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Proton Therapy at Siteman Cancer Center: Conversation with Dr. Stephanie Perkins

In May of this year at the National Proton Conference, Dr. Lionel Bouchet, SVP of Commercial Development at Mevion Medical Systems, sat down with Dr. Stephanie Perkins, Director of the S. Lee Kling Proton Therapy Center, and Chief of the Pediatric Radiotherapy Service at Washington University School of Medicine to discuss the proton therapy program at Siteman Cancer Center.

The full recording of the interview can be viewed here:

Early Beginnings

The discussion started off with a brief overview of Siteman Cancer Center’s history. The center has been open for almost 10 years, with the first patient being treated in 2013. To date, almost 1,500 patients have been treated. Proton therapy is used for a wide array of cancers, including pediatric.

“It has been such a good venture for us and such an improvement of care for our patients,” said Dr. Perkins, “We have also used proton therapy for a wide variety of cancers and are really trying to change the field and push things forward for the patients and for the technology.”

Over the past several years, Siteman has increasingly leveraged proton therapy for: 

•    Adolescent young adults 
•    Increase in re-irradiation 
•    Stereotactic Body Radiation Therapy (SBRT)

Benefits of Integrated Proton Therapy

For the hospital and the clinical team, it is imperative that the proton therapy services be fully integrated with the existing department.  In 2006, the decision was made to partner with Mevion to reduce the size of proton therapy technology to be closer to conventional LINAC. 

“The benefits are important to us, as we don’t require special proton coverage for physician presence, it's just integrated into our center, into our existing processes and workflows, and that has been really important to us,” commented Dr. Perkins.

Proton Therapy with Diagnostic CT-On-Rails

“One of our two proton vaults includes a diagnostic CT-on-Rails, which gives our clinicians the ability to replan treatments very quickly if needed. And the image quality is really great, there’s really no guessing when you are getting the daily imaging, as to what’s going on, what changes you might need to make,” said Dr. Perkins.


Proton Therapy For pediatric Patients

Proton therapy has become increasingly critical in treating pediatric patients at Siteman and has become a standard of care for pediatric brain tumors. As the proton therapy system is onsite with the St. Louis Children’s Hospital, the coordination for treating pediatric patients has been operating efficiently and seamlessly since inception. About 1/3 of pediatric patients at Siteman require craniospinal irradiation. “That’s a pretty big part of our service and something that we’ve streamlined to be straightforward and easy for young children to complete without sedation,” said Dr. Perkins. 

The typical treatment time is around 5-10 minutes per field. For a 3-field posterior fossa boost, the patient should be in and out within 20 – 25 minutes. And for craniospinal, depending on the height of the patient, the treatment can range from 35 – 50 minutes. Dr. Perkins indicated that when compared to X-Ray therapy, proton therapy offers much more rapid and accurate dosimetry.

The Future of Proton Therapy at Siteman

The future of proton therapy at Siteman includes fostering the use of proton adaptive therapy with the upcoming second room expansion. Perkins indicated that they hope to treat their first adaptive proton patient later this year. The center is also looking ahead at utilizing proton grid therapy, and the proton team is working on conducting 3 fraction grid treatments towards the latter part of the year. Finally, Siteman is exploring FLASH* dosimetry (ultra-fast delivery of radiation therapy at dose rates), and they hope to grow their expertise in this area over the next several years with preclinical trials on animal models.


For more proton therapy information, visit our Mev-Ionosphere blog.

*FLASH therapy is not yet available for clinical use. 

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