Intensity modulated radiation therapy (IMRT) refers to a technique of conformal radiation planning and delivery, in which non-uniform intensity beams produce unique radiation dose distributions that are designed to better target the lesion with better sparing of surrounding normal tissue than with conventional radiation therapy, thereby limiting side effects. IMRT also allows for dose escalation, when clinically appropriate, which can improve local control of a tumor. 

Medically Necessary:

IMRT of the prostate is considered medically necessary in patients with non-metastatic prostate cancer for dose escalation >75 Gy.

IMRT is considered medically necessary in the treatment of patients with head and neck cancer, with the exception of patients with early stage larynx cancer (stage I and II).

IMRT is considered medically necessary in patients with CNS lesions with close proximity to the optic nerve or brain stem.

IMRT is considered medically necessary in patients with pediatric tumors (e.g., Ewing Sarcoma, Wilms’ Tumor).

Investigational/Not Medically Necessary:

IMRT is considered investigational/not medically necessary in patients with all other types of cancer including, but not limited to, lung cancer, breast cancer, abdominal cancers and cancers of unknown primary.

Rationale

While IMRT is a rapidly evolving technique, which affords a more precise radiation dose delivery of escalated doses, in appropriate cases, to targeted tumors, while sparing nearby healthy tissue structures.  The FDA clearance of numerous devices for the technical delivery of IMRT is based on the capability of this technology to incorporate accurate dose calculation algorithms, associated with a verifiable dose distribution, as managed by the treating physician, (i.e., radiation oncologist). 

For every normal tissue in the human body, the risk of developing a radiation-induced complication is a function of the dose of radiation delivered and the volume of tissue irradiated. The risk of normal tissue complications after treatment of prostate cancer with three-dimensional conformal radiation therapy (3D-CRT) is a clinically significant problem. The available data suggest that the IMRT technique is associated with improved health outcomes in patients with prostate cancer and head and neck cancer.

In prostate cancer, IMRT allows delivery of higher doses of radiation therapy up to 84 Gy (Gray), which may be associated with improved local control.  In head and neck cancer, conventional 3D conformal radiation therapy is not feasible, due to the typically concave shape of the radiation fields. However, the risk of xerostomia, due to salivary gland damage after radiation treatment of head and neck cancers with conventional radiation therapy (CRT), is a clinically significant problem that can result in speech and swallowing dysfunction, nutritional deficiency, oral ulcers, dental carries and osteoradionecrosis of the mandible and maxilla, (when treating cancers of multiple locations and cancers of unknown primary site requiring treatment of large areas). Recent dosimetry studies of head and neck cancer cases, using both CRT and IMRT with comparisons using dose volume histogram (DVH) analysis, would appear to demonstrate that use of IMRT reduces the amount of radiation received by surrounding normal tissue, providing better parotid gland sparing. 

Although, to date, no randomized trials have matured to document long-term outcomes data and efficacy for IMRT, the scientific evidence currently available indicates that IMRT permits better treatment planning and sparing of surrounding tissues, which is of particular usefulness with “Radiosensitive” tumors of the head/neck, prostate and CNS lesions where the target volume is in close proximity to critical healthy structures that must be protected.   These results may be extrapolated to the treatment of other cancers at other anatomic sites; however, a number of technical issues need to be resolved before IMRT can be recommended for broader use, particularly the issue of tumor mobility must be addressed, (e.g., a lung tumor moving with respiration or a prostate that shifts, due to stool in the rectum or urine in the bladder).

Background/Overview

Intensity modulated radiation therapy (IMRT) refers to a technique of conformal radiation planning and delivery that is designed to better target the lesion, while sparing surrounding normal tissue.  The reduced morbidity, which is the expected outcome of IMRT, may also permit higher dosing to the target lesions, thus reducing the risk of local recurrence.  One distinguishing feature of IMRT is that the radiation fluence varies across the beam, in contrast to conventional radiation therapy in which a homogeneous radiation dose is delivered to the tumor target, minimally modulated by the use of traditional wedges, blocks and compensators.  Specifically, in IMRT, non-uniform intensities are assigned to tiny subdivisions of beams, called "beamlets," enabling custom design of optimum dose distributions.

