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PurposeThe Audio-Visual Assisted Therapeutic Ambience in Radiotherapy (AVATAR) system was the first published radiation therapy (RT)-compatible system to reduce the need for pediatric anesthesia through video-based distraction. We evaluated the feasibility of AVATAR implementation and effects on anesthesia use, quality of life, and anxiety in a multicenter pediatric trial.Methods and materialsPediatric patients 3 to 10 years of age preparing to undergo RT at 10 institutions were prospectively enrolled. Children able to undergo at least 1 fraction of RT using AVATAR without anesthesia were considered successful (S). Patients requiring anesthesia for their entire treatment course were nonsuccessful (NS). The PedsQL3.0 Cancer Module (PedsQL) survey assessed quality of life and was administered to the patient and guardian at RT simulation, midway through RT, and at final treatment. The modified Yale Preoperative Anxiety Scale (mYPAS) assessed anxiety and was performed at the same 3 time points. Success was evaluated using the χ2 test. PedsQL and mYPAS scores were assessed using mixed effects models with time points evaluated as fixed effects and a random intercept on the subject.ResultsEighty-one children were included; median age was 7 years. AVATAR was successful at all 10 institutions and with photon and proton RT. There were 63 (78%) S patients; anesthesia was avoided for a median of 20 fractions per patient. Success differed by age (P=.04) and private versus public insurance (P < .001). Both patient (P=.008) and parent (P=.006) PedsQL scores significantly improved over the course of RT for patients aged 5 to 7. Anxiety in the treatment room decreased for both S and NS patients over RT course (P < .001), by age (P < .001), and by S versus NS patients (P < .001).ConclusionsIn this 10-center prospective trial, anesthesia avoidance with AVATAR was 78% in children aged 3 to 10 years, higher than among age-matched historical controls (49%; P < .001). AVATAR implementation is feasible across multiple institutions and should be further studied and made available to patients who may benefit from video-based distraction.

Purpose The aim of this study was to examine current practice patterns in pediatric total body irradiation (TBI) techniques among COG member institutions. Methods and Materials Between November 2019 and February 2020, a questionnaire containing 52 questions related to the technical aspects of TBI was sent to medical physicists at 152 COG institutions. The questions were designed to obtain technical information on commonly used TBI treatment techniques. Another set of 9 questions related to the clinical management of patients undergoing TBI was sent to 152 COG member radiation oncologists at the same institutions. Results Twelve institutions were excluded because TBI was not performed in their institutions. A total of 88 physicists from 88 institutions (63% response rate) and 96 radiation oncologists from 96 institutions (69% response rate) responded. The anterior-posterior/posterior-anterior (AP/PA) technique was the most common technique reported (49 institutions [56%]); 44 institutions (50%) used the lateral technique, and 14 (16%) used volumetric modulated arc therapy or tomotherapy. Midplane dose rates of 6 to 15 cGy/min were most commonly used. The most common specification for lung dose was the midlung dose for both AP/PA techniques (71%) and lateral techniques (63%). Almost all physician responders agreed with the need to refine current TBI techniques, and 79% supported the investigation of new TBI techniques to further lower the lung dose. Conclusions There was no consistency in the practice patterns, methods for dose measurement, and reporting of TBI doses among COG institutions. The lack of standardization precludes meaningful correlation between TBI doses and clinical outcomes including disease control and normal tissue toxicity. The COG radiation oncology discipline is currently undertaking several steps to standardize the practice and dose reporting of pediatric TBI using detailed questionnaires and phantom-based credentialing for all COG centers.

Extraneural metastases are rare in pediatric high-grade gliomas and little is known about the genomic profiles of tumors that disseminate beyond the central nervous system. We describe a pediatric patient with H3 K27M-mutant diffuse midline glioma of the brain and spine with biopsy-confirmed osseous metastases present at diagnosis and suspected metastatic parenchymal pulmonary disease. Several potentially clinically and/or therapeutically relevant genomic alterations were identified, including H3F3A and TP53 mutations as well as MET, CDK6, EMSY, and PIK3CG amplifications. Sequencing is critical to improve our understanding of the molecular drivers of distant metastases and discover therapeutic targets that penetrate all disease sites.

To better document the risk of permanent hair and nail loss after total skin electron beam therapy (TSEBT) for mycosis fungoides (MF).Interviews and evaluations were conducted in 13 patients with MF treated with TSEBT alone and two patients treated with concomitant TSEBT and chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Evaluated parameters included time to hair and nail loss and regrowth, the density of hair regrowth, and quality of hair and nail regrowth.Most patients had complete loss of scalp hair during treatment, and new growth appeared about 2 months following treatment completion. After 18 months, most patients felt their hair had regrown to about 70% of baseline thickness without cosmetically obvious alopecia. The patients treated with TSEBT and concomitant chemotherapy had substantially less scalp hair regrowth with persistent cosmetically obvious alopecia. Some lost eyebrows and eyelashes, but complete or near-complete regrowth generally occurred. Most patients lost their nails following TSEBT, with complete regrowth noted by most patients 5 months after treatment. New nails were most often normal, but a few patients developed post-therapy nail dystrophies.This data can be used to better inform patients of likely long-term changes of hair and nails following TSEBT.

