IMMU-04. FIRST-IN-CHILDREN PHASE 1B STUDY USING THE IDO PATHWAY INHIBITOR INDOXIMOD IN COMBINATION WITH RADIATION AND CHEMOTHERAPY FOR CHILDREN WITH NEWLY DIAGNOSED DIPG (NCT02502708, NLG2105)

Background

Diffuse intrinsic pontine glioma (DIPG) is a uniformly fatal brain tumor with no available cure. Indoximod blocks the IDO (indoleamine 2,3-dioxygenase) pathway, thereby reversing IDO-mediated immune suppression in the tumor microenvironment.

Methods

Patients aged 3 to 21 years with treatment-naive DIPG were eligible for this phase 1b dose-confirmation study of indoximod. The treatment regimen comprised continuous oral indoximod (38.4 mg/kg/day divided twice daily) with conformal photon radiation (54 Gy in 30 fractions), followed by cycles of indoximod with temozolomide (200 mg/m2/day, days 1–5 in 28-day cycles).

Results

Thirteen patients (median age 9 years, range 5 to 20 years) with DIPG were treated. Median OS was 14.5 months (follow-up ranged 4.8 to 29.3 months), 12-month OS was 61.5% (8/13), and 18-month OS was 30.8% (4/13), with 1 patient remaining in follow-up at the data cutoff. This compared favorably to expected median OS of approximately 10.8 months, 12-month OS of 45.3%, and 18-month OS of 16.2% taken from published historical data from the Pediatric Brain Tumor Consortium. Two patients showed near-complete responses lasting until relapsing after 7.6 months and 13.3 months of study therapy, respectively. Many patients had increased circulating non-classical monocytes (nc-Monos, CD16+, CD14neg, CD33+, HLA-DR+) within the first 3 treatment cycles, and elevation of this early pharmacodynamic marker was predictive of subsequent OS. Patients with nc-Monos >10% (n=7) had median OS of 19 months, whereas patients with nc-Monos below 10% (n=5) had median OS of 7 months (p=0.0047). No patients stopped therapy for toxicity. The most common indoximod-attributed adverse events were thrombocytopenia, neutropenia, nausea, vomiting, dizziness, and fatigue.

Conclusions

Adding indoximod immunotherapy to conventional radiation and chemotherapy for front-line treatment of pediatric patients with DIPG was well-tolerated. Improved outcomes were observed in patients having evidence of pharmacodynamic response. A follow-on phase 2 study is in progress (NCT04049669).

Gene expression signature to predict radiation response in lower-grade gliomas

2019

Background: Standard of care for lower-grade glioma (LGG) is maximal safe resection and risk-adaptive adjuvant therapy. While patients who benefit the most from adjuvant chemotherapy have been elucidated in prospective randomized studies, comparable insights for adjuvant radiotherapy (RT) are lacking. We sought to identify and validate patterns of gene expression that are associated with differential outcomes among LGG patients treated by RT from two large genomics databases. Methods: Patients from The Cancer Genome Atlas (TCGA) with LGG (WHO grade II–III gliomas) treated by surgery and adjuvant RT were randomized 1:1 to a training set or an internal validation set. Using patients in the training set, association between gene expression from resected tumor and progression-free survival (PFS) as well as overall survival (OS) was evaluated with adjustment for clinicopathologic covariates. A genomic risk score (GRS) was then constructed from the expression levels of top genes also screened for involvement in glioma carcinogenesis. The prognostic value of GRS was subsequently validated in the internal validation set of TCGA and a second distinct database, compiled by the Chinese Glioma Genome Association (CGGA). Results: From TCGA, 289 patients with LGG received adjuvant RT alone (38 grade II, 30 grade III) or chemoradiotherapy (CRT) (51 grade II, 170 grade III) between 2009 and 2015. From CGGA, 178 patients with LGG received adjuvant RT alone (40 grade II, 13 grade III) or CRT (41 grade II, 84 grade III) between 2004 and 2016. The genes comprising GRS are MAP3K15, MAPK10, CCL3, CCL4, and ADAMTS1, involved in MAP kinase activity, T cell chemotaxis, and cell cycle transition. High GRS, defined as having a GRS in the top third, was significantly associated with worse outcomes independent of age, sex, glioma histology, WHO grade, IDH mutation, 1p/19q co-deletion, and chemotherapy status in the training set (OS HR 2.74, P < 0.001; PFS HR 1.61, P = 0.014). These findings were further validated in the internal validation set (OS HR 1.84, P = 0.015; PFS HR 1.58, P = 0.027) and again in the CGGA external validation set (OS HR 1.72, P = 0.001). Association between GRS and outcomes was observed only among patients who received RT (RT alone or CRT), in both TCGA and CGGA. Conclusions: This study successfully identified an expression signature of five genes that stratified outcomes among LGG patients who received adjuvant RT, with two rounds of validation leveraging independent genomics databases. Expression levels of the highlighted genes were associated with survival only among patients whose treatments included RT, but not among those with omission of RT, suggesting that expression of these genes may be predictive of radiation treatment response. While additional prospective studies are warranted, interrogation of these genes to determine high/low GRS may be considered in the multidisciplinary management of LGGs.

