SPOTLIGHT EDUCATION
BEAMING WITH INSIGHT Dr . Everett ' s Elective Rotation Investigating Proton Dosimetry and Physics
By : Ashlyn Everett , M . D . | UAB Radiation Oncology Resident
ABOVE : The University of Florida proton gantry where Dr . Everett completed her elective rotation .
Along the sunny coast of Florida , there is another form of energy beaming down on the residents of Jacksonville . In 2006 , the University of Florida opened a proton facility with three proton gantries , one proton beam line room , and two LINAC gantries . Their facility treats between 100-120 proton patients daily , operating from 6:00 am until well after midnight most nights to accommodate their patient volume .
During the month of December , I had the opportunity to visit their bustling facility to learn about the clinical and dosimetric advantages or disadvantages with proton therapy . I spent a majority of my time working under physicians treating prostate , lymphoma , lung , or head and neck cancers .
In the clinical realm , proton therapy is similar to conventional photon therapy , with the theoretical benefit of less toxicity due to less normal tissue exposure to ionizing radiation . However , I also observed some patients with brisk skin reaction after head and neck proton radiation due to the high surface dose . My primary goal while at the UF Proton Institute was to learn the unique features of proton dosimetry and physics , from a physicians ’ perspective .
First , I learned that treatment response during radiation greatly affects proton therapy as compared to conventional photons . Tumor shrinkage can lead to changes in dose distribution , both to tumor and normal structures , further complicating proton therapy . In some situations , patients required multiple imaging scans and updated plans to account for the change in tissue density , most notably in the treatment of lung tumors .
This required coordinating a large team of nurses , dosimetrists , therapists , and physicians to provide the best care for patients . Fortunately , there was a solid infrastructure supporting these unique issues relating to proton therapy .
Second , I learned that proton treatment can offer dosimetric advantage compared to photon therapy in appropriately selected patients . While on my elective rotation , I participated in a retrospective dosimetry study investigating the role of proton therapy for patients with mediastinal lymphoma . For a series of 22 patients , we compared IMRT photon to proton therapy , and looked at the doses to organs at risk including the heart , lungs , esophagus , thyroid , and nontarget body tissues . Protons therapy significantly reduced dose to these normal tissues ; however , the clinical benefit of these findings remains unknown . Our results were submitted to ASTRO for presentation at the 60th annual meeting this fall , and we are excited to share these results with the radiation oncology community .
Proton therapy is an exciting treatment option for many patients , and I am looking forward to having it at UAB for our patients . While similarities with photon treatment exist , there are specific issues relating to proton therapy that require an astute team of physicians , dosimetrists , and physicists . Delivering appropriate care requires seamless team coordination and attention to detail to ensure that our proton therapy is accurate and precise . I am confident that UAB will continue to provide excellent care as we have the exciting opportunity to provide proton treatment to patients in Alabama and across the Southeast .
17 | RAYS OF HOPE