Medical Policy


Subject: Image-guided Radiation Therapy (IGRT) with External Beam Radiation Therapy (EBRT)
Document #: THER-RAD.00011 Publish Date:    12/27/2017
Status: Reviewed Last Review Date:    11/02/2017


This document addresses image-guided radiation therapy (IGRT) when used in combination with conformal external beam radiation therapy (EBRT).  IGRT refers to pre-treatment imaging used to verify correct positioning of an individual in cases where sub-centimeter accuracy is required.  Multiple technologies may be utilized for IGRT, including ultrasound, computed tomography (CT), continuous intra-fraction position monitoring, and stereoscopic x-ray guidance.

Note: Please see the following related document for additional information:

Note: This document does not address IGRT when used with intensity modulated radiation therapy (IMRT), stereotactic body radiotherapy (SBRT), stereotactic radiosurgery (SRS) or proton beam therapy.

Position Statement

Medically Necessary:

Image guidance for radiation therapy (IGRT) is considered medically necessary in conjunction with external beam radiation therapy (EBRT) when any of the following indications are met:

  1. There is significant setup variation affecting the treatment target, for example:
    1. There is significant organ movement (for example, tumor moves due to respiration) and a 4D planning CT scan was performed with documentation demonstrating that the treatment plan addresses tumor motion that is both accounted for and managed; or
    2. Individual is morbidly-obese (body mass index [BMI] greater than 35) and receiving treatment of tumors in the mediastinum, abdomen or pelvis; or
  2. Implanted fiducial markers have been placed; or
  3. Bony anatomy fails to accurately delineate a tumor location and fiducial markers or intensity modulated radiation therapy (IMRT) are not indicated (for example, head and neck cancer); or
  4. Use of IGRT will allow significant reduction of radiation dose to sensitive normal structures, for example:
    1. Individual is receiving left-sided breast cancer treatment with deep inspiration breath hold technique (DIBH); or
    2. Narrow planning margins are required to reduce treatment-related toxicity; or
  5. The individual’s treatment field abuts a previously irradiated area.

Investigational and Not Medically Necessary:

Image guidance for radiation therapy (IGRT), in conjunction with external beam radiation therapy (EBRT) is considered investigational and not medically necessary when the criteria above are not met and for all other indications.


Published practice guidelines address elements where IGRT may be useful, including use when fiducial markers are placed when the tumor target is not clearly visualized and the bone anatomy is insufficient to align the target area.  To assess intrafraction organ motion, CT images, 4-dimensional (4D) CT imaging, 4D positron emission tomography (PET) imaging and dynamic fluoroscopic imaging of fiducial markers or targets may be utilized (American College of Radiology [ACR]-American Society for Therapeutic Radiology and Oncology [ASTRO], 2014; Potters, 2010).

Image-guided deep inspiration breath hold (DIBH) techniques have been demonstrated to reduce cardiac exposure to radiation.  The feasibility of IGRT for cardiac sparing in individuals with left-sided breast cancer was investigated in a prospective study authored by Borst and colleagues (2010).  A total of 19 women with left-sided breast cancer were treated with the DIBH technique during IGRT.  Use of DIBH in these subjects reduced mean cardiac dose (1.7 Gy vs. 5.1 Gy), the maximum dose (37 Gy vs. 49 Gy) and the volume of heart receiving 30 Gy (0.3 cc vs. 6.3 cc) compared with the free breathing technique.  Similar results have been described in a larger series recently published by Comsa and colleagues (2014; n=50).  In these participants, the D10cc was reduced from 34.8 Gy for the free breathing group to 6.7 Gy for the DIBH group (p<0.001).

Liao (2010) reported a retrospective nonrandomized comparative study of 4D-CT simulation (CT imaging combined with respiratory gating) IMRT (4D-CT/IMRT) and 3D-CRT for disease outcomes and toxicities in 409 subjects with locally advanced and unresectable non-small cell lung cancer (NSCLC) treated at a single institution with concomitant chemotherapy.  Both groups received a median dose of 63 Gy.  The study included 318 subjects who received 3D-CRT and chemotherapy between 1999-2004, and 91 subjects who received 4D-CT/IMRT and chemotherapy from 2004-2006.  Mean follow-up times in the 3D-CRT group were 2.1 years (range 0.1-7.9) and 1.3 years (range 0.1-3.2) for the 4D-CT/IMRT group.  Locoregional progression (LRP), distant metastases (DM), and overall survival (OS) were compared.  While the rates of LRP (p=0.37) and DM (p=0.81) were not different between the two treatment groups, OS was significantly better in the 4D-CT/IMRT group (p=0.039).  The lung mean dose in this comparison was similar in the two treatment groups, however the V20 (volume of lung receiving 20 Gy) was higher in the 3D-CRT group (p=0.0013) and the incidence (79/371 for both groups combined) of Grade 3 or greater radiation pneumonitis was significantly less for the 4D-CT/IMRT group (p=0.017).  Based on this study and clinical expert input received, in individuals where long term side effects of increased radiation are a significant concern, the use of IGRT may be appropriate in the treatment of primary lung cancers when the treatment plan demonstrates reductions in the dose to normal lung tissue, and lung motion is adequately accounted for and addressed.

