I agree that there are no useful conclusions to be drawn from Medicare claims data. Here was my reply when it came out last year:
An analysis of medicare claims data from 2008 to 2011 published this week seems to indicate higher toxicity for SBRT than conventional IMRT.
The difference was statistically significant for GU claims at 6, 12 & 24 months. At 6 months, 15.6% of SBRT patients had a claim for treatment-related GU toxicity vs 12.6% of IMRT patients; at 12 months, 27.1% for SBRT vs 23.2% for IMRT; at 24 months, 43.9% for SBRT vs 36.3% for IMRT.
At 6 months after treatment, SBRT patients had more claims for GI toxicity compared to conventional IMRT patients, 5.8% for SBRT vs 4.1% for IMRT. The difference was not statistically significant at 12 and 24 months.
An important caveat is that the claims data is irrespective of the grade of toxicity, so a visit to the doctor for a problem that is resolved by a prescript
ion for Flomax is counted the same as a visit to the ER for catheterization for urinary retention.
The dates of this analysis may include many ROs who were on the early part of the learning curve for SBRT. Experience may make a difference.
Here's a link to the abstract:
Stereotactic Body Radiation Therapy Versus Intensity-Modulated Radiation Therapy for Prostate Cancer: Comparison of ToxicityI just looked at the late term urinary morbidity by grade as reported for high dose IMRT (80 Gy) at Memorial Sloan Kettering (Alicikus) and compared it to the QOL results reported by Georgetown after 2 years.
Georgetown reports for their patients 2 years after SBRT: 26% Grade 1 late urinary symptoms + 17% Grade 2 urinary symptoms, and 1% Grade 3 and no Grade 4 symptoms. For those unfamiliar with this terminology, Grade 1 is mild, Grade 2 is what I would call annoying (e.g., getting up to pee more than twice a night), Grade 3 is serious, requiring medical intervention, and Grade 4 is life-threatening. For IMRT, Alicikus at MSK reports late term urinary toxicities of 23% Grade 1, 9% Grade 2, and 5% Grade 3.
So at Georgetown (SBRT), 44% of patients had a reported visit to their doctor, while at MSK (IMRT), 37% saw their doctor with a urinary complaint - 16% less for IMRT.
Yet IMRT had 5 times as high a rate of serious (Grade 3) urinary complaints.The other question is - are ROs who are relatively new to a procedure (as many were in 2008-2011) more likely to refer their patients to a urologist with even minor complaints? Maybe this occurs in the same way that new mothers are more likely to call pediatricians when their first baby sneezes, while by the third or fourth child, they seldom would.
There were 3 published disputations of the original article by Dr. Yu, one of which cites data from Dr. Katz. I'm glad that such things are addressed in print.
Perils of Comparing Toxicities Between Stereotactic Body Radiation and Intensity-Modulated Radiation Therapy for Prostate Cancer on the Basis of Incomplete Demographic Registries - King, Steinberg & KupelianRegarding Relative Toxicities of Stereotactic Body Radiation Therapy Versus Intensity-Modulated Radiation Therapy for Prostate Cancer - FullerStereotactic Body Radiation Therapy for Prostate Cancer: The Need to Assess Patient-Reported Outcomes -Vordermark- Allen