Definitions

Brachytherapy: a type of radiation therapy is which radioactive materials are placed in direct contact with the tissue being treated

Gy (Gray): the new international system unit of absorbed dose of radiation

Radiation therapy: treatment with high energy radiation from X-rays or other sources of radiation

Xerostomia: a dryness of the mouth

Coding

The following codes for treatments and procedures applicable to this policy 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 are Medically Necessary: 

CPT    

ICD-9 Diagnosis

When services may be Medically Necessary when criteria are met:  

For the procedure codes listed above, for the following diagnoses:

ICD-9 Diagnosis    

When services are Investigational/Not Medically Necessary:

For the procedure codes listed above, for all other diagnosis not listed; or when the code describes a procedure indicated in the Policy section as investigational/not medically necessary.

References

Peer Reviewed Publications:

1. Adams EJ, Nutting CM, Convery DJ, et al.  Potential role of intensity modulated radiotherapy in the treatment of tumors of the maxillary sinus.  Int J Radiat Oncol Biol Phys. 2001; 51:579-588. 
2. Allen, AM, Czerminska, MS, Janne, PA, et al. Fatal pneumonitis associated with intensity-modulated radiation therapy for mesothelioma.  Int. J. Radiation Oncology Biol. Phys. 2006; 65(3):640-645.
3. Baxter NN, Tepper JE, Durham SB, et al. Increased risk of rectal cancer after prostate radiation: a population-based study.  Gastroenterology. 2005; 128(4):819-824. 
4. Brizel DM. Does amifostine have a role in chemoradiation treatment? Lancet. 2003; 4:378-381. (Also in: J Clin Oncol. 2000; 18(19):3339-3345.)
5. Chan HM, Zelefsky MJ, Fuks Z, et al. Long-term outcome of high dose intensity modulated radiotherapy for clinically localized prostate cancer.  Int J Radiat Oncol Biol Phys. 2004; 60(1 Suppl):S169-S170.
6. Chang SX, Cullip TJ, Deschesne KM, et al. Compensators: an alternative IMRT delivery technique.  J Appl Clin Med Phys. 2004 Summer; 5(3):15-36.
7. Chao KS, Majhail N, Huang CJ, et al.  Intensity modulated radiation therapy reduces late salivary toxicity without compromising tumor control in patients with oropharyngeal carcinoma: A comparison with conventional techniques.  Radiother Oncol. 2001; 61:275-280. 
8. Coles CE, Moody AM, Wilson CB, et al. Reduction of radiotherapy-induced late complications in early breast cancer: The role of intensity-modulated radiation therapy and partial breast irradiation.  Part II – Radiotherapy strategies to reduce radiation-induced late effects.  Clin Oncol. (R Coll Radiol). 2005; 17(2):98-110.
9. Cozzi L, Fogliata A, Lomax A, Bolsi A.  A treatment planning comparison of 3D conformal therapy, intensity modulated photon therapy and proton therapy for treatment of advanced head and neck tumours.  Radiother Oncol. 2001; 61:287-297.  
10. Creutzberg CL, van Putten WLJ, Koper PC, et al. The morbidity of treatment for patients with stage I endometrial cancer: results from a randomized trial.  Int J Radiat Oncol Biol Phys. 2001; 51(5):1246-1255.
11. Critz FA, Levinson K. 10-year disease-free survival rates after simultaneous irradiation for prostate cancer with a focus on calculation methodology.  J Urol. 2004; 172(6 Pt 1):2232-2238.
12. Dearnaley DP, Hall E, Lawrence D, et al. Phase III pilot study of dose escalation using conformal radiotherapy in prostate cancer: PSA control and side effects.  Br J Radiol. 2005; 92(3):988-998.
13. De Meerleer G, Vakaet L, De Gersem W, et al. Radiotherapy of prostate cancer with and without intensity modulated beams: a planning comparison.  Int J Radiat Oncol Biol Phys. 2000; 47:639-648.
14. Ding M, Newman F, Raben D. New radiation therapy techniques for the treatment of head and neck cancer.  Otolaryngol Clin N Am. 2005; 38:371-395.
15. Eisbruch A, Kim HM, Terrell JE, et al. Xerostomia and its predictors following parotid-sparing irradiation of head-and-neck cancer. Int J Radiat Oncol Biol Phys. 2001; 50:695-704. 
16. Fonteyne V, Vakaet L, Villeirs G, et al. Intensity-modulated radiotherapy (IMRT) as primary therapy for prostate cancer – Part 2: late toxicity.  2006 Prostate Cancer Symposium, Alexandria, VA. 
