Quality-of-life evaluations in children and adolescents with Ewing sarcoma treated with pencil-beam-scanning proton therapy.

BACKGROUND: With improved survival rates for children with cancer, quality-of-life (QoL) issues have increasingly become the focus of attention. We report the QoL of children with Ewing sarcoma (EWS) treated with pencil-beam-scanning proton therapy (PT). METHODS: A PEDQOL (QoL questionnaire for children 4-18 years) self/proxy questionnaire was used to prospectively assess the QoL of 23 children <18 years with EWS treated with PT. This questionnaire evaluates eight different domains. Children (self-rating) and parents (proxy-rating) filled out the questionnaire at the start of PT (E1), 2 months after treatment (E2), and thereafter once yearly (E≥3). RESULTS: Compared with healthy controls, parents rated the QoL of their children at E1 significantly worse in all but two (cognition and social functioning-family) domains. At E4, significant differences between the two groups only remained in three of eight domains. At E1, children self-rated their QoL significantly worse in the domain Physical functioning (p = .004) and significantly better in the domain Body image (p = .044) compared to healthy controls, whereas no significant differences were observed at E4. For the longitudinal comparison E1 versus E4, according to parents, Emotional functioning, Cognition and Social functioning-peers were slightly decreased 2 years after PT. The children rated Emotional functioning and Body image poorly 2 years after PT. CONCLUSIONS: Children with EWS usually recovered seemingly well to normal QoL levels 2 years after the end of PT. They tended to rate their QoL substantially higher than their parents. However, in the longitudinal analysis at 2 years, children rated their Emotional functioning and Body image scores poorly.

Clinical outcomes and quality of life in children and adolescents with primary brain tumors treated with pencil beam scanning proton therapy.

BACKGROUND: Long-term treatment-related toxicity may substantially impact well-being, quality of life (QoL), and health of children/adolescents with brain tumors (CBTs). Strategies to reduce toxicity include pencil beam scanning (PBS) proton therapy (PT). This study aims to report clinical outcomes and QoL in PBS-treated CBTs. PROCEDURE: We retrospectively reviewed 221 PBS-treated CBTs aged <18 years. Overall-free (OS), disease-free (DFS), and late-toxicity-free survivals (TFS), local control (LC) and distant (DC) brain/spinal control were calculated using Kaplan-Meier estimates. Prospective QoL reports from 206 patients (proxies only ≤4 years old [yo], proxies and patients ≥5 yo) were descriptively analyzed. Median follow-up was 51 months (range, 4-222). RESULTS: Median age at diagnosis was 3.1 years (range, 0.3-17.7). The main histologies were ependymoma (n = 88; 39.8%), glioma (n = 37; 16.7%), craniopharyngioma (n = 22; 10.0%), atypical teratoid/rhabdoid tumor (ATRT) (n = 21; 9.5%) and medulloblastoma (n = 15; 6.8%). One hundred sixty (72.4%) patients received chemotherapy. Median PT dose was 54 Gy(relative biological effectiveness) (range, 18.0-64.8). The 5-year OS, DFS, LC, and DC (95% CI) were 79.9% (74-85.8), 65.2% (59.8-70.6), 72.1% (65.4-78.8), and 81.8% (76.3-87.3), respectively. Late PT-related ≥G3 toxicity occurred in 19 (8.6%) patients. The 5-year ≥G3 TFS was 91.0% (86.3-95.7). Three (1.4%) secondary malignancies were observed. Patients aged ≤3 years at PT (P = .044) or receiving chemotherapy (P = .043) experienced more ≥G3 toxicity. ATRT histology independently predicted distant brain failure (P = .046) and death (P = .01). Patients aged ≥5 years self-rated QoL higher than their parents (proxy assessment). Both reported lower social functioning and cognition after PT than at baseline, but near-normal long-term global well-being. QoL was well below normal before and after PT in children ≤4 years. CONCLUSIONS: The outcome of CBTs was excellent after PBS. Few patients had late ≥G3 toxicity. Patients aged <5 years showed worse QoL and toxicity outcomes.

Tumor control and QoL outcomes of very young children with atypical teratoid/rhabdoid tumor treated with focal only chemo-radiation therapy using pencil beam scanning proton therapy.

