Nivolumab and ipilimumab with concurrent stereotactic radiosurgery for intracranial metastases from non-small cell lung cancer: analysis of the safety cohort for non-randomized, open-label, phase I/II trial

BACKGROUND

Up to 20% of patients with non-small cell lung cancer (NSCLC) develop brain metastasis (BM), for which the current standard of care is radiation therapy with or without surgery. There are no prospective data on the safety of stereotactic radiosurgery (SRS) concurrent with immune checkpoint inhibitor therapy for BM. This is the safety cohort of the phase I/II investigator-initiated trial of SRS with nivolumab and ipilimumab for patients with BM from NSCLC.

PATIENTS AND METHODS

This single-institution study included patients with NSCLC with active BM amenable to SRS. Brain SRS and systemic therapy with nivolumab and ipilimumab were delivered concurrently (within 7 days). The endpoints were safety and 4-month intracranial progression-free survival (PFS).

RESULTS

Thirteen patients were enrolled in the safety cohort, 10 of whom were evaluable for dose-limiting toxicities (DLTs). Median follow-up was 23 months (range 9.7-24.3 months). The median interval between systemic therapy and radiation therapy was 3 days. Only one patient had a DLT; hence, predefined stopping criteria were not met. In addition to the patient with DLT, three patients had treatment-related grade ≥3 adverse events, including elevated liver function tests, fatigue, nausea, adrenal insufficiency, and myocarditis. One patient had a confirmed influenza infection 7 months after initiation of protocol treatment (outside the DLT assessment window), leading to pneumonia and subsequent death from hemophagocytic lymphohistiocytosis. The estimated 4-month intracranial PFS rate was 70.7%.

CONCLUSION

Concurrent brain SRS with nivolumab/ipilimumab was safe for patients with active NSCLC BM. Preliminary analyses of treatment efficacy were encouraging for intracranial treatment response.

Concurrent intrathecal and intravenous nivolumab in leptomeningeal disease: phase 1 trial interim results

There is a critical need for effective treatments for leptomeningeal disease (LMD). Here, we report the interim analysis results of an ongoing single-arm, first-in-human phase 1/1b study of concurrent intrathecal (IT) and intravenous (IV) nivolumab in patients with melanoma and LMD. The primary endpoints are determination of safety and the recommended IT nivolumab dose. The secondary endpoint is overall survival (OS). Patients are treated with IT nivolumab alone in cycle 1 and IV nivolumab is included in subsequent cycles. We treated 25 patients with metastatic melanoma using 5, 10, 20 and 50 mg of IT nivolumab. There were no dose-limiting toxicities at any dose level. The recommended IT dose of nivolumab is 50 mg (with IV nivolumab 240 mg) every 2 weeks. Median OS was 4.9 months, with 44% and 26% OS rates at 26 and 52 weeks, respectively. These initial results suggest that concurrent IT and IV nivolumab is safe and feasible with potential efficacy in patients with melanoma LMD, including in patients who had previously received anti-PD1 therapy. Accrual to the study continues, including in patients with lung cancer. ClinicalTrials.gov registration: NCT03025256 .

Cardiac Angiosarcomas: Risk of Brain Metastasis and Hemorrhage Warrants Frequent Surveillance Imaging and Early Intervention

PURPOSE

We evaluated a cohort of patients with cardiac angiosarcomas (CA) who developed brain metastases (BM) to define outcomes and intracranial hemorrhage (IH) risk.

METHODS

We reviewed 26 consecutive patients with BM treated between 1988 and 2020 identified from a departmental CA (n=103) database. Causes of death were recorded, and a terminal hemorrhage (TH) was defined as an IH that caused death or prompted a transfer to hospice.

RESULTS

The prevalence of BM was 25% (n=26/103). A total of 23 patients (88%) had IH, including 21 (81%) at initial BM diagnosis, of which 18 (86%) required hospitalization. The median platelet count at the time of IH was 235k (interquartile range, 108 to 338k).Nearly all patients died of disease (n=23, 88%) and most patients died from TH (n=13, 57%). TH occurred at BM presentation in 6 (46%) patients, whereas 3 (23%) had TH from known but untreated lesions, 2 (15%) had continued uncontrolled IH during radiation therapy, and 2 (15%) from new BM. Platelet count <50k was not associated with TH (P=0.25).Subsequent IH occurred in 9 patients (35%), and importantly, no patients who completed radiation therapy (n=10) for BM died from TH.

CONCLUSION

Patients with CA frequently develop BM, and the risk of IH is high, resulting in an alarming rate of TH despite normal platelet counts. Therefore, early diagnosis and intervention are warranted. We recommend surveillance brain imaging, and importantly, once BM is detected, prompt local therapy is warranted to try and mitigate the risk of TH.

A prospective phase II randomized trial of proton radiotherapy vs intensity-modulated radiotherapy for patients with newly diagnosed glioblastoma

BACKGROUND

To determine if proton radiotherapy (PT), compared to intensity-modulated radiotherapy (IMRT), delayed time to cognitive failure in patients with newly diagnosed glioblastoma (GBM).

METHODS

Eligible patients were randomized unblinded to PT vs IMRT. The primary endpoint was time to cognitive failure. Secondary endpoints included overall survival (OS), intracranial progression-free survival (PFS), toxicity, and patient-reported outcomes (PROs).

RESULTS

A total of 90 patients were enrolled and 67 were evaluable with median follow-up of 48.7 months (range 7.1-66.7). There was no significant difference in time to cognitive failure between treatment arms (HR, 0.88; 95% CI, 0.45-1.75; P = .74). PT was associated with a lower rate of fatigue (24% vs 58%, P = .05), but otherwise, there were no significant differences in PROs at 6 months. There was no difference in PFS (HR, 0.74; 95% CI, 0.44-1.23; P = .24) or OS (HR, 0.86; 95% CI, 0.49-1.50; P = .60). However, PT significantly reduced the radiation dose for nearly all structures analyzed. The average number of grade 2 or higher toxicities was significantly higher in patients who received IMRT (mean 1.15, range 0-6) compared to PT (mean 0.35, range 0-3; P = .02).

CONCLUSIONS

In this signal-seeking phase II trial, PT was not associated with a delay in time to cognitive failure but did reduce toxicity and patient-reported fatigue. Larger randomized trials are needed to determine the potential of PT such as dose escalation for GBM and cognitive preservation in patients with lower-grade gliomas with a longer survival time.

Phase II trial of proton therapy versus photon IMRT for GBM: secondary analysis comparison of progression-free survival between RANO versus clinical assessment

Background

This secondary image analysis of a randomized trial of proton radiotherapy (PT) versus photon intensity-modulated radiotherapy (IMRT) compares tumor progression based on clinical radiological assessment versus Response Assessment in Neuro-Oncology (RANO).

