Clinical Corner - May 2024

Proton Therapy and the Cancer Registry

Soon, we will be opening a Proton Therapy Treatment Center at my cancer institute. Rather than using a conventional photon beam, the proton treatment has gained favor in its ability to be extremely focused on a specific tumor, while protecting surrounding non-cancerous tissue from radiation injury. Since the first operational proton center opened in 1990, this therapy has transformed from a little-known niche technology to become widespread and well-known to both providers and patients.

When considering appropriate indications for proton therapy, the end goal needs to be prespecified, either dose-escalation beyond that which can reasonably be achieved with photons or toxicity minimization. Classic indications include dose escalation for radio-resistant tumors such as chordoma and chondrosarcoma, with improved tumor control or facilitation of a more comprehensive therapy that may otherwise be too toxic, such as craniospinal irradiation (CSI). Alternatively, late toxicity mitigation for pediatric patients may lead to less risk of secondary malignancies, or a reduction in heart dose for patients with breast cancer may reduce the rate of treatment-related cardiac events and subsequent associated costs of care.

Another intriguing value-based consideration is acute toxicity mitigation, which may be particularly relevant for elderly or frail patients who are less able to tolerate definitive combined modality therapy or may not even be offered curative intent therapy at all. Reducing acute toxicity may reduce treatment breaks, hospital admissions, and consequent medical procedures that outweigh the up-front cost of therapy for vulnerable patients. In addition, patient quality of life and treatment preference are major considerations, and patients should be included in the investigatory process to capture what is most important to them as they weigh their treatment decisions.

Awareness of these indications, considerations, and the complete cost of care will ultimately answer the value-based proposition and better define the role of proton therapy in the field of oncology. Finally, just as conventional radiation treatment has been captured in our cancer registries, the specific characteristics of proton therapy must be included in our patient abstracts, thus allowing for adequate evaluation of outcomes using this exciting, new technology.