BACKGROUND In preclinical studies, FLASH therapy (radiation delivered at ultra-high dose rates ≥40 Gy/second) has been shown to cause less injury to normal tissues than radiotherapy delivered at conventional dose rates. This first-in-human clinical investigation is designed to assess the workflow feasibility of proton FLASH therapy treatment in a clinical setting for the treatment of painful bone metastases in the extremities. A single dose of 8 Gy will be administered, as this dose is well established for palliative therapy from prior investigations using conventional dose-rate photon radiotherapy. Use of this dose regimen will permit an assessment of FLASH treatment efficacy and toxicity relative to the historical comparators. OBJECTIVE The FAST-01 study is a prospective, single-center study. Primary endpoints include assessing the workflow feasibility as well as the toxicities of FLASH treatment. The secondary endpoint is pain response at the treated site(s) as measured by patient reported pain scores, use of pain medication, and any flare in bone pain after treatment. METHODS Following informed consent, 10 subjects ≥18 years old with up to 3 painful bone metastases in the extremities (excluding feet, hands, wrists) will be enrolled. A treatment field selected from a pre-defined library of plans with fixed field sizes (from 7.5 cm x 7.5 cm up to 7.5 cm x 20 cm) will be used for treatment, and subjects will receive 8 Gy in a single fraction. A FLASH-enabled Varian ProBeam™ Proton Therapy unit will be used to deliver treatment to the target volume at a dose rate of ≥40 Gy/sec using the plateau (transmission) portion of the proton beam. After treatment, patients will be assessed for pain response as well as any side-effects of FLASH radiation. RESULTS Results will be compared to historically reported results with conventional dose-rate photon radiotherapy using the same radiation dose and fractionation. CONCLUSIONS The results of this investigation will contribute to further developing and optimizing the FLASH- enabled ProBeam™ Proton Therapy System workflow. The pain response and toxicity data acquired on this study will provide greater understanding of FLASH treatment effects on tumor response and normal tissue toxicities, and they will inform future FLASH trial design. CLINICALTRIAL ClinicalTrials.gov NCT04592887

PURPOSE/OBJECTIVES: Treatment with radiation therapy (RT) can cause anxiety and distress for pediatric patients and their families. Radiation oncology teams have developed strategies to reduce the negative psychological impact. This survey study aimed to characterize these methods. MATERIALS/METHODS: A 37-item questionnaire was sent to all radiation oncology members of the Children’s Oncology Group to explore strategies to improve the pediatric patient experience. The Wilcoxon rank-sum test was used to assess factors associated with use of anesthesia for older children. RESULTS: Surveys were completed by 106 individuals from 84/210 institutions (40%). Respondents included 89 radiation oncologists and 17 supportive staff. Sixty-one percent of centers treated ≤50 children per year. Respondents described heterogenous interventions. The median age at which most children no longer required anesthesia was 6-years-old (range: ≤3-years-old to ≥ 8-years-old). Routine anesthesia use at an older age was associated with physicians’ lack of awareness of these strategies (p=.04) and 45 minutes in the radiation oncology department daily. Twenty-six percent of respondents planned to implement new strategies, with 65% focusing on video-based distraction therapy and/or augmented reality/virtual reality. CONCLUSIONS: Many strategies are used to improve children’s experience during RT. Lack of awareness of these interventions is a barrier to their implementation and is associated with increased anesthesia use. This study aims to disseminate these methods with the goal of raising awareness, facilitating implementation, and, ultimately, improving the experience of pediatric cancer patients and their caregivers.

Cyclin-dependent kinase-retinoblastoma (CDK-RB) pathway is dysregulated in some diffuse intrinsic pontine gliomas (DIPG). We evaluated safety, feasibility, and early efficacy of the CDK4/6-inhibitor ribociclib, administered following radiotherapy in newly-diagnosed DIPG patients. Following radiotherapy, eligible patients received ribociclib in 28-day cycles (350 mg/m2; 21 days on/7 days off). Feasibility endpoints included tolerability for at least 6 courses, and a less than 2-week delay in restarting therapy after 1 dose reduction. Early efficacy was measured by 1-year and median overall survival (OS). Patient/parent-by-proxy reported outcomes measurement information system (PROMIS) assessments were completed prospectively. The study included 10 evaluable patients, 9 DIPG and 1 diffuse midline glioma (DMG)—all 3.7 to 19.8 years of age. The median number of courses was 8 (range 3–14). Three patients required dose reduction for grade-4 neutropenia, and 1 discontinued therapy for hematological toxicity following course 4. The most common grade-3/4 toxicity was myelosuppression. After 2 courses, MRI evaluations in 4 patients revealed increased necrotic volume, associated with new neurological symptoms in 3 patients. The 1-year and median OS for DIPG was 89% and 16.1 months (range 10–30), respectively; the DMG patient died at 6 months post-diagnosis. Five patients donated brain tissue and tumor; 3 were RB+ . Ribociclib administered following radiotherapy is feasible in DIPG and DMG. Increased tumor necrosis may represent a treatment effect. These data warrant further prospective volumetric analyses of tumors with necrosis. Feasibility and stabilization findings support further investigation of ribociclib in combination therapies. NCT02607124.

