Purpose
Preclinical studies suggest that inhibition of vascular endothelial growth factor (VEGF) improves glioma response to radiotherapy. Bevacizumab, a monoclonal antibody against VEGF, has shown promise in recurrent gliomas, but the safety and efficacy of the concurrent use of bevacizumab with brain irradiation has not been extensively studied. The objectives of this study were to determine the safety and activity of this combination in malignant gliomas.
Methods and Materials
After prior treatment with standard radiation therapy patients with recurrent glioblastoma (GBM) and anaplastic gliomas (AG) received bevacizumab (10 mg/kg IV) every 2 weeks of 28-day cycles until tumor progression. Patients also received 30 Gy of hypofractionated stereotactic radiotherapy (HFSRT) in 5 fractions after the first cycle of bevacizumab.
Results
Twenty-five patients (20 GBM and 5 AG) median age of 56 years (range, 30 to 80) and median KPS 90 (range, 70 to 100) received a median of 7 cycles of bevacizumab. One patient did not undergo HFSRT because overlap with prior radiotherapy would exceed the safe dose allowed to the optic chiasm. Three patients discontinued treatment due to: grade 3 CNS intratumoral hemorrhage, wound dehiscence and bowel perforation. Other non-hematologic and hematologic toxicities were transient. No radiation necrosis was seen in these previously-irradiated patients. For the GBM cohort, overall response rate was 50%, 6-month progression free survival was 65%; median overall survival was 12.5 months and 1-year survival was 54%.
Discussion
Bevacizumab in combination with HFSRT is safe and well tolerated. Radiographic responses, duration of disease control and survival suggest that this regimen is active in recurrent malignant glioma.
Purpose/Objective
To evaluate local control following surgical resection and postoperative stereotactic radiosurgery (SRS) for brain metastases.
Methods and Materials
Forty-nine patients (50 lesions) were enrolled and available for analysis. Eligibility criteria included histologically confirmed malignancy with 1 or 2 intraparenchymal brain metastases, age ≥18, and KPS ≥70. Cox proportional hazard regression model was used to test for significant association between clinical factors and overall survival (OS). Competing risks regression models, as well as cumulative incidence functions, were fit using the method of Fine and Gray in order to assess the association between clinical factors and both local failure (LF, recurrence within surgical cavity or SRS target), and regional failure (RF, intracranial metastasis outside of treated volume).
Results
The median follow-up was 12.0 months (mos, range: 1.0–94.1 mos). Following surgical resection, 39 patients with 40 lesions were treated a median of 31 days (range: 7–56 days) later with SRS to the surgical bed to a median dose of 1800 cGy (range: 1500–2200 cGy). Of the 50 lesions, 15 (30%) demonstrated LF after surgery. The cumulative LF and RF rates were 22% and 44% at 12 mos. Patients who went on to receive SRS had significantly lower incidence of LF (p=0.008). Other factors associated with improved local control includes NSCLC histology (p=0.048), tumor diameter <3 cm (p=0.010), and deep parenchymal tumors (p=0.036). Large tumors (≥3 cm) with superficial dural/pial involvement showed the highest risk for LF (53.3% at 12 mos). Large, superficial lesions treated with SRS had 54.5% LF. Infratentorial lesions were at higher risk of developing RF compared to supratentorial lesions (p <0.001).
Conclusions
Postoperative SRS is associated with high local control, especially for deep brain metastases <3 cm. Tumors ≥3 cm with superficial dural/pial involvement demonstrate the highest risk in LF.
We have previously demonstrated high pathologic response rates after neoadjuvant concurrent chemoradiation in patients with locally advanced breast cancer (LABC). We now report disease-free survival (DFS) and overall survival (OS) in the context of pathologic response. 105 LABC patients (White 46%, Non-White 54%) were treated with paclitaxel (30 mg/m2 intravenously twice a week) for 10–12 weeks. Daily radiotherapy was delivered to breast, axillary, and supraclavicular lymph nodes during weeks 2–7 of paclitaxel treatment, at 1.8 Gy per fraction to a total dose of 45 Gy with a tumor boost of 14 Gy at 2 Gy/fraction. Pathological complete response (pCR) was defined as the absence of invasive cancer in breast and lymph nodes and pathological partial response (pPR) as the persistence of <10 microscopic foci of invasive carcinoma in breast or lymph nodes. Pathologic response (pCR and pPR) after neoadjuvant chemoradiation was achieved in 36/105 patients (34%) and was associated with significantly better DFS and OS. Pathological responders had a lower risk of recurrence or death (HR = 0.35, P = 0.01) and a longer OS (HR = 4.27, P = 0.01) compared with non-responders. Median DFS and OS were 57 and 84 months for non-responders, respectively, and have not yet been reached for responders. Importantly, pathologic response was achieved in 54% of patients with HR negative tumors (26/48). In conclusion, pathologic response to concurrent paclitaxel-radiation translated into superior DFS and OS. Half of the patients with HR negative tumors achieved a pathologic response.
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