Methods

Eligible patients were enrolled in the randomized trial and had MR imaging at baseline and follow-up beyond 12 weeks from completion of radiotherapy. “Clinical progression” was based on a clinical radiology report of progression and/or change in treatment for progression.

Results

Of 90 enrolled patients, 66 were evaluable. Median clinical progression-free survival (PFS) was 10.8 (range: 9.4–14.7) months; 10.8 months IMRT versus 11.2 months PT (P = .14). Median RANO-PFS was 8.2 (range: 6.9, 12): 8.9 months IMRT versus 6.6 months PT (P = .24). RANO-PFS was significantly shorter than clinical PFS overall (P = .001) and for both the IMRT (P = .01) and PT (P = .04) groups. There were 31 (46.3%) discrepant cases of which 17 had RANO progression more than a month prior to clinical progression, and 14 had progression by RANO but not clinical criteria.

Conclusions

Based on this secondary analysis of a trial of PT versus IMRT for glioblastoma, while no difference in PFS was noted relative to treatment technique, RANO criteria identified progression more often and earlier than clinical assessment. This highlights the disconnect between measures of tumor response in clinical trials versus clinical practice. With growing efforts to utilize real-world data and personalized treatment with timely adaptation, there is a growing need to improve the consistency of determining tumor progression within clinical trials and clinical practice.

RADT-13. EARLY CONCURRENT IMMUNOTHERAPY WITH STEREOTACTIC RADIOSURGERY IS ASSOCIATED WITH PROLONGED SURVIVAL AND DECREASED DISTANT BRAIN FAILURE IN PATIENTS WITH NEWLY DIAGNOSED MELANOMA BRAIN METASTASES (MBM)

INTRODUCTION

We evaluated outcomes of patients with newly diagnosed MBM treated with concurrent immune checkpoint inhibition (ICI) and stereotactic radiosurgery (SRS) (concurrentTx), defined as treatment delivery within 30 days of each other.

METHODS

Screening of 2,617 melanoma patients who received ICI (anti-CTLA4/anti-PD1/both) between 2011-2019 identified 151 pts who received concurrentTx for MBM. Among these, 51 had newly-diagnosed MBM and received no prior ICI or SRS, and were included in the current study. Overall survival (OS) and distant brain failure (DBF) were estimated using the Kaplan-Meier method. Incidence of radiation necrosis (RN) was captured.

RESULTS

Median follow up from treatment initiation (either ICI or SRS, whichever occurred first) was 37 months. Median OS was 30 months. Median interval between ICI/SRS was 12 days (range: 1-29). Twenty-two patients received ICI first and 29 received SRS first, without differences in OS (p=0.22), DBF (p=0.91), or development of RN (p=0.86). However, the interval between ICI and SRS was significant. Patients who received concurrentTx 1-11 days apart (n=25, “early”) experienced a significant improvement in OS and DBF compared to 12-29 days apart (n=26, “delayed”) (p=0.01, HR 2.8; 95%CI 1.3-6.2 for OS and p=0.02, HR 2.5; 95%CI 1.2-5.6 for DBF). OS and DBF at 36 months were 67% vs. 26% and 60% vs. 27%, respectively, for the early vs. delayed groups. Time to concurrentTx as a continuous variable was significantly associated with DBF (p=0.02), but not OS (p=0.06). Although not significant, more patients developed RN in the early (26.0%) versus delayed (3.8%) group (p=0.07). No additional patient or treatment differences were identified.

CONCLUSIONS

Early concurrentTx was associated with prolonged OS and improved DBF in newly diagnosed MBM patients who did not receive prior CNS-directed therapy. This finding suggests therapeutic synergism related to combined early treatment and should be validated in a prospective clinical trial.

Ventricular apparent diffusion coefficient measurements in patients with neoplastic leptomeningeal disease

Background

To test the hypothesis that intraventricular ADC values can be used to determine the presence of neoplastic leptomeningeal disease (LMD).

Materials and methods

ADC values were measured at multiple sites in the ventricular system in 32 patients with cytologically-proven LMD and 40 control subjects. Multiple linear regression analysis was used to determine the mean difference of ADCs between the LMD and control groups after adjusting for ventricle size and tumor type. Receiver operating characteristics (ROC) analysis was performed and optimal ADC value cut-off point for predicting the presence of LMD. ADC was compared to T1 enhancement and FLAIR signal hyperintensity for determining the presence of LMD.

Results

After adjusting for ventricular volume and tumor type, the mid body of lateral ventricles showed no significant difference in ventricular volume and a significant difference in ADC values between the control and LMD groups (p > 0.05). In the mid-body of the right lateral ventricle the AUC was 0.69 (95% CI 0.57–0.81) with an optimal ADC cut off point of 3.22 × 10^− 9 m²/s (sensitivity, specificity; 0.72, 0.68). In the mid-body of left lateral ventricle the AUC was 0.7 (95% CI 0.58–0.82) with an optimal cut-off point of 3.23 × 10^− 9 m²/s (0.81, 0.62). Using an average value of HU measurements in the lateral ventricles the AUC was 0.73 (95% CI 0.61–0.84) with an optimal cut off point was 3.11 × 10^− 9 m²/s (0.78, 0.65). Compared to the T1 post-contrast series, ADC was predictive of the presence of LMD in the mid-body of the left lateral ventricle (p = 0.036).

Conclusion

Complex interactions affect ADC measurements in patients with LMD. ADC values in the lateral ventricles may provide non-invasive clues to the presence of LMD.

Distinguishing Recurrent Thyroid Cancer from Residual Nonmalignant Thyroid Tissue Using Multiphasic Multidetector CT

BACKGROUND AND PURPOSE

During thyroidectomy incomplete resection of the thyroid gland may occur. This complicates the imaging surveillance of these patients as residual thyroid needs to be distinguished from local recurrence. Therefore, the purpose of this study was to determine if multiphasic multi-detector computed tomography (4D-MDCT) can differentiate residual nonmalignant thyroid tissue and recurrent thyroid carcinoma after thyroidectomy.

MATERIALS AND METHODS

In this retrospective study, Hounsfield unit values on multiphasic multidetector CT in precontrast, arterial (25 seconds), venous (55 seconds), and delayed (85 seconds) phases were compared in 29 lesions of recurrent thyroid cancer, 29 with normal thyroid, and 29 with diseased thyroid (thyroiditis/multinodular thyroid). The comparison of Hounsfield unit values among lesion types by phase was performed using ANOVA. The performance of Hounsfield unit values to predict recurrence was evaluated by logistic regression and receiver operating characteristic analysis.

