading careers and contributions. Disclaimer: The content is the personal opinion of the authors and not their organizations

The Children's Oncology Group Radiation Oncology Discipline: 15 Years of Contributions to the Treatment of Childhood Cancer

PURPOSE

Our aim was to review the advances in radiation therapy for the management of pediatric cancers made by the Children's Oncology Group (COG) radiation oncology discipline since its inception in 2000.

METHODS AND MATERIALS

The various radiation oncology disease site leaders reviewed the contributions and advances in pediatric oncology made through the work of the COG. They have presented outcomes of relevant studies and summarized current treatment policies developed by consensus from experts in the field.

RESULTS

The indications and techniques for pediatric radiation therapy have evolved considerably over the years for virtually all pediatric tumor types, resulting in improved cure rates together with the potential for decreased treatment-related morbidity and mortality.

CONCLUSIONS

The COG radiation oncology discipline has made significant contributions toward the treatment of childhood cancer. Our discipline is committed to continuing research to refine and modernize the use of radiation therapy in current and future protocols with the goal of further improving the cure rates and quality of life of children with cancer.

SU-E-T-295: Factors Affecting Accuracy in Proton Therapy

PURPOSE

To examine the various processes involved and to assess their effects on the accuracy in proton therapy.

METHODS

Proton therapy involved several processes: (1) Beam commissioning. (2) CT scan of patient. (3) Contouring. (4) Treatment planning. (5) Output factor measurements for each field. (6) Patient setup verification with image guidance. (7) Dose delivery. (8) Neutron dose and proton RBE at the distal edge. Within each step, there are several sub-processes that each may contribute to the uncertainty in the treatment. By analyzing each of the subprocesseswithin each process, based on measurements or published data, we estimated a % uncertainty to each sub-process and/or a distance uncertainty (in millimeter) on the proton range. A total uncertainty in proton therapy is estimated.

RESULTS

The uncertainties assessed for the various processes are : (1) ±1.5%; (4) ±3.0%, and 1-3mm; (5) ±2.0%; (6) ±2 mm; (7) ±2.0%, ±2mm. The uncertainties in (2) CT, (3) contouring and neutron dose in (8) strongly depend on the location and type of the tumor. On the other hand, the proton RBE at the distal edge in (9) is still debatable and may affect the dose uncertainty from 0-20% depending on which value we want to accept. Thus the overall uncertainty in proton therapy is at least ±4.5% and ±4 mm (by adding the various uncertainties in quadrature), without consideration of processes (2), (3) and (8), and the RBE effect.

CONCLUSIONS

Due to the complexity in proton therapy and the various factors that may affect the accuracy in proton therapy, it is far more complicated to assess the accuracy in proton therapy. Our preliminary study showed that the accuracy in proton therapy is at least ± 4.5% in dose delivered to a tumor with an uncertainty of ±4mm to the distal edge of the SOBP.

Release of tumor necrosis factor by alveolar macrophages of patients with sarcoidosis

Tumor necrosis factor (TNF) is a monokine released by macrophages and is important in the inflammatory response. We compared the spontaneous release of TNF by alveolar macrophages (AMs) from patients with symptomatic pulmonary sarcoidosis, some of whom were receiving corticosteroid therapy, with AMs from control smokers. TNF was released from AMs of sarcoidosis patients at significantly higher levels than was released by control AM subjects (sarcoids, 15 U/ml [0 to 1140 U (median [range]]); controls, all less than 5 U/ml, p less than 0.01). By using a specific polyclonal antibody, the detected TNF was found to be TNF-alpha. Among the sarcoidosis patients, the amount of TNF released was significantly lower for those patients given treatment with corticosteroids (5 U/ml [0 to 15 U/ml]) compared with untreated persons (50 U/ml [0 to 1140 U/ml], p less than 0.05). In vitro studies demonstrated that incubation of peripheral blood monocytes or AMs with dexamethasone for 42 hours suppressed subsequent release of TNF. We conclude that AMs from sarcoidosis patients often spontaneously release TNF and this release is suppressed by prolonged corticosteroid therapy.

Isolation of functionally active pleural macrophages

Pleural fluid provides an easily accessible source of tissue macrophages (MACS). We established a method for retrieval and isolation of these cells. Thirty thoracenteses were performed on patients with the clinical diagnosis of congestive heart failure or malignancy. Within 4 hr of thoracentesis, the specimen was placed on a Ficoll-Hypaque gradient, centrifuged, and the mononuclear cells were isolated. Assessment for total cell count, cell viability, and percentage of cells which were MACS as determined by nonspecific esterase staining was recorded. Pleural MACS were separated by glass adherence. In 24 cases, sufficient cells were available to measure the release of hydrogen peroxide spontaneously and with phorbol myristate acetate (PMA) stimulation. Nine of 24 specimens had spontaneous hydrogen peroxide release. In all cases, stimulation of pleural MACS resulted in a significant increase in the amount of hydrogen peroxide released. We report a simple method for retrieving viable and functionally active pleural macrophages.