Functional Imaging of Treatment Effects: A Companion Protocol to a Phase II Study of Extracranial Stereotactic Radioablation (a.k.a. Stereotactic Body Radiotherapy) in Early Stage Non-Small Cell Lung Cancer.
One of the shortcomings of the trial design recognized in the phase I study had to do with
the assessment of local effects, both relating to tumor control and adjacent tissue
toxicity. For example, response rates were generally incomplete to the therapy, especially
at the lower dose level cohorts, and it was not clear if those patients had residual viable
tumor capable of sustaining growth. Repeat biopsies in this population are prohibitively
toxic. We generally followed these patients with chest x-rays and CT's until there was
evidence of progression. At that point, we would perform a PET scan and repeat systemic
staging. Since the majority of patients will retain residual "abnormalities" worrisome for
residual disease, ideally, there would be data or testing capable of characterizing these
abnormalities earlier in the post-treatment course. In the same token, several patients in
the phase I study had post treatment imaging changes around the tumor targets. If these
patients had symptomatic decline, it was never clear if the treatment effects around the
target were actually involved in the overall decline. Certainly, the patient population
selected has other medical problems that will continue to cause poor health. Ideally,
though, we would refer to data indicating the degree of damage to surrounding normal lung
from the ESR such that a realistic assessment of percentage of overall organ damage from the
therapy can be ascertained.
Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label
To characterize the effect of treatment on tumor metabolic activity as a function of time.
5 years from enrollment
Ronald McGarry, MD
Indiana University - Department of Radiation Oncology
United States: Food and Drug Administration