Global Trends in Radiation Oncology

Global Trends in Radiation Oncology

The number of newly diagnosed cancers per year is on a path to nearly double over the next two decades, continuing to pose a major threat to human health.[1] Radiation oncology is a critical component of cancer management, fueled by rapid progress in the application of advanced imaging techniques, availability of functional information and a more thorough understanding of cancer biology to enable more precise and effective cancer therapies. In the interest of building individualized, patient-centric treatments, radiation oncologists use a multitude of available resources and innovations in radiation oncology to improve the patient experience and generate the best health outcome for each and every patient.

A recent webinar hosted by GE Healthcare brought together a panel of key opinion leaders in radiation oncology from across the globe to discuss current trends, as well as the potential paths toward maximizing precise and effective cancer therapies. The panel discussed patient-centric treatment options such as the move toward hypofractionation, the importance of pretreatment imaging, precision radiation therapy in terms of physical as well as biological precision, dose optimization, Theranostics and the integration of advanced imaging and artificial intelligence (AI) tools to inform adaptive radiation therapy.  

Optimizing efficiency in radiation oncology treatment planning

Imaging has an essential role in the planning and delivery of radiation therapy. The integration of imaging technology into modern radiation therapy treatment systems has led to an increase in the precision and accuracy of radiation delivery.[2]

Jonathan Haas, MD, Chairman of Radiation Oncology at the Perlmutter Cancer Center at NYU Long Island School of Medicine shared his thoughts on how imaging has affected the treatment planning process. “It’s really the technology that is exploding right now for the benefit of the patient,” he explained. “We’re using imaging to advance precision in the clinic, integrating imaging with our CT simulators, MR simulators, functional imaging, and PET/CT integration with our planning process.”

The first step in being able to deliver precision radiation therapy is accurate target delineation during the planning process. Advanced multi-modality diagnostic imaging including computed tomography (CT), high-resolution magnetic resonance imaging (MRI) and positron emission tomography (PET)/CT imaging form part of the routine staging process for a number of tumor types.[3]

Enabling a greater understanding of tumor biology, functional imaging techniques such as PET/CT, or perfusion and kinetic perfusion studies can provide visibility to tumor characteristics at a metabolic level, which can potentially highlight areas of the tumor that would be more likely resistant to radiation therapy and those areas where a focused dose would potentially be more effective. As the most widely used imaging modality for cancer staging and response assessment, advances in CT, particularly the availability of iterative reconstruction algorithms and increased detector sensitivity to reduce ionizing radiation dose to the patient, as well as continuous improvements in noise and artifact correction have enabled a number of new quantitative CT techniques that can also characterize tissue and illustrate metabolic function.[4]

JJ Wyatt, Radiotherapy Physicist and Associate Lecturer at Newcastle University and Newcastle Hospitals in the UK added, “The use of not just CT, but the use of MR and the use of PET provide you with a much bigger and richer picture of the tumor. But also a more precise and more efficient delineation because of the improved image quality and also the additional functional and metabolic information that you get. I believe we’ll be moving away from delivering homogeneous [radiation] doses over the whole of the target and rather identifying, using functional imaging, areas of particular sub-volumes or particular activity, given the higher doses to those regions.”

Other recent advances in imaging have led to the development of advanced radiation therapy techniques—including image-guided radiation therapy, intensity-modulated radiation therapy, stereotactic body radiation therapy and proton beam therapy.

Adaptive radiation therapy is also a topic discussed by the panelists. Using a closed-loop radiation treatment process, the treatment plan can be modified using a systematic feedback of measurements intended to improve treatment by systematically monitoring treatment variations and incorporating them to re-optimize the treatment plan early on during the course of treatment. In this process, field margin and treatment dose can be routinely customized to each individual patient to achieve a safe dose escalation.[5]

The use of advanced imaging and hypofractionation to improve radiation therapy

The optimal applications of advanced multi-modality imaging in radiation oncology might enable higher doses of radiation to be delivered to the tumor, while sparing normal surrounding tissues.[6] The hypofractionated radiation therapy treatment approach delivers fewer, larger doses of radiation therapy to the tumor.  According to the panelists, the move into hypofractionation is mainstream and being accepted clinically but would not be possible without the integration of advanced functional imaging techniques.

“To oversimplify what we do,” explained Dr. Haas. “It’s marksmanship. And it all starts with how you’d see the tumor. We’re getting better and more precise. As the precision gets more accurate, you can escalate the dose within a tumor, and deescalate the dose outside the tumor. That’s where the trend continues to go.”

Sen Bai, MD, Chief Technologist, Department of Radiotherapy from West China Hospital of Sichuan University in Chengdu city, China, agreed and added, “The combination of tumor targeting, and precise treatments has become very important. We’ve seen that further development of imaging technologies during treatment is needed,” he explained. “Cardiac radioablation is a kind of hypofraction treatment. And because other organs are at risk, precise target area of segmentation is very important. Pretreatment imaging, including heart structural imaging and functional imaging can help distinguish the heart area from normal tissue.”

Dr. Bai explained his team also commonly uses 4D-CT imaging to generate an internal target volume contour that represents the volume in which the tumor moves throughout a patient’s respiration. Respiration motion can cause tumor displacement that affects the accuracy of the radiation therapy.

Integrating theragnostics to improve the effectiveness of radiation therapy treatment

“Theragnostics is going to be a major part of what we do in radiation oncology,” noted Dr. Haas. “It’s going to be a whole new frontier in terms of treatment. We are definitely already using it in diagnostics. If you have targets that you can now attach therapeutic agents to, it’s really going to impact how we design radiation fields.”

Srinivas Chilukuri, MD, Senior Consultant Radiation Oncologist at Apollo Proton Cancer Center in Chennai, India, said that theragnostics is already widely used in some clinical applications in India. “We’ve been using PSMA PET scans for the last ten years or so,” Dr. Chilukuri explained. “Similarly, we have been using theragnostics for hepatocellular cancers, for neuroendocrine tumors or prostate cancers, and many other cancers because it’s an extremely targeted therapy with radiation therapy. It’s really combining the best of chemotherapy, systemic therapy and radiation therapy.”

Dr. Bai agreed, saying, “Theragnostics in combination with external radiation therapy will help doctors have a more comprehensive understanding of the patient’s condition and to choose suitable treatment methods, which could provide patients with individualized therapy.”

AI and the future of radiation oncology

Throughout their discussion, the panelists agreed that while all the advances in imaging and in therapy planning and treatments will have a tremendous affect on the health outcomes of patients, the ability to aggregate and integrate the data to gain holistic insights for treatment planning and monitoring is critical.

“You end up with a situation where you have a lot of different data sources, a lot of different data streams feeding into your decision making,” explained Dr. Wyatt. “Many of them are coming in from different systems that aren’t compatible, and that can be a real challenge to work out how to utilize them best within the radiation therapy setting. We need to make sure those data streams can easily line up so that the critical information can be seamlessly tied together.”

New AI tools and deep learning-based algorithms are being developed to provide ways of aggregating different channels of data so that radiation oncologists are able to integrate all possible resources as they plan treatments for patients. This will be both a challenge, as well as a major area of growth in the near future, according to the panelists.

Please view the on-demand webinar, Trends in Radiation Oncology, to learn more.   

 

The information represents the clinical practice and views of the included key opinion leaders in radiation oncology. Factors that should be considered by clinicians include cleared and approved product labeling and guidelines provided by medically sourced organizations. The included speakers specialize in radiation oncology.

 

---