Proton Beam Radiation Therapy Treatment of Pediatric Patients: A 2011 Survey of the U.S. Proton Centers
Reporting Author: Abigail T. Berman, MD
Last Modified: June 10, 2013
Presenting Author: A. Chang, MD
Presenting Author Affiliation: Hampton University Proton Therapy Institute, Hampton
- Proton beam radiation has unique physical characteristics that allow optimal dose distribution to tumors while minimizing normal tissue irradiation.
- Pediatric patients are at particular risk for the late side effects of normal tissue irradiation. In addition to the increased potential for radiation induced secondary malignancy accompanying the increased life span following cure, many tissues are still developing.
- This puts pediatric patients for high risk of abnormal bone growth, impaired muscle development, organ atrophy, and neurocognitive delay.
- The purpose of this study was to survey proton therapy centers in the United States to evaluate their treatment of pediatric patients.
Materials and Methods
- A survey was developed and distributed to all clinical proton therapy facilities (9) in the United States that were in operation at any point in 2011.
- Anonymized patient information including age range, tumor site, and diagnosis were collected for each pediatric patient treated between January 1, 2011 through December 31, 2011.
- All facilities had treated at least 1 patient.
- A total of 613 pediatric patients were treated. In 2010, 485 children and adolescents were treated. These figures represented a 31.8% increase from 2010 to 2011.
- 58.7% of patients under 10 years of age and approximately half of the treated patients required anesthesia for at least half the treatments.
- The most common tumor diagnosis treated was ependymoma, followed by medulloblastoma, then low-grade glioma, rhabdomyosarcoma, craniopharyngioma, and Ewing's sarcoma.
- Three of the top 6 diagnoses require concurrent chemotherapy.
- Brain was the most common site treated, consisting of 64% of the tumor sites, followed by base of skull / head and neck at 16%, and thoraxa/abdomen/pelvis in 12%.
- There has been widespread acceptance of proton beam radiation therapy for pediatric patients in the US.
- In 2010 and 2011, all operating proton therapy centers were treating pediatric patients.
- A wide variety of diagnoses and tumor sites were being treated with proton beam radiation, with the most common being young patients with central nervous system tumors.
- A multi-disciplinary team is important, with anesthesia support and the co-operation of pediatric medical oncologists as 3 of the top 6 diagnoses required concurrent chemotherapy.
- This is an interesting survey study on the treatment of pediatric tumors at proton therapy centers. Its strengths include that the survey was sent to all proton centers, and there was a 100% response rate.
- The increased pediatric volume from 2010 to 2011 demonstrates a potential need for more proton therapy centers. The authors also showed their preliminary results from the 2012 survey and found that at 10 centers, 694 patients were treated, representing an increase of 13.2%. Over the next 5 years, another 5-10 proton centers are planning to open.
- As more proton therapy centers open, it will be essential to also train the highly-specialized staff needed to these patients.
- In addition, a new question revealed that 19% of pediatric patients treated at US proton therapy centers were from outside of the US (range 0-61%). This highlights that many children and their families must move a far distance to receive proton therapy at the current time; the psychosocial effects of this should not be underestimated.
- Additional data on the trend over time of percentage of patients from outside of the US would be very useful.
- It is important to note that pediatric proton treatments are among the most complex and often time-consuming. First, many radiation plans require multiple fields, as in the case of craniospinal treatment. Image-guidance is also of the utmost importance in these cases. This study also highlights the complexity of pediatric care with ½ of the most common tumor requiring concurrent chemotherapy and half needing anesthesia support.
- It would be interesting to see how many proton therapy centers are directly associated with a children's hospital and, for those who are not, what other infrastructures are used to provide the necessary multidisciplinary care.