Paratesticular rhabdomyosarcoma (PT-RMS) carries a favorable prognosis, but questions persist regarding optimal management. Our goal was to determine the importance of primary tumor resection and surgical assessment of retroperitoneal lymph nodes during staging in patients with PT-RMS. We analyzed patients with localized PT-RMS enrolled onto one of four Children's Oncology Group studies (D9602, ARST0331, D9803 or ARST0531). Surgical resection of the primary tumor prior to chemotherapy and radiotherapy was encouraged when possible with retroperitoneal lymph node dissection (RPLND) recommended for patients ≥10 years of age. Among 279 patients (median 8.1 years old), most tumors were resected with negative margins (78.5%) and most patients did not have radiographic enlargement of regional lymph nodes (90.3%). In patients older than 10 years, imaging alone will miss over 51.5% of nodal disease. Five-year event-free survival (EFS) was 92.0% (95% CI 88.4%-95.6%). Sampling ≥7 to 12 retroperitoneal lymph nodes appeared optimal for detecting positive nodes; while there was a trend toward improved EFS among those undergoing template RPLND, this was not statistically significant (P = .068). Age (P = .28), N-stage (P = .39), T-stage (P = .11) and pathologic node involvement (P = .53) were not associated with overall survival. However, older age and larger tumor size had an additive impact on EFS (P = .027) though not overall survival (P = .13). In conclusion, outcomes for patients with PT-RMS are excellent. Reliance on imaging to detect nodal involvement will miss pathologic node involvement and may result in undertreatment. Surgical nodal staging requires at least 7 to 12 nodes to accurately identify patients with regional nodal disease.

ImportanceTo our knowledge, there have been no clinical trials of ultra-high-dose-rate radiotherapy delivered at more than 40 Gy/sec, known as FLASH therapy, nor first-in-human use of proton FLASH.ObjectivesTo assess the clinical workflow feasibility and treatment-related toxic effects of FLASH and pain relief at the treatment sites.Design, Setting, and ParticipantsIn the FAST-01 nonrandomized trial, participants treated at Cincinnati Children’s/UC Health Proton Therapy Center underwent palliative FLASH radiotherapy to extremity bone metastases. Patients 18 years and older with 1 to 3 painful extremity bone metastases and life expectancies of 2 months or more were eligible. Patients were excluded if they had foot, hand, and wrist metastases; metastases locally treated in the 2 weeks prior; metal implants in the treatment field; known enhanced tissue radiosensitivity; and implanted devices at risk of malfunction with radiotherapy. One of 11 patients who consented was excluded based on eligibility. The end points were evaluated at 3 months posttreatment, and patients were followed up through death or loss to follow-up for toxic effects and pain assessments. Of the 10 included patients, 2 died after the 2-month follow-up but before the 3-month follow-up; 8 participants completed the 3-month evaluation. Data were collected from November 3, 2020, to January 28, 2022, and analyzed from January 28, 2022, to September 1, 2022.InterventionsBone metastases were treated on a FLASH-enabled (≥40 Gy/sec) proton radiotherapy system using a single-transmission proton beam. This is consistent with standard of care using the same prescription (8 Gy in a single fraction) but on a conventional-dose-rate (approximately 0.03 Gy/sec) photon radiotherapy system.Main Outcome and MeasuresMain outcomes included patient time on the treatment couch, device-related treatment delays, adverse events related to FLASH, patient-reported pain scores, and analgesic use.ResultsA total of 10 patients (age range, 27-81 years [median age, 63 years]; 5 [50%] male) underwent FLASH radiotherapy at 12 metastatic sites. There were no FLASH-related technical issues or delays. The average (range) time on the treatment couch was 18.9 (11-33) minutes per patient and 15.8 (11-22) minutes per treatment site. Median (range) follow-up was 4.8 (2.3-13.0) months. Adverse events were mild and consistent with conventional radiotherapy. Transient pain flares occurred in 4 of the 12 treated sites (33%). In 8 of the 12 sites (67%) patients reported pain relief, and in 6 of the 12 sites (50%) patients reported a complete response (no pain).Conclusions and RelevanceIn this nonrandomized trial, clinical workflow metrics, treatment efficacy, and safety data demonstrated that ultra-high-dose-rate proton FLASH radiotherapy was clinically feasible. The treatment efficacy and the profile of adverse events were comparable with those of standard-of-care radiotherapy. These findings support the further exploration of FLASH radiotherapy in patients with cancer.Trial RegistrationClinicalTrials.gov Identifier: NCT04592887

Simple Summary Rhabdomyosarcoma is a pediatric malignancy for which radiation therapy plays a significant role, along with surgery and chemotherapy. The approach to treatment varies by disease site as well as the histologic and molecular characterization of tumors. The head and neck represents a particularly complex location for radiation planning given the proximity of numerous critical structures. As a result, there is a great deal of complexity in terms of selecting radiation dose and technique that continues to evolve through large-scale trials by organizations such as the Children’s Oncology Group. This article aims to outline the management of head and neck rhabdomyosarcoma, describe the historical foundations of therapy for this disease, and provide a summary of current treatment recommendations, with a focus on radiation therapy. Abstract The use of radiation therapy is an important part of multimodality treatment for rhabdomyosarcoma. The specific doses, treatment volumes, and techniques used in radiation therapy can vary dramatically based upon a number of factors including location, tumor size, and molecular characteristics, resulting in complex decisions in treatment planning. This article reviews the principles of evaluation and management for head and neck rhabdomyosarcoma including a summary of the historical studies upon which current management is based.

This report by the Radiation Oncology Discipline of Children’s Oncology Group (COG) describes the practice patterns of pediatric image-guided radiotherapy (IGRT) based on a member survey and provides practice recommendations accordingly. The survey comprised of 11 vignettes asking clinicians about their recommended treatment modalities, IGRT preferences, and frequency of in-room verification. Technical questions asked physicists about imaging protocols, dose reduction, setup correction, and adaptive therapy. In this report, the COG Radiation Oncology Discipline provides an IGRT modality/frequency decision tree and the expert guidelines for the practice of ionizing image guidance in pediatric radiotherapy patients.

