Local Control After Proton Therapy for Pediatric Chordoma.

PURPOSE: Due to the location and high dose required for disease control, pediatric chordomas are theoretically well-suited for treatment with proton therapy, but their low incidence limits the clinical outcome data available in the literature. We sought to report the efficacy and toxicity of proton therapy among a single-institution cohort. METHODS AND MATERIALS: Between 2008 and 2019, 29 patients with a median age of 14.8 years (range, 3.8-21.8) received passive-scattered proton therapy for nonmetastatic chordoma. No patient received prior irradiation. Twenty-four tumors arose in the clivus/cervical spine region and 5 in the lumbosacral spine. Twenty-six tumors demonstrated classic well-differentiated histology and 3 were dedifferentiated or not otherwise specified. Approximately half of the tumors underwent specialized testing: 14 were brachyury-positive and 10 retained INI-1. Three patients had locally recurrent tumors after surgery alone (n = 2) or surgery + chemotherapy (n = 1), and 17 patients had gross disease at the time of radiation. The median radiation dose was 73.8 Gy relative biological effectivness (range, 69-75.6). RESULTS: With a median follow-up of 4.3 years (range, 1.0-10.7), the 5-year estimates of local control, progression-free survival, and overall survival rates were 85%, 82%, and 86%, respectively. No disease progression was observed beyond 3 years. Excluding 3 patients with dedifferentiated/not-otherwise-specified chordoma, the 5-year local control, progression-free survival, and overall survival rates were 92%, 92%, and 91%, respectively. Serious toxicities included 3 patients with hardware failure or related infection requiring revision surgery, 2 patients with hormone deficiency, and 2 patients with Eustachian tube dysfunction causing chronic otitis media. No patient experienced brain stem injury, myelopathy, vision loss, or hearing loss after radiation. CONCLUSIONS: In pediatric patients with chordoma, proton therapy is associated with a low risk of serious toxicity and high efficacy, particularly in well-differentiated tumors. Complete resection may be unnecessary for local control, and destabilizing operations requiring instrumentation may result in additional complications after therapy.

Outcomes following limited-volume proton therapy for multifocal spinal myxopapillary ependymoma.

PURPOSE: Spinal myxopapillary ependymoma (MPE) often presents with a multifocal distribution, complicating attempts at resection. There remains no standard approach to irradiating these patients. We report disease control and toxicity in pediatric patients with multifocal spinal MPE treated with limited-volume proton therapy. MATERIALS/METHODS: Twelve patients (≤21 years old) with multifocal spinal MPE were treated between 2009 and 2018 with limited-volume brain-sparing proton therapy. Median age was 13.5 years (range, 7-21). Radiotherapy was given as adjuvant therapy after primary surgery in five patients (42%) and for recurrence in seven (58%). No patient received prior radiation. Eleven patients (92%) had evidence of gross disease at radiotherapy. Eleven patients received 54 GyRBE; one received 50.4 GyRBE. Treatment toxicity was graded per the CTCAEv4.0. We estimated disease control and survival using the Kaplan-Meier product-limit method. RESULTS: The median follow-up was 3.6 years (range, 1.8-10.6). The five-year actuarial rates of local control, progression-free survival, and overall survival were 100%, 92%, and 100%, respectively. One patient experienced an out-of-field recurrence in the spine superior to the irradiated region. No patients developed in-field recurrences. Following surgery and irradiation, one patient developed grade three spinal kyphosis and one patient developed grade 2 unilateral L5 neuropathy. CONCLUSION: 54 GyRBE to a limited volume appears effective for disseminated spinal MPE in both the primary and salvage settings, sparing children the toxicity of full craniospinal irradiation. Compared with historical reports, this approach using proton therapy improves the therapeutic ratio, resulting in minimal side effects and high rates of disease control.

Particle beam radiation therapy for sinonasal malignancies: Single institutional experience at the Shanghai Proton and Heavy Ion Center.

