Intensity-modulated radiotherapy (IMRT) allows adequate dosing to the tumor while minimizing radiation exposure to surrounding normal tissues and critical structures, especially the heart in left-sided breast cancer. Using CT and magnetic resonance imaging (MRI), IMRT offers better dose conformality than 3-dimensional conformal radiation therapy (3D CRT) through its ability to modulate the intensity of overlapping radiation beams. The radiation oncologist delineates the target on each CT slice and specifies the prescribed radiation dose, adjacent normal tissue volumes to avoid, and acceptable dose limits. Using these parameters and digitally reconstructed radiographic images of the tumor, surrounding tissues, and organs at risk, computer software optimizes the location, shape and intensity of the radiation beams to achieve the treatment goals. Enhanced conformality may allow escalation of tumor doses without increasing toxicity, potentially improving local tumor control and reducing both acute and late radiation toxicities. Improved dose homogeneity within the target may also further reduce the risk of underdosing the tumor or overdosing normal tissues.

BCBST uses MCG Care Guidelines for all other uses of IMRT - Intensity Modulated Radiation Therapy (IMRT) ACG: A-0455

POLICY

Intensity-modulated radiotherapy (IMRT) is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
Intensity-modulated radiotherapy (IMRT) for palliative treatment of lung cancer is considered investigational.
Intensity-modulated radiotherapy (IMRT) for the treatment of the following is considered investigational:
- Partial breast irradiation after breast-conserving surgery
- Irradiation of the chest wall post-mastectomy

MEDICAL APPROPRIATENESS

Intensity-modulated radiotherapy (IMRT) is considered medically appropriate if ANY ONE of the following are met:
- Whole-breast irradiation for left-sided breast cancer if ALL of the following are met:
  - Individual had breast-conserving surgery
  - Significant cardiac radiation exposure cannot be avoided using alternative radiation techniques
- Whole-breast irradiation in individuals with large breasts if ALL of the following are met:
  - Individual had breast-conserving surgery
  - Documentation in medical records state that 3-D conformal radiation therapy cannot achieve adequate precision and will result in hot spots (focal regions with dose variation greater than 10% of target)
- Treatment is indicated for lung cancer if ALL of the following are met:
  - Intent is curative
  - Documentation in the medical records state 3-dimensional (3-D) conformal radiation therapy will expose greater than 35% of normal lung tissue to more than 20 Gy dose-volume and IMRT demonstrates a reduction in normal tissue exposure by a minimum of 10%

IMPORTANT REMINDERS

Any specific products referenced in this policy are just examples and are intended for illustrative purposes only. It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available. These examples are contained in the parenthetical e.g. statement.
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan or government program (e.g., TennCare), the express terms of the health plan or government program will govern.

ADDITIONAL INFORMATION

Studies on IMRT for partial-breast irradiation are limited and have not demonstrated improvements in health outcomes. No studies have reported on health outcomes after IMRT for chest wall irradiation in post-mastectomy cases.

SOURCES

American Society for Radiation Oncology. (2020). Radiation therapy for small cell lung cancer: an ASTRO clinical practice guideline. Retrieved November 11, 2022 from https://www.astro.org/.

American Society for Radiation Oncology. (2024). Partial breast irradiation for patients with early-stage invasive breast cancer or ductal carcinoma in situ: an ASTRO clinical guideline. Retrieved February 13, 2026 from https://www.astro.org/.

BlueCross BlueShield Association. Evidence Positioning System. (8:2025). Intensity-modulated radiotherapy of the breast and lung. (8.01.46). Retrieved February 13, 2026 from www.bcbsaoca.com/eps/. (40 articles and/or guidelines reviewed)

CMS.gov: Centers for Medicare & Medicaid Services. Palmetto GBA. (2025, December). Radiation Therapies. (LCD ID L39553). Retrieved February 13, 2026 from https://www.cms.gov.

Hanna, S. A., Mota, B. S., Moraes, F. Y., Marta, G. N., Carvalho, H. A., & Riera, R. (2024). Intensity-modulated radiation therapy for early-stage breast cancer: a systematic review and meta-analysis. Sao Paulo Medical Journal, 143 (1), doi: 10.1590/1516-3180. (Level 1 evidence)

Livi, L., Meattini, I., Marrazzo, L., Simontacchi, G., Pallotta, S., Saieva, C., et al. (2015). Accelerated partial breast irradiation using intensity-modulated radiotherapy versus whole breast irradiation: 5-year survival analysis of a phase 3 randomised controlled trial. European Journal of Cancer, 51 (4), 451-463. Abstract retrieved June 27, 2016 from PubMed database.

National Comprehensive Cancer Network. (2025, December). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Non-small cell lung cancer, V3.2026. Retrieved February 13, 2026 from the National Comprehensive Cancer Network.

National Comprehensive Cancer Network. (2026, January). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Breast cancer, V1.2026. Retrieved February 13, 2026 from the National Comprehensive Cancer Network.

National Comprehensive Cancer Network. (2025, September). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Small cell lung cancer, V2.2026. Retrieved February 13, 2026 from the National Comprehensive Cancer Network.

ORIGINAL EFFECTIVE DATE: 11/18/2015

MOST RECENT REVIEW DATE: 4/9/2026

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Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.

This document has been classified as public information.