Determination of the Optimal Planning Target Volume for Brain Metastases Treated With Stereotactic Radiosurgery
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 49
- Locations
- 2
- Primary Endpoint
- 12-month Local Control Rate
Study Overview
Brief Summary
The purpose of this study is to estimate the rate of local control at the treated site of the metastasis as a function of 1mm versus 3mm expansion about the gross tumor volume (GTV). Each lesion, not each patient will be ranndomized to either the 1mm or 3mm margin with 40 lesions randomized to each arm.
Detailed Description
Stereotactic radiosurgery (SRS) is used either as definitive treatment alone or as a "boost" in combination with whole-brain radiotherapy (WBRT) for the treatment of brain metastases. To establish a target for SRS, the gross tumor volume (GTV) is typically defined as the contrast-enhancing volume on T1-weighted axial MRI images. In turn, the volume chosen for treatment (the planning target volume or PTV) is generated by expanding the GTV to account for microscopic extension of tumor beyond the MRI-visualized volume and deviations in patient positioning at the time of treatment., However, the optimal PTV in patients undergoing SRS of brain metastases has not been established.
This pilot randomized study of approximately 49 patients (representing a total of 80 brain lesions) should be sufficient to explore the effect of margin expansion around the GTV for brain metastases. The patients enrolled in this study will undergo radiosurgery to a planning treatment volume generated by expanding the GTV of each lesion by either a 1mm or 3mm margin. Each lesion, not each patient, will be randomized to receive either the 1mm or 3mm margin with 40 lesions randomized to each arm (a patient with multiple lesions potentially could have a lesion randomized to the 1mm arm and a different lesion randomized to the 3mm arm). The primary outcome of 12-month local recurrence and the secondary outcome of the rate of radionecrosis at the SRS treatment site will be lesion-specific outcomes. All other secondary outcomes will be patient-specific outcomes.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Single Group
- Primary Purpose
- Treatment
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age >18 years
- •Life expectancy of at least 6 months.
- •Karnofsky Performance Score greater than 70
- •Graded prognostic assessment (GPA score 0.5 or greater
- •1 to 3 brain metastases unresectable
- •Maximum tumor diameter no larger than 4cm
Exclusion Criteria
- •Primary lesion with radiosensitive histology (such as: small cell carcinoma, germ-cell tumors, lymphoma, leukemia, and multiple myeloma.
- •Metastases in the brain stem, pons or medulla or within 5 mm of optic apparatus
- •Previous cranial radiation
- •Pregnancy
Outcomes
Primary Outcomes
12-month Local Control Rate
Time Frame: 12 months after SRS
The 12-month local control rate is the percentage of lesions without recurrence at the lesion site 12 months after SRS. Time to local recurrence was defined as the time between SRS and local recurrence. If local recurrence did not occur, the time to local recurrence was censored at last follow-up (including deaths without local recurrence). Kaplan-Meier methods were used to describe the time to local recurrence.
Secondary Outcomes
- 12 Month Rate of Distant Brain Metastases(12 month after SRS)
- Cognition at 3 Months After SRS as Measured by the Trail Making Test (TMT)(Baseline to 3 months after SRS)
- Quality of Life at 3 Months After SRS as Measured by the Functional Assessment of Cancer Therapy-Brain (FACT-Br)(Baseline to 3 months after SRS)
- Rate of Death Due to Neurologic Causes(24 months after SRS)
- Rate of Radionecrosis at SRS Treatment Site(24 months after SRS)
- Median Overall Survival(24 months after SRS)
- Cognition at 3 Months After SRS as Measured by the Mini-Mental State Exam (MMSE)(Baseline to 3 months after SRS)