The aim of this analysis was to assess the early clinical results of pencil beam scanning proton therapy (PT) in the treatment of young children with non-metastatic atypical teratoid/rhabdoid tumor (ATRT) of the CNS. Fifteen children (male, n = 8, 53 %) were treated with PT between May 2008 and January 2013. Mean age at diagnosis was 17.4 ± 7.0 months. The localization was infratentorial in 9 (60 %) patients. Gross total resection of the primary tumors was achieved in 7 (47 %) patients. The dose administered focally under sedation was 54 Gy (RBE). After a median follow-up of 33.4 months (range 9.7-69.2), 3 (20 %), 4 (27 %) and 2 (13 %) patients presented with local failure (LF), distant brain failure (DBF) and spinal failure (SF), respectively. Six patients died, all of tumor progression. The 2-year overall- and progression-free survival was 64.6 and 66.0 %. Tumor location (supratentorial) and the extent of surgical resection (non-gross total resection) were negative prognostic factors for both OS and PFS. PT was well tolerated. No grade >2 acute toxicity was observed. The estimated 2-year toxicity-free survival was 90 %. As assessed by the PedsQoL proxy, no decrease in QoL was observed after PT. We conclude that PBS PT is an effective treatment for young children with ATRT. After PT, with or without concomitant chemotherapy, two third of the patients survived >2 years. Acute toxicity was manageable. Longer follow-up and larger numbers of patients are needed to assess long-term outcomes and treatment-induced toxicity.

Pencil Beam Scanning Proton Therapy for Adolescents and Young Adults with Head and Neck Sarcomas.

Purpose: To assess clinical outcomes of adolescents and young adults (AYAs) with head and neck sarcomas (HNSs) treated with pencil beam scanning proton therapy (PBSPT) and to report quality of life (QoL). Materials and Methods: Twenty-eight AYAs (aged 15 to 39 years) with HNS treated between January 2001 and July 2022 at our institution were included. The median age was 21.6 years. Rhabdomyosarcoma (39.3%), Ewing sarcoma (17.9%), chondrosarcoma (14.3%), and osteosarcoma (14.3%) were the most frequent diagnoses. Three (10.7%) patients were metastatic before PBSPT and 13 (46.4%) patients had a tumor with intracranial extension. The median total radiation dose was 63 GyRBE (range, 45 to 74 GyRBE). Thirteen (46.4%) patients received concomitant chemotherapy. Toxicity was reported according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0 (US National Institutes of Health, Bethesda, Maryland). Survival was estimated using the Kaplan-Meier method. QoL was assessed using a PEDQOL (Pediatric Quality of Life Questionnaire) questionnaire. Self-reported outcomes were assessed using institutional questionnaires. Results: With a median follow-up of 57 months (range, 3.7 to 243 months), 5 patients (17.8%) had local failure (LF) only, 2 (7.1%) experienced distant failure (DF) only, and 2 (7.1%) had LF and DF. The estimated 5-year local control (LC) and distant control (DC) rates were 71.8% and 80.5%, respectively. The median times to LF and DF were 13.4 and 22.2 months, respectively. Four (14.3%) patients died, all but one from their HNS. Estimated 5-year overall survival was 90.7%. Six (21.4%) patients developed nonocular grade ≥3 toxicity, which consisted of otitis media (n = 2), hearing impairment (n = 2), osteoradionecrosis (n = 1), and sinusitis (n = 1). Four (14.3%) patients developed cataracts that required surgery. The 5-year freedom from nonocular grade 3 toxicity was 91.1%. No grade 4 or higher toxicity was observed. Adolescents rated their quality of life before treatment worse than their parents did. Conclusion: Excellent outcomes with acceptable late-toxicity rates were observed for AYAs with HNS after PBSPT.

Quality of Life, Clinical, and Patient-Reported Outcomes after Pencil Beam Scanning Proton Therapy Delivered for Intracranial Grade WHO 1-2 Meningioma in Children and Adolescents.