Osteosarcoma

Osteosarcoma is a rare tumor that requires complex multidisciplinary management. This paper reviews the general management and standard radiotherapy guidelines for osteosarcoma in both North America and Europe in a joined effort between the Children's Oncology Group and International Society of Pediatric Oncology. Standard treatment involves multiagent induction chemotherapy followed by surgical resection for local tumor control and consolidation local control to metastatic sites. Radiotherapy is reserved for cases with a marginal or incomplete resection or for definitive treatment in the case of unresectable disease. We present supporting data for the role of chemotherapy, surgery, and radiation therapy.

Ewing sarcoma

Ewing sarcoma is a rare tumor that requires complex multidisciplinary management. This report describes the general management and standard radiotherapy guidelines in both North America (Children's Oncology Group) and Europe (International Society of Pediatric Oncology). Standard treatment involves multiagent induction chemotherapy followed by local treatment with surgery, definitive radiation, or a combination of surgery and radiation followed by additional chemotherapy and consolidation local treatment to metastatic sites. The data supporting the role of chemotherapy, surgery, and radiation and specific radiation therapy guidelines are presented.

Long-term health-related quality of life in pediatric brain tumor survivors receiving proton radiotherapy at <4 years of age

BACKGROUND

The purpose of this analysis is to report long-term health-related quality of life (HRQoL) among brain tumor survivors treated with proton therapy (PRT) at a very young age.

METHODS

Fifty-nine children <4 years old received PRT between 2000 and 2011. Forty families participated. HRQoL was assessed by child self-report (CSR; age ≥5) and parent proxy report (PPR; age 2+) using the PedsQL Core.

RESULTS

The median age was 2.5 years (range, 0.3-3.8) at PRT and 9.1 years (5.5-18) at last follow-up. The most common diagnoses were ependymoma (n = 22) and medulloblastoma (n = 7). Median follow-up is 6.7 years (3-15.4). Follow-up mean CSR and PPR scores were: total core (78.4 and 72.9), physical (82.9 and 75.2), psychosocial (76.0 and 71.6), emotional (74.4 and 70.7), social (81.2 and 75.1), and school (72.4 and 69.9). Parent-reported HRQoL fell within a previously defined range for healthy children in 37.5% of patients, and for children with severe health conditions in 45% of patients. PPR HRQoL was stable from baseline to last follow-up among all domains except for social functioning. History of gastrostomy tube was significantly associated with poorer CSR and PPR HRQoL on multivariable analysis. Ninety percent of children functioned in a regular classroom, 14 (36%) used a classroom aid, 9 (23%) used an outside tutor, and 18 (46%) had an individualized education plan.

CONCLUSION

Long-term HRQoL among brain tumor survivors treated with PRT at a very young age is variable, with over a third achieving HRQoL levels commensurate with healthy children.

KEY POINTS

1. One third of survivors reported long-term HRQoL scores comparable to those of healthy children.2. Treatment for hydrocephalus or a feeding tube was associated with significantly lower HRQoL.3. Total core HRQoL scores remained stable from baseline to last follow-up.

Optimal timing of chemoradiotherapy after surgical resection of glioblastoma: Stratification by validated prognostic classification

BACKGROUND

Previous studies examining the time to initiate chemoradiation (CRT) after surgical resection of glioblastoma have been conflicting. To better define the effect that the timing of adjuvant treatment may have on outcomes, the authors examined patients within the National Cancer Database (NCDB) stratified by a validated prognostic classification system.

METHODS

Patients with glioblastoma in the NCDB who underwent surgery and CRT from 2004 through 2013 were analyzed. Radiation Therapy Oncology Group recursive partitioning analysis (RPA) class (III, IV, V) was extrapolated for the cohort. Time intervals were grouped weekly, with weeks 4 to 5 serving as the reference category for analyses. Kaplan-Meier analysis, log-rank testing, and multivariate (MVA) Cox proportional hazards regression were performed.

