Blue Cross and Blue Shield of Montana (BCBSMT) considers intensity-modulated radiation therapy (IMRT) medically necessary in the treatment of localized prostate cancer. The standard radiation dose for IMRT of the prostate is 75 to 80 Gy.
The National Comprehensive Cancer Network (NCCN) guidelines for prostate cancer (v.2.2009) indicate “no further workup or treatment” for those patients with prostate cancer and a life expectancy of 5 years or less who are asymptomatic until symptoms occur. An exception is noted for the “high-risk patient” where high-risk factors include bulky T3-T4 disease or Gleason score 8–10. In these high-risk patients, complications such as hydronephrosis or metastasis can occur within 5 years and androgen deprivation therapy or radiation therapy may be considered. (http://www.nccn.org/professionals/physician_gls/PDF/prostate.pdf )
The U.S. Preventive Services Task Force (USPSTF) recommendations on screening for prostate cancer include the following statements: “Even if prostate cancer screening is determined to be effective, the length of time required to experience a mortality benefit is greater than 10 years. Because a 75-year-old man has an average life expectancy of about 10 years, very few men age 75 years or older would experience a mortality benefit. Similarly, men younger than age 75 years who have chronic medical problems and a life expectancy of fewer than 10 years are also unlikely to benefit from screening and treatment.” (http://www.ahrq.gov/clinic/uspstf08/prostate/prostaters.htm )
As noted in the Description section, intensity-modulated radiation therapy (IMRT) detects the areas of radiation and adjusts the dose weighting and delivery to process the radiation plan. In contrast to 3-dimensional conformal radiation that is accurate to within 7 to 10 mm, IMRT restricts the dose and provides accuracy within 1 to 3 mm.
Recent systematic reviews have evaluated the use of IMRT in patients with prostate cancer. This policy focused on the recent systematic reviews in drawing its conclusions.
The most recent published review is a comparative effectiveness study of therapies for clinically localized prostate cancer. (1) Based on review of the data, this analysis reached the following conclusions:
“IMRT. There was no direct evidence that IMRT results in better survival or disease-free survival than other therapies for localized prostate cancer. Based on nonrandomized data, the absolute risks of clinical and biochemical outcomes (including tumor recurrence), toxicity, and quality of life after IMRT are comparable with conformal radiation.
“[For IMRT,] The percents of Grade 1 and 2 acute GI toxicity were 22% and 4%, respectively, and rectal bleeding 1.6–10%.
“Case series data suggested that IMRT provide at least as good a radiation dose to the prostate with less radiation to the surrounding tissues (that is undesirable) compared with conformal radiation therapy.”
Another recent review by the Institute for Clinical and Economic Review (2) reached the following conclusions:
“The literature on comparative rates of toxicity has serious methodological weaknesses. There are no prospective randomized trials or cohort trials, and the case series that exist are hampered by the lack of contemporaneous cohorts and/or by a failure to describe the selection process by which patients were assigned to IMRT vs. 3D-CRT. Published case series demonstrate consistent findings of a reduced rate of GI toxicity for IMRT at radiation doses from approximately 75–80 Gy. Data on GU toxicity have not shown superiority of IMRT over 3D-CRT, nor do the existing data suggest that IMRT provided a lower risk of erectile dysfunction.
“The literature suggests that the risk of Grade 2 GI toxicity is approximately 14% with 3D-CRT and 4% with IMRT. Thus, the number of patients needed to treat to prevent one case of moderate-severe proctitis is 10, and for every 100 patients treated with IMRT instead of 3D-CRT, 10 cases of GI toxicity would be expected to be prevented.”
The most recent National Comprehensive Cancer Network (NCCN) guidelines (2007) for principles of radiation therapy for prostate cancer indicate that for external-beam radiotherapy, three-dimensional conformal (3D CRT), or IMRT techniques should be employed. (3)
Thus, based on the published literature that provides data on outcomes of treatment, IMRT is another technique that can be used to deliver radiation therapy in the treatment of localized prostate cancer. Its use in this clinical application may be considered medically necessary.
The policy was updated with a literature search using MEDLINE through January 2009. Zelefsky and colleagues reported on the incidence and predictors of treatment-related toxicity at 10 years after 3D-CRT and IMRT for localized prostate cancer. (4) Between 1988 and 2000, 1,571 patients with stages T1-T3 prostate cancer were treated with 3D-CRT or IMRT with doses ranging from 66 to 81 Gy. Twenty-two percent were considered to be at low risk, as based on NCCN guidelines. The median follow-up was 10 years. The actuarial likelihood at 10 years for the development of Grade 2 or higher gastrointestinal (GI) toxicities was 9%. The use of IMRT significantly reduced the risk of GI toxicities compared with patients treated with conventional 3D-CRT (13% to 5%; p<0.001). Among patients who experienced acute symptoms, the 10-year incidence of late toxicity was 42%, compared with 9% for those who did not experience acute symptoms. The 10-year incidence of late Grade 2 or higher genitourinary (GU) toxicity was 15%. Patients treated with 81 Gy (IMRT) had a 20% incidence of GU symptoms at 10 years, compared with 12% for patients treated with lower doses (p=0.01). Among patients who had developed acute symptoms during treatment, the incidence of late toxicity at 10 years was 35%, compared with 12%. The incidence of Grade 3 GI and GU toxicities was 1% and 3%, respectively. The authors concluded that serious late toxicity was unusual despite the delivery of high radiation dose levels in these patients. They also noted that higher doses were associated with increased GI and GU Grade 2 toxicities, but the risk of proctitis was significantly reduced with IMRT.
Cohlon and colleagues reported on preliminary biochemical outcomes and toxicity with high-dose IMRT to a dose of 86.4 Gy for localized prostate cancer. (5) For this study, 478 patients were treated between August 1997 and March 2004 with 86.4 Gy using a 5- to 7-field IMRT technique. The median follow-up was 53 months. Thirty-seven patients (8%) experienced acute Grade 2 GI toxicity; none had acute Grade 3 or 4 GI toxicity; 105 patients (22%) experienced acute Grade 2 GU toxicity; and 3 patients (0.6%) had Grade 3 GU toxicity. Sixteen patients (3%) developed late Grade 2 GI toxicity; 2 patients (<1%) developed late Grade 3 GI toxicity; 60 patients (13%) had late Grade 2 GU toxicity; and 12 (<3%) experienced late Grade 3 GU toxicity. The 5-year actuarial PSA relapse-free survival, according to the nadir plus 2 ng/mL definition, was 98%, 85%, and 70% for the low-, intermediate-, and high-risk NCCN prognostic groups. The authors concluded that treatment with ultra-high radiation dose levels of 86.4 Gy using IMRT for localized prostate cancer is well tolerated and the early excellent biochemical control rates are encouraging. These results based on a case series should be considered as preliminary.
Based on information reviewed for the 2009 update, the policy statement is unchanged.
Code 77338 is to be reported only once per IMRT plan and should not be reported with 0073T.