Laack, Nadia N.

Abstract PurposeTo clarify the role of stereotactic radiosurgery (SRS) for atypical meningiomas (AM).MethodsA retrospective analysis of 68 patients with AM having SRS from 1995 until 2019. Nineteen patients (28%) had undergone prior external beam radiation therapy (EBRT) (median dose, 54 Gy). The median follow-up period was 52 months.ResultsEighteen (26%), 17 (25%), and 33 (49%) patients received SRS as an upfront adjuvant (≤ 6 months), early salvage (7-18 months), or late salvage treatment (> 18 months), respectively. The 3-, 5-, and 10-year progression-free survivals (PFSs) were 52%, 35%, and 25%, respectively. The 3-, 5-, and 10-year disease-specific survivals (DSSs) were 85%, 78%, and 61%, respectively. Adverse radiation events (AREs) were observed in 12 patients (18%), with increased or new seizures being the most frequent complication (n=7). Prior EBRT was associated with reduced PFS (HR = 5.92, P <0.01), reduced DSS (HR = 5.84, P <0.01), and an increased risk of ARE (HR = 3.31, P = 0.04). Timing of SRS was correlated with reduced PFS for patients having early salvage treatment compared to upfront adjuvant (HR = 3.17, P = 0.01) or late salvage treatment (HR = 4.39, P <0.01). ConclusionPFS for patients with residual/recurrent AM remains poor despite SRS. Prior EBRT was associated with worse tumor control, higher tumor-related mortality, and an increased risk of ARE. Further study on the timing of SRS is needed to determine if upfront adjunctive SRS improves tumor control compared to salvage SRS.

Background: Myxopapillary ependymomas (MPE) are intradural spinal tumors with a predilection to the filum terminale. Damage to conus medullaris during surgery can result in sphincteric and sexual dysfunction. The purpose of this study is to determine how myxopapillary ependymoma proximity to the conus impacts patient presentation, extent of resection, and clinical outcomes. Methods: Fifty-one patients who underwent surgical resection of pathologically confirmed myxopapillary ependymoma with at least 1 year of follow-up were included in the study. We collected initial presenting symptoms, distance of the tumor from the conus, extent of resection, and postoperative clinical outcomes including bladder dysfunction. Results: Average age was 38 years (range 7–75 years) with a male to female ratio of 1.43:1. Patients most commonly presented with pain symptoms (88%), and 12 patients (23.5%) had urologic symptoms on presentation. The mean tumor distance from the tip of the conus was 1.60 cm (10 cm above to 21 cm below the tip of the conus). Patients with tumors in contact with the conus had a significantly higher rate of preoperative urinary symptoms and were more likely (32% vs. 14%) to suffer postoperative urinary sphincteric disturbances. Tumors with direct invasion of the conus medullaris were more likely to require intralesional resection and fail to achieve a gross total resection (GTR). Conclusion: Patients with MPE in close proximity to the conus were more likely to suffer from long-term morbidity related to urologic issues following surgical resection. Adjuvant radiotherapy may be a viable option for patients who fail to achieve GTR.

Abstract PURPOSE We investigated the long term impact of SRS and WBRT in two large prospective phase III trials. METHODS Patients with 1–4 BMs +/- resection were randomized to SRS or WBRT. Cognitive deterioration was a drop of &gt;1 standard deviation from baseline in &gt;2/6 cognitive measures (CM). Quality of life (QOL) scores were scored 0–100 point scale. CM and QOL scores were modeled using baseline adjusted Linear Mixed Models (LMM) with uncorrelated random intercept for subject and random slopes for time. Differences over time between groups and the effect of &gt;2 cognitive scores with &gt;2 SD change from baseline were assessed. RESULTS 88 patients were included with median follow up of 24 months. We observed decreasing CM over time (SRS: 4/6; WBRT: 5/6). Mean CM was significantly higher in SRS for Total recall and Delayed Recall at 3, 6, 9, 12 months. More patients in WBRT arm declined 1 SD in &gt;1 and &gt;2 CM at the 3, 6, 9, and 12 months. A 1 SD decline in &gt;3 CM at 1 year was 21% SRS vs 47% WBRT (p=0.02). SRS had fewer patients with a 2 SD decline in &gt;1 CM at every time point. SRS had fewer patients with a 2 SD decline at &gt;2 and &gt;3 CM. WBRT had lower QOL at 3 months, but switched to SRS having lower QOL at 24 months for PWB, EWB, FWB, FactG, BR, and FactBR (p&lt; 0.05). A 2 SD decline in cognition decreased mean FWB by 6.4 units (95% CI: -11, -1.75; p=0.007) and decreased QOL by 5.1 units (95% CI: -7.7, -2.5; p&lt; 0.001). CONCLUSIONS We report the first pooled prospective study demonstrating the long term outcomes of patients with BMs after cranial radiation. WBRT was associated with worse cognitive outcomes. Impaired cognition is associated with worse QOL.

