There are few times in a doctor’s career in which you see a remarkable leap forward in care – 2021-22 has been that year for me. Our first-of-its-kind head and neck cancer study, DARTBOARD, feels revolutionary in terms of precision, patient-centricity, and enhancing quality of life.
Officially known as Daily Adaptive Radiotherapy to Better Organ-at-Risk Doses in Head and Neck Cancer, DARTBOARD is the first randomized study of daily adaptive radiation therapy in head and neck cancer.
UT Southwestern is the only site for the study, which will implement the smallest head and neck irradiated volume ever delivered and analyzed. A novel, highly focused treatment plan will be designed in part by an AI algorithm developed by UT Southwestern’s Radiation Oncology team. A daily patient-specific treatment will be delivered using our two specialized Varian Ethos machines.
Though head or neck cancer treatment has improved dramatically in the last 30 years, there is room to improve the side effects of head and neck cancer radiation therapy – namely xerostomia (dry mouth) due to salivary gland damage caused by standard radiation therapy.
It can take six months or longer to improve dry mouth after treatment ends, and most patients experience some degree of this symptom for life. To the average person, dry mouth might seem miniscule. But saliva plays an important role in chewing, swallowing, tasting, and talking – dry mouth can make these activities difficult or uncomfortable.
The primary goal of DARTBOARD, which is receiving financial support from Varian Medical Systems, is to determine whether daily adaptive radiation therapy – delivering radiation to an increasingly smaller area of tissue based on a patient’s real-time anatomy – can reduce dry mouth after treatment compared with traditional radiation therapy.
Further, our ongoing goal for DARTBOARD and subsequent studies is to enhance cancer treatment through personalized radiation therapy at Harold C. Simmons Comprehensive Cancer Center.
Pushing the limits of standard radiation therapy
Intensity-modulated radiotherapy (IMRT) is the current standard of care for head and neck squamous cell carcinoma, which occurs in the mucous membranes of the nose, mouth, and throat.
IMRT was originally designed in part to reduce radiation doses to the salivary glands, and it did this well. However, there is always room to improve processes and outcomes.
As an example, our team has developed a focused method of treating the lymph nodes in the neck. Conventional treatment irradiates the whole neck as an insurance policy in case there are small lymph nodes that cannot be visualized on imaging. This approach delivers a significant dose to normal tissue across the head and neck.
Through the use of an AI-based model developed at UT Southwestern, we have eliminated this prophylactic dose and just focused on suspicious lymph nodes, significantly reducing the dose to normal tissues. Our previous study of this approach has been successful, and we are implementing it in the next innovation in our department: daily adaptive radiotherapy.
Designing a typical IMRT radiation plan takes 10-15 hours and, therefore, we traditionally use a single plan for the patient over a six- to seven-week course of treatment. However, a lot can change in that time. The patient may lose weight, and the tumor may begin to change in size and shape.
Traditional IMRT can’t adjust for those daily changes, meaning the delivered dose of radiation may be higher or broader than originally planned. Daily adaptive radiotherapy may be the next step toward eliminating that extra exposure without compromising outcomes.
How daily adaptive radiotherapy works
With daily adaptive radiotherapy, we go through the same set-up imaging as we would to start a traditional head and neck radiation fraction, including mini-CT scans that show us the size and shape of the tumor.
Using the Varian Ethos system, we can take the patient’s mini-scan, make a new plan based on the patient’s anatomy each day, and deliver the plan immediately to a personalized, targeted field – like a dart hitting a bullseye.
For providers, this strategy reduces replanning time from hours to approximately 10 minutes. In addition, because we are optimizing each day’s treatment based on the anatomy at that time, the safety margins needed to account for day-to-day variation are dramatically reduced, minimizing normal tissue irradiation.
For patients, daily adaptive therapy allows us to adjust the plan on-the-fly each session based on the patient’s positioning and anatomy that day. This process is subtly iterative, meaning today’s plan becomes the base for tomorrow’s session.
The main benefit to patients is reducing the radiation dose to normal tissue, therefore lessening side effects such as dry mouth. The tradeoff is the need to remain in the treatment room longer each day by approximately 20 minutes.
Who qualifies for DARTBOARD
Approximately 75% of non-surgical patients in our head and neck cancer clinic will be eligible for the DARTBOARD trial. Eligible participants will have:
- Stage I-IVB oropharyngeal squamous cell carcinoma, treated with definitive radiotherapy or chemoradiotherapy
- Stage I-IVB laryngeal squamous cell carcinoma, excluding glottis T1-2 carcinoma
- Stage I-IVB hypopharyngeal squamous cell carcinoma
The cancer cannot have metastasized or have been surgically treated, and the patient cannot have had a prior head or neck cancer that was treated with radiation or chemotherapy.
This study is a randomized trial, which means that half of the participants will benefit from the focused nodal therapy without adaptation, and half of the participants will receive the focused nodal therapy with reduced margins and daily adaptation. This daily adaptive radiotherapy will take place once a day, Monday through Friday, for seven weeks. This means participants will need to live in the area or be able to stay in the area during the treatment period.
Choosing to participate in a clinical study is a personal decision. Talk with your doctor about whether you are eligible and whether participation is recommended for you.
The Era of Adaptive Radiation
In August 2021, UT Southwestern expanded its radiation oncology services by adding 71,000 square feet of space to our leading-edge treatment and research facility. It ushered in an exciting new phase in the field of radiation oncology: adaptive therapy, which delivers ultra-precise treatment that can quickly be adapted to patients’ needs. Take a tour of our facility and see adaptive radiation therapy at work.
Enhancing quality of life after head and neck cancer
Our goal is always ultra-personalized care for each patient. We don’t believe in a one-size-fits-all treatment approach for head and neck cancer, and we are hopeful DARTBOARD will show that daily adaptive radiation therapy can improve patients’ quality of life.
UT Southwestern is uniquely positioned to develop and execute this clinical trial. Our team of head and neck cancer specialists treats only head and neck cancer, giving us a level of expertise found in few U.S. specialist centers. We also have access to two Varian Ethos systems in our recently expanded radiation oncology building in Dallas.
Our unique sets of skills and technologies allow our team to think outside the box and more aggressively target cancer to enhance patients’ quality of life.
While we hope DARTBOARD improves dry mouth after head and neck cancer treatment, this approach and our AI-driven planning process could become something bigger one day. DARTBOARD might be the first steps toward providing daily adaptive radiation therapy for other types of cancer – with more precision and personalization that ever before.
To find out whether you or a loved one might be eligible for the DARTBOARD trial, call 214-645-8525 or request an appointment online.