How to Target Cancer and Security with Safe and Secure Radiation Technologies

Part 1: Exploring a radiation therapy modality and the multifaceted challenges of source-based and non-source-based radiation technologies.  

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Part 1: Exploring a radiation therapy modality and the multifaceted challenges of source-based and non-source-based radiation technologies.   

Radioactive isotopes are widely used in medicine to diagnose and treat diseases, including cancer. Radiation therapy is a major cancer treatment modality that uses a radioactive isotope, which has the potential to be used for malevolent purposes. It is a necessary, life-saving cancer treatment that utilizes high doses of radiation to shrink tumors and involves a precise beam of radiation, focused directly on the tumor for targeted therapy. Two major categories of radiation therapy are widely available: 1) radioactive isotope-based and 2) linear accelerator (LINAC) based that does not use any radioactive isotope. Both are mature technology options that have been in use for decades in treating cancer, but the presence of a radioactive isotope, such as cobalt-60, introduces a variation between both technologies. LINACs rely on x-ray or electron beams to treat tumors, while cobalt-60-based devices produce gamma rays to destroy tumor cells. Efforts to enhance radiation therapy by substituting cobalt-60 devices with LINACs have been gaining traction in the international community but have proven to be especially challenging “in poorer countries where cancer treatment is grossly inadequate.” A coinciding challenge is the threat posed by the material contained in cobalt-60 radiation therapy devices. There is a heightened risk of radiological terrorism as the radioactive material has the potential to be used as a weapon. Through literature review and analysis, this article series will unravel and explore diverse challenges present within this growing global health and security nexus. 

In 2002, the World Health Organization published the National Cancer Control Programmes Policies and Managerial Guidelines, stressing the importance of different sectors coming together with international organizations and governmental and nongovernmental leaders in the cancer field to tackle issues with cancer control programs. While evidence points to LINACs providing favorable treatment due to sharper precision, developing countries with limited resources struggle to sustainably implement a LINAC technology transfer that involves more significant infrastructure requirements than a cobalt-60 device. According to R. Ravichandran, there are undeniable infrastructure demands posed using a LINAC that are not present with the use of a cobalt-60 machine: 

In addition, no one can deny the facts like simple infrastructure requirements (power supply, less power consumption, beam stability, and ease of operations) sufficient for tele-cobalt machines offering cost effective and un-interrupted treatments to large number of patients even in a rural set up where power fluctuations are commonly encountered.  

Further complicating matters, radioactive isotopes present proliferation risks and are linked to radiological safety and security concerns. If a radioactive isotope is separated or removed from its shielding, it can be weaponized and inflict harm. According to a report titled Treatment, Not Terror, “terrorists could use radioactive sources to cause harm in several ways, such as placing them in locations that expose the public over a long period of time (radiologic exposure devices [REDs]), or by dispersing the sources through food or water supplies, or by contaminating an area to deny long-term access (radiologic dispersal devices [RDDs]).” Further confounding the risk of radiological terrorism are the weaknesses present in the “international architecture for radiological security.” According to the Nuclear Threat Initiative’s 2020 Radioactive Source Security Assessment, “thousands of radioactive sources remain vulnerable to theft from hospitals, university labs, and industrial sites where they are used for a variety of beneficial purposes.” As such, vulnerabilities between security and cancer care continue to persist, and there is a renewed opportunity to raise awareness and promote safe and secure radiation technology options. In 2015, the United Nations General Assembly released 17 interlinked Sustainable Development Goals (SDG). Among the goals announced, SDG 3 issued a plan to ensure healthy lives and promote well-being for all ages, which listed a specific target geared towards the improvement of national control programs across countries in efforts to reduce premature non-communicable disease (NCD) mortality by one-third by 2030. Given that cancer is categorized as an NCD with >50% of patients requiring radiation therapy, there is an urgent need to both address existing radiation therapy infrastructure gaps and understand how national and international security interests may be compromised with the use of isotope-based radiotherapy devices. 

Conversations about the safety and security of radioactive sources for medical applications are not a new phenomenon. Government entities, international organizations, security experts, and medical practitioners worldwide have developed formal and informal forums to exchange information and lessons learned about source-based and non-source-based technologies. One such organization leading many security and safety discussions is the International Atomic Energy Agency (IAEA), as it promotes cooperation in the nuclear field. The IAEA regularly hosts international conferences, distributes information about technical documents, and encourages collaboration on the safety and security of radioactive materials. The IAEA also sponsors a non-legally binding Code of Conduct on the Safety and Security of Radioactive Sources. The document was strengthened following the 9/11 terror attacks and continues to be politically supported by member states. The IAEA has also led the development of documents in other technical areas, including the import and export of radiological sources and the management of disused radioactive sources. Furthermore, the IAEA has created a five-category system for radioactive sources, where sources are categorized “in terms of the A/D ratio, that is the activity of the source (A) and the level at which a source is deemed to be dangerous (D).” Based on this rating scale, “Category 1 sources are considered to pose a high risk to human health if not managed safely and securely, and Category 5 sources a low risk.” The IAEA considers different factors, including “the nature of the work, the mobility of the source, experience from reported accidents, and typical vs. unique activities within an application.” Radiation therapy devices, also referred to as teletherapy machines, are listed as Category 1 sources as per the IAEA categorization, pointing to the high-risk nature that radioactive isotopes in these devices pose. Policymakers are aware of the risks involved with the use of radioactive materials and the resource constraints faced by low-and-middle-income countries (LMICs) interested in replacing radioactive isotope-based technologies with non-radioactive isotope-based options. Given the interconnected nature of these considerations, a growing nexus has surfaced between these “two potentially contradictory goals.” 