RESULTS

In total, 30,414 patients were included. RPA classes III, IV, and V contained 5250, 20,855, and 4309 patients, respectively. On MVA, no time point after week 5 was associated with a change in overall survival for the entire cohort or for any RPA class subgroup. The periods of weeks 0 to 1 (hazard ratio [HR], 1.18; 95% CI, 1.02-1.36), >1 to 2 (HR, 1.23; 95% CI, 1.16-1.31), and >2 to 3 (HR, 1.11; 95% CI, 1.07-1.15) demonstrated slightly worse overall survival (all P < .03). The detriment to early initiation was consistent across each RPA class subgroup.

CONCLUSIONS

The current data provide insight into the optimal timing of CRT in patients with glioblastoma and describe RPA class-specific outcomes. In general, short delays beyond 5 weeks did not negatively affect outcomes, whereas early initiation before 3 weeks may be detrimental.

Hemorrhagic and Cystic Brain Metastases Are Associated With an Increased Risk of Leptomeningeal Dissemination After Surgical Resection and Adjuvant Stereotactic Radiosurgery

BACKGROUND

Brain metastases (BM) treated with surgical resection and focal postoperative radiotherapy have been associated with an increased risk of subsequent leptomeningeal dissemination (LMD). BMs with hemorrhagic and/or cystic features contain less solid components and may therefore be at higher risk for tumor spillage during resection.

OBJECTIVE

To investigate the association between hemorrhagic and cystic BMs treated with surgical resection and stereotactic radiosurgery and the risk of LMD.

METHODS

One hundred thirty-four consecutive patients with a single resected BM treated with adjuvant stereotactic radiosurgery from 2008 to 2016 were identified. Intracranial outcomes including LMD were calculated using the cumulative incidence model with death as a competing risk. Univariable analysis and multivariable analysis were assessed using the Fine & Gray model. Overall survival was analyzed using the Kaplan-Meier method.

RESULTS

Median imaging follow-up was 14.2 mo (range 2.5-132 mo). Hemorrhagic and cystic features were present in 46 (34%) and 32 (24%) patients, respectively. The overall 12- and 24-mo cumulative incidence of LMD with death as a competing risk was 11.0 and 22.4%, respectively. On multivariable analysis, hemorrhagic features (hazard ratio [HR] 2.34, P = .015), cystic features (HR 2.34, P = .013), breast histology (HR 3.23, P = .016), and number of brain metastases >1 (HR 2.09, P = .032) were independently associated with increased risk of LMD.

CONCLUSION

Hemorrhagic and cystic features were independently associated with increased risk for postoperative LMD. Patients with BMs containing these intralesion features may benefit from alternative treatment strategies to mitigate this risk.

Reduced-volume tumor-bed boost is not associated with inferior local control and survival outcomes in high-risk medulloblastoma

BACKGROUND

Radiotherapy boost to the entire posterior fossa (PF) is standard of care for high-risk (H-R) medulloblastoma patients; the utility of tumor bed (TB)-only boost is unclear. The purpose of this study was to examine the impact of PF versus TB boost volume on tumor control and survival in the H-R medulloblastoma population.

METHODS

Single-institution records for patients with H-R medulloblastoma were reviewed. The median craniospinal irradiation dose was 36 Gy (range, 23.4-45 Gy), and boost doses to either PF or TB were 54 to 55.8 Gy. PF (local) failures were scored as in-field, marginal (between 80% and 95% isodose lines), or distant. Kaplan-Meier methods and Cox proportional hazards were used to assess the impact of radiation boost technique on local control (LC) and survival endpoints.

RESULTS

Thirty-two patients with H-R medulloblastoma were treated between 1990 and 2015, with a median follow-up length of 5.12 years. Twenty-two patients received PF boost, and 10 received TB boost. Patient and disease characteristic were comparable between groups. A total of 11 PF failures occurred, including 3 isolated LFs (2 in the PF and 1 in the TB group). Most PF failures were in-field: three of four in the TB group and six of seven in the PF group; the remainder were marginal failures. TB boost was not associated with inferior LC (hazard ratio [HR] 0.86, log-rank P = 0.81) or overall survival (HR 1.40, P = 0.56) compared with PF boost.

CONCLUSION

Reduced-volume radiotherapy boost to the TB does not appear to compromise LC or survival in patients with H-R medulloblastoma; it may reduce the risk of ototoxicity.