Stereotactic radiosurgery is increasingly used in patients with limited brain metastases and good baseline performance to avoid the toxicities of whole brain radiotherapy (WBRT). Patients with resected brain metastases are undergoing cavity-directed radiosurgery, withholding WBRT. Multiple institutions have published concerning incidences of leptomeningeal disease (LMD) when using this approach. We assess the risk of LMD in patients treated with this approach and identify risk factors for developing LMD. We identified 58 patients treated at our institution with cavity-directed SRS without WBRT for brain metastases between 2009 and 2015. Fifty-one (87.9%) had adequate follow-up for analysis, and 50 were treated to 30 Gy in 5 fractions to the resection cavity and are analyzed here. Patient demographics, tumor characteristics, and clinical outcomes were evaluated. With a median follow-up of 12.9 months (range, 1.9–63.2), the 1-year and 2-year incidences of LMD were 20 and 24%, respectively. The median time from SRS to the development of LMD was 6.0 months (range, 0.7–14.5). On multivariate analysis, ventricle violation during surgery (HR = 7.1, P = .030) and number of metastases (HR = 1.9, P = .034) were associated with an increased risk of LMD. One-year and 2-year leptomeningeal failure-free survival was 76 and 64%, and 1-year and 2-year survival of the entire cohort was 56 and 32%, respectively. LMD incidence is relatively high in patients receiving postoperative cavity-directed SRS. Ventricular violation during surgery causes a significantly higher risk of LMD, and consideration of WBRT, greater SRS target volumes, or preoperative treatment in these patients may be warranted.

Purpose Treatment recommendations for localized paratesticular rhabdomyosarcoma (PT RMS) differ in North America and Europe. We conducted a pooled analysis to identify demographic features and treatment choices that affect outcome. Patients and Methods We retrospectively analyzed the effect of nine demographic variables and four treatment choices on event-free survival (EFS) and overall survival (OS) from 12 studies conducted by five cooperative groups. Results Eight hundred forty-two patients with localized PT RMS who enrolled from 1988 to 2013 were included. Patients age ≥ 10 years were more likely than younger patients to have tumors that were > 5 cm, enlarged nodes (N1), or pathologically involved nodes ( P ≤ .05 each). With a median follow-up of 7.5 years, Kaplan-Meier estimates for 5-year EFS and OS were 87.7% and 94.8%, respectively. Of demographic variables, cooperative group, era of enrollment, age category, tumor size, Intergroup Rhabdomyosarcoma Study group, and T stage affected EFS ( P ≤ .05 each). Surgical assessment of regional nodes, which was performed in 23.5% of patients—usually in those age ≥ 10 years or with suspicious or N1 nodes—was the only treatment variable associated with EFS by univariable and multivariable analyses ( P ≤ .05 each) in patients age ≥ 1 year. A variable selection procedure on a proportional hazards regression model selected era of enrollment, age, tumor size, and surgical assessment of regional nodes as significant ( P ≤ .05 each) in the EFS model, and era of enrollment, age, tumor size, and histology ( P ≤ .05 each) in the OS model. Conclusion Localized PT RMS has a favorable prognosis. Age ≥ 10 years at diagnosis and tumor size larger than 5 cm are unfavorable prognostic features. Surgical assessment of regional nodes is important in patients age ≥ 10 years and in those with N1 nodes as it affects EFS.

Purpose Our aim was to review the advances in radiation therapy for the management of pediatric cancers made by the Children's Oncology Group (COG) radiation oncology discipline since its inception in 2000. Methods and Materials The various radiation oncology disease site leaders reviewed the contributions and advances in pediatric oncology made through the work of the COG. They have presented outcomes of relevant studies and summarized current treatment policies developed by consensus from experts in the field. Results The indications and techniques for pediatric radiation therapy have evolved considerably over the years for virtually all pediatric tumor types, resulting in improved cure rates together with the potential for decreased treatment-related morbidity and mortality. Conclusions The COG radiation oncology discipline has made significant contributions toward the treatment of childhood cancer. Our discipline is committed to continuing research to refine and modernize the use of radiation therapy in current and future protocols with the goal of further improving the cure rates and quality of life of children with cancer.

BACKGROUND BMI-1 is highly expressed in DIPG. Downregulation leads to inhibition of cell proliferation, cell cycle signaling, self-renewal, telomerase expression, activity, and suppression of DIPG cell migration. Targeted inhibition of BMI-1 sensitizes DIPG cells to radiation and drug-induced DNA damage. PTC596 (formulated by PTC Therapeutics, Inc.) is a novel, orally available drug that inhibits microtubule polymerization, resulting in G2/M cell cycle arrest and post-translational modification of BMI-1 protein and reduced BMI-1 protein levels. OBJECTIVES: To estimate the maximum tolerated dose and describe dose limiting toxicities, pharmacokinetics and pharmacodynamics of PTC596 in children 3–21 years of age with newly diagnosed diffuse intrinsic pontine glioma and high-grade gliomas. METHODS PTC596 is administered twice per week orally during radiotherapy and as maintenance for up to two years. The starting dose of PTC596 was 200 mg/m2, with a subsequent dose level of 260mg/m2/dose. Pharmacokinetics are performed in Cycles 1 and 2. RESULTS This study is currently ongoing. Nine patients (7 with DIPG, 2 with HGG), 8 evaluable, have been enrolled. At dose level 1, 200 mg/m2, three evaluable patients were enrolled and experienced no DLTs. At dose level 2, among 5 evaluable patients, 2 experienced dose-limiting grade 4 neutropenia. PTC596 has been otherwise well tolerated. Five patients remain in Cycles 2–11. CONCLUSION This phase I trial is ongoing. PTC596 is tolerable at dose level 1. We are amending the protocol to introduce tablets that can be dissolved in liquid to allow enrollment of younger patients and those unable to swallow whole tablets.

