Diagnosis: Lung Cancer
Treatment: Proton Radiation Therapy
The insurer denied proton radiation therapy.
The denial is upheld.

The patient is an adult female with a diagnosis of at least stage IIIB left lung cancer. Definitive radiation therapy was recommended, and proton therapy was requested.

The requested proton radiation therapy is not medically necessary.

Although there are studies showing possible dosimetric advantage of proton beam therapy for the treatment of lung cancer, there is insufficient long-term clinical data showing that proton therapy is safer or more effective compared to photon IMRT (intensity-modulated radiation therapy) in well conducted randomized trials.

A study from the Provincial Agency for Proton Therapy in Italy conducted a systematic review of the current data on the treatment of NSCLC (non-small cell lung cancer) with proton therapy. A total of 113 reports were analyzed, and the authors concluded that "Although from a physical point of view PT is a good option for the treatment of NSCLC, limited data are available on its application in the clinical practice. Furthermore, the application of PT [proton therapy] to lung cancer does present technical challenges. Because of the small number of institutions involved in the treatment of this disease, number of patients, and methodological weaknesses of the trials it is therefore not possible to draw definitive conclusions about the superiority of PT with respect to the photon techniques currently available for the treatment of NSCLC."

The American College of Chest Physicians (ACCP) has published evidenced-based practice guidelines for the treatment and management of lung cancer. These guidelines discuss treatment options for various stages of specific tumor types, including bronchioloalveolar lung cancer, small cell lung cancer, NSCLC stages I and II, NSCLC stage IIIA, NSCLC stage IIIB, NSCLC stage IV, and other forms of lung cancer. In these guidelines, the ACCP does not present PBRT (proton beam radiation therapy) as a treatment option for the management of lung cancer.

A more recent study from Chang, et al evaluated unresectable stage III lung cancer patients treated with proton beam radiotherapy and concurrent chemotherapy. The authors concluded, "Concurrent chemotherapy and PBT [proton beam therapy] to treat unresectable NSCLC afford promising clinical outcomes and rates of toxic effects compared with historical photon therapy data." However, "Further optimization of proton therapy, particularly intensity-modulated proton therapy, is still needed."

Another 2018 randomized trial from MD (Monroe Dunaway) Anderson Cancer Center and Massachusetts General Hospital compared IMRT and proton therapy for locally advanced lung cancer. The authors concluded, "No benefit was noted in RP (radiation pneumonitis) or LF (local failure) after PSPT (passive scattering proton therapy)."

In this case, the patient's provider stated that proton therapy is better than photon therapy in sparing the surrounding critical structures. However, there was no comparison DVH (dose-volume histogram) information provided showing that photon IMRT is inadequate in sparing the surrounding critical structures. IMRT photon radiation therapy has been shown to be safe and effective for the treatment of lung cancer and is currently the standard of care. Proton beam therapy is, therefore, not considered medically necessary due to insufficient randomized clinical data showing clinical superiority of proton therapy over IMRT.