Abstract Background Patterns of recurrence and survival with different surgical and radiotherapy (RT) techniques were evaluated to guide RT target volumes for patients with temporal lobe glioma. Methods and Materials This retrospective cohort study included patients with World Health Organization grades II to IV temporal lobe glioma treated with either partial (PTL) or complete temporal lobectomy (CTL) followed by RT covering both the parenchymal and dural resection bed (whole-cavity radiotherapy [WCRT]) or the parenchymal resection bed only (partial-cavity radiotherapy [PCRT]). Patterns of recurrence, progression-free survival (PFS) and overall survival (OS) were evaluated. Results Fifty-one patients were included and 84.3% of patients had high-grade glioma (HGG). CTL and PTL were performed for 11 (21.6%) and 40 (78.4%) patients, respectively. Median RT dose was 60 Gy (range, 40-76 Gy). There were 82.4% and 17.6% of patients who received WCRT and PCRT, respectively. Median follow-up time was 18.4 months (range, 4-161 months). Forty-six patients (90.2%) experienced disease recurrence, most commonly at the parenchymal resection bed (76.5%). No patients experienced an isolated dural recurrence. The median PFS and OS for the PCRT and WCRT cohorts were 8.6 vs 10.8 months (P = .979) and 19.9 vs 18.6 months (P = .859), respectively. PCRT was associated with a lower RT dose to the brainstem, optic, and ocular structures, hippocampus, and pituitary. Conclusion We identified no isolated dural recurrence and similar PFS and OS regardless of postoperative RT volume, whereas PCRT was associated with dose reduction to critical structures. Omission of dural RT may be considered a reasonable alternative approach. Further validation with larger comparative studies is warranted.

Abstract PURPOSE We investigated the long term impact of SRS and WBRT in two large prospective phase III trials. METHODS Patients with 1–4 BMs +/- resection were randomized to SRS or WBRT. Cognitive deterioration was a drop of &gt;1 standard deviation from baseline in &gt;2/6 cognitive measures (CM). Quality of life (QOL) scores were scored 0–100 point scale. CM and QOL scores were modeled using baseline adjusted Linear Mixed Models (LMM) with uncorrelated random intercept for subject and random slopes for time. Differences in trend over time between groups and the effect of &gt;2 cognitive scores with &gt;2 SD change from baseline were assessed. RESULTS 88 patients were included with median follow up of 24 months. We observed decreasing CM over time (SRS: 4/6; WBRT: 5/6). Mean CM was significantly higher in SRS for Total recall and Delayed Recall at 3, 6, 9, 12 months. More patients in WBRT arm declined 1 SD in &gt;1 and &gt;2 CM at the 3, 6, 9, and 12 months. A 1 SD decline in &gt;3 CM at 1 year was 21% SRS vs 47% WBRT (p=0.02). SRS had fewer patients with a 2 SD decline in &gt;1 CM at every time point. SRS had fewer patients with a 2 SD decline at &gt;2 and &gt;3 CM. WBRT had lower QOL at 3 months, but switched to SRS having lower QOL at 24 months for PWB, EWB, FWB, FactG, BR, and FactBR (p&lt;0.05). A 2 SD decline in cognition decreased mean FWB by 6.4 units (95% CI: -11, -1.75; p=0.007) and decreased QOL by 5.1 units (95% CI: -7.7, -2.5; p&lt;0.001). CONCLUSIONS We report the first pooled prospective study demonstrating the long term outcomes of patients with BMs after cranial radiation. WBRT was associated with worse cognitive outcomes. Impaired cognition is associated with worse QOL.