RESULTS

All 3 tissue types had near-parallel enhancement characteristics, with a wash-in-washout pattern. Statistically different Hounsfield unit density was noted between the recurrence (lowest Hounsfield unit), diseased (intermediate Hounsfield unit), and normal (highest Hounsfield unit) thyroid groups throughout all 4 phases (P < .001 for each group and in each phase). Dichotomized recurrence-versus-diseased/normal thyroid tissue with univariate logistic regression analysis demonstrated that the area under the receiver operating characteristic curve for differentiating benign from malignant thyroid for the various phases of enhancement was greatest in the precontrast phase at 0.983 (95% CI, 0.954-1), with a cutoff value of ≤62 (sensitivity/specificity, 0.966/0.983) followed by the arterial phase.

CONCLUSIONS

Recurrent thyroid carcinoma can be distinguished from residual nonmalignant thyroid tissue using multiphasic multidetector CT with high accuracy. The maximum information for discrimination is in the precontrast images, then the arterial phase. An optimal clinical protocol could be built from any number of phases but should include a precontrast phase.

Comparison of tumor delineation using dual energy computed tomography versus magnetic resonance imaging in head and neck cancer re-irradiation cases

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GTVs on the 60 kV and 140 kV from DECT, and the T1c and T2 from MRI were compared.

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Delineation was the most consistent using T1c (no interobserver difference in DSC).

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T1c MRI provided higher interobserver agreement for skull base tumors.

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60 kV DECT provided higher interobserver agreement for non-skull base tumors.

In treatment planning, multiple imaging modalities can be employed to improve the accuracy of tumor delineation but this can be costly. This study aimed to compare the interobserver consistency of using dual energy computed tomography (DECT) versus magnetic resonance imaging (MRI) for delineating tumors in the head and neck cancer (HNC) re-irradiation scenario. Twenty-three patients with recurrent HNC and had planning DECT and MRI were identified. Contoured tumor volumes by seven radiation oncologists were compared. Overall, T1c MRI performed the best with median DSC of 0.58 (0–0.91) for T1c. T1c MRI provided higher interobserver agreement for skull base sites and 60 kV DECT provided higher interobserver agreement for non-skull base sites.

NIMG-03. PROSPECTIVE PHASE II RANDOMIZED TRIAL COMPARING PROTON THERAPY VS. PHOTON IMRT FOR GBM: SECONDARY ANALYSIS COMPARISON OF PROGRESSION FREE SURVIVAL BETWEEN RANO VS. CLINICAL AND RADIOLOGICAL ASSESSMENT

PURPOSE

To compare tumor progression based on clinical radiological assessment and on Response Assessment in Neuro-Oncology (RANO) criteria between GBM patients treated with proton radiotherapy (PT) vs. photon intensity modulated radiotherapy (IMRT).

METHODS

Eligible patients were enrolled on the described prospective phase II trial and had MR imaging at baseline and follow-up beyond 12 weeks from treatment completion. ‘Clinical’ progression was based on a radiology report of progression in combination with changes in treatment due to suspected disease progression. A single blinded observer applied RANO criteria to determine the RANO-based tumor progression.

RESULTS

Of 90 enrolled patients, 66 were evaluable, with median follow-up of 19.8 (Range: 3.2–65.1) months; median of 22.6 months for PT (n=25) vs. 18.9 months for IMRT (n=41). Median time to progression (TTP) was 7.9 months based on clinical progression criteria (8.1 months IMRT, 6.3 months PT) and 7.2 months (7.3 months IMRT, 5.7 months PT) by RANO criteria (p=ns for all). Median ‘clinical’ progression-free survival (PFS) was 8.7 (Range: 6.4–11.1) months; 8.9 months IMRT vs. 8.7 months PT (p=0.065). Median RANO PFS was 8.3 (range, 5.8–11.6) months: 8.3 months IMRT vs. 6.9 months PT (p=0.226). There were 14 discrepant cases: 3 had progression based on ‘clinical’ but not RANO criteria, and 11 had progression based on RANO but not ‘clinical’ criteria.

CONCLUSION

Based on this secondary analysis of a randomized trial of PT vs. IMRT for GBM, there was no difference in tumor progression relative to treatment technique used. There was no statistical difference in PFS noted between clinical and RANO-based assessments, but RANO criteria identified progression more often than clinical assessment, and TTP was shortened with the use of RANO criteria alone. Further development of tumor assessment tools that improve consistency and accuracy of determining tumor progression are needed to guide therapeutic trials in GBM.

MLTI-10. ESTABLISHMENT OF A MULTIDISCIPLINARY BRAIN METASTASIS CLINIC TO FACILITATE PATIENT-CENTERED CARE AND COORDINATED RESEARCH

BACKGROUND: ~30% cancer patients develop brain metastases (BM), reflected by ~1600 BM patients treated at MD Anderson Cancer Center annually. With advances in systemic therapy and extracranial disease control, BM is a growing challenge. Multi-disciplinary BM management is critical and complex requiring coordination of multiple oncology sub-specialties. There is limited data on pragmatic clinic models to streamline and advance care. METHODS: Recognizing deficiency in BM treatment and research, a steering committee was formed at MDACC to establish an interdisciplinary BM clinic (BMC), with a multi-disciplinary BM research retreat held in 2016. The goal of BMC was to centralize patient referrals, improve patient outcomes and experience, and advance research by developing clinical trials and biomarker discovery programs. Meetings were held to address BMC format, workflow, EMR integration, data collection infrastructure, and staffing model. RESULTS: MDACC BMC clinic opened in 01/2019 with two half-day clinics staffed by neurosurgery, neuro-radiation oncology, neuro-radiology and medical/neuro oncology. A dedicated advanced practice provider screens the referrals according to a well-developed algorithm. A multidisciplinary conference is held immediately before each clinic where patient images are reviewed, cases are discussed and consensus recommendations are developed. The treatment plan and follow up appointments are arranged at the completion of the clinic visit to expedite care. ~50 patients have been seen with excellent patient satisfaction response and reduced time to treatment. ~20% patients had major change in treatment plan following multi-disciplinary evaluation. Additional efforts to develop a central BM database along with clinical and translational research programs are on-going. CONCLUSIONS: Establishment of a multi-disciplinary BMC to facilitate care and centralize research programs addresses a critical need for coordinated patient-centered BM management. This endeavor has enhanced patient experience through multi-specialty collaboration. Our program demonstrates the feasibility and effectiveness of a dedicated BMC in the treatment of this complex patient population.

