Researchers have developed new imaging guidelines, representing a major shift in the management of patients with head and neck cancers, according to a study published by Henson et al in The Lancet Oncology. The guidelines may lay the foundation for these patients to be treated with tailored therapies that are less invasive and to avoid major, potentially debilitating surgical procedures.
Background
“The impetus for the study is that today, approximately 80% of head and neck cancers are associated with an HPV [human papillomavirus] infection rather than smoking and tobacco use,” explained lead study author Christina Henson, MD, Assistant Professor at the University of Oklahoma (OU) College of Medicine, a radiation oncologist at OU Health and a faculty member at OU. “Because HPV-related head and neck cancers respond much better to treatment than tobacco-related cancers do, many patients can undergo minimally invasive surgeries or receive radiation treatment. Such organ-sparing therapies will keep them from a complex surgery in which they might lose their voice box or part of their tongue,” she emphasized.
However, in order to administer the appropriate therapy, a patient’s oncology team needs to determine whether the patient has an extranodal extension—signaling an aggressive type of cancer requiring radiation therapy and chemotherapy rather than surgery.
If a patient undergoes surgery and an extranodal extension is found in the lymph nodes that were removed, the patient may then need to undergo radiation therapy and chemotherapy after surgery, all of which comes with the risk of separate sets of side effects. For this reason, the oncology team may attempt to avoid surgery in patients with extranodal extensions because they may be better treated with radiation therapy and chemotherapy. Identifying extranodal extensions through an imaging test prior to surgery could allow patients to avoid unnecessary surgical procedures and receive radiation therapy and chemotherapy. The new imaging guidelines could fill this gap in knowledge.
Study Methods and Results
In the recent study, a team of researchers—comprising head and neck cancer experts from 29 countries across the world—developed imaging guidelines for head and neck cancers by conducting their evaluation according to the Delphi consensus. The experts were presented with questions for their feedback on the details of defining and identifying extranodal extensions. Questions that didn’t result in agreement were revisited until all nuances had been addressed.
Conclusions
The researchers emphasized that as a result of the findings, imaging techniques such as computed tomography (CT), positron-emission tomography (PET), and magnetic resonance imaging (MRI) can be better utilized to determine cancer aggressiveness and determine which patients may benefit from radiation therapy instead of surgery. The guidelines may also be used to inform the next edition of staging protocols for head and neck cancers, the criteria of which were last updated in 2018.
“Until now, there have been no criteria by which to interpret the presence or absence of extranodal extensions on imaging. Radiologists have seen what they believe to be extranodal extensions, but they have been hesitant to call it [that] because there have been no criteria to follow, [b]ut now we have established guidelines that will give radiologists confidence to make that call so that patients can be appropriately treated,” Dr. Henson said. “Radiation therapy certainly has its own side effects, but it is significant to provide a treatment that will save [patients] from having issues with their swallowing and their voice down the road,” she commented.
The researchers are currently working toward incorporating the new imaging guidelines into practice. Radiologists are familiarizing themselves with the guidelines and testing the new approach to continue establishing its reliability. In addition, a related study is ongoing to determine which imaging techniques may be most accurate in identifying extranodal extensions. Thus far, the researchers have found that a combination of CT and MRI scans appear to provide the highest accuracy.
The recent study was part of a series of four articles published in the current edition of The Lancet Oncology. A separate study followed the same Delphi process to refine existing guidelines that pathologists follow for interpreting extranodal extensions. The remaining two studies established a common language for defining and measuring recurrent/metastatic head and neck cancers and for assessments in curative-intent trials in head and neck cancers. The results may be significant for future clinical trials.
“Both of the last two studies were looking at endpoint definitions—for example, when there is a clinical trial, what is it measuring and how is survival defined? It is crucial to have standardized definitions of endpoints we’re using in clinical trials so that when we use a term, we are all meaning the same thing,” Dr. Henson concluded.
Disclosure: For full disclosures of the study authors, visit thelancet.com.
