Real-Time Intra-Fraction Motion Management During Radiation Therapy

POLICY NUMBER

L.2.03.401

DESCRIPTION

This policy discusses the use of real-time intra-fraction target tracking during radiotherapy (“real-time tracking”). These techniques enable adjustment of the target radiation while it is being delivered (i.e., intra-fraction adjustments) to compensate for movement of the organ inside the body. Real-time tracking, which may or may not use radiographic images, is one of many techniques referred to as “image-guided radiotherapy” (IGRT). For this policy, real-time tracking is defined as frequent or continuous target tracking in the treatment room during radiotherapy, with periodic or continuous adjustment to targeting made on the basis of target motion detected by the tracking system. This policy does not address approaches used to optimize consistency of patient positioning in setting up either the overall treatment plan or individual treatment sessions (i.e., inter-fraction adjustments); instead it deals with approaches to monitor target movement within a single treatment session, which includes technologies using respiratory gating. This policy does not address IGRT used as part of stereotactic (body) radiation therapy.

In general, intra-fraction adjustments can be grouped into two categories: online and off-line. An online correction occurs when corrections or actions occur at the time of radiation delivery on the basis of predefined thresholds. An off-line approach refers to target tracking without immediate intervention.

During radiotherapy, it is important to target the tumor so that radiation treatment is delivered to the tumor, but surrounding tissue is spared. This targeting seems increasingly important as dose-escalation is used in an attempt to improve long-term tumor control and improve patient survival. Over time, a number of approaches have evolved to improve targeting of the radiation dose. Better targeting has been achieved through various approaches to radiotherapy, such as 3-D conformal treatment (3D-CRT), and intensity-modulated radiation therapy (IMRT). For prostate cancer, use of a rectal balloon has been reported to improve consistent positioning of the prostate and thus reduce rectal tissue irradiation during radiotherapy treatment of prostate cancer. In addition, more sophisticated imaging techniques, including use of implanted fiducial (radio-opaque) markers, has been used to better position the tumor (patient) as part of treatment planning and individual radiation treatment sessions.

Intra-fraction target motion can be caused by many things including breathing, cardiac and bowel motion, swallowing or sneezing. Data also suggests that a strong relationship may exist between obesity and organ shift, indicating that without some form of target tracking, the target volume may not receive the intended dose for patients who are moderately to severely obese. Respiration affects the position of all thoracic and abdominal organs, primarily the lungs, liver, and breast. The American Association of Physicists in Medicine Task Group 76 recommends motion management for tumor motion that exceeds 5 mm in any direction or if significant normal tissue-sparing can be gained. Measurement of tumor motion commonly uses fluoroscopy or 4-dimensional computed tomography (4D-CT), a sequence of 3D-CT images over time, with or without fiducial markers.

Five principal respiratory motion management techniques are commonly used: integration of respiratory movements (ie, mean tumor position, range of motion) into treatment planning; abdominal compression plates to force shallow breathing; breath-hold, often using spirometry; respiratory gating; and real-time tumor-tracking. Respiratory gating delivers radiation during a particular portion of the breathing cycle. This “gate” is defined by monitoring respiratory motion with external sensors and selecting a constant cycle amplitude or phase (eg, end-inspiration or end-expiration) for radiation delivery. Respiratory gating assumes a consistent association between the respiratory cycle and tumor position. For patients in whom this association is unreliable, real-time target tracking techniques can be used. These techniques involve fluoroscopic, radiograph, or digital tracking of external respiratory surrogates, eg, an abdominal belt, or, like other real-time tumor-tracking techniques described here, implanted fiducial markers.

As previously noted, the next step in this evolving process of improved targeting is the use of devices to track the target (tumor motion) during radiation treatment sessions and allow adjustment of the radiation dose during a session based on tumor movement. Some of the devices cleared by the U.S. Food and Drug Administration (FDA) are referred to as “4-D imaging” (not to be confused with 4D-CT, described earlier). One such device is the Calypso® 4D Localization System (Varian Medical Systems; Palo Alto, CA). This system uses a group of 3 electromagnetic transponders (Beacon®) implanted in or near the tumor to allow continuous localization of a treatment isocenter. Beacon® transponders are 8.5 mm long and have a diameter of 1.85 mm. The 3 transponders have a “field of view” of 14-cm square with a depth of 27 cm.

The Calypso® 4D Localization System obtained FDA clearance for prostate cancer in March 2006 through the 510(k) process (K060906) and for other soft tissue tumors in May 2003 (K080726). This system was considered equivalent to existing devices such as implanted fiducials and other body-positioning technologies.

Respiratory-gating systems by several manufacturers have received FDA-approval, eg, Real-time Position Management™ (RPM, Varian Medical Systems, Palo Alto, CA; K102024), Active Breathing Coordinator System®, (ABC, Aktina, Congers, NY; K003330), and SDX™ (Dyn’R, Toulouse, France; K092479).

This policy does not address IGRT used as part of stereotactic (body) radiation therapy.

POLICY

Real-time intra-fraction target tracking duringradiotherapy to adjust radiation doses or monitor target movement during individual radiation therapy treatment sessions is consideredinvestigational.

Respiratory gating techniques for the delivery of radiotherapy are considered investigational.

POLICY EXCEPTIONS

Federal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

This policy only addresses real-time tracking and devices defined as devices that allow for the adjustment of radiation doses during individual radiation treatment sessions.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting. 

POLICY HISTORY

5/30/2008: Policy added

12/31/2008: Code reference section updated per 2009 CPT/HCPCS revisions 

05/13/2010: Policy title changed from “Image-Guided Radiation Therapy for Prostate Cancer” to “Real-Time Intra-Fraction Target Tracking During Radiation Therapy.”  Terminology used to describe the technology changed in the policy description and statement. Specific references to prostate cancer removed.  Policy statement revised to state that this technology is considered not medically necessary, rather than investigational. Add new CPT codes 32553 and 49411. Revised the description of CPT code 55876. FEP verbiage added to the Policy Exceptions section.

04/13/2011: Policy reviewed; no changes.

02/24/2012: Policy reviewed; no changes.

04/03/2013: Policy reviewed; no changes.

09/16/2014: Policy title revised to change "Target Tracking" to "Motion Management." Policy description updated regarding motion management. Policy statement revised to add "tracking" and change "radiation therapy" to "radiotherapy" and "not medically necessary" to "investigational." Added the following investigational statement: Respiratory gating techniques for the delivery of radiotherapy are considered investigational. Policy guidelines updated to state that this policy only addresses real-time tracking and devices defined as devices that allow for the adjustment of radiation doses during individual radiation treatment sessions.

12/31/2014: Added the following new 2015 HCPCS code to the Code Reference section: G6017.

07/27/2015: Code Reference section updated for ICD-10.

05/03/2016: Investigative definition updated in policy guidelines section. Removed deleted CPT code 0197T from the Code Reference section.

06/08/2016: Policy number L.2.03.401 added.

05/10/2023: Policy reviewed. Policy statements unchanged. Code Reference section updated to change "Not Medically Necessary Codes" to "Investigational Codes."

06/24/2024: Policy reviewed; no changes.

SOURCE(S)

Blue Cross & Blue Shield Association Policy # 2.03.10

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy.

Investigational Codes

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