Patient Outcomes after Reirradiation of Small Skull Base Tumors using Stereotactic Body Radiotherapy, Intensity Modulated Radiotherapy, or Proton Therapy

Purpose  The aim of this study was to evaluate outcomes of patients who received reirradiation for small skull base tumors utilizing either intensity modulated radiotherapy (IMRT), stereotactic body radiotherapy (SBRT), and proton radiotherapy (PRT). Methods  Patients who received IMRT, SBRT or PRT reirradiation for recurrent or new small skull base tumors (< 60 cc) between April 2000 and July 2016 were identified. Those with < 3 months follow-up were excluded. Clinical outcomes and treatment toxicity were assessed. The Kaplan-Meier method was used to estimate the local control (LC), regional control (RC), distant control (DC), progression free survival (PFS), and overall survival (OS). Results  Of the 75 patients eligible, 30 (40%) received SBRT, 30 (40%) received IMRT, and 15 (20%) received PRT. The median retreatment volume was 28 cc. The median reirradiation dose was 66 Gy in 33 fractions for IMRT/PRT, and 45 Gy in 5 fractions for SBRT. The median time to reirradiation was 41 months. With a median follow-up of 24 months, the LC, RC, DC, PFS, and OS rates were 84%, 79%, 82%, 60%, and 87% at 1 year, and 75%, 72%, 80%, 49%, and 74% at 2 years. There was no difference in OS between radiation modalities. The 1- and 2-year late Grade 3 toxicity rates were 3% and 11% respectively.. Conclusions  Reirradiation of small skull base tumors utilizing IMRT, PRT, or SBRT provided good local tumor control and low rates of Grade 3 late toxicity. A prospective clinical trial is needed to guide selection of radiation treatment modalities.

Solitary Parathyroid Adenoma Localization in Technetium Tc99m Sestamibi SPECT and Multiphase Multidetector 4D CT

BACKGROUND AND PURPOSE

Minimally invasive parathyroid surgery relies critically on image guidance, but data comparing the efficacy of various imaging modalities are scarce. Our aim was to perform a blinded comparison of the localizing capability of technetium Tc99m sestamibi SPECT, multiphase multidetector 4D CT, and the combination of these 2 modalities (technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT).

MATERIALS AND METHODS

We reviewed the records of 31 (6 men, 25 women; median age, 56 years) consecutive patients diagnosed with biochemically confirmed primary hyperparathyroidism between November 2009 and March 2010 who underwent preoperative technetium Tc99m sestamibi SPECT and multiphase multidetector 4D CT performed on the same scanner with pathologic confirmation by resection of a single parathyroid adenoma. Accuracy was determined separately for localization to the correct side and quadrant using surgical localization as the standard of reference.

RESULTS

Surgical resection identified 14 left and 17 right parathyroid adenomas and 2 left inferior, 12 left superior, 11 right inferior, and 6 right superior parathyroid adenomas. For left/right localization, technetium Tc99m sestamibi SPECT achieved an accuracy of 93.5% (29 of 31), multiphase multidetector 4D CT achieved 96.8% accuracy (30 of 31), and technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT achieved 96.8% accuracy (30 of 31). For quadrant localization, technetium Tc99m sestamibi SPECT accuracy was 67.7% (21 of 31), multiphase multidetector 4D CT accuracy was 87.1% (27 of 31), and technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT accuracy was 93.5% (29 of 31). Reader diagnostic confidence was consistently ranked lowest for technetium Tc99m sestamibi SPECT and highest for technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT.

CONCLUSIONS

For left/right localization of parathyroid adenomas, all modalities performed equivalently. For quadrant localization, technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT is superior to technetium Tc99m sestamibi SPECT.

Primary Leptomeningeal Oligodendroglioma, IDH-Mutant, 1p/19q-Codeleted

We present a case of a 43-year-old woman with a history of headaches and blurry vision. Ophthalmologic examination identified papilledema. MR imaging demonstrated a right parietal region mass with patchy areas of contrast enhancement and focal calcifications. Intraoperative examination and exploration revealed an extra-axial mass with no apparent parenchymal involvement. Microscopic examination revealed solid sheets of tumor cells with clear cell cytologic features and no discernable intra-parenchymal tumor component. Molecular studies demonstrated the presence of IDH1 IDH1 c.395G>A p.R132H and CIC c.601C>T p.R281W mutations and 1p/19q codeletion. The radiographic features, gross appearance, and microscopic and molecular characteristics of the mass support the diagnosis of primary leptomeningeal oligodendroglioma, IDH-mutant, 1p/19-codeleted. This case represents one of a very few reported instances of molecularly-defined solitary, primary, intracranial oligodendroglioma, without definitive involvement of the brain parenchyma.

A prospective in silico analysis of interdisciplinary and interobserver spatial variability in post-operative target delineation of high-risk oral cavity cancers: Does physician specialty matter?

Background

The aim of this study was to determine the interdisciplinary agreement in identifying the post-operative tumor bed.

Methods

Three radiation oncologists (ROs), four surgeons, and three radiologists segmented post-operative tumor and nodal beds for three patients with oral cavity cancer. Specialty cohort composite contours were created by STAPLE algorithm implementation results for interspecialty comparison. Dice similarity coefficient and Hausdorff distance were utilized to compare spatial differentials between specialties.

Results

There were significant differences between disciplines in target delineation. There was unacceptable variation in Dice similarity coefficient for each observer and discipline when compared to the STAPLE contours. Within surgery and radiology disciplines, there was good consistency in volumes. ROs and radiologists have similar Dice similarity coefficient scores compared to surgeons.

Conclusion

There were significant interdisciplinary differences in perceptions of tissue-at-risk. Better communication and explicit description of at-risk areas between disciplines is required to ensure high-risk areas are adequately targeted.

Stereotactic radiosurgery for trigeminal pain secondary to recurrent malignant skull base tumors

OBJECTIVE

The objective of this study was to assess outcomes after Gamma Knife radiosurgery (GKRS) re-irradiation for palliation of patients with trigeminal pain secondary to recurrent malignant skull base tumors.

METHODS

From 2009 to 2016, 26 patients who had previously undergone radiation treatment to the head and neck received GKRS for palliation of trigeminal neuropathic pain secondary to recurrence of malignant skull base tumors. Twenty-two patients received single-fraction GKRS to a median dose of 17 Gy (range 15-20 Gy) prescribed to the 50% isodose line (range 43%-55%). Four patients received fractionated Gamma Knife Extend therapy to a median dose of 24 Gy in 3 fractions (range 21-27 Gy) prescribed to the 50% isodose line (range 45%-50%). Those with at least a 3-month follow-up were assessed for symptom palliation. Self-reported pain was evaluated by the numeric rating scale (NRS) and MD Anderson Symptom Inventory-Head and Neck (MDASI-HN) pain score. Frequency of as-needed (PRN) analgesic use and opioid requirement were also assessed. Baseline opioid dose was reported as a fentanyl-equivalent dose (FED) and PRN for breakthrough pain use as oral morphine-equivalent dose (OMED). The chi-square and Student t-tests were used to determine differences before and after GKRS.