An open invitation to join the Pediatric Proton/Photon Consortium Registry to standardize data collection in pediatric radiation oncology

OBJECTIVE

The Pediatric Proton/Photon Consortium Registry (PPCR) is a comprehensive data registry composed of pediatric patients treated with radiation. It was established to expedite outcomes-based research. The attributes which allow the PPCR to be a successful collaboration are reviewed.

METHODS AND MATERIALS

Current eligibility criteria are radiotherapy patients < 22 years treated at one of the 15 US participating institutions. Detailed health and treatment data are collected about the disease presentation and treatment exposures, and annually thereafter, in REDCap (Research Electronic Data Capture). DICOM (Digital Imaging and Communications in Medicine) imaging and radiation plans are collected through MIM/MIMcloud. An optional patient-reported quality-of-life (PedsQL) study is administered at 10 sites.

RESULTS

Accrual started October 2012 with 2,775 participants enrolled as of 25 July 2019. Most patients, 62.0%, were treated for central nervous system (CNS) tumors, the most common of which are medulloblastoma (n = 349), ependymoma (n = 309), and glial/astrocytoma tumors (n = 279). The most common non-CNS diagnoses are rhabdomyosarcoma (n = 284), Ewing's sarcoma (n = 153), and neuroblastoma (n = 130). While the majority of participants are US residents, 18.7% come from 36 other countries. Over 685 patients participate in the PedsQL study.

CONCLUSIONS

The PPCR is a valuable research platform capable of answering countless research questions that will ultimately improve patient care. Centers outside of the USA are invited to participate directly or may engage with the PPCR to align data collection strategies to facilitate large-scale international research.

ADVANCES IN KNOWLEDGE

For investigators looking to carry out research in a large pediatric oncology cohort or interested in registry work, this paper provides an updated overview of the PPCR.

The use of Hypofractionated Radiosurgery for the Treatment of Intracranial Lesions Unsuitable for Single-Fraction Radiosurgery

Stereotactic radiosurgery (SRS) is commonly used in the treatment of brain metastases, benign tumors, and arteriovenous malformations (AVM). Single-fraction radiosurgery, though ubiquitous, is limited by lesion size and location. In these cases, hypofractionated radiosurgery (hfSRS) offers comparable efficacy and toxicity. We review the recent literature concerning hfSRS in the treatment of brain metastases, benign tumors, and AVMs that are poorly suited for single-fraction SRS. Published retrospective analyses suggest that local control rates for brain metastases and benign tumors, as well as the rates of AVM obliteration, following hfSRS treatment are comparable to those reported for single-fraction SRS. Additionally, the toxicities from hypofractionated treatment appear comparable to those seen with single-fractioned SRS to small lesions.

The Role of Standard and Advanced Imaging for the Management of Brain Malignancies From a Radiation Oncology Standpoint

Radiation therapy (RT) plays a critical role in the overall management of many central nervous system (CNS) tumors. Advances in RT treatment planning, with techniques such as intensity modulated radiation therapy, volumetric modulated arc therapy, and stereotactic radiosurgery, now allow the delivery of highly conformal dose with great precision. These techniques rely on high-resolution 3-dimensional anatomical imaging modalities such as computed tomography or magnetic resonance imaging (MRI) scans to accurately and reliably define CNS targets and normal tissue avoidance structures. The integration of cross-sectional imaging into radiation oncology has directly translated into improvements in the therapeutic window of RT, and the union between radiation oncology and imaging is only expected to grow stronger. In addition, advanced imaging modalities including diffusion, perfusion, and spectroscopic MRIs as well as positron emission tomography (PET) scans with novel tracers are being utilized to provide additional insight into tumor biology and behavior beyond anatomy. Together, these standard and advanced imaging modalities hold significant potential to improve future RT delivery and response assessment. In this review, we will discuss the current utilization of standard/advanced imaging for CNS tumors from a radiation oncology perspective as well as the implications of novel MRI and PET modalities currently under investigation.

Proton vs. Photon Radiation Therapy for Primary Gliomas: An Analysis of the National Cancer Data Base

Background: To investigate the impact of proton radiotherapy (PBT) on overall survival (OS) and evaluate PBT usage trends for patients with gliomas in the National Cancer Data Base (NCDB).

Methods: Patients with a diagnosis of World Health Organization (WHO) Grade I-IV glioma treated with definitive radiation therapy (RT) between the years of 2004–13 were identified. Patients were stratified based on WHO Grade and photon radiotherapy (XRT) vs. PBT. Univariate (UVA) and multivariable analysis (MVA) with OS were performed by Cox proportional hazards model and log-rank tests. Propensity score (PS) weighting was utilized to account for differences in patient characteristics and to minimize selection bias.