BACKGROUND: Sinonasal malignancies (SNM) include malignant neoplasms of various histologies that originate from the paranasal sinuses or nasal cavity. This study reported the safety and efficacy of particle-beam radiation therapy (PBRT) for the treatment of sinonasal malignancies. METHODS AND MATERIALS: One-hundred-and-eleven patients with nonmetastatic sinonasal malignancies received definitive (82.9%) or salvage (31.5%) PBRT. The majority (85.6%) of patients presented with T3/4 disease, and only 19 (17.1%) had R0 or R1 resection. Seventy (63.1%) patients received carbon-ion radiotherapy (CIRT), 37 received proton radiotherapy (PRT) followed by CIRT boost, and 4 received PRT alone. Prognostic factors were analyzed using Cox regression for univariate and multiple regression. Toxicities were reported using the Common Terminology Criteria for Adverse Events (version 4.03). RESULTS: The median follow-up was 20.2 months for the entire cohort. The 2-year local progression-free survival (LPFS), regional progression-free survival (RPFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) rates were 83%, 97.2%, 85.9%, 66%, and 82%, respectively. Re-irradiation and large GTV were the significant factors for OS. Melanoma and sarcoma patients had significantly higher distant metastatic rate, and poorer OS and PFS. Late toxicity occurred in 22 (19.8%) patients, but only 4 (3.6%) patients experienced grades 3-4 late toxicity. CONCLUSIONS: Particle-beam radiation therapy results in excellent local-regional control with extremely low serve toxicities for patients with SNM. Sarcoma and melanoma were featured with a greater risk of death from distant dissemination. Patients who underwent re-irradiation had significantly worse OS. PBRT is feasible and safe in the management of SNM.

Carbon ion radiation therapy for sinonasal malignancies: Promising results from 2282 cases from the real world.

The aim of this study is to compare the effectiveness of carbon ion radiation therapy (CIRT), proton radiation therapy (PRT), and photon-based intensity-modulated radiation therapy (IMRT) in the treatment of sinonasal malignancies. We identified studies through systematic review and divided them into three cohorts (CIRT group/PRT group/IMRT group). Primary outcomes of interest were overall survival (OS) and local control (LC). We pooled the outcomes with meta-analysis and compared the survival difference among groups using Chi2 (χ2 ) test. A representative sample of 2282 patients with sinonasal malignancies (911 in the CIRT group, 599 in the PRT group, and 772 in the IMRT group) from 44 observation studies (7 CIRT, 16 PRT, and 21 IMRT) was included. The pooled 3-year OS, LC, distant metastasis-free survival, and progression-free survival rates were 67.0%, 72.8%, 69.4%, and 52.8%, respectively. Through cross-group analysis, the OS was significantly higher after CIRT (75.1%, 95% CI: 67.1%-83.2%) than PRT (66.2%, 95% CI: 57.7%-74.6%; χ2  = 13.374, P < .0001) or IMRT (63.8%, 95% CI: 55.3%-72.3%; χ2  = 23.814, P < .0001). LC was significantly higher after CIRT (80.2%, 95% CI: 73.9%-86.5%) than PRT (72.9%, 95% CI: 63.7%-82.0%; χ2  = 8.955, P = .003) or IMRT (67.8%, 95% CI: 59.4%-76.2%; χ2  = 30.955, P < .0001). However, no significant difference between PRT and IMRT for OS and LC was observed. CIRT appeared to provide better OS and LC for patients with malignancies of nasal cavity and paranasal sinuses. A prospective randomized clinical trial is needed to confirm the superiority of CIRT in the treatment of sinonasal tumors.

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.

Outcomes of adolescents and young adults treated for brain and skull base tumors with pencil beam scanning proton therapy.

BACKGROUND: The use of proton therapy (PT) in adolescents and young adults (AYAs) is becoming increasingly popular. This study aims to assess the outcomes and late toxicity consequences in AYAs (15-39 years) with brain/skull base tumors treated with pencil beam scanning proton therapy. METHODS: One hundred seventy six AYAs treated curatively at the Paul Scherrer Institute (PSI) were identified. Median age was 30 years (range 15-39) and median prescribed dose was 70.0 Gy (relative biological effectiveness [RBE]) (range 50.4-76.0). The most common tumors treated were chordomas/chondrosarcomas (61.4%), followed by gliomas (15.3%), and meningiomas (14.2%). RESULTS: After a median follow up of 66 months (range 12-236), 24 (13.6%) local only failures and one (0.6%) central nervous system (CNS) distant only failure were observed. The 6-year local control, distant progression-free survival, and overall survival were 83.2%, 97.4%, and 90.2%, respectively. The 6-year high-grade (≥grade [G] 3) PT-related late toxicity-free survival was 88.5%. Crude late toxicity rates were 26.2% G1, 37.8% G2, 12.2% G3, 0.6% G4, and 0.6% G5. The one G4 toxicity was a retinopathy and one G5 toxicity was a brainstem hemorrhage. The 6-year cumulative incidences for any late PT-related pituitary, ototoxicity, and neurotoxicity were 36.3%, 18.3%, and 25.6%; whilst high-grade (≥G3) ototoxicity and neurotoxicity were 3.4% and 2.9%, respectively. No secondary malignancies were observed. The rate of unemployment was 9.5% pre-PT, increasing to 23.8% post-PT. Sixty-two percent of survivors were working whilst 12.7% were in education post-PT. CONCLUSIONS: PT is an effective treatment for brain/skull base tumors in the AYA population with a reasonable late toxicity profile. Despite good clinical outcomes, around one in four AYA survivors are unemployed after treatment.