RESULTS

Seven patients (29%) were excluded due to local disease progression. Two experienced progression at the first follow-up, and 5 had local recurrence from disease outside the GKRS volume. Nineteen patients were assessed for symptom palliation with a median follow-up duration of 10.4 months (range 3.0-34.4 months). At 3 months after GKRS, the NRS scores (n = 19) decreased from 4.65 ± 3.45 to 1.47 ± 2.11 (p < 0.001); MDASI-HN pain scores (n = 13) decreased from 5.02 ± 1.68 to 2.02 ± 1.54 (p < 0.01); scheduled FED (n = 19) decreased from 62.4 ± 102.1 to 27.9 ± 45.5 mcg/hr (p < 0.01); PRN OMED (n = 19) decreased from 43.9 ± 77.5 to 10.9 ± 20.8 mg/day (p = 0.02); and frequency of any PRN analgesic use (n = 19) decreased from 0.49 ± 0.55 to 1.33 ± 0.90 per day (p = 0.08). At 6 months after GKRS, 9 (56%) of 16 patients reported being pain free (NRS score 0), with 6 (67%) of the 9 being both pain free and not requiring analgesic medications. One patient treated early in our experience developed a temporary increase in trigeminal pain 3-4 days after GKRS requiring hospitalization. All subsequently treated patients were given a single dose of intravenous steroids immediately after GKRS followed by a 2-3-week oral steroid taper. No further cases of increased or new pain after treatment were observed after this intervention.

CONCLUSIONS

GKRS for palliation of trigeminal pain secondary to recurrent malignant skull base tumors demonstrated a significant decrease in patient-reported pain and opioid requirement. Additional patients and a longer follow-up duration are needed to assess durability of symptom relief and local control.

Retrospective review of metastatic melanoma patients with leptomeningeal disease treated with intrathecal interleukin-2

Objectives

Metastatic melanoma patients with leptomeningeal disease (LMD) have an extremely poor prognosis, with a median survival measured in weeks, and few treatment options. Outcomes of a retrospective cohort of patients with LMD that were treated with intrathecal interleukin-2 (IT IL-2) were reviewed to assess the long-term efficacy of this therapy.

Methods

The records of metastatic melanoma patients with LMD who were treated with IT IL-2 from 2006 to 2014 in a Compassionate Investigational New Drug study were reviewed. IL-2 (1.2 mIU) was administered intrathecally via Ommaya reservoir up to five times per week in the inpatient setting for 4 weeks; patients with good tolerance and clinical benefit received maintenance IT IL-2 every 1–3 months thereafter.

Results

The cohort included 43 patients. The median age of the patients was 47 years (range 18–71), and 32 (74%) were male. 23 patients (53%) had positive cerebrospinal fluid (CSF) cytology and radiographic evidence of LMD, 8 (19%) had positive CSF cytology only, 9 (21%) had radiographic evidence only and 3 (7%) were diagnosed based on pathology review after craniotomy. The median overall survival (OS) from initiation of IT IL-2 was 7.8 months (range, 0.4–90.8 months), with 1-year, 2-year and 5-year OS rates of 36%, 26% and 13%. The presence of neurological symptoms (HR 2.1, P=0.03), positive baseline CSF cytology (HR 4.1, P=0.001) and concomitant use of targeted therapy (HR 3.0, P=0.02) was associated with shorter OS on univariate analysis. All patients developed symptoms due to increased intracranial pressure which was managed with supportive medications and/or CSF removal, and there were no treatment-related deaths.

Conclusion

These results demonstrate that despite their historically dismal prognosis a subset of metastatic melanoma patients with LMD treated with IT IL-2 can achieve long-term survival, but these data need to be verified in a prospective trial setting.

Analysis of pseudoprogression after proton or photon therapy of 99 patients with low grade and anaplastic glioma

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No difference in pseudoprogression rate six months after proton or photon therapy.

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Oligodendrogliomas develop pseudoprogression sooner after protons vs. photons.

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Astrocytomas develop pseudoprogression at similar time after protons vs. photons.

Background and purpose

Proton therapy is increasingly used to treat primary brain tumors. There is concern for higher rates of pseudoprogression (PsP) after protons compared to photons. The purposes of this study are to compare the rate of PsP after proton vs. photon therapy for grade II and III gliomas and to identify factors associated with the development of PsP.

Materials and methods

Ninety-nine patients age >18 years with grade II or III glioma treated with photons or protons were retrospectively reviewed. Demographic data, IDH and 1p19q status, and treatment factors were analyzed for association with PsP, progression free survival (PFS), and overall survival (OS).

Results

Sixty-five patients were treated with photons and 34 with protons. Among those with oligodendroglioma, PsP developed in 6/42 photon-treated patients (14.3%) and 4/25 proton-treated patients (16%, p = 1.00). Among those with astrocytoma, PsP developed in 3/23 photon-treated patients (13%) and 1/9 proton-treated patients (11.1%, p = 1.00). There was no difference in PsP rate based on radiation type, radiation dose, tumor grade, 1p19q codeletion, or IDH status. PsP occurred earlier in oligodendroglioma patients treated with protons compared to photons, 48 days vs. 131 days, p < .01. On multivariate analyses, gross total resection (p = .03, HR = 0.48, 95%CI = 0.25–0.93) and PsP (p = .04, HR = 0.22, 95% CI = 0.05–0.91) were associated with better PFS; IDH mutation was associated with better OS (p < .01, HR = 0.22, 95%CI = 0.08–0.65).

Conclusions

Patients with oligodendroglioma but not astrocytoma develop PsP earlier after protons compared to photons. PsP was associated with better PFS.

A predictive model for distinguishing radiation necrosis from tumour progression after gamma knife radiosurgery based on radiomic features from MR images

OBJECTIVES

To develop a model using radiomic features extracted from MR images to distinguish radiation necrosis from tumour progression in brain metastases after Gamma Knife radiosurgery.

METHODS

We retrospectively identified 87 patients with pathologically confirmed necrosis (24 lesions) or progression (73 lesions) and calculated 285 radiomic features from four MR sequences (T1, T1 post-contrast, T2, and fluid-attenuated inversion recovery) obtained at two follow-up time points per lesion per patient. Reproducibility of each feature between the two time points was calculated within each group to identify a subset of features with distinct reproducible values between two groups. Changes in radiomic features from one time point to the next (delta radiomics) were used to build a model to classify necrosis and progression lesions.

RESULTS

A combination of five radiomic features from both T1 post-contrast and T2 MR images were found to be useful in distinguishing necrosis from progression lesions. Delta radiomic features with a RUSBoost ensemble classifier had an overall predictive accuracy of 73.2% and an area under the curve value of 0.73 in leave-one-out cross-validation.

CONCLUSIONS

Delta radiomic features extracted from MR images have potential for distinguishing radiation necrosis from tumour progression after radiosurgery for brain metastases.

KEY POINTS

• Some radiomic features showed better reproducibility for progressive lesions than necrotic ones • Delta radiomic features can help to distinguish radiation necrosis from tumour progression • Delta radiomic features had better predictive value than did traditional radiomic features.