Radiation therapy (RT) is often used as a palliative treatment for children with recurrent malignant disease to ameliorate or prevent symptoms. However, no guidelines exist regarding the clinical indications or dose fractionation for palliative RT. The goal of this report is to provide guidelines for the use of palliative RT in children with cancer. In this guideline, appropriate indications for palliative RT, recommended dose-fractionation schedules, relevant toxicities, and avenues for future research are explored. RT is an effective palliative treatment for bone, brain, liver, lung, abdominopelvic and head-and-neck metastases, spinal cord compression, superior vena cava syndrome, and bleeding. Single-fraction regimens (8 Gy in one fraction) for children with short life expectancy are recommended for simple, uncomplicated bone metastases and can be considered for some patients with lung or liver metastases. A short, hypofractionated regimen (20 Gy in five fractions) may be used for other indications to minimize overall burden of therapy. There are little data supporting use of more prolonged fractionation regimens, though they may be considered for patients with very good performance status. Future research should focus on response and outcomes data collection, and to rigorously evaluate the role of stereotactic body RT in well-designed, prospective studies.

Purpose Craniospinal irradiation (CSI) is an important component of therapy for many pediatric central nervous system malignancies. Proton therapy is increasingly available and used for minimizing radiation exposure to normal tissues. The absence of an exit dose with proton therapy mandates decisions regarding coverage of the vertebral bodies (VB) in non–skeletally mature patients. Although the contents within the thecal sac represent the true clinical target volume (CTV), some physicians target the entire VB in growing children because of concerns over asymmetrical growth. This study aims to assess current practice patterns regarding VB coverage for pediatric patients undergoing CSI. Methods and Materials Pediatric radiation oncologists were identified from the Particle Therapy Co-Operative Group pediatric subcommittee membership or affiliation with US proton centers. Potential participants were contacted by e-mail with a link to an institutional review board–approved, anonymized web-based survey distributed in June 2017 with follow-up in October 2017. The survey used skip logic and included up to 11 questions regarding practice patterns. Results Thirty-three physicians responded to the survey (39%), 5 of which were excluded for lack of recent pediatric proton CSI experience. Of the 28 included responses, 23 physicians sometimes treat the entire VB and 5 physicians report always treating the entire VB. Most common responses regarding anterior CTV expansion for uncertainty were no expansion (n = 9) and 3 to 4 mm (n = 8). Most physicians modify the anterior CTV margin to protect normal structures, most commonly esophagus (n = 15), thyroid (n = 6), heart (n = 5), bowel (n = 4), and pharynx (n = 2). Conclusions Vertebral body coverage in proton CSI varies among radiation oncologists in respect to target delineation, CTV expansions, and modifications for organs at risk. These data suggest the radiation oncology community may benefit from a standardized approach to pediatric proton-based CSI.

BACKGROUND Failure-free survival (FFS) and overall survival (OS) rates were found to improve on Intergroup Rhabdomyosarcoma Study (IRS) IV (IRS-IV) compared with IRS-III for patients with subset 2 (IRS stage 1, group III nonorbit or stage 3, group I/II) low-risk embryonal rhabdomyosarcoma with the addition of cyclophosphamide (total cumulative cyclophosphamide dose of 26.4 g/m2 ) to the combination of vincristine and dactinomycin (VAC). The goal of Children's Oncology Group ARST0331 for subset 2 low-risk patients was to reduce the total cumulative cyclophosphamide dose without compromising FFS. METHODS Therapy included 4 cycles of VAC (total cumulative cyclophosphamide dose of 4.8 g/m2 ) followed by 12 cycles of vincristine and dactinomycin over 46 weeks. Patients with group II or III tumors received radiotherapy, except for girls with group III vaginal tumors who enrolled before September 2009 and achieved a complete response with chemotherapy with or without delayed surgical resection. RESULTS Among 66 eligible patients who were followed for a median of 3.5 years, there were 20 failures versus 10.53 expected failures. The estimated 3-year FFS and OS rates were 70% (95% confidence interval [95% CI], 57%-80%) and 92% (95% CI, 83%-97%), respectively. The estimated 3-year FFS rate was 57% (95% CI, 33%-75%) for girls with subset 2 genital tract embryonal rhabdomyosarcoma (21 patients) and 77% (95% CI, 61%-87%) for all other subset 2 patients (45 patients) (P = .02). CONCLUSIONS The authors observed suboptimal FFS among patients with subset 2 low-risk rhabdomyosarcoma using reduced total cyclophosphamide. Eliminating radiotherapy for girls with group III vaginal tumors in combination with reduced total cyclophosphamide appeared to contribute to the suboptimal outcome. Cancer 2017;123:2368-2375. © 2017 American Cancer Society.