17. Giordano SH, Kuo Y, Freeman JL, et al. Risk of cardiac death after adjuvant radiotherapy for breast cancer.  J Natl Cancer Inst.  2005; 97:419-424.
18. Guerrero Urbano MT, Nutting CM. Clinical use of intensity-modulated radiotherapy: Part I.  Brit J Radiol. 2004a; 77:88-96.
19. Guerrero Urbano MT, Nutting CM. Clinical use of intensity-modulated radiotherapy: Part II. Brit J Radiol. 2004b; 77:177-182.
20. Hurksmans CW, et al. Reduction of cardiac and lung complication probabilities after breast irradiation using conformal radiotherapy with or without intensity modulation. Radiother Oncol. 2002; 62(2):163-171. 
21. Kam MK, Leung SF, Zee B, et al. Impact of intensity-modulated radiotherapy (IMRT) on salivary gland function in early stage nasopharyngeal carcinoma (NPC) patients: a prospective randomized study.  Proc of ASCO. 2005; Suppl. Abstract No. 5501.
22. Kavanagh BD, Schefter TE, Wu, O, et al. Clinical application of intensity-modulated radiotherapy for locally advanced cervical cancer. Semin Radiat Oncol. 2002; 12(3):260-271.
23. Kruger, EA, Fraas BA, Pierce LJ. Clinical aspects of intensity-modulated radiotherapy in the treatment of breast cancer. Semin Radiat Oncol. 2002; 12(3):250-259.
24. Nutting CM, Convery DJ, Cosgrove VP, et al.  Improvements in target coverage and reduced spinal cord irradiation using intensity-modulated radiotherapy in patients with carcinoma of the thyroid gland.  Radiother Oncol. 2001; 60:173-180. 
25. Nutting CM, Rowbottom CG, Cosgrove VP, et al.  Optimisation of radiotherapy for carcinoma of the parotid gland: A comparison of conventional, three dimensional conformal and intensity-modulated technique.  Radiother Oncol. 2001; 60:163-170.
26. Palchoke HD, et al. Comment: compared IMRT and CRT treated patients using a validated xerostomia scoring system. Am J Clin Oncol. 2005; 28(4):351-358.
27. Penagaricano JA, Papanikolaou N, Yan Y, et al. Application of intensity-modulated radiation therapy for pediatric malignancies.  Med Dosim. 2004; 29(4):247-253.
28. Peschel RE, Colberg JW. Surgery, brachytherapy, and external-beam radiotherapy for early prostate cancer.  Lancet. 2003; 4:233-241. 
29. Pollack A, Zagars GK, Starkschall G, et al. Prostate cancer radiation dose response: results of the M.D. Anderson Phase III randomized trial.  Int J Radiat Oncol Biol Phys. 2002; 53(5):1097-1105.
30. Pollack A, Hanlon A, Horwitz EM, et al. Radiation therapy dose escalation for prostate cancer: a rationale for IMRT.  World J Urol. 2003; 21(4):200-208.
31. Roach M. Reducing the toxicity associated with the use of radiotherapy in men with localized prostate cancer.  Urol Clin N Am. 2004; 31:353-366.
32. Rudat V, Munter M, Rades D, et al. The effect of amifostine or IMRT to preserve the parotid function after radiotherapy of the head and neck region.  Proc of ASCO. 2005; Suppl. Abstract No. 5502.
33. Smith RP, Heron DE, Huq MS, Yue NJ. Modern radiation treatment planning and delivery – from Rontgen to real time.  Hematol Oncol Clin N Am. 2006; 20:45-62.
34. Ting JY, Scarbrough TJ. Intensity-modulated radiation therapy and image-guided radiation therapy: small clinic implementation.  Hematol Oncol Clin N Am. 2006; 20:63-86.
35. Zelefsky MJ, Fuks Z, Hunt M, et al.  High dose radiation delivered by intensity modulated conformal radiotherapy improves the outcomes of localized prostate cancer.  J Urol. 2001; 166(3):876-881.
36. Zelefsky MJ, Fuks Z, Happensett L, et al. Clinical experience with intensity-modulated radiation therapy (IMRT) in prostate cancer.  Radiotherapy and Oncol. 2000; 55:241-249.
37. Zelefsky MJ, Fuks Z, Leibel SA. Intensity-modulated radiation therapy for prostate cancer.  Seminars Rad Oncol. 2002a; 12:229-237.
38. Zelefsky MJ, Fuks Z, Hunt M, et al. High-dose intensity modulated radiation therapy for prostate cancer: early toxicity and biochemical outcome in 772 patients.  Int J Radiat Oncol Biol Phys. 2002b; 53(5):1111-1116.
39. Zietman AL, DeSilvio M, Slater JD, et al. A randomized trial comparing conventional dose (70.2 GyE) and high dose (79.2 GyE) conformal radiation in early stage adenocarcinoma of the prostate: results of an interim analysis of PROG 95-09.  Int J Radiat Oncol Biol Phys. 2004; 60(1 Suppl):S131-S132. 