Results: There were a total of 49,405 patients treated with XRT and 170 patients treated with PBT. Median follow-up time was 62.1 months. On MVA, the following factors were associated with receipt of PBT (all p < 0.05): WHO Grade I-II gliomas, treatment at an academic/research program, west geographic facility location, and surgical resection. After PS weighting, all patients treated with PBT were found to have superior median and 5 year survival than patients treated with XRT: 45.9 vs. 29.7 months (p = 0.009) and 46.1 vs. 35.5% (p = 0.0160), respectively.

Conclusions: PBT is associated with improved OS compared to XRT for patients with gliomas. This finding warrants verification in the randomized trial setting in order to account for potential patient imbalances not adequately captured by the NCDB, such as tumor molecular characteristics and patient performance status.

Importance of the Study: This is the first study that compares the outcomes of patients treated with photon based radiotherapy vs. proton based radiotherapy for patients with gliomas. In this retrospective analysis, the results demonstrate that proton therapy is associated with improved outcomes which support ongoing prospective, randomized clinical trials comparing the two modalities in patients with gliomas.

Fractionated Radiotherapy Is Associated with Lower Rates of Treatment-Related Edema than Stereotactic Radiosurgery in Magnetic Resonance Imaging-Defined Meningiomas

OBJECTIVE

Both stereotactic radiosurgery (SRS) and fractionated radiation therapy (FRT) techniques are used for treatment of intracranial meningiomas with excellent local control (LC) rates. Although SRS techniques are convenient, toxicity including treatment-related edema can significantly impact patient quality of life. The long-term clinical outcomes of patients with magnetic resonance imaging (MRI)-defined meningiomas treated with radiation therapy (RT) alone are reported.

METHODS

The charts of 211 patients with meningiomas diagnosed by contrast-enhanced MRI treated with either SRS or FRT between 1991 and 2012 at a single institution were reviewed. Actuarial rates for LC and development of treatment-related radiographic edema (TRE) were determined by the Kaplan-Meier method.

RESULTS

There were 211 patients who received radiation therapy for 223 lesions. Median follow-up was 5.7 years. Eleven patients experienced a local failure; of these, 2 were ultimately found to have pathologically proven metastatic carcinoma. Two- and 5-year LC was 97.8% and 94.6%, respectively, with no significant difference based on modality of therapy. Actuarial rate for development of TRE at 1 and 2 years was 30.1% and 34.6% for the SRS group and 1.6% and 2.5% for the FRT group, respectively (P < 0.001).

CONCLUSIONS

RT alone using a limited margin is an effective treatment option for MRI-defined meningiomas and should be considered even without biopsy if surgery will present significant morbidity. Although LC with SRS versus FRT was comparable, FRT was associated with a significantly decreased risk of TRE.

Musculoskeletal outcomes and the effect of radiation to the vertebral bodies on growth trajectories for long-term survivors of high-risk neuroblastoma

OBJECTIVE

Here, we report musculoskeletal outcomes and the impact of radiotherapy dose on vertebral body growth for an institutional series of long-term survivors of high-risk neuroblastoma.

METHODS

We conducted a retrospective study of 23 patients who were disease-free and at least 36 months from the end of treatment. The patients were initially treated from July 2003 to May 2012. Patient records were reviewed for growth percentiles (obtained at approximately 6-month intervals from onset of treatment to the last follow-up) and musculoskeletal comorbidities. RT plans and most recent surveillance CT scans were reviewed for locations of in-field vertebral bodies and corresponding vertebral growth patterns.

RESULTS

The median follow-up was 7.93 years. The median prescribed radiation dose was 21.6 Gy. Musculoskeletal abnormalities included scoliosis (5 patients), muscular hypoplasia (3), and hypodontia (1). The median growth percentile at treatment onset was 35.5 (range, 4.7-100) versus 10 (0-94.1) at the last follow-up. The median numbers of vertebral bodies encompassed (by at least half of their volume) by the 5-, 10-, 15-, and 20-Gy isodose lines were 7 (mean, 6.78), 7 (6.56), 6 (6.17), and 6 (5.52), respectively. Sixteen patients (70.0%) had in-field abnormalities in vertebral body growth, manifesting as stretches of successive vertebral bodies at the same height, while normally there is a gradual vertebral body height increase progressing caudally down the spinal column.