Single-fraction stereotactic radiosurgery(SRS) for meningioma has high rates of symptomatic perilesional edema in some settings. Fractionated stereotactic radiosurgery(fSRS) could decrease edema rates while maintaining tumor control.Patients at an institution were retrospectively reviewed(2013-2017). Adults receiving definitive, linear accelerator(linac)-based fSRS (25-30Gy/5 fractions) were included. fSRS was recommended for tumors at high risk for perilesional edema with SRS due to large size, prior irradiation, or proximity to organs at risk. Endpoints included rates of symptomatic, radiographically-defined perilesional edema and local control(LC).12 Patients with 13 meningiomas met criteria. 24-month actuarial LC and overall survival were 87% and 100%. Symptomatic, post-treatment edema was identified on follow-up MRI in 31% of cases. No variables predicted edema, but affected lesions were larger(6.82 v. 2.46cc).Linac-based fSRS for meningioma has high local control and modest toxicity rates similar to SRS in the literature. Prospective studies comparing fSRS/SRS are warranted.

Purpose For infants with localized rhabdomyosarcoma who were enrolled on Children's Oncology Group ARST0331 and ARST0531, local therapy guidelines were provided, but adherence was not mandated because of toxicity concerns. We examined adherence to protocol for local therapy guidelines, treatment variations, and outcomes for these patients. Methods Children aged ≤24 months who were enrolled on ARST0331 and ARST0531 were evaluated. Data were verified through radiologic, surgical, pathologic, and clinical records. Local therapy was assessed for adherence to protocol guidelines, with variations termed “individualized local therapy.” The subdistribution hazards model assessed local failure, the Kaplan-Meier product limit method assessed event-free survival (EFS) and overall survival, and the log-rank test was used to evaluate prognostic impact. Results The median age of the patients was 14 months, and 124 patients were eligible. Common primary sites were genitourinary (40%), parameningeal (14%), and the extremities (11%). Most patients had unresected disease (group 3, 64%) and embryonal histology (73%). Fifty-eight percent of patients received radiation therapy at a median of week 12 (weeks 1-45). The median radiation dose was 48.6 Gy (30.6-54 Gy). Forty-three percent of patients received individualized local therapy (outside protocol guidelines), typically omission or delay of radiation therapy. Delayed primary excision was performed in 28% at a median of week 14 (weeks 7-34). With a median follow-up of 5.6 years, the 5-year local failure, EFS, and overall survival rates were 24%, 68%, and 82%, respectively. Local failure was significantly higher (35%) in patients receiving individualized local therapy than in patients who received protocol-specified local therapy (16%; P = .02). The site of failure was local in 64% of patients, local and distant in 5%, and distant only in 23%. EFS was significantly higher among patients who were aged 12 to 24 months, had tumors ≤5 cm, had group 1/2 disease, and underwent protocol-specified therapy. Conclusions Local recurrence was the predominant pattern of failure and was more common in those receiving individualized local therapy. De-escalation of effective therapies because of concerns about treatment toxicity should be considered cautiously.

Neurofibromatosis (NF) types 1 and 2 are classified as phacomatoses with an autosomal-dominant inheritance pattern. They are important in the field of neuro-oncology as they predispose affected patients to a number of CNS tumors including acoustic schwannoma, meningioma, glioma, ependymoma, and malignant peripheral nerve sheath tumor (MPNST). Management of tumors in patients with NF can differ from that in the non-NF population owing to a natural history that may be more aggressive, a greater need to preserve function in patients with acoustic schwannoma, and the concern for increased risk of radiation-induced tumors in this population. The management of NF-related acoustic schwannoma, meningioma, and MPNST is discussed here, while management of glioma and ependymoma is presented in separate chapters.

In patients with pituitary adenomas (PA) who are unable to undergo complete surgical resection, radiation therapy (RT), specifically stereotactic radiosurgery (SRS), results in excellent local control. However, the utility of radiosurgery may be limited by the proximity of the lesion to the optic chiasm (OC). We evaluate the efficacy of debulking surgery in increasing the PA-OC separation to convert patients into SRS candidates. From 2007 to 2015, 31 patients with PA

International Commission on Radiotherapy Units (ICRU) definitions (Prescribing, Recording, and Reporting Photon Beam Therapy, ICRU report 62)

Genomic sequencing studies have uncovered alterations of checkpoint cell cycle regulators (CDK4/6, CDK2NA) in diffuse intrinsic pontine gliomas (DIPG) and high-grade gliomas (HGG). Ribociclib (LEE011) is an orally bioavailable, small molecule inhibitor of CDK4/CyclinD1 and CDK6/CyclinD3 complexes resulting in hypophosphorylation of RB and cell cycle arrest. In a feasibility, phase II study, patients with newly-diagnosed DIPG or HGG received radiation therapy prior to enrollment. All HGG patients and any DIPG patient who had undergone biopsy were screened for total RB protein by immunohistochemistry. Ribociclib was administered daily for 21 of 28 days at 350 mg/m/day. Feasibilty endpoints included toxic death, Grade 3/4 toxicities possibly related to ribociclib resulting in drug discontinuation, > 2 weeks delay in the start of any course or discontinuation of the protocol therapy even after appropriate dose modification. Efficacy was measured by the overall survival distribution for DIPG and HGG. Of the 10 patients enrolled (median 6.5 years; range:4–20), 9 received treatment (8 DIPG, 1 HGG) and one developed leptomeningeal disease prior to therapy. To date, the median number of courses are 4.5 (range: 1–10). Ribociclib was well-tolerated; three patients required dose reduction for grade 4 neutropenia; no patients have come off therapy for toxicity. The most common adverse events were leukopenia, neutropenia, lymphopenia, nausea, vomiting, and fatigue. MRI evaluations in 2 patients revealed increased T2 FLAIR signal with new neurological symptoms within the first 2 cycles of therapy. These patients were responsive to steroids and remain on study. Six patients remain on active therapy at a median of 9 months post diagnosis (range: 3–12). The preliminary analysis demonstrates that ribociclib, administered post radiation therapy is well-tolerated in children and young adults with DIPG and RB+ HGG. Analyses for efficacy and correlative studies will be presented at the meeting.