Government Agency, Medical Society, and Other Authoritative Publications:

1. American College of Radiology (ACR).  ACR Practice Guideline for Intensity Modulated Radiation Therapy.  2002 (Res. 17).  ACR Practice Guideline.  Reston, VA: ACR; effective January 1, 2003:705-710.  Available at:
   http://www.acr.org/s_acr/bin.asp?TrackID=&SID=1&DID=12234&CID=1075&VID=2&DOC=File.PDF  Accessed on April 4, 2007.
2. American Society for Therapeutic Radiology and Oncology (ASTRO).  Available at: http://www.astro.org/publications.  Accessed on April 4, 2007.
3. Blue Cross Blue Shield Association.  Special Report: Intensity Modulation Radiation Therapy for Cancer of the Breast or Lung.  TEC Assessment.  Chicago, IL.  December 2005; 20(13).
4. National Comprehensive Cancer Network (NCCN).  Clinical Guidelines in Oncology. Prostate cancer v.2.2005. Rockledge, PA: NCCN; 2005.  Available at: http://www.nccn.org/professionals/physician_gls/PDF/prostate.pdf.  Accessed on April 4, 2007.
5. National Comprehensive Cancer Network (NCCN).  Clinical guidelines in Oncology.  Breast cancer v.2.2006.  Rockledge, PA: NCCN; 2006.  Available at: http://www.nccn.org/professionals/physician_gls/PDF/breast.pdf.  Accessed on April 4, 2007.
6. National Cancer Institute (NCI).  Intensity-modulated radiotherapy: current status and issues of interest.  Intensity Modulated Radiation Therapy Collaborative Working Group. Int J Rad Oncol Biol Phys. 2001; 51(4):880-914.  Available at: http://www3.cancer.gov/rrp/Documents/IMRT.pdf.  Accessed on April 4, 2007.
7. National Cancer Institute (NCI). The National Cancer Institute Guidelines for the use of Intensity-Modulated Radiation Therapy in Clinical Trials.  Bethesda, MD: NCI; January 14, 2005.  Available at: http://www3.cancer.gov/rrp/imrt2004.pdf.  Accessed on April 4, 2007.

1. Radiological Society of North America, Inc. (RSNA).  Intensity-modulated radiotherapy IMRT.  Available at: http://www.radiologyinfo.org/pdf/imrt.pdf.  Accessed on April 4, 2007.

Index

Intensity Modulated Radiation Therapy (IMRT)
Tomotherapy

Policy History

Federal and State law, as well as contract language, including definitions and specific contract provisions/exclusions, take precedence over Medical Policy and must be considered first in determining eligibility for coverage. The member's contract benefits in effect on the date that services are rendered must be used. Medical Policy, which addresses medical efficacy, should be considered before utilizing medical opinion in adjudication. Medical technology is constantly evolving, and we reserve the right to review and update Medical Policy periodically.

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