PURPOSE: The purpose of this study was to report the clinical and patient-reported outcomes of children and adolescents with intracranial meningioma treated with pencil beam scanning proton therapy (PBS-PT). MATERIAL AND METHODS: Out of a total cohort of 207 intracranial meningioma patients treated with PBS-PT between 1999 and 2022, 10 (4.8%) were children or adolescents aged < 18 years. Median age was 13.9 years (range, 3.2-17.2). Six (60%) children were treated as primary treatment (postoperative PT, n = 4; exclusive PT, n = 2) and four (40%) at the time of tumor recurrence. Acute and late toxicities were registered according to Common Terminology Criteria of Adverse Events (CTCAE). Quality of life (QoL) before PBS-PT was assessed using PEDQOL questionnaires. Educational, functional, and social aspects after PT were assessed through our in-house developed follow-up surveys. Median follow-up time was 71.1 months (range, 2.5-249.7), and median time to last questionnaire available was 37.6 months (range, 5.75-112.6). RESULTS: Five (50%) children developed local failure (LF) at a median time of 32.4 months (range, 17.7-55.4) after PBS-PT and four (80%) were considered in-field. One patient died of T-cell lymphoma 127.1 months after PBS-PT. Estimated 5-year local control (LC) and overall survival (OS) rates were 19.4% and 100.0%, respectively. Except for one patient who developed a cataract requiring surgery, no grade ≥3 late toxicities were reported. Before PT, patients rated their QoL lower than their parents in most domains. During the first year after PT, one child required educational support, one needed to attend to a special school, one had social problems and another three children required assistance for daily basic activities (DBA). Three years after PT, only one child required assistance for DBA. CONCLUSIONS: The outcome of children with intracranial meningioma treated with PBS-PT is in line with other centers who have reported results of radiation therapy delivered to this particular patient group. This therapy provides acceptable functional status profiles with no high-grade adverse radiation-induced events.

A Prospective Study on Health-Related Quality of Life and Patient-Reported Outcomes in Adult Brain Tumor Patients Treated with Pencil Beam Scanning Proton Therapy.

Proton therapy (PT) is delivered to complex brain tumors to obtain an optimal curative treatment with limited toxicity. Value-based oncological medicine is increasingly important, particularly when long-term survival is to be expected. This study aims to evaluate health-related quality of life (HRQOL) and patient reported outcomes (PROs) in patients treated with PT for brain tumors. Adult patients with brain tumors treated with PT filled out the EORTC-QLQ-C30 and BN20 questionnaires up to three years following PT. Toxicity was scored using the CTCAE v4.03. QoL and PRO were correlated to clinical factors. Three-year overall survival, distant brain control and local control rates were 98%, 97% and 84%, respectively. No ≥G3 acute toxicity was observed. Late PT-related ≥G3 severe toxicity occurred in seven patients (5.7%). Lower global QoL scores after PT were significantly correlated to low Karnofsky performance status (KPS) before PT (p = 0.001), surgical complications before PT (p = 0.04) and progressive disease (p = 0.017). A low QLQ-30 summary score at one year follow-up was correlated to sex (p = 0.015), low KPS before PT (p < 0.001), and central nervous system symptoms before PT (p = 0.018). Reported QLQ-BN20 neurological symptoms were correlated to lower KPS at baseline (p < 0.001) and surgical complications before PT (p = 0.03). PT-related toxicity only influenced reported symptoms directly following PT, but not QoL. Although global QoL temporarily decreased after treatment, it improved again from one year onwards. Global QoL and reported symptoms over time were not correlated with the proton therapy and were more related to preexisting symptoms and progressive disease. This study assists in improving patient support in patients with brain tumors receiving PT.

Radiation-induced optic neuropathy after pencil beam scanning proton therapy for skull-base and head and neck tumours.

