AN OVERVIEW OF RADIATION ONCOLOGY WITH DR RYAN LANNING
Presenter:
Ryan Lanning, MD, University of Colorado School of Medicine
Conference:
2024 Meeting of the Oncology Nursing Society (ONS) Metro Denver Chapter
At the 2024 Meeting of the Oncology Nursing Society (ONS) Metro Denver Chapter Dr. Ryan Lanning from University of Colorado School of Medicine provided a comprehensive overview of the role of radiation therapy in cancer care, explaining its various uses, delivery methods, and associated side effects. Dr Lanning emphasized that radiation therapy plays a vital role in both curative and palliative oncology care, with nearly half of all cancer patients receiving radiation at some point during treatment.
Radiation therapy works by delivering ionizing radiation, which targets the DNA within cancer cells, causing lethal damage and effectively preventing their ability to replicate. There are various types of radiation therapy which can be used, depending on the cancer's location and depth. These include megavoltage X-rays (for deeper tumors), brachytherapy (for more localized cancers such as prostate cancer), and proton therapy, which offers the potential for reduced side effects. Dr. Lanning noted, however, that while promising, proton therapy has not yet shown a survival benefit for patients relative to standard radiation in most cases. Other more specialized forms of radiotherapy, such as neutron therapy, are limited to more selective applications such as salivary gland cancers.
Radiation can be delivered using a device known as a linear accelerator, which is the standard equipment for X-ray radiation. The treatment planning process involves a computed tomography (CT)-guided simulation to determine the precise area for radiation. This is followed by several days to weeks of preparation in order to optimize dose delivery. For more complex cases, intensity-modulated radiation therapy (IMRT) is used to shape the radiation field while minimizing exposure to the surrounding healthy tissue. IMRT has also been particularly effective in reducing side effects, such as dry mouth when used in head and neck cancers, as compared to older methods.
Radiation therapy is tailored to specific clinical situations. It may serve as neoadjuvant therapy (pre-surgery) as a means to shrink tumors and improve surgical outcomes, or as adjuvant therapy (post-surgery) to eliminate traces of microscopic residual disease. In certain cancers, like prostate and head and neck cancers, radiation may be the primary treatment modality. Radiation is also commonly used in the palliative care setting, to relieve symptoms like pain or bleeding and to improve the overall quality of life for patients living with metastatic disease.
Dr. Lanning also outlined some of the acute and long-term side effects of radiation therapy which can be widely variable, based on the treatment site and overall duration. Some of the most common side effects include fatigue, radiation dermatitis, and nausea, with some symptoms, such as dry mouth, persisting for months or even years after treatment. He emphasized that fractionated dose radiation—which delivers smaller doses over multiple sessions—can give healthy tissue time to repair between treatments, thereby reducing toxicity. In addition, more modern techniques such as stereotactic body radiation therapy (SBRT) enables high-dose radiation to be delivered over fewer sessions, which is particularly useful for lung metastases, or in cases where there are only a few metastatic sites (oligometastatic disease).
One current area of active investigation is the strategy of combining immunotherapy with radiation therapy. Dr. Lanning explained the concept of the abscopal effect, where radiation in combination with immunotherapy can enhance systemic anti-tumor responses, leading to regression of distant metastases. The potential mechanisms underlying this synergy remains an area of ongoing research.
Dr Lanning’s presentation also addressed some of the practical challenges when using radiotherapy, such as the controversy around tooth extractions before radiation therapy for head and neck cancers. He noted that, while older protocols recommended prophylactic tooth extractions to avoid the possible complication of osteonecrosis of the jaw, with modern IMRT techniques, the risk of such complications has decreased significantly. As such, current approaches are more conservative, with extractions only recommended if the tooth extraction was otherwise necessary, regardless of cancer treatment.
Lastly, Dr Lanning highlighted the importance of team-based care in radiation oncology, given the complexity of treatment planning and the need for patient support throughout the therapeutic process. For example, radiation oncologists will work closely with surgeons, medical oncologists, and other healthcare providers in order to tailor the treatment plan for the individual patient. Oncology nurses play a critical role in managing side effects and ensuring patient compliance with treatment schedules, which can usually extend over several weeks.
Radiation oncology remains a cornerstone of cancer treatment, offering both curative and palliative options across a wide range of cancers. Advances in techniques like IMRT and SBRT have improved patient outcomes by reducing toxicity, while new research is exploring how radiation can be integrated with novel anti-cancer treatments, such as immunotherapy, to further enhance treatment. Dr. Lanning emphasized that with proper planning and collaboration, radiation therapy can provide substantial benefits to cancer patients, improving both survival and quality of life.
Speaker Disclosure Information: Dr Lanning reported no disclosures for this presentation.
You can see Dr Lanning’s full presentation from the 2024 Meeting of the Oncology Nursing Society (ONS) Metro Denver Chapter here.