e14507 Background: Serious gastrointestinal injury (SGI) is a rare but documented side effect that can occur independently with agents that affect the vascular endothelial growth factor (VEGF) receptor or with stereotactic body radiotherapy (SBRT). The risk of SGI in patients treated with the combination of SBRT sequentially followed by a VEGF inhibitor (VEGF-i) is not yet quantified. We explored the incidence of SGI in patients treated with SBRT with or without VEGF-i therapy at a single institution. Methods: From May 2008 to August 2011, 76 patients with 84 primary or metastatic intraabdominal lesions underwent SBRT (median dose, 50 Gy in 5 fractions). Twenty of these patients (26%) received a VEGF-i within two years of completing SBRT (bevacizumab, n=14; sorafenib, n=4; pazopanib, n=1; sunitinib, n=1). The most common site treated with SBRT was the liver (n=43, 57%), and the most common histology was colorectal adenocarcinoma (n=18, 24%). Other common histologies included melanoma of the skin (n=14, 18%) and non-small cell lung cancer (n=10, 13%). The incidence of SGI (CTCAE v4.0 grade 3 to 5 ulceration or perforation) after SBRT was obtained, and the relationship between SGI and VEGF-i was examined. Other factors that could potentially contribute to SGI, such as radiotherapy dose to bowel, were also analyzed. Results: Seven patients (9%) experienced SGI at a median 4.6 months (range, 3-17 months) after SBRT. All seven had received a VEGF-i prior to SGI and within 13 months of completing SBRT, and five received the VEGF-i within three months of SBRT. The six-month estimate of SGI in patients receiving a VEGF-i within three months of SBRT was 38%. No SGI was noted in the 63 patients not receiving VEGF-i therapy after SBRT. The Log-Rank test showed a significant correlation between SGI and VEGF-i therapy within three months of SBRT (p=0.0006) but not between SGI and maximum radiotherapy bowel dose (p=0.20). Conclusions: The combination of SBRT and VEGF-i therapy results in a much higher risk of SGI than would be expected with either treatment given independently. Local therapies other than SBRT should be considered if a patient is likely to be treated with a VEGF-i in the future.

AbstractBackgroundThe optimal radiation dose for adult supratentorial low-grade glioma is unknown. The aim of this study was to provide a final update on oncologic and cognitive outcomes of high-dose versus low-dose radiation for low-grade glioma.MethodsBetween 1986 and 1994, 203 patients with supratentorial low-grade glioma were randomized (1:1) to 50.4 Gy in 28 fractions versus 64.8 Gy in 36 fractions after any degree of resection.ResultsFor all patients, median overall survival (OS) was 8.4 years (95% CI: 7.2–10.8). Median progression-free survival (PFS) was 5.2 years (95% CI: 4.3–6.6). Median follow-up is 17.2 years for the 33 patients still alive. High-dose radiation did not improve 15-year OS (22.4%) versus low-dose radiation (24.9%, log-rank P = 0.978) or 15-year PFS (high dose, 15.2% vs low dose, 9.5%; P = 0.7142). OS was significantly better for patients with preoperative tumor diameter &lt;5 cm and baseline Mini-Mental State Examination (MMSE) &gt;27 and who underwent gross total resection. PFS was improved for patients with oligodendroglioma versus astrocytoma, preoperative tumor diameter &lt;5 cm, patients who had gross total resection, and patients with baseline MMSE &gt;27. For patients who had normal MMSE at baseline, at 7 years only 1 patient (5%) had a clinically significant decrease in MMSE from the previous time point, with the remainder (95%) stable. None had decrease in MMSE at 10, 12, or 15 years.ConclusionsLong-term follow-up indicates no benefit to high-dose over low-dose radiation for low-grade gliomas. Cognitive function appeared to be stable after radiation as measured by MMSE.