Wong and colleagues (2009) reported data from a retrospective study of the correlation of elevated body mass index (BMI) and deviations from the radiation beam isocenters.  The subgroups were normal weight, overweight, mildly obese and severely obese.  Comparison of daily displacements demonstrated obese individuals had larger (>10 mm) shifts in prostate position.  In individuals who were morbidly obese, there was a significantly higher frequency (50%) of the radius shift compared to the other groups (8-18%).  Given the high frequency of organ shift for obese and severely obese individuals, the authors concluded these individuals may be at higher risk for treatment failure.  Therefore, the use of IGRT for this cohort of individuals was recommended.

In a retrospective nonrandomized single center study, a total of 186 men with prostate cancer were enrolled with fiducial markers placed for treatment with radiotherapy and IGRT.  Outcomes from this group were compared to a cohort of 190 similar individuals with prostate cancer who were treated at the same center with IMRT at the same radiotherapy dose and no fiducial markers utilized (non-IGRT cohort).  With a median follow-up of 2.8 years (range, 2-4 years), the IGRT cohort had significant improvement in biochemical control in high-risk individuals at 3-years with IGRT versus non-IGRT (97% vs. 77.7%, respectively; p=0.05).  IGRT also demonstrated significantly less acute and late genitourinary toxicities compared to the non-IGRT group (p=0.05 and p=0.02, respectively).  The authors suggest the use of fiducial markers and IGRT may be a preferred mode for delivery of EBRT for prostate cancer.  The results will need to be validated in prospective studies (Zelefsky, 2012).

The ASTRO’s Image guided radiation therapy coding and physician supervision guidelines (2013) states:

IGRT allows radiation oncologists to ensure that the target volume is treated with the planned dose of radiation. Whenever a target volume is located near or within critical structures and/or in tissue with inherent setup variation, IGRT may be indicated to further the therapeutic ratio. Such situations include where:

In the National Comprehensive Cancer Network® (NCCN) Clinical Practice Guidelines in Oncology® there are 2A recommendations for the use IGRT to (1) “deliver adequate tumor doses while respecting normal tissue dose constraints” (Small Cell Lung Cancer V1.2017), (2) when organs at risk are in close proximity to high dose regions, (3) complex motion management techniques are being used, or (4) to decrease the planning target volume (PTV) (Non-Small Cell Lung Cancer V9.2017).

Multiple publications have documented the additional radiation exposure which occurs in conjunction with IGRT.  The ACR-ASTRO (2014) practice parameter reports:

The imaging dose per-image ranges from 0.1 to 0.6 mGy for planar kV imaging, 1 to 3 mGy for MV planar imaging, and 10 to 50 mGy for 3D X-ray imaging. For 4-D image acquisition or tracking with radiation-based systems, accumulated dose from these imaging should be evaluated, eg, imaging dose from fluoroscopy can reach over 1,000 mGy/hour.

As with any medical procedure, the risks of this exposure must be weighed against the benefits of daily imaging.  Given the lack of demonstrable benefit of using IGRT for every radiation therapy session, there are concerns about potential harms of this technology when used outside the IMRT and SBRT setting.  Even in clinical scenarios where IGRT is considered medically necessary, the technique chosen should expose the individual to the minimum amount of radiation needed to achieve adequate visualization.


According to the ACR-ASTRO practice parameters (2014), IGRT is a procedure that is separate from the actual radiation therapy, and “…refines the delivery of therapeutic radiation by applying image-based target relocalization to allow proper patient repositioning for the purpose of ensuring accurate treatment and minimizing the volume of normal tissue exposed to ionizing radiation.”  Various imaging modalities may be utilized in an IGRT system, for example images obtained by ultrasound, CT scan, and kV imaging.  The radiation oncologist collaborates with a medical physicist and dosimetrist to develop the treatment plan.

IGRT has proven an effective method for improving the accuracy and efficacy of radiation therapy with select radiation procedures and is deemed an integral part of the delivery of highly conformal treatments such as IMRT, SBRT and SRS.


External beam radiation therapy (EBRT): A form of radiation therapy (such as, three dimensional conformal radiation therapy [3D-CRT]) which is used to stop the growth of cancer cells. A linear accelerator directs a photon or electron beam from outside the body through normal or healthy body tissue to reach the cancer.  The radiation is typically given 5 days a week for a period of 3 to 8 weeks.