Purpose Intergroup Rhabdomyosarcoma Study Group (IRSG) studies III and IV showed improved failure-free survival (FFS) rates with vincristine, dactinomycin, and cyclophosphamide (VAC; total cumulative cyclophosphamide dose, 26.4 g/m2) compared with vincristine and dactinomycin (VA) for patients with subset-one low-risk embryonal rhabdomyosarcoma (ERMS; stage 1/2 group I/II ERMS or stage 1 group III orbit ERMS). The objective of Children's Oncology Group ARST0331 was to reduce the length of therapy without compromising FFS for this subset of low-risk patients by using VA in combination with lower-dose cyclophosphamide (total cumulative dose, 4.8 g/m2) plus radiotherapy (RT). Patients and Methods This noninferiority prospective clinical trial enrolled newly diagnosed patients with subset-one clinical features. Therapy included four cycles of VAC followed by four cycles of VA over 22 weeks. Patients with microscopic or gross residual disease at study entry received RT. Results With a median follow-up of 4.3 years, we observed 35 failures among 271 eligible patients versus 48.4 expected failures, calculated using a fixed outcome based on the FFS expected for similar patients treated on the IRSG D9602 protocol. The estimated 3-year FFS rate was 89% (95% CI, 85% to 92%), and the overall survival rate was 98% (95% CI, 95% to 99%). Patients with paratesticular tumors had the most favorable outcome. Three-year cumulative incidence rates for any local, regional, or distant failures were 7.6%, 1.5%, and 3.4%, respectively. Conclusion Shorter-duration therapy that included lower-dose cyclophosphamide and RT did not compromise FFS for patients with subset-one low-risk ERMS.

Purpose Currently, most high-grade glioma patients undergo a 1.5T brain magnetic resonance (MR) for radiation treatment planning. We hypothesized that 3T MR imaging (MRI) scanning is superior to 1.5T due to higher signal-to-noise ratio (SNR), and thus will result in more accurate quantification of tumor volumes. The purpose of this prospective study was to determine differences in radiation planning volumes for high-grade gliomas when scanned on 3T MR versus 1.5T MR. Methods and materials In this prospective controlled trial, 23 patients with high-grade gliomas underwent brain MRI scanning in both 1.5T and 3T field strengths within a 24-hour period; no steroids or treatment changes were made in-between scans. After 3 investigators contoured the T2 fast low-angle inversion recovery (FLAIR) abnormality (gross tumor volumes or [GTV]) for all patients, clinical target volume (CTV) and planning treatment volumes (PTV) were defined. Calculations by an independent investigator included volumes, standard deviations, SNRs, and contrast-to-noise ratios (CNRs); statistical analysis was performed on raw data. Results Planning treatment volume ratios (3T:1.5T) for each investigator were 0.95 ± 0.12 (range, 0.64-1.10), 0.98 ± 0.10 (range, 0.64-1.16), and 0.99 ± 0.06 (range, 0.86-1.13). By paired 2-tailed t test, these volumes were not statistically different ( P = .051), although there is a trend to 3T producing smaller volumes than 1.5T. Dice similarity coefficients were 0.90 ± 0.05, 0.90 ± 0.06, and 0.91 ± 0.05 for the investigators. Conclusions Planning target volumes for high-grade gliomas were similar at 3T and 1.5T MR using our standard imaging protocols. However, in some patients, the 3T MR may reveal substantially smaller tumor volume due to inferior conspicuity of the lesion. These findings imply that while overall the radiation target volumes are comparable, there are differences in CNR and SNR that lead to differences in individual patients. The 1.5T may be better for gaining conspicuity of the tumor.

This case report documents the migration of 3 iodine-125 (125I) seeds from the tumor resection cavity into brain parenchyma over a 7-year period. A 66-year-old woman had a history of metastatic ovarian carcinoma, nickel allergy, and reaction to a titanium hip implant that required reoperation for hardware removal. In this unique case of parenchymal migration, the seed paths seemed to follow white matter tracts, traveling between 18.5 and 35.5 mm from the initial implant site. The patient's initial neurological decline, which was thought to be related to radiation necrosis, appeared to stabilize with medical therapy. She subsequently developed progressive right hemispheric edema that resulted in neurological deterioration and death. Considering her previous reactions to nickel and titanium, the authors now speculate that her later clinical course reflected an allergic reaction to the titanium casing of the 125I seeds. Containing a trace amount of nickel, 125I seeds can elicit a delayed hypersensitivity reaction in patients with a history of nickel dermatitis. Preoperative patch testing is recommended in these patients, and 125I seed implantation should be avoided in those who test positive.

