Advances in Radiation Oncology: Current Status and Future Directions in India

Abstract

Radiation therapy is one of the core components of the comprehensive cancer care. Several new advancements in the radiation physics, radiation biology, and technical upgradation have led us in to a new era of radiation oncology. The access to quality radiation therapy treatment however remains a concern, and this mini-review emphasizes on these issues and also focuses on the future directions for radiation oncology in India.

India is ushering in to the next decade as a country with “cancer epidemic” with continuously growing burden of cancer. While the expected number of incident cancer cases in 2020 was approximately 14 lakh, this is projected to double in the next two decades. Majority of them (50–70%) are still among the preventable cancers [1]. In the recent results from the PURE prospective cohort study on variation in common disease, hospital admission, and death, it has been observed that death from cancer has surpassed the death from cardiovascular diseases in high-income countries and some upper middle–income countries [2]. As the Indian population grows, ages, and urbanizes in the coming decades, cancer will become the leading cause of death in the near future.

The problem of cancer care in our country is multifaceted with challenges arising not only out of the burden but also from several other issues, which includes presentation of most of them in advanced stages, socioeconomic factors, out-of-pocket expenditure, availability of cancer facilities, affordability etc. Radiotherapy is a core component of the comprehensive cancer care, and several challenges need to be addressed for affordable and high-quality radiation therapy to be available throughout India. As per the International Atomic Energy Agency directory of radiotherapy centers (DIRAC), one radiotherapy machine is available for 120,000 people, 1 million people, and about 5 million people respectively in high-, middle-, and low-income countries [3] In our country, there are 741 external beam radiotherapy machines (including 546 linear accelerators, 156 telecobalt units, 23 tomotherapy units, 14 gamma, and cyberknife machines) and 320 remote after loading brachytherapy systems. With a population of over 1.35 billion people and only about 741 machines, we are certainly underequipped. It has been estimated that if by 2035 every cancer patient who needs radiotherapy has access to it, almost one million lives may be saved every year worldwide.

Radiotherapy is at the core of cancer care. Forty to 50% of cancers (notably head and neck cancers and cancer of uterine cervix) are cured with radiotherapy alone; radiotherapy is also delivered in combination with surgery/systemic therapy for many types of cancers and at the same time quintessential for palliation of advanced/incurable diseases. It is also very useful in a variety of benign diseases. Significant advancement in the medical technology, information technology, and imaging has changed the carpet of radiation therapy in the last couple of decades. Advanced technologies like intensity modulated radiotherapy (IMRT), image guided radiotherapy (IGRT), volumetric modulated arc radiotherapy (VMAT), and stereotactic radiotherapy (SRT) are being practiced routinely now in many centers. All these have revolutionized the treatment landscapes, reducing the treatment uncertainties and improving the therapeutic index. Radiation oncology is one of the most technologically integrated specialties in the medical field. Such therapy is an effective, personalized cancer treatment that has benefited tremendously from various technological advances associated with the growing ability to identify and target tumors with accuracy and precision. Innovative technology plays a vital role in improving the quality of care and improving outcomes for patients receiving radiation therapy. Impressive improvement in imaging and radiation delivery technology includes advancements in hardware, software, and algorithms to facilitate fast computations and enable automations.

The advancement in technology has also increased the cost of the radiation treatment by many folds. However, tremendous effort is being done in our country to solve such issues by indigenization, import substitution, and mass production of commonly required equipment both for the diagnosis and management of cancer. The Society for Applied Microwave Electronics Engineering and Research (SAMEER), an organization of the Ministry of Electronics and Information Technology, has developed a 6-MV linear accelerator named “SIDDHARTH” for medical applications. Bhabha Atomic Research Centre (BARC) has designed an indigenous telecobalt unit named as “Bhabhatron.” The Panacea Medical Technology Pvt. Ltd, based in Karnataka is marketing both of them. It has also developed a ring gantry–based SBRT Linear Accelerator, which has also received US FDA 510 K approval. Such innovations in India’s indigenous infrastructure and technology are very promising and encouraging, because they have the potential to meet growing needs of our country.

While the advancement in radiotherapy mostly focuses on delivery of photon therapy, recently, great emphasis is being given for the use of particle therapy. Such treatments, like proton therapy, carbon ion therapy etc. have unique advantages in sparing the organs at risk and delivering the optimum dose to target owing to the physical phenomenon of “Bragg Peak.” The first proton therapy facility in India is already functional at the Apollo Hospital, Chennai. The second proton beam facility is also available at ACTREC, TMC, Mumbai. The boron neutron capture therapy (BNCT) and carbon ion therapy are present in only limited parts of the world and are yet to enter our country.

While the tumor control has certainly improved for many tumor sites, the acute and late toxicities of conventionally fractionated radiotherapy remain a concern. Many researchers are working on this aspect. An innovative solution to address such issues has emerged in the last few years in the form of a novel treatment delivery technique which entails ultra-rapid radiation treatment with dose rate more than approximately 40 Gray/s as opposed to the current modern linear accelerators, which operates at 10 Gray/min under clinical conditions (in the flattening filter free mode). This ultra-fast delivery of radiotherapy with dose rates of several orders of magnitude greater than conventional LINACs is termed as “FLASH radiation therapy.” Interestingly, this technique has also demonstrated reduced normal tissue toxicity while maintaining anti-tumor response, and this biological effect is referred to as “FLASH effect.” Thus, in essence, FLASH is both a physical and radiobiological entity and a conjoint of radio-physical parameters producing a unique radiobiological FLASH effect with a potential to be used for dose escalation as well as normal tissue sparing. The ultra-short treatment time would further help in reducing/eliminating intra-fraction motion issues, virtually freezing the tumor during treatment. This may also allow smaller tumor margins to be used, essentially reducing the normal tissue toxicities. The radiobiological effects of FLASH RT are real but still needs a lot of work before translation into routine clinical practice. However, there is no denial that FLASH RT is emerging as one of the promising “silver lined magic bullet” having potential to revolutionize cancer care in the near future [4].

Digital technology has revolutionized healthcare in the last two decades. Robotic nurse assistants, artificial retina, use of light bulbs that disinfects and kills bacteria, development of digestible sensors etc. stand testimony to the advancements and innovations in healthcare. A range of connecting and converging digital health technology is challenging existing service models. Video telemedicine, use of mobile remote monitoring, and information technology in healthcare delivery have become the harbinger of digitized health sciences. Interoperability and interconnection between primary health care giver, hospitals, public health specialties, laboratory, and pharmacy services are promising.

One more innovation in the field of radiation oncology is IHE-RO (integrating the health care enterprise in radiation oncology). IHE-RO aims to identify key elements of the process of providing radiation therapy (RT specific actors) and select/adopt standards of interchange between elements (transactions). This is an initiative of health care professionals and industry representatives working together to improve the sharing of information between computer systems in health care. With technology at the core of delivering care in radiation oncology, it is imperative that patient safety is not compromised. IHE-RO is an initiative that helps to ensure a safe, efficient radiation oncology practice by improving system-to-system connections. The IHE-RO task force develops IHE Integration Profiles, which specify how industry standards are to be used to address specific clinical problems and ambiguities [5]

We are sure that the technological innovations in health care and radiation oncology would further bring us in to a new era of radiation oncology in the time to come.

Declarations

Conflict of Interest

The authors declare no competing interests.