Outcomes, Prognostic Factors and Salvage Treatment for Recurrent Chordoma After Pencil Beam Scanning Proton Therapy at the Paul Scherrer Institute.

AIMS: The outcome of chordoma patients with local or distant failure after proton therapy is not well established. We assessed the disease-specific (DSS) and overall survival of patients recurring after proton therapy and evaluated the prognostic factors affecting DSS. MATERIALS AND METHODS: A retrospective analysis was carried out of 71 recurring skull base (n = 36) and extracranial (n = 35) chordoma patients who received adjuvant proton therapy at initial presentation (n = 42; 59%) or after post-surgical recurrence (n = 29; 41%). The median proton therapy dose delivered was 74 GyRBE (range 62-76). The mean age was 55 ± 14.2 years and the male/female ratio was about one. RESULTS: The median time to first failure after proton therapy was 30.8 months (range 3-152). Most patients (n = 59; 83%) presented with locoregional failure only. There were only 12 (17%) distant failures, either with (n = 5) or without (n = 7) synchronous local failure. Eight patients (11%) received no salvage therapy for their treatment failure after proton therapy. Salvage treatments after proton therapy failure included surgery, systemic therapy and additional radiotherapy in 45 (63%), 20 (28%) and eight (11%) patients, respectively. Fifty-three patients (75%) died, most often from disease progression (47 of 53 patients; 89%). The median DSS and overall survival after failure was 3.9 (95% confidence interval 3.1-5.1) and 3.4 (95% confidence interval 2.5-4.4) years, respectively. On multivariate analysis, extracranial location and late failure (≥31 months after proton therapy) were independent favourable prognostic factors for DSS. CONCLUSION: The survival of chordoma patients after a treatment failure following proton therapy is poor, particularly for patients who relapse early or recur in the skull base. Although salvage treatment is administered to most patients with uncontrolled disease, they will ultimately die as a result of disease progression in most cases.

Clinical outcomes following proton therapy for adult craniopharyngioma: a single-institution cohort study.

BACKGROUND: Craniopharyngioma is a benign tumor that commonly develops within the suprasellar region. The tumor and treatment can have debilitating consequences for pediatric and adult patients, including vision loss and pituitary/hypothalamic dysfunction. Most craniopharyngioma series focus on treatment of the pediatric population. We evaluated the outcomes of all adult craniopharyngioma patients treated at our institution using proton therapy to report outcomes for disease control, treatment-related toxicity, and tumor response. METHODS: We analyzed 14 adult patients (≥ 22 years old). All patients had gross disease at the time of radiotherapy. Five were treated for de novo disease and 9 for recurrent disease. Patients received double-scattered conformal proton therapy to a mean dose of 54 GyRBE in 1.8 GyRBE/fraction (range 52.2-54 GyRBE). Weekly magnetic resonance imaging (MRI) helped to evaluate tumor changes during radiotherapy. RESULTS: With median clinical and radiographic follow-up of 29 and 26 months, respectively, the 3-year local control and overall survival rates were both 100%. There were no grade 3 or greater acute or late radiotherapy-related side effects. There was no radiotherapy-related vision loss or optic neuropathy. No patients required intervention or treatment replanning due to tumor changes during radiotherapy. Two patients experienced transient cyst expansion at their first post-radiotherapy MRI. Both patients were followed closely clinically and radiographically and had subsequent dramatic tumor/cyst regression, requiring no interventions. CONCLUSIONS: Our data support the safety and efficacy of proton therapy in the treatment of adult craniopharyngioma as part of primary or salvage treatment. We recommend early consideration of radiotherapy. This trial was registered at www.clinicaltrials.gov as #NCT03224767.

Proton radiotherapy and treatment delay in head and neck squamous cell carcinoma.

OBJECTIVE: For patients with head and neck squamous cell carcinoma (HNSCC), delays in the initiation of radiotherapy (RT) have been closely associated with worse outcomes. We sought to investigate whether RT modality (proton vs. photon) is associated with differences in the time to initiation of RT. METHODS: The National Cancer Database was queried for patients diagnosed with nonmetastatic HNSCC between 2004 and 2015 who received either proton or photon RT as part of their initial treatment. Wilcoxon rank-sum and chi-square tests were used to compare continuous and categorical variables, respectively. Multivariable logistic regression was used to determine the association between use of proton RT and delayed RT initiation. RESULTS: A total of 175,088 patients with HNSCC receiving either photon or proton RT were identified. Patients receiving proton RT were more likely to be white, reside in higher income areas, and have private insurance. Proton RT was associated with delayed RT initiation compared to photon RT (median 59 days vs. 45, P < 0.001). Receipt of proton therapy was independently associated with RT initiation beyond 6 weeks after diagnosis (adjusted OR [aOR, definitive RT] = 1.69; 95% confidence interval [CI] 1.26-2.30) or surgery (aOR [adjuvant RT] = 4.08; 95% CI 2.64-6.62). In the context of adjuvant proton RT, increases in treatment delay were associated with worse overall survival (weeks, adjusted hazard ratio = 1.099, 95% CI 1.011-1.194). CONCLUSION: Use of proton therapy is associated with delayed RT in both the definitive and adjuvant settings for patients with HNSCC and could be associated with poorer outcomes. LEVEL OF EVIDENCE: 2b Laryngoscope, 122:0000-0000, 2019 Laryngoscope, 130:E598-E604, 2020.