CONCLUSIONS

Musculoskeletal abnormalities, below average height, and stunted in-field vertebral body growth are routine in long-term survivors of high-risk neuroblastoma. Sparing vertebral bodies when feasible may lead to improvement in patient growth trajectories.

Does size matter? Investigating the optimal planning target volume margin for postoperative stereotactic radiosurgery to resected brain metastases

OBJECTIVE

The optimal margin size in postoperative stereotactic radiosurgery (SRS) for brain metastases is unknown. Herein, the authors investigated the effect of SRS planning target volume (PTV) margin on local recurrence and symptomatic radiation necrosis postoperatively.

METHODS

Records of patients who received postoperative LINAC-based SRS for brain metastases between 2006 and 2016 were reviewed and stratified based on PTV margin size (1.0 or > 1.0 mm). Patients were treated using frameless and framed SRS techniques, and both single-fraction and hypofractionated dosing were used based on lesion size. Kaplan-Meier and cumulative incidence models were used to estimate survival and intracranial outcomes, respectively. Multivariate analyses were also performed.

RESULTS

A total of 133 patients with 139 cavities were identified; 36 patients (27.1%) and 35 lesions (25.2%) were in the 1.0-mm group, and 97 patients (72.9%) and 104 lesions (74.8%) were in the > 1.0-mm group. Patient characteristics were balanced, except the 1.0-mm cohort had a better Eastern Cooperative Group Performance Status (grade 0: 36.1% vs 19.6%), higher mean number of brain metastases (1.75 vs 1.31), lower prescription isodose line (80% vs 95%), and lower median single fraction-equivalent dose (15.0 vs 17.5 Gy) (all p < 0.05). The median survival and follow-up for all patients were 15.6 months and 17.7 months, respectively. No significant difference in local recurrence was noted between the cohorts. An increased 1-year rate of symptomatic radionecrosis was seen in the larger margin group (20.9% vs 6.0%, p = 0.028). On multivariate analyses, margin size > 1.0 mm was associated with an increased risk for symptomatic radionecrosis (HR 3.07, 95% CI 1.13-8.34; p = 0.028), while multifraction SRS emerged as a protective factor for symptomatic radionecrosis (HR 0.13, 95% CI 0.02-0.76; p = 0.023).

CONCLUSIONS

Expanding the PTV margin beyond 1.0 mm is not associated with improved local recurrence but appears to increase the risk of symptomatic radionecrosis after postoperative SRS.

Brainstem dose is associated with patient-reported acute fatigue in head and neck cancer radiation therapy

BACKGROUND AND PURPOSE

Radiation (RT) dose to the central nervous system (CNS) has been implicated as a contributor to treatment-related fatigue in head and neck cancer (HNC) patients undergoing radiation therapy (RT). This study evaluates the association of RT dose to CNS structures with patient-reported (PRO) fatigue scores in a population of HNC patients.

MATERIALS AND METHODS

At pre-RT (baseline), 6th week of RT, and 1-month post-RT time points, Multidimensional Fatigue Inventory (MFI-20) scores were prospectively obtained from 124 patients undergoing definitive treatment for HNC. Medulla, pons, midbrain, total brainstem, cerebellum, posterior fossa, and pituitary dosimetry were evaluated using summary statistics and dose-volume histograms, and associations with MFI-20 scores were analyzed.

RESULTS

Maximum dose (Dmax) to the brainstem and medulla was significantly associated with MFI-20 scores at 6th week of RT and 1-month post-RT time points, after controlling for baseline scores (p<0.05). Each 1Gy increase in medulla Dmax resulted in an increase in total MFI-20 score over baseline of 0.30 (p=0.026), and 0.25 (p=0.037), at the 6th week of RT and 1-month post-RT, respectively. Each 1Gy increase in brainstem Dmax resulted in an increase in total MFI-20 score over baseline of 0.30 (p=0.027), and 0.25 (p=0.037) at the 6th week of RT, 1-month post-RT, respectively. Statistically significant associations were not found between dosimetry for the other CNS structures and MFI-20 scores.

CONCLUSIONS

In this analysis of PRO fatigue scores from a population of patients undergoing definitive RT for HNC, maximum dose to the brainstem and medulla was associated with a significantly increased risk of acute patient fatigue.