Cobalt-60 radiation therapy devices are still “regarded as a very viable and cost-effective option” in LMICs. As LMICs often deal with resource constraints, cancer centers must assess several competing priorities when finalizing the procurement of radiation therapy technology. In many instances, LMICs “are financially constrained and often must rely on equipment donations from high-income countries, which often removes some of the decision-making power from the donation recipients and can lead to the acquisition of inappropriate equipment. Such equipment can be faulty or come with strings attached or without needed capabilities such as trained professionals or funding to operate or maintain it.” Nonetheless, LMICs would benefit significantly from investing in LINACs, but there are clear challenges and barriers permitting this type of technology transfer. According to the International Cancer Expert Corps, a non-governmental organization specializing in improving the outcome of cancer care in LMICs, “the annual global incidence of cancer is projected to rise to 27.5 million cases by 2040, leading to more than 13 million deaths. Up to 70 percent of these will occur in [LMICs].” Increasing treatment times present another factor contributing to inequity in cancer care in LMICs. After prolonged use of cobalt-60 based radiation therapy, patient treatment times change due to the radioactive isotope’s half-life induced radioactive decay. This results in a decrease in radiation being emitted, therefore requiring longer patient treatment times. Given many of these constraints, experts consider cobalt-60 machines to be an old modality used in countries with “limited technical resources.” 

Another challenge of cobalt-60 use is a tangible global security threat in resource-poor settings such as Nigeria. “According to the [IAEA], the biggest gap between radiotherapy machine availability and need is in Nigeria. Nigeria has only one radiotherapy machine per population of 19.4 million people, compared to one machine per 250,000 people in high-income countries.” Even with the limited presence of cobalt-60 radiotherapy devices across Nigeria, there is still concern about the associated radiological risks. Nigeria has seen the emergence of powerful terrorist groups such as Boko Haram, and according to Bernard B. Fyanka, “it is likely that Boko Haram may switch tactics, especially considering the lack of biochemical detection protocols in Nigeria’s counterterrorism strategy and also the inconsistency in public and private sector collaboration.” More robust consideration should be placed internationally on developing more cost-effective, non-source-based technologies to address an already complicated dichotomy between security and human health.  

Rapid growth in radiotherapy technology innovation may conversely exacerbate existing gaps in infrastructure in LMICs. As imaging, physics, and computer science capabilities improve the accuracy of radiotherapy treatment, these advancements might be introducing new barriers to adopting non-source-based radiotherapy technologies in LMICs. Health experts continue to study the disproportionate increase of NCDs in countries already dealing with “weak health care and economic infrastructure.” Yet, these specialized techniques are predominantly implemented in countries where newer radiotherapy technology options are accessible. The availability of cutting-edge radiotherapy technologies plays a pivotal role in delivering options for patients requiring more personalized and customizable treatment plans. The use of conformal radiotherapy was one such shift as it altered treatments and presented a three-dimensional dose distribution tailored to the shape of a tumor and focused on “spatially confining the dose strictly around the tumor to spare the surrounding normal tissues.” Advances have also been made in developing additional radiotherapy modalities such as intensity-modulated radiotherapy and image-guided radiotherapy. What differentiates these radiotherapy modalities are the specialized capabilities in treating tumors near sensitive organs. The radiotherapy technology landscape continues to grow with more specialized techniques, including proton therapy, stereotactic body radiation therapy, and tomotherapy options entering the market. These newer techniques, while efficient and accurate in treating tumors, require a robust infrastructure built around supporting the functionality of these customizable modalities.  

The replacement of source-based external beam radiation therapy devices with safe and secure radiation technologies is now more critical than ever. With the improved effectiveness of non-source-based technologies, many countries are adopting LINAC-based radiation technology that is safe and secure. Rising cancer incidence and evolving security environments have reiterated the growing need to adopt safer radiation technologies. Combatting the challenges and barriers involved in LMICs adopting non-radioactive isotope technologies requires a much more tailored approach by identifying more cost-effective LINACs that are accessible and affordable. Currently, non-source-based technologies such as LINACs “offer state-of-the-art treatment, but this technology is expensive to acquire, operate, and service, especially for [LMICs] and often their harsh environment negatively affects the performance of LINACs, causing downtime.” Given that source-based devices, such as cobalt-60 radiation therapy machines, are associated with potential malicious intent, it is important to continue exploring new approaches to further integrate clinical considerations and radiological risks by involving perspectives across disciplines in understanding these two areas of concern.  

Pallabi Mitra (@pallabimc) is currently a staff member at the Sandia National Laboratories Livermore, California campus where she supports the International Nuclear/Radiological Security Program. She is interested in exploring the nexus between science, technology and policy and leads efforts in her office to strengthen outreach and collaborative activities with international organizations and associations on radiological security. She holds a MSc in Media, Communication and Development from the London School of Economics and Political Science.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. 

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