Charged-particle beams consisting of protons or helium ions are a type of particulate radiation therapy. They contrast with conventional electromagnetic (i.e., photon) radiation therapy due to several unique properties including minimal scatter as particulate beams pass through tissue, and deposition of ionizing energy at precise depths (i.e., the Bragg peak). Thus, radiation exposure of surrounding normal tissues is minimized. The theoretical advantages of protons and other charged-particle beams may improve outcomes when the following conditions apply:

• Conventional treatment modalities do not provide adequate local tumor control;
• Evidence shows that local tumor response depends on the dose of radiation delivered; and
• Delivery of adequate radiation doses to the tumor is limited by the proximity of vital radiosensitive tissues or structures.

The use of proton or helium ion radiation therapy has been investigated in 2 general categories of tumors/abnormalities:

1. Tumors located near vital structures, such as intracranial lesions or lesions along the axial skeleton, such that complete surgical excision or adequate doses of conventional radiation therapy are impossible. These tumors/lesions include uveal melanomas, chordomas, and chondrosarcomas at the base of the skull and along the axial skeleton.

2. Tumors that are associated with a high rate of local recurrence despite maximal doses of conventional radiation therapy. The most common tumor in this group is locally advanced prostate cancer (i.e., Stages C or D1 [without distant metastases], also classified as T3 or T4). These patients are generally not candidates for surgical resection, and the 5- and 10-year local recurrence rate associated with conventional radiation is estimated at 24%–28% and 39%–42%, respectively.

Note: The use of proton or helium radiation in conjunction with stereotactic guidance for central nervous system (CNS) applications is addressed in a separate policy on stereotactic radiosurgery (policy No. 6.01.10 ).

Charged-particle irradiation with proton or helium ion beams may be considered medically necessary in the following clinical situations:

• primary therapy for melanoma of the uveal tract (iris, choroid, or ciliary body), with no evidence of metastasis or extrascleral extension, and with tumors up to 24 mm in largest diameter and 14 mm in height;

• postoperative therapy (with or without conventional high-energy x-rays) in patients who have undergone biopsy or partial resection of chordoma or low-grade (I or II) chondrosarcoma of the basisphenoid region (skull-base chordoma or chondrosarcoma) or cervical spine. Patients eligible for this treatment have residual localized tumor without evidence of metastasis.

Charged-particle irradiation with proton beams using standard treatment doses is considered not medically necessary in patients with clinically localized prostate cancer, because the clinical outcomes with this treatment have not been shown to be superior to other approaches including intensity modulated radiation therapy (IMRT) or conformal radiation therapy yet proton beam therapy is generally more costly than these alternatives. (See Benefit Application section for contractural items that may impact use in this condition.)

Other applications of charged-particle irradiation are considered investigational.

The use of proton beam or helium ion radiation therapy typically consists of a series of CPT codes describing the individual steps required: medical radiation physics, clinical treatment planning, treatment delivery, and clinical treatment management. It should be noted that the code for treatment delivery primarily reflects the costs related to the energy source used and not physician work. The following CPT codes have been used:

Medical radiation physics

77399: Unlisted procedure, medical radiation physics, dosimetry, and treatment devices, and special services

Clinical Treatment Planning

77299: Unlisted procedure, therapeutic radiology clinical treatment planning

Treatment delivery

The codes used for treatment delivery will depend on the energy source used, typically either photons or protons. For photons (i.e., with a Gamma Knife or LINAC device) nonspecific radiation therapy treatment delivery CPT codes may be used based on the voltage of the energy source (i.e., codes 77402–77416). When proton beam therapy is used the following specific CPT codes are available:

77520: Proton treatment delivery; simple, without compensation

77522: Proton treatment delivery; simple with compensation

77523: Proton treatment delivery; intermediate

77525: Proton treatment delivery; complex

Note: Codes for treatment delivery primarily reflect the costs related to the energy source used, and not physician work.

Clinical treatment management

77499: Unlisted procedure, therapeutic radiology treatment management

Note: If stereotactic guidance is used, please refer to policy No. 6.01.10

BlueCard/National Account Issues

Charged particle radiation therapy is a specialized procedure that may require out of network referral.

Because proton beam therapy is generally more costly than alternative therapies but has not been shown to lead to improved outcomes compared to those obtained with alternatives, it is considered not medically necessary using the MPRM medical necessity definition.
For contracts that do not use this definition of medical necessity, other contract provisions including contract language concerning use of out of network providers and services may be applied. That is, if the alternative therapies (e.g., IMRT or conformal treatments) are available in-network but proton beam therapy is not, proton beam therapy would not be considered an in-network benefit. In addition, benefit or contract language describing the "least costly alternative" may also be applicable for this choice of treatment.

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Charged Particle (Proton or Helium Ion) Irradiation
Helium Ion or Proton Beam Radiotherapy
Irradiation, Charged Particle (Proton or Helium Ion)
Proton or Helium Ion Beam Radiotherapy