Methotrexate-induced leukoencephalopathy presenting as stroke in the emergency department

Methotrexate-induced leukoencephalopathy is to be considered as a potential etiology in any patient presenting with stroke-like symptoms after receiving methotrexate. One of our cases suggests that the method of administration of the methotrexate can be IV or intrathecal and still results in leukoencephalopathy.

Most common sites on MRI of intracranial neoplastic leptomeningeal disease

Neoplastic leptomeningeal disease (LMD) represents infiltration of the leptomeninges by tumor cells. Knowledge of the frequencies of locations of LMD on MRI may assist in early detection, help elucidate the process of leptomeningeal spread of cancer and understand how LMD affects the central nervous system. Our goal was to identify intracranial sites of neoplastic LMD predilection on MRI in patients with cytologically-proven LMD. The presence of FLAIR signal hyperintensity and T1-weighted post-contrast enhancement in the sulci of the supratentorial compartment and cerebellum and enhancement of the cranial nerves (CNs), basal cisterns, pituitary stalk, and ependymal surface of the lateral ventricles, as well as the presence of parenchymal metastasis were recorded. Within each imaging sequence, sites were ordered by prevalence and compared using McNemar's test. The study included 270 patients. Positive MRI findings were present in 185/270 (68.5%) patients. FLAIR signal hyperintensity was significantly more common (p≤0.003) in the cerebellum (n=96) and occipital lobe (n=92) relative to the other lobes. Leptomeningeal enhancement was also significantly more common (p≤0.009) in the cerebellum (n=82) and occipital lobe (n=67) relative to the other lobes. Enhancement was most commonly found involving CN VII/VIII and the ependymal surface of the lateral ventricles compared to other sites. Parenchymal metastases were present in 110 (40.1%) of the patients. In conclusion, neoplastic LMD predominantly involves the cerebellum and occipital lobes, CN VII/VIII, and the ependymal lining of the lateral ventricles. Parenchymal metastases are frequently present in patients with neoplastic LMD.

Post-operative stereotactic radiosurgery versus observation for completely resected brain metastases: a single-centre, randomised, controlled, phase 3 trial

Background

After brain metastasis resection, whole-brain radiation therapy (WBRT) decreases local recurrence but may cause cognitive decline. We performed this study to determine if stereotactic radiosurgery (SRS) to the surgical cavity improved local tumor tumor-free recurrence rates compared to surgical resection alone as an alternative to the need for immediate WBRT.

Methods

The main entry criteria for the study included patients >3 years of age, with a Karnofsky Performance Score ≥ 70, who were able to undergo an MRI scan and who had a complete resection of 1–3 brain metastases (the maximum diameter of the resection cavity had to be ≤4cm). Patients were assigned randomly to either SRS treatment of the resection cavity (within 30 days of surgery) or observation (OBS). Patients were stratified by histology, tumor size, and number of metastases. Patients were recruited at a single tertiary cancer center. The primary endpoint was time to local recurrence in the resection cavity assessed by blinded central review of brain MRI scans in the intention-to-treat population. The trial was registered at clinicaltrials.gov (Trial NCT00950001, status: closed to new participants).

Findings

Between 8/13/2009 and 2/16/2016, 132 patients were randomized to OBS (N=68) or SRS (N=64), with 128 patients available for analysis. We stratified by metastasis size (maximum diameter of ≥3 cm vs. <3 cm), histology (melanoma vs. other), and number of metastases (one vs. two or three). The 12-month local tumor recurrence-free rate was 43% (OBS) (95% CI 31%–59%) and 72% (SRS) (95% CI 60%–87%) (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.24–0.88, p=0.015).

Interpretation

This prospective randomized trial of patients undergoing surgical resection for 1–3 brain metastases indicates that SRS administered to the resection cavity significantly lowers local recurrence compared to observation alone. Thus, the use of SRS after brain metastasis resection is an alternative to WBRT.

Association between 18F-FDG PET/CT and MRI appearance of spinal leptomeningeal disease before and after treatment at a tertiary referral center

OBJECTIVE

Leptomeningeal disease (LMD), the presence of metastasis in the subarachnoid space, has devastating implications if left untreated. The gold standard for LMD diagnosis is cytologic analysis of cerebrospinal fluid (CSF); MRI is also used to evaluate suspected LMD. The purpose of this study was to compare the appearance of LMD in the spinal canal on 18F-FDG PET/CT imaging with the appearance of LMD on MRI and with CSF cytology.

METHODS

In twenty-one patients with cytologically-proven spinal LMD, findings on 18F-FDG PET/CT, MRI, and CSF cytology at diagnosis of LMD and after the initiation of treatment for LMD were retrospectively reviewed.

RESULTS

At diagnosis of LMD, abnormal 18F-FDG avidity was demonstrated in the spinal canal in six patients, and the anatomic distribution of 18F-FDG activity corresponded to the sites of LMD on MRI. All six of these patients were then treated with intrathecal chemotherapy. Follow-up 18F-FDG PET/CT and MRI were obtained in four of the six cases. In all four cases, normalization of 18F-FDG activity in the spinal canal and reduction of enhancement on MRI corresponded to the cytologic response to treatment, as determined by CSF analysis.

CONCLUSION

18F-FDG avidity in the spinal canal greater than the normal contents of the canal can suggest spinal LMD. This abnormal avidity may be detected before the diagnosis of LMD has been established with MRI or CSF cytology. The spinal canal should be routinely evaluated on 18F-FDG PET/CT in patients with suspected LMD so that appropriate treatment is initiated.

Central Nervous System and Head and Neck Histiocytoses: A Comprehensive Review on the Spectrum of Imaging Findings

The histiocytoses are a rare group of varied but related disorders characterized by abnormal tissue proliferation of macrophages and dendritic cells within tissues. The purpose of this article was to review the imaging findings in patients presenting with CNS and with head and neck manifestations of these disorders. Histiocytoses include but are not limited to Rosai-Dorfman disease, Erdheim Chester disease, Langerhans cell histiocytosis, histiocytic sarcoma, and juvenile xanthogranuloma. A review of the literature was performed to determine the sites of disease involvement. This article includes the demographics, histopathologic criteria for diagnosis, and imaging features of these histiocytoses, and describes the manifestations in locations known to harbor disease: intraaxial and extra-axial intracranial regions, the calvaria, skull base, hypothalamopituitary axis, orbits, paranasal sinuses, spine, and the head and neck region. Histiocytoses have variable imaging appearances in the CNS and in the head and neck region, and radiologists should be aware of the spectrum of findings to avoid mistaking them for other disease processes.

Learning Objective

To understand the general pathophysiology, clinical presentation, and typical imaging characteristics of the most common histiocytoses; comprehend the morphologic and immunohistochemical characteristics of these histiocytoses and the hallmark findings on pathology; and be able to differentiate between these disorders based on their most common presentations.