OBJECTIVE: To assess the radiation-induced optic neuropathy (RION) prevalence, following high dose pencil beam scanning proton therapy (PBSPT) to skull base and head and neck (H&N) tumours. METHODS: Between 1999 and 2014, 216 adult patients, median age 47 years (range, 18-77), were treated with PBS PT for skull base or H&N malignancies, delivering ≥45 GyRBE to the optic nerve(s) (ON) and/or optic chiasma (OC). The median administered dose to the planning target volume was 74.0 GyRBE (range, 54.0-77.4). The median follow-up was 5.3 years (range, 0.8-15.9). RESULTS: RION was observed in 14 (6.5%) patients at a median time of 13.2 months (range, 4.8-42.6) following PBSPT. Most (92.9%) of RION were symptomatic. Most affected patients (11/14; 79%) developed unilateral toxicity. Grade 4, 3, 2 and 1 toxicity was observed in 10, 2, 1 and 1 patients, respectively. On univariate analyses, age (<70 vs ≥70 years; p < 0.0001), hypertension (p = 0.0007) and tumour abutting the optic apparatus (p = 0.012) were associated with RION. OC's V60 GyRBE was of border line significance (p = 0.06). None of the other evaluated OC-ON dose/volume metrics (Dmax, Dmean, V40-60) were significantly associated with this complication. CONCLUSION: These data suggest that high-dose PBS PT for skull base and H&N tumours is associated with a low prevalence of RION. Caution should be however exercised when treating elderly/hypertensive patients with tumours abutting the optic apparatus. ADVANCES IN KNOWLEDGE: This is the first study reporting the risk of developing RION following proton therapy with PBS technique, demonstrating the safety of this treatment.

Proton therapy for brain tumours in the area of evidence-based medicine.

ADVANCES IN KNOWLEDGE: This review details the indication of brain tumors for proton therapy and give a list of the open prospective trials for these challenging tumors.

Clinical outcomes of head and neck adenoid cystic carcinoma patients treated with pencil beam-scanning proton therapy.

OBJECTIVE: The aim of this study was to evaluate the outcome of patients with head and neck adenoid cystic carcinoma (ACC) treated using pencil beam scanning proton therapy (PBS PT) at our institution. MATERIALS AND METHODS: Thirty-five patients who underwent treatment with PBS PT for ACC between 2001 and 2017 were included. Local control (LC), distant control (DC), progression-free survival (PFS), overall survival (OS) and their prognostic factors were evaluated. Adverse effects were prospectively assessed. RESULTS: The median patient follow-up was 30 months. Prior to PT, 26 patients (74.3%) underwent surgery with R0/R1/R2 outcome in 5, 13 and 8 cases, respectively. Nine patients (25.7%) presented with inoperable disease. The 2-year LC, DC, PFS and OS was 92.2%, 77.8%, 74.3% and 88.8%, respectively. LC was influenced by patient age (p = 0.002) with a significant difference between local and distant failure (median 61.3 vs. 42.3 years, p = 0.005). Tumor T stage was a significant risk factor for PFS (p = 0.045) and tumor prognostic group affected OS (p = 0.049). No significant survival advantage for operable vs. inoperable disease could be identified. The acute and late grade 3 toxicity rates were 14.3% and 6.1%, respectively. No acute or late grade 4/5 toxicities were observed. CONCLUSIONS: PBS PT is an effective and safe treatment for patients with head & neck ACC in both definitive and adjuvant setting. Distant metastases are the main pattern of failure. Age, tumor stage and clinical stage had a significant negative impact on LC, OS and PFS.

Long-Term Clinical Safety of High-Dose Proton Radiation Therapy Delivered With Pencil Beam Scanning Technique for Extracranial Chordomas and Chondrosarcomas in Adult Patients: Clinical Evidence of Spinal Cord Tolerance.

