Appeal type: Experimental/Investigational
Decision: Upheld

Nature of Statutory Criteria/Case Summary: An enrollee has requested authorization and coverage for proton beam therapy, 10 visits (two weeks). Findings:  The physician reviewer found that  the patient who was diagnosed with benign appearing calcifications in the left axillary tail on mammogram.  Repeat mammogram  six months later showed stable calcifications in the left axillary tail, but a new 2 cm mass in the lateral left breast with architectural distortion and associated calcifications. She had an associated palpable lump, and mammographic findings were verified with ultrasound. Biopsy demonstrated estrogen receptor-positive/progesterone receptor-positive (ER/PR) and Her2Neu negative invasive lobular carcinoma. Breast magnetic resonance imaging (MRI) showed a benign appearing nodule in the right breast (although biopsy was recommended), and no additional lesions in the left breast. Lumpectomy and sentinel lymph node biopsy were performed . Pathology showed a 2 cm focus of invasive lobular carcinoma (close cranial margin was re-excised showing no residual disease), and a 2.5 mm focus of ductal carcinoma in situ removed with close margins. Seven lymph nodes were removed and were all negative. Her case is being reviewed on the appropriateness of using proton therapy for post lumpectomy radiotherapy. The patient requested coverage for proton beam therapy ,10 visits (two weeks). The Health Plan denied the request indicating that the requested services are investigational for treatment of this patient. There is a lack of support in the medical literature for the superior efficacy of proton beam therapy over the standard treatment options in this clinical setting. While proton therapy will almost always appear superior to photon therapy dosimetrically due to its Bragg peak, this does not necessarily translate into a clinical benefit. Appropriate cardiac dose constraints for breast radiation are unclear. The most commonly used constraint, mean heart dose, was not established until 2013. Specifically, a study suggested a 7.4% relative increase in major coronary events for each increase of 1 Gy in mean heart dose for photon therapy, with no safe threshold dose below which coronary events did not occur. However, it is suspected that yet unknown dosimetric constraints for smaller cardiac substructures are likely to be more clinically relevant than mean dose to the entire heart. Assuming that the Darby model is applicable to proton therapy, a recent study modeled cardiac toxicity for proton therapy versus photon therapy for left-sided breast radiation (including comprehensive nodal irradiation) and demonstrated that the expected cardiac morbidity was only 0.5-1.0% with photons, compared to 0.06% with protons. While the model did suggest cardiac morbidity rates were near zero with protons, it is easily arguable that the cardiac toxicity with photons is already sufficiently low. Overall, the use of proton therapy in the treatment of breast cancer is a highly controversial. It is unknown whether or not the study model applies to proton therapy, and even then, the clinical benefit in decreasing cardiac toxicity is likely small. The uncertainty of the above issues with proton therapy is reflected in a recently started trial designed specifically to look at cardiac toxicity for photons versus  protons, including dose-volume analysis of cardiac substructures . In sum, proton beam therapy, 10 visits (two weeks), is not likely to be more effective than standard therapies for treatment of this patient.  Final Result: The reviewers, 3 of 3  determined that the requested services are not likely to be more beneficial for treatment of the patients medical condition than any available standard therapy. Therefore, the Health Plans denial should be upheld .Credentials/Qualifications: Physician reviewers 1, 2 & 3 are board certified in radiation oncology and are actively practicing. The reviewers are experts in the treatment of the enrollees medical condition and knowledgeable about the proposed treatment through recent or current actual clinical experience treating those with the same or a similar medical condition.