The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services may be Medically Necessary when criteria are met:
For the following procedure codes when done in conjunction with external beam radiation treatment delivery





Computed tomography guidance for placement of radiation therapy fields



Guidance for localization of target volume for delivery of radiation treatment delivery, includes intrafraction tracking, when performed









Ultrasonic guidance for placement of radiation therapy fields



Stereoscopic X-ray guidance for localization of target volume for the delivery of radiation therapy



Intra-fraction localization and tracking of target or patient motion during delivery of radiation therapy (eg, 3D positional tracking, gating, 3D surface tracking), each fraction of treatment



ICD-10 Diagnosis



All diagnoses

When services are Investigational and Not Medically Necessary:
For the procedure codes listed above when criteria are not met or when the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.


Peer Reviewed Publications:

  1. Alcorn SR, Chen MJ, Claude L, et al. Practice patterns of photon and proton pediatric image guided radiation treatment: results from an International Pediatric Research consortium. Pract Radiat Oncol. 2014; 4(5):336-341.
  2. Andersen ES, Noe KO, Sørensen TS, et al. Simple DVH parameter addition as compared to deformable registration for bladder dose accumulation in cervix cancer brachytherapy. Radiother Oncol. 2013; 107(1):52-57.
  3. Borst GR, Sonke JJ, den Hollander S, et al. Clinical results of image-guided deep inspiration breath hold breast irradiation. Int J Radiat Oncol Biol Phys. 2010; 78(5):1345-1351.
  4. Comsa D, Barnett E, Le K, et al. Introduction of moderate deep inspiration breath hold for radiation therapy of left breast: Initial experience of a regional cancer center. Pract Radiat Oncol. 2014; 4(5):298-305.
  5. Hou J, Guerrero M, Suntharalingam M, et al. Response assessment in locally advanced head and neck cancer based on RECIST and volume measurements using cone beam CT images. Technol Cancer Res Treat. 2015; 14(1):19-27.
  6. Liao ZX, Komaki RR, Thames HD Jr, et al. Influence of technologic advances on outcomes in patients with unresectable, locally advanced non-small-cell lung cancer receiving concomitant chemoradiotherapy. Int J Radiat Oncol Biol Phys. 2010; 76(3):775-781.
  7. Mohammed N, Kestin L, Ghilezan M, et al. Comparison of acute and late toxicities for three modern high-dose radiation treatment techniques for localized prostate cancer. Int J Radiat Oncol Biol Phys. 2012; 82(1):204-212.
  8. Ricardi U, Franco P, Munoz F, et al. Three-dimensional ultrasound-based image-guided hypofractionated radiotherapy for intermediate-risk prostate cancer: results of a consecutive case series. Cancer Invest. 2015; 33(2):23-28.
  9. Tharavichitkul E, Sivasomboon C, Wanwilairat S, et al. Preliminary results of MRI-guided brachytherapy in cervical carcinoma: the Chiangmai University experience. J Radiat Res. 2012; 53(2):313-318.
  10. Wong JR, Gao Z, Merrick S, et al. Potential for higher treatment failure in obese patients: correlation of elevated body mass index and increased daily prostate deviations from the radiation beam isocenters in an analysis of 1,465 computed tomographic images. Int J Radiat Oncol Biol Phys. 2009; 75(1):49-55.
  11. Zelefsky MJ, Kollmeier M, Cox B, et al. Improved clinical outcomes with high-dose image guided radiotherapy compared with non-IGRT for the treatment of clinically localized prostate cancer. Int J Radiat Oncol Biol Phys. 2012; 84(1):125-129.

Government Agency, Medical Society, and Other Authoritative Publications:

  1. American College of Radiology (ACR)-American Society for Therapeutic Radiology and Oncology (ASTRO) Practice Parameter for Image-guided Radiation Therapy (IGRT). Revised 2014. Available at: Accessed on September 29, 2017.
  2. ASTRO. Image guided radiation therapy coding and physician supervision guidelines. 2013. Available at:  Accessed on September 29, 2017.
  3. NCCN Clinical Practice Guidelines in Oncology®. © 2017. National Comprehensive Cancer Network, Inc. For additional information: Accessed on September 29, 2017.
    • Non-small Cell Lung Cancer (V9.2017). Revised September 28, 2017.
    • Small Cell Lung Cancer (V1.2018). Revised September 18, 2017.
  4. Potters L, Gaspar LE, Kavanagh B, et al. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) practice guidelines for image-guided radiation therapy (IGRT). Int J Radiat Oncol Biol Phys. 2010; 76(2):319-325.
Websites for Additional Information
  1. American Cancer Society (ACS). Available at: Accessed on September 29, 2017.
  2. National Cancer Institute (NCI). Radiation therapy for cancer. Reviewed June 30, 2010. Available at: Accessed on September 29, 2017.

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Document History






Medical Policy & Technology Assessment Committee (MPTAC) review.



Hematology/Oncology Subcommittee Meeting review. Updated header language from “Current Effective Date” to “Publish Date.” Updated References section.



MPTAC review.



Hematology/Oncology Subcommittee Meeting review. Updated formatting in Position Statement section. Updated References section.



MPTAC review.



Hematology/Oncology Subcommittee Meeting review.  Initial document development.