Gamma Knife Stereotactic Radiosurgery for Brain Metastases Using Only 3 Pins

BACKGROUND

Removal of a pin during Gamma Knife stereotactic radiosurgery (GK-SRS) may be necessary to prevent collision and allow treatment.

OBJECTIVE

To investigate outcomes after GK-SRS for treatment of brain metastases using a head frame immobilized to the skull with only 3 pins.

METHODS

Between 2009 and 2014, we retrospectively reviewed the records of 1971 patients and identified 20 patients with multiple brain metastases treated with GK-SRS in which 1 anterior pin was removed immediately before treatment of a single posterior lesion. GK-SRS was also delivered to 116 other lesions in these 20 patients using the standard 4 pins during the same session, serving as an internal control for comparison. Endpoints included local control, dosimetric parameters, toxicity, and overall survival.

RESULTS

The median number of lesions treated per session was 6 (range, 2-14). The lesions treated using 3 pins were located in the occipital lobe (n = 14) or the cerebellum (n = 6). Median follow-up was 12.3 months. There was 1 local failure involving a control lesion. Lesions treated using 3 pins had a lower prescription isodose line. GK-SRS of a lesion using 3 pins did not cause any clinical toxicities or increase in radiographic edema or hemorrhage.

CONCLUSION

Treating posteriorly located brain metastases with GK-SRS using only 3 pins provided excellent local control and no difference in treatment toxicity, which may make it a safe and reasonable option for lesions that may otherwise be difficult to treat.

Systemic and CNS activity of the RET inhibitor vandetanib combined with the mTOR inhibitor everolimus in KIF5B-RET re-arranged non-small cell lung cancer with brain metastases

In-frame fusion KIF5B (the-kinesin-family-5B-gene)-RET transcripts have been characterized in 1-2% of non-small cell lung cancers and are known oncogenic drivers. The RET tyrosine kinase inhibitor, vandetanib, suppresses fusion-induced, anchorage-independent growth activity. In vitro studies have shown that vandetanib is a high-affinity substrate of breast cancer resistance protein (Bcrp1/Abcg2) but is not transported by P-glycoprotein (P-gp), limiting its blood-brain barrier penetration. A co-administration strategy to enhance the brain accumulation of vandetanib by modulating P-gp/Abcb1- and Bcrp1/Abcg2-mediated efflux with mTOR inhibitors, specifically everolimus, was shown to increase the blood-brain barrier penetration. We report the first bench-to-bedside evidence that RET inhibitor combined with an mTOR inhibitor is active against brain-metastatic RET-rearranged lung cancer and the first evidence of blood-brain barrier penetration. A 74-year-old female with progressive adenocarcinoma of the lung (wild-type EGFR and no ALK rearrangement) presented for therapy options. A deletion of 5'RET was revealed by FISH assay, indicating RET-gene rearrangement. Because of progressive disease in the brain, she was enrolled in a clinical trial with vandetanib and everolimus (NCT01582191). Comprehensive genomic profiling revealed fusion of KIF5B (the-kinesin-family-5B-gene) and RET, in addition to AKT2 gene amplification. After two cycles of therapy a repeat MRI brain showed a decrease in the intracranial disease burden and PET/CT showed systemic response as well. Interestingly, AKT2 amplification seen is a critical component of the PI3K/mTOR pathway, alterations of which has been associated with both de novo and acquired resistance to targeted therapy. The addition of everolimus may have both overcome the AKT2 amplification to produce a response in addition to its direct effects on the RET gene. Our case report forms the first evidence of blood-brain barrier penetration by vandetanib in combination with everolimus. Further research is required in this setting.

Gamma knife stereotactic radiosurgery in the treatment of brainstem metastases: The MD Anderson experience

BACKGROUND

Brainstem metastases (BSMs) represent a significant treatment challenge. Stereotactic radiosurgery (SRS) is often used to treat BSM. We report our experience in the treatment of BSM with Gamma Knife SRS (GK_SRS).

METHODS

The records of 1962 patients with brain metastases treated with GK_SRS between 2009 and 2013 were retrospectively reviewed. Seventy-four patients with 77 BSMs and follow-up brain imaging were identified. Local control (LC), overall survival (OS), progression-free survival (PFS), and toxicity were assessed.

RESULTS

Median follow-up was 5.5 months (range, 0.2-48.5 months). Median tumor volume was 0.13 cm³ (range, 0.003-5.58 cm³). Median treatment dose was 16 Gy (range, 10-20 Gy) prescribed to 50% isodose line (range, 40%-86%). Crude LC was 94% (72/77). Kaplan-Meier estimate of median OS was 8.5 months (95% CI, 5.6-9.4 months). Symptomatic lesions and larger lesions, especially size ≥2 cm³, were associated with worse LC (HR = 8.70, P = .05; HR = 14.55, P = .02; HR = 62.81, P < .001) and worse OS (HR = 2.00, P = .02; HR = 2.14, P = .03; HR = 2.81, P = .008). Thirty-six percent of BSMs were symptomatic, of which 36% (10/28) resolved after SRS and 50% (14/28) had stable or improved symptoms. Actuarial median PFS was 3.9 months (95% CI, 2.7-4.9 months). Midbrain location was significant for worse PFS (HR = 2.29, P = .03). Toxicity was low (8%, 6/74), with size and midbrain location associated with increased toxicity (HR 1.57, P = .05; HR = 5.25, P = .045).

CONCLUSIONS

GK_SRS is associated with high LC (94%) and low toxicity (8%) for BSMs. Presence of symptoms or lesion size ≥ 2 cm³ was predictive of worse LC and OS.

Prognostic significance of EGFR and KRAS mutations in NSCLC patients with brain metastases treated with radiosurgery†

PURPOSE

Determine whether EGFR and KRAS mutations carry prognostic significance in non-small cell lung cancer (NSCLC) patients with brain metastases treated with stereotactic radiosurgery.

METHODS AND MATERIALS

Ninety-four NSCLC patients with brain metastases initially treated with stereotactic radiosurgery were retrospectively reviewed. Both EGFR and KRAS mutation status were recorded in 67 patients: EGFR+/KRAS- status in 9 patients, EGFR-/KRAS+ in 15 patients, and EGFR-/KRAS- in 43 patients. Survival was determined using the Kaplan-Meier method. Cox regression was used to assess the effects of patient factors on overall survival, local control, and distant brain control - all from time of brain metastasis diagnosis.