PURPOSE: To assess the radiation dose tolerance of the spinal cord by reviewing our institutional experience regarding the incidence of radiation-induced spinal cord toxicity after high-dose pencil beam scanning proton therapy (PBSPT). METHODS AND MATERIALS: Seventy-six patients (median age 53 years; range, 23-79 years) treated for spinal chordoma (n=55) or chondrosarcoma (n=21) met the following criteria and were retrospectively analyzed: PBSPT only, no reirradiation or concomitant chemotherapy, maximum dose (Dmax) to the spinal cord of ≥45 Gy(relative biological effectiveness [RBE]), ≥18 years of age, and follow-up of ≥12 months. The delivered dose was 59.4 to 75.2 Gy(RBE) [median 73.9 Gy(RBE)] delivered with conventional fractionation between 2000 and 2014. The Dmax, D2%, and V40-V60 of the surface (sSC) and center (cSC) of the spinal cord were recorded. Toxicity was scored according to the Common Terminology Criteria for Adverse Events, version 4.03. RESULTS: Median follow-up was 65.5 months (range, 13-173 months). Patients received a mean Dmax and D2% to the sSC of 59.0 (median 58.7; range, 48.3-75.9) and 55.3 (median 52.7; range, 43.1-73.8) Gy(RBE), respectively. The corresponding values for the cSC were 52.3 (median 52.7; range, 32.3-73.3) and 51.1 (median 52.0; range, 25.3-73.1) Gy(RBE), respectively. Four patients (5%) developed acute radiation-induced neurotoxicity (grade [G] 1, n=1; G2, n=3). Twelve patients (16%) experienced late neurologic toxicities (G1, n=7; G2, n=4; G4, n=1). One patient with a history of pre-PBSPT symptomatic spinal cord compression redeveloped tetraplegia (G4) after receiving a Dmax of 57.8 Gy(RBE) to the sSC and 54.1 Gy(RBE) to the cSC. No significant correlation was found between sSC Dmax and D2%, cSC Dmax and D2%, or the length of CTV and toxicity. CONCLUSIONS: High-dose conformal PBSPT may be delivered safely in close proximity to the spinal cord with minimal neurotoxicity. Dose constraints of 64 Gy(RBE) as D2% for the sSC and 54 Gy(RBE) for the cSC seem appropriate for clinical use.

Long-Term Outcomes and Prognostic Factors After Pencil-Beam Scanning Proton Radiation Therapy for Spinal Chordomas: A Large, Single-Institution Cohort.

PURPOSE: To evaluate the efficacy and safety of high-dose pencil-beam scanning proton therapy (PBS-PT) in the adjuvant treatment of spinal chordomas. METHODS AND MATERIALS: Between 1997 and 2015, 100 patients with spinal chordomas (median age, 56 years; range, 25-81 years) were treated with adjuvant PBS-PT at the Paul Scherrer Institute: cervical (n = 46), thoracic (n = 4), lumbar (n = 12), and sacral (n = 38). The majority (88%) received PBS-PT alone rather than combined photon-proton therapy. The median radiation therapy dose prescribed was 74 Gy (relative biological effectiveness [RBE]) (range, 59.4-77 Gy [RBE]). Thirty-nine patients (39%) had undergone surgical stabilization, primarily with titanium hardware, before radiation therapy. RESULTS: With a median follow-up of 65 months (range, 13-175 months), 5-year local control, disease control, and overall survival rates were 63% (95% confidence interval [CI] 57.7-68.7%; median, 103 months), 57% (95% CI 50.9-62.1%; median, 82 months), and 81% (95% CI 76.8-85.6%; median, 157 months), respectively. On univariate and multivariate analyses, the presence of surgical stabilization was highly prognostic for worsened outcomes. Multivariate analysis also revealed the extent of treatment volumes and presence of gross residual disease to be important in predicting outcomes. High-grade (grade ≥3) toxicities were rare in both the acute (8%) and late (6%) settings. CONCLUSION: For spinal chordomas, PBS-PT remains a highly effective and safe method for delivery of dose-escalated adjuvant radiation therapy. The presence of metallic surgical stabilization prognosticates for worsened outcomes. Further investigation is warranted to characterize ideal treatment volumes and effect of surgical stabilization on therapy for these challenging tumors.

Radiation Necrosis and White Matter Lesions in Pediatric Patients With Brain Tumors Treated With Pencil Beam Scanning Proton Therapy.