Is less more? Comparing chemotherapy alone with chemotherapy and radiation for high-risk grade 2 glioma: An analysis of the National Cancer Data Base

BACKGROUND

The addition of chemotherapy to adjuvant radiotherapy (chemotherapy and radiation therapy [CRT]) improves overall survival (OS) for patients with high-risk grade 2 gliomas; however, the impact of chemotherapy alone (CA) is unknown. This study compares the OS of patients with high-risk grade 2 gliomas treated with CA versus CRT.

METHODS

Patients with high-risk grade 2 gliomas (subtotal resection or age ≥ 40 years) with oligodendrogliomas, astrocytomas, or mixed tumors were identified with the National Cancer Data Base. Patients were grouped into CA and CRT cohorts. Univariate analyses and multivariate analyses (MVAs) were performed. Propensity score (PS) matching was also implemented. The Kaplan-Meier method was used to analyze OS.

RESULTS

A total of 1054 patients with high-risk grade 2 gliomas were identified: 496 (47.1%) received CA, and 558 (52.9%) received CRT. Patients treated with CA were more likely (all P values < .05) to have oligodendroglioma histology (65.5% vs 34.2%), exhibit a 1p/19q codeletion (22.8% vs 7.5%), be younger (median age, 47.0 vs 48.0 years), and receive treatment at an academic facility (65.2% vs 50.3%). The treatment type was not a significant predictor for OS (P = .125) according to the MVA; a tumor size > 6 cm, astrocytoma histology, and older age were predictors for worse OS (all P values < .05). After 1:1 PS matching (n = 331 for each cohort), no OS difference was seen (P = .696) between the CA and CRT cohorts at 5 (69.3% vs 67.4%) and 8 years (52.8% vs 56.7%).

CONCLUSIONS

No long-term OS difference was seen in patients with high-risk grade 2 gliomas treated with CA versus CRT. These findings are hypothesis-generating, and prospective clinical trials comparing these treatment paradigms are warranted. Cancer 2018;124:1169-78. © 2017 American Cancer Society.

Evaluating Intensity Modulated Proton Therapy Relative to Passive Scattering Proton Therapy for Increased Vertebral Column Sparing in Craniospinal Irradiation in Growing Pediatric Patients

PURPOSE

At present, proton craniospinal irradiation (CSI) for growing children is delivered to the whole vertebral body (WVB) to avoid asymmetric growth. We aimed to demonstrate the feasibility and potential clinical benefit of delivering vertebral body sparing (VBS) versus WVB CSI with passively scattered (PS) and intensity modulated proton therapy (IMPT) in growing children treated for medulloblastoma.

METHODS AND MATERIALS

Five plans were generated for medulloblastoma patients, who had been previously treated with CSI PS proton radiation therapy: (1) single posteroanterior (PA) PS field covering the WVB (PS-PA-WVB); (2) single PA PS field that included only the thecal sac in the target volume (PS-PA-VBS); (3) single PA IMPT field covering the WVB (IMPT-PA-WVB); (4) single PA IMPT field, target volume including thecal sac only (IMPT-PA-VBS); and (5) 2 posterior-oblique (-35°, +35°) IMPT fields, with the target volume including the thecal sac only (IMPT2F-VBS). For all cases, 23.4 Gy (relative biologic effectiveness [RBE]) was prescribed to 95% of the spinal canal. The dose, linear energy transfer, and variable-RBE-weighted dose distributions were calculated for all plans using the tool for particle simulation, version 2, Monte Carlo system.

RESULTS

IMPT VBS techniques efficiently spared the anterior vertebral bodies (AVBs), even when accounting for potential higher variable RBE predicted by linear energy transfer distributions. Assuming an RBE of 1.1, the V10 Gy(RBE) decreased from 100% for the WVB techniques to 59.5% to 76.8% for the cervical, 29.9% to 34.6% for the thoracic, and 20.6% to 25.1% for the lumbar AVBs, and the V20 Gy(RBE) decreased from 99.0% to 17.8% to 20.0% for the cervical, 7.2% to 7.6% for the thoracic, and 4.0% to 4.6% for the lumbar AVBs when IMPT VBS techniques were applied. The corresponding percentages for the PS VBS technique were higher.

CONCLUSIONS

Advanced proton techniques can sufficiently reduce the dose to the vertebral body and allow for vertebral column growth for children with central nervous system tumors requiring CSI. This was true even when considering variable RBE values. A clinical trial is planned for VBS to the thoracic and lumbosacral spine in growing children.