Diffuse intrinsic pontine glioma (DIPG) is a devastating pediatric disease, with a median survival of1 year. Here, we review our institution's DIPG experience over an 8-year interval and perform a systematic review of the literature, specifically evaluating reports of reirradiation (reRT) for DIPG.We retrospectively reviewed the medical records of 26 patients who underwent definitive intensity modulated radiation therapy (IMRT) for DIPG at a single institution between 2007 and 2015. Three of these patients underwent reRT for progressive disease. Clinical endpoints, including progression-free survival and overall survival (OS), were assessed. We then performed a thorough PubMed search of the literature discussing reRT for patients with DIPG.Twenty-four of the 26 patients (92%) completed the initial course of radiation (54 Gy in 1.8-Gy fractions using IMRT). Median age at diagnosis was 6.0 years (range, 2.0-26.5). With respect to systemic therapy, 1 (4.2%) received no systemic therapy, 1 (4.2%) received concurrent systemic therapy alone, 4 (16.7%) received adjuvant therapy alone, and 18 (75%) received a combination of concurrent and adjuvant therapy. Median follow-up time was 11 months from the date of initial diagnosis. Median OS for the cohort was 12 months, with a 1-year OS of 51%. The 3 patients who underwent reRT received 20 Gy in 10 daily fractions using IMRT alone with no treatment toxicity noted.Radiation therapy is essential in the definitive management of DIPG. With advances in treatment techniques, it is feasible to reirradiate select patients with progressive disease; however, further research is warranted to optimize dose, delivery, and patient selection in the recurrent/progressive setting. In the future, it may be reasonable to propose more focal delivery of reRT (ie, hypofractionated radiation) in select patients with the goal of reducing treatment time and providing effective palliation.

Failure-free survival (FFS) and overall survival (OS) rates were found to improve on Intergroup Rhabdomyosarcoma Study (IRS) IV (IRS-IV) compared with IRS-III for patients with subset 2 (IRS stage 1, group III nonorbit or stage 3, group I/II) low-risk embryonal rhabdomyosarcoma with the addition of cyclophosphamide (total cumulative cyclophosphamide dose of 26.4 g/mTherapy included 4 cycles of VAC (total cumulative cyclophosphamide dose of 4.8 g/mAmong 66 eligible patients who were followed for a median of 3.5 years, there were 20 failures versus 10.53 expected failures. The estimated 3-year FFS and OS rates were 70% (95% confidence interval [95% CI], 57%-80%) and 92% (95% CI, 83%-97%), respectively. The estimated 3-year FFS rate was 57% (95% CI, 33%-75%) for girls with subset 2 genital tract embryonal rhabdomyosarcoma (21 patients) and 77% (95% CI, 61%-87%) for all other subset 2 patients (45 patients) (P = .02).The authors observed suboptimal FFS among patients with subset 2 low-risk rhabdomyosarcoma using reduced total cyclophosphamide. Eliminating radiotherapy for girls with group III vaginal tumors in combination with reduced total cyclophosphamide appeared to contribute to the suboptimal outcome. Cancer 2017;123:2368-2375. © 2017 American Cancer Society.

Purpose To analyze the effect of reduced-dose radiotherapy on local control in children with low-risk rhabdomyosarcoma (RMS) treated in the Children's Oncology Group D9602 study. Methods and Materials Patients with low-risk RMS were nonrandomly assigned to receive radiotherapy doses dependent on the completeness of surgical resection of the primary tumor (clinical group) and the presence of involved regional lymph nodes. After resection, most patients with microscopic residual and uninvolved nodes received 36 Gy, those with involved nodes received 41.4 to 50.4 Gy, and those with orbital primary tumors received 45 Gy. All patients received vincristine and dactinomycin, with cyclophosphamide added for patient subsets with a higher risk of relapse in Intergroup Rhabdomyosarcoma Study Group III and IV studies. Results Three hundred forty-two patients were eligible for analysis; 172 received radiotherapy as part of their treatment. The cumulative incidence of local/regional failure was 15% in patients with microscopic involved margins when cyclophosphamide was not part of the treatment regimen and 0% when cyclophosphamide was included. The cumulative incidence of local/regional failure was 14% in patients with orbital tumors. Protocol-specified omission of radiotherapy in girls with Group IIA vaginal tumors ( n = 5) resulted in three failures for this group. Conclusions In comparison with Intergroup Rhabdomyosarcoma Study Group III and IV results, reduced-dose radiotherapy does not compromise local control for patients with microscopic tumor after surgical resection or with orbital primary tumors when cyclophosphamide is added to the treatment program. Girls with unresected nonbladder genitourinary tumors require radiotherapy for postsurgical residual tumor for optimal local control to be achieved.

Purpose Postoperative radiation therapy (RT) is recommended for patients with rhabdomyosarcoma having microscopic disease. Sometimes RT dose/volume is reduced or omitted in an attempt to avoid late effects, particularly in young children. We reviewed operative bed recurrences to determine if noncompliance with RT protocol guidelines influenced local-regional control. Methods and Materials All operative bed recurrences among 695 Group II rhabdomyosarcoma patients in Intergroup Rhabdomyosarcoma Study Group (IRS) I through IV were reviewed for deviation from RT protocol. Major/minor dose deviation was defined as >10% or 6–10% of the prescribed dose (40–60 Gy), respectively. Major/minor volume deviation was defined as tumor excluded from the RT field or treatment volume not covered by the specified margin (preoperative tumor volume and 2- to 5-cm margin), respectively. No RT was a major deviation. Results Forty-six of 83 (55%) patients with operative bed recurrences did not receive the intended RT (39 major and 7 minor deviations). RT omission was the most frequent RT protocol deviation (19/46, 41%), followed by dose (17/46, 37%), volume (9/46, 20%), and dose and volume deviation (1/46, 2%). Only 7 operative bed recurrences occurred in IRS IV (5% local-regional failure) with only 3 RT protocol deviations. Sixty-three (76%) patients with recurrence died of disease despite retrieval therapy, including 13 of 19 nonirradiated children. Conclusion Over half of the operative bed recurrences were associated with noncompliance; omission of RT was the most common protocol deviation. Three fourths of children die when local-regional disease is not controlled, emphasizing the importance of RT in Group II rhabdomyosarcoma.