PURPOSE: To assess the rate of radiation necrosis (RN) and white matter lesions (WMLs) in pediatric patients with primary brain tumors treated with pencil beam scanning (PBS) proton therapy (PT) with or without concomitant chemotherapy at the PSI. METHODS AND MATERIALS: Between 1999 and 2015, 171 pediatric patients (age <18 years) were treated with PT. Median age at diagnosis was 3.3 years (range, 0.3-17.0 years), and the median delivered dose was 54 Gy (relative biological effectiveness) (range, 40.0-74.1 Gy). Radiation necrosis and WMLs were defined as a new area of abnormal signal intensity on T2-weighted images or increased signal intensity on T2-weighted images, and contrast enhancement on T1 occurring in the brain parenchyma included in the radiation treatment field, which did not demonstrate any abnormality before PT. Radiation necrosis and WMLs were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. The median follow-up period for the surviving patients was 49.8 months (range, 5.9-194.7 months). RESULTS: Twenty-nine patients (17%) developed RN at a median time of 5 months (range, 1-26 months), most of them (n = 17; 59%) being asymptomatic (grade 1). Grade 2, 4, and 5 toxicities occurred in 8, 2, and 2 patients, respectively. Eighteen patients (11%) developed WMLs at a median time of 14.5 months (range, 2-62 months), most of them (n = 13; 72%) being asymptomatic (grade 1). White matter lesion grade 2 and 3 toxicities occurred in 4 and 1 patient(s), respectively. The 5-year RN-free and WML-free survival was 83% and 87%, respectively. In univariate analysis, neoadjuvant (P = .025) or any (P = .03) chemotherapy, hydrocephalus before PT (P = .035), and ependymoma (P = .026) histology were significant predictors of RN. CONCLUSIONS: Children treated with PT demonstrated a low prevalence of symptomatic RN (7%) or WML (3%) compared with similar cohorts treated with either proton or photon radiation therapy. Chemotherapy, ependymomal tumors and hydrocephalus as an initial symptom were significant risk factors for RN.

Long-Term Clinical Outcomes of Pencil Beam Scanning Proton Therapy for Benign and Non-benign Intracranial Meningiomas.

PURPOSE: To assess and report long-term clinical outcomes regarding local control, overall survival, and toxicity-free survival after pencil beam scanning proton therapy for intracranial meningiomas at a single institution. PATIENTS AND METHODS: Ninety-six patients (male/female, 29/67; median age 52.8 years) with intracranial meningiomas (World Health Organization [WHO] grade 1, n=61 [63.5%]; WHO grade 2, n=33 [34.4%]; WHO grade 3, n=2 [2.1%]) were treated with pencil beam scanning proton therapy (n=53 [55.2%] at diagnosis, n=17 [17.7%] at recurrence, and n=26 [27.1%] for tumor progression). Median gross tumor volume before PBSPT was 21.4 cm3 (range, 0.0-546.5 cm3), with a median planning target volume of 123.4 cm3 (range, 4.6-1142.0 cm3). Median duration of follow-up was 56.9 months (range, 12.1-207.2 months). Late toxicity was graded according to the Common Terminology Criteria for Adverse Events, version 4.0. RESULTS: Thirteen failures (14%) (male/female, 6/7) were observed, of which the majority (n=9, 69%) were of non-benign histology. The 5-year actuarial local control and overall survival were 86.4% and 88.2%, respectively. Five-year grade ≥3 toxicity-free survival was 89.1%. On univariate analysis, local control was worse for patients with higher WHO grade (P≤.001), those treated after at least 1 recurrence (P=.006), those with non-skull base tumor location (P=.014), and males (P=.032). Significant prognosticators for 5-year overall survival were local control (P≤.001), age (P=.002), and timing of proton therapy (initial vs recurrence) (P=.002). CONCLUSIONS: Pencil beam scanning proton therapy is an effective and safe treatment for patients with intracranial meningiomas, resulting in high local control rates with limited toxicity. Up-front radiation likely results in improved outcomes and should be considered, especially for patients with non-benign tumors and/or for those with incomplete resections.

Clinical and Radiologic Outcomes in Adults and Children Treated with Pencil-Beam Scanning Proton Therapy for Low-Grade Glioma.