Postoperative stereotactic radiosurgery for resected brain metastases: A comparison of outcomes for large resection cavities

PURPOSE

Although historical trials have established the role of surgical resection followed by whole brain irradiation (WBRT) for brain metastases, WBRT has recently been shown to cause significant neurocognitive decline. Many practitioners have employed postoperative stereotactic radiosurgery (SRS) to tumor resection cavities to increase local control without causing significant neurocognitive sequelae. However, studies analyzing outcomes of large brain metastases treated with resection and postoperative SRS are lacking. Here we compare outcomes in patients with large brain metastases >4 cm to those with smaller metastases ≤4 cm treated with surgical resection followed by SRS to the resection cavity.

METHODS AND MATERIALS

Consecutive patients with brain metastases treated at our institution with surgical resection and postoperative SRS were retrospectively reviewed. Patients were stratified into ≤4 cm and >4 cm cohorts based on preoperative maximal tumor dimension. Cumulative incidence of local failure, radiation necrosis, and death were analyzed for the 2 cohorts using a competing-risk model, defined as the time from SRS treatment date to the measured event, death, or last follow-up.

RESULTS

A total of 117 consecutive cases were identified. Of these patients, 90 (77%) had preoperative tumors ≤4 cm, and 27 (23%) >4 cm in greatest dimension. The only significant baseline difference between the 2 groups was a higher proportion of patients who underwent gross total resection in the ≤4 cm compared with the >4 cm cohort, 76% versus 48%, respectively (P <.01). The 1-year rates of local failure, radiation necrosis, and overall survival for the ≤4 cm and >4 cm cohorts were 12.3% and 16.0%, 26.9% and 28.4%, and 80.6% and 67.6%, respectively (all P >.05). The rates of local failure and radiation necrosis were not statistically different on multivariable analysis based on tumor size.

CONCLUSIONS

Brain metastases >4 cm in largest dimension managed by resection and radiosurgery to the tumor cavity have promising local control rates without a significant increase in radiation necrosis on our retrospective review.

Association of Lymphovascular Space Invasion With Locoregional Failure and Survival in Patients With Node-Negative Oral Tongue Cancers

Importance

The indications for adjuvant therapy in resected oral tongue cancers are based on both clinical and pathological factors, with clear evidence for adjuvant radiation in patients with pathologically positive neck lymph nodes, positive margins, and extracapsular extension, but the data for patients with no nodal disease are sparse.

Objective

To investigate determinants of failure and survival in patients with node-negative oral tongue cancer.

Design, Setting, and Participants

Medical records for patients with oral tongue cancer treated with definitive surgery from 2003 to 2013 were reviewed. All patients were cN0 negative and classified as pathologically node-negative (pN0) if a neck dissection was performed. Patients received adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) based on standard clinical and pathological determinants.

Main Outcomes and Measures

Kaplan-Meier and multivariable (MVA) logistic regression and Cox proportional hazard regression analyses were performed to identify patient, tumor, and treatment characteristics predictive of locoregional control (LRC) and overall survival (OS).

Results

A total of 180 patients met entry criteria, with a median follow-up time of 4.9 years (range, 0.9-12.5 years); 102 patients (56.7%) were female and 42 patients (23.3%) were younger than 45 years at diagnosis. One hundred fifty-three patients (85%) had T1/T2 tumors, and 112 patients (62%) had elective neck dissections with confirmed pN0. Lymphovascular space invasion (LVSI) was present in 36 patients (20%). On MVA, LVSI (OR, 0.06; 95% CI, 0.02-0.19; P < .01) was associated with worse LRC. Elective neck dissection (odds ratio [OR], 2.99; 95% CI, 1.16-7.73; P = .02) and receipt of RT (OR, 7.74; 95% CI, 2.27-26.42; P < .01) were associated with improved LRC. Three-year LRC rates were significantly lower for patients with LVSI (38.8%; 95% CI, 22.8%, 54.6%) than those without LVSI (81.9%; 95% CI, 74.4%, 87.4%). On MVA, only LVSI (hazard ratio, 2.20; 95% CI, 1.19-4.06; P = .01) and age greater than 44 years (hazard ratio, 4.38; 95% CI, 1.34-14.27; P = .01) were associated with worse OS. Three-year OS rates were significantly lower in patients with LVSI (71.3%; 95% CI, 53.2%-83.4%) than those without LVSI (90.3%; 95% CI, 83.8%-94.3%).

Conclusions and Relevance

Lymphovascular space invasion in patients with node-negative oral tongue cancer treated with upfront definitive surgery is associated with worse LRC and OS. Node-negative oral cavity cancers with LVSI warrant consideration of further adjuvant therapy, which should be further evaluated in a prospective setting.