RESULTS

Median overall survival from time of brain metastasis diagnosis was 30.6 months for EGFR+/KRAS- patients, 9.8 months for EGFR-/KRAS+ patients, and 19.1 months for EGFR-/KRAS- patients (p=0.094). Local control at 2 years was 100% for EGFR+/KRAS- patients, 66.7% for EGFR-/KRAS+ patients, and 97.2% for EGFR-/KRAS- patients (p=0.399). Distant brain control at 12 months was achieved in 66.7% of EGFR+/KRAS- patients, 30.0% of EGFR-/KRAS+ patients, and 73.7% of EGFR-/KRAS- patients (p=0.039). On multivariate analysis, the most important predictors of mortality were baseline DS-GPA>2 (HR=0.27; p=0.001), EGFR mutation positivity (HR=0.30; p=0.054), and KRAS mutation positivity (HR=2.12; p=0.056); the most important predictors of distant brain failure were KRAS status (HR=4.44; p=0.004) and extracranial disease (HR=3.28; p=0.058); there was no statistically significant multivariate model identified for local control.

CONCLUSIONS

In NSCLC patients with brain metastases, KRAS mutations portend higher rates of distant brain failure. Our data also suggests that EGFR portends better overall survival and KRAS portends worse overall survival, though this still needs to be verified by a larger study.

Stereotactic radiosurgery for intraventricular brain metastases

Object

The authors' institution previously reported a 69% rate of crude local control for surgical management of lateral ventricle metastases at the University of Texas MD Anderson Cancer Center. For comparison, the authors here report their institutional experience with use of stereotactic radiosurgery (SRS) to treat intraventricular metastases.

Methods

To identify patients with intraventricular metastases for this retrospective review, the authors queried an institutional SRS database containing the medical records of 1962 patients with 5800 brain metastases who consecutively underwent SRS from June 2009 through October 2013. End points assessed were local control (crude and locoregional), distant failure–free survival, progression-free survival, and overall survival.

Results

Of the 1962 records examined, those for 25 (1.3%) patients with 30 (0.52%) intraventricular metastases were identified. Median patient age at SRS was 55.8 years. The most common primary malignancy was renal cell carcinoma (n = 13), followed by melanoma (n = 7) and breast adenocarcinoma (n = 5). Median tumor volume was 0.75 cm3 (range 0.01–5.6 cm3). Most lesions were located in the lateral ventricles (n = 25, 83.3%) and were treated to a median dose of 20 Gy (range 14–20 Gy). A total of 12 (48%) patients received whole-brain radiation therapy, most (n = 10) before SRS. With a median follow-up of 11.4 months (range 1.6–39.2 months), the rate of crude local control was 93.3%, and the rates of 6-month and 1-year actuarial locoregional control were 85.2% and 56.2%, respectively. The median overall survival time after SRS was 11.6 months (range 1.3–38.9 months), and the 6-month and 1-year actuarial rates were 87.1% and 46.7%, respectively. Disease dissemination developed in 7 (28%) patients as a second intraventricular metastatic lesion (n = 3, 12%), leptomeningeal disease (n = 3, 12%), or both (n = 1, 4%). Radiographic changes developed in 5 (20%) patients and included necrosis (n = 2, 8%) and hemorrhage (n = 3, 12%). A primary diagnosis of renal cell carcinoma was associated with an improved rate of distant failure–free survival (p = 0.05) and progression-free survival (p = 0.08).

Conclusions

SRS provides excellent local control for intraventricular metastases, with acceptable treatment-related toxicity, thereby supporting nonsurgical treatment for these lesions. The propensity for intraventricular dissemination among intraventricular metastases seems to be histologically dependent.

Multidetector CT with 3-dimensional volume rendering in the evaluation of the spine in patients with Neurofibromatosis type 1: a retrospective review in 73 patients

INTRODUCTION

Neurofibromatosis type 1 (NF-1) may involve the spine as various abnormalities including bony dysplasia, scoliosis, and nerve sheath tumors. Surgery may be performed for stabilization of the spine. We have seen an increase in requests for multidetector CT (MDCT) imaging with the (three-dimensional) 3D-volume rendered (VR) images in patients evaluated at our institution. We, therefore, investigated how MDCT could be best utilized in this patient population.

METHODS

Seventy-three patients with NF-1 were identified in whom MDCT imaging was performed for diagnostic, pre-operative, or post-operative evaluation of spinal abnormalities. True axial source images and two dimensional (2D) orthogonal reconstructed MDCT images, as well as the VR images, were compared with plain radiographs and MRI. In addition, the MDCT study was compared to the VR images. These studies were reviewed to compare assessment of A) bony abnormalities such as remodeling from dural ectasia, dysplasia, and fusion, B) abnormal spinal curvature, C) nerve sheath tumors, and D) surgical instrumentation.

RESULTS

When compared to plain radiographs, the MDCT and VR images were rated as helpful for evaluating the abnormalities of the spine in 19 of 24 patients for a total of 30 findings. This included the following categories A) (n = 6), B) (n = 5), C) (n = 7), and D) (n = 12). Compared to MR, the MDCT and VR study was helpful in evaluating the findings of NF-1 in 24 of 36 patients for a total of 40 findings. This included the following categories A) (n = 12), B) (n = 10), C) (n = 3), and D) (n = 15). When the VR images were compared to the orthogonal MDCT, the VR images was rated as helpful in 41 of 73 patients for a total of 60 findings, including the following categories: A) (n = 11), B) (n = 24), C) (n = 0), and D) (n = 25).

CONCLUSION

MDCT has distinct advantages over plain radiographs and MR imaging, and the VR images over MDCT in the evaluation of the spine in patients with NF-1, especially for the assessment of bony abnormalities, abnormal spinal curvature, and spinal instrumentation.

Pediatric patients with refractory central nervous system tumors: experiences of a clinical trial combining bevacizumab and temsirolimus

BACKGROUND

Pre-clinical findings suggest that combination treatment with bevacizumab and temsirolimus could be effective against malignant pediatric central nervous system (CNS) tumors.

PATIENTS AND METHODS

Six pediatric patients were treated as part of a phase I trial with intravenous temsirolimus 25 mg on days 1, 8, 15, and bevacizumab at 5, 10, or 15 mg/kg on day 1 of each 21-day cycle until disease progression or patient withdrawal.

RESULTS

The median patient age was six years (range=3-14 years). The primary diagnoses were glioblastoma multiforme (n=2), medullobalstoma (n=2), pontine glioma (n=1) and ependymoma (n=1). All patients had disease refractory to standard-of-care (2-3 prior systemic therapies). Grade 3 toxicities possibly related to drugs used occurred in two patients: anorexia, nausea, and weight loss in one, and thrombocytopenia and alanine aminotransferase elevation in another. One patient with glioblastoma multiforme achieved a partial response (51% regression) and two patients (with medulloblastoma and pontine glioma) had stable disease for four months or more (20 and 47 weeks, respectively). One other patient (with glioblastoma multiforme) showed 18% tumor regression (duration=12 weeks).

CONCLUSION

The combination of bevacizumab with temsirolimus was well-tolerated and resulted in stable disease of at least four months/partial response in three out of six pediatric patients with chemorefractory CNS tumors.