PURPOSE: We assessed clinical and radiologic outcomes in adults and children with low-grade glioma (LGG) of the brain treated with pencil-beam scanning (PBS) proton therapy (PT). MATERIALS AND METHODS: Between 1997 and 2014, 28 patients were treated with PBS PT, 20 (71%) of whom were younger than 18 years. Median age at start of PT was 12.3 years (range, 2.2-53.0 years). Nine patients (32%) underwent at least a subtotal resection; 12 (43%) underwent biopsy; and 7 (25%) were diagnosed radiographically. Twelve patients (43%) had grade II and 9 (32%) had grade I gliomas. Eleven patients (39%) received chemotherapy before PT. A median dose of 54 Gy (relative biologic effectiveness) was administered. Radiologic response to PT was determined using the Response Evaluation Criteria in Solid Tumors (RECIST). Eight domains of quality of life (QoL) for 16 pediatric patients were assessed prospectively by patients' parents using the pediatric QoL proxy questionnaire. Progression-free survival and overall survival (OS) were estimated by the Kaplan-Meier method. Median follow-up was 42.1 months for living patients. RESULTS: Ten patients (36%) developed local, clinical failure. Three patients (11%) died, all of tumor progression. Radiographic tumor response by RECIST was evaluable in 11 patients: 9 (82%) with stable disease, 1 (9%) with partial response, and 1 (9%) with complete response to PT. Three-year OS and progression-free survival were 83.4% and 56.0%, respectively. No ≥ grade III acute toxicities were observed. Grade III, late radiation necrosis developed in 1 patient (4%). No appreciable change in pediatric QoL proxy scores in children was noted in any of the 8 domains at any time point. CONCLUSION: Treatment with PBS PT is effective for LGG, with minimal acute toxicity and, in children, no appreciable decline in QoL. More patients and longer follow-up are needed to determine the long-term efficacy and toxicity of PT for LGG.

Long term outcomes of patients with skull-base low-grade chondrosarcoma and chordoma patients treated with pencil beam scanning proton therapy.

PURPOSE: To evaluate the long term tumor control and toxicity of skull base tumors treated with pencil beam scanning proton therapy (PT). MATERIALS AND METHODS: PT was delivered to 151 (68%) and 71 (32%) chordoma and chondrosarcoma (ChSa) patients, respectively. Mean age of patients was 40.8±18.4years and the male to female ratio was 0.53. The postoperative tumor was abutting the brainstem or optic apparatus in 71 (32.0%) patients. The postoperative mean gross tumor volume (GTV) was 35.7±29.1cm(3). The delivered mean PT dose was 72.5±2.2GyRBE. RESULTS: After a mean follow-up of 50 (range, 4-176) months, 35 local (15.8%) failures were observed between 10.9 and 85.4months. The estimated 7-year LC rate for chordoma (70.9%; CI95% 61.5-81.8) was significantly lower compared to the LC rate for ChSa patients (93.6%; 95%CI 87.8-99.9; P=0.014). The estimated 7-year distant metastasis-free- and overall survival rate was 91.6% (95%CI 91.6-98.6) and 81.7% (95%CI 74.7-89.5), respectively. On multivariate analysis, optic apparatus and/or brainstem compression, histology and GTV were independent prognostic factors for LC and OS. The 7-year high grade toxicity-free survival was 87.2 (95%CI 82.4-92.3). CONCLUSIONS: PBS PT is an effective treatment for skull base tumors with acceptable late toxicity. Optic apparatus and/or brainstem compression, histology and GTV allow independent prediction of the risk of local failure and death in skull base tumor patients.

Tumour control and Quality of Life in children with rhabdomyosarcoma treated with pencil beam scanning proton therapy.

PURPOSE: To assess clinical outcomes in children with rhabdomyosarcoma (RMS) treated with pencil beam scanning (PBS) proton therapy (PT). METHODS AND MATERIALS: Eighty-three RMS (embryonal, n=74; 89%) patients treated between January 2000 and December 2014 were included. The median age was 4.5years (range, 0.8-15.5). All patients received systemic chemotherapy according to prospective protocols. Patients had low-, intermediate-, and high-risk disease in 24%, 63%, and 13% of cases, respectively. The median total dose delivered was 54Gy(RBE) (range, 41.4-64.8). RESULTS: After a median follow-up time of 55.5 months (range, 0.9-126.3), local failure occurred in 16 patients. The 5-year local-control survival rate was 78.5% [95% confidence interval (CI), 69.5-88.5%]. Significant predictors for local failure were group/stage, tumour location, and size. Fourteen patients (16%) died, all from tumour progression. The 5-year overall survival was 80.6% (95%CI, 71.8-90.0%). The 5-year incidence of grade 3 non-ocular late toxicity was 3.6% (95%CI, 1-12%). No grade 4-5 late toxicities were observed. One radiation-induced malignancy was observed (1.2%). The Quality of Life (QoL) scores increased significantly after PT compared to baseline values. CONCLUSIONS: PBS PT led to excellent outcome in children with RMS. Late non-ocular toxicity was minimal and QoL good.