Outcomes following proton therapy for Ewing sarcoma of the cranium and skull base.

PURPOSE: Despite the dosimetric advantages of proton therapy, little data exist on patients who receive proton therapy for Ewing sarcoma of the cranium and skull base. This study reports local disease control and toxicity in such patients. MATERIALS/METHODS: We reviewed 25 patients (≤21 years old) with nonmetastatic Ewing sarcoma of the cranium and skull base treated between 2008 and 2018. Treatment toxicity was graded per the Common Terminology Criteria for Adverse Events v4.0. The Kaplan-Meier product limit method provided estimates of disease control and survival. RESULTS: Median patient age was 5.9 years (range, 1-21.7). Tumor subsites included the skull base (48%), non-skull-base calvarial bones (28%), paranasal sinuses (20%), and nasal cavity (4%). All patients underwent multiagent alkylator- and anthracycline-based chemotherapy; 16% underwent gross total resection (GTR) before radiation. Clinical target volume (CTV) 1 received 45 GyRBE and CTV2 received 50.4 GyRBE following GTR or 54-55.8 GyRBE following biopsy or subtotal resection. Median follow-up was 3.7 years (range, 0.26-8.3); no patients were lost. The 4-year local control, disease-free survival, and overall survival rates were 96%, 86%, and 92%, respectively. Two patients experienced in-field recurrences. One patient experienced bilateral conductive hearing loss requiring aids, two patients developed intracranial vasculopathy, and 6 patients required hormone replacement therapy for neuroendocrine deficits. None developed a secondary malignancy. CONCLUSION: Proton therapy is associated with a favorable therapeutic ratio in children with large Ewing tumors of the cranium and skull base. Despite its high conformality, we observed excellent local control and no marginal recurrences. Treatment dosimetry predicts limited long-term neurocognitive and neuroendocrine side effects.

Clinical outcomes of previously untreated patients with unresectable intrahepatic cholangiocarcinoma following proton beam therapy.

BACKGROUND: The effectiveness of proton beam therapy (PBT) as initial treatment for patients with unresectable intrahepatic cholangiocarcinoma (ICC) is unclear, particularly as related to ICC histological subtypes. We performed this study to address this gap in knowledge. METHODS: Thirty-seven patients with unresectable ICC who underwent PBT as their initial treatment were evaluated. Twenty-seven patients had Child-Pugh class A liver function, 11 exhibited jaundice, and 10 had multiple tumors. Nineteen, 7, and 11 tumors were classified as mass forming (MF), periductal infiltrating (PI), and intraductal growth (IG) types, respectively, based on gross appearance in imaging studies. Patients were classified into the curative group (n = 25) and palliative group (n = 12) depending on whether the planning target volume covered all the macroscopic tumors. RESULTS: The 1- and 2-year overall survival rates were 60.3, and 41.4%, respectively; the median survival time (MST) was 15 months for all patients. The MSTs for curative and palliative groups were 25 and 7 months, respectively. Curative treatment and adjuvant chemotherapy significantly improved overall survival, while the presence of periductal infiltrating type tumors was a negative prognostic factor. In the curative group, the 1- and 2-year local control rates were 100 and 71.5%, respectively, while the 1-, and 2-year progression-free survival rates were 58.5, and 37.6%, respectively. No severe acute toxicities were observed. Three patients experienced grade 3 biliary tract infection, although it was unclear whether this was radiotherapy-related. CONCLUSION: PBT may yield to improve survival and local tumor control among patients with unresectable ICC.

Oncologic and visual outcomes after postoperative proton therapy of localized conjunctival melanomas.

INTRODUCTION: conjunctival melanomas have high local relapse rates. Oncologic and visual outcomes can be improved with proton therapy and no-touch surgery. MATERIAL AND METHODS: a monocentric retrospective study of consecutive patients treated with surgery and proton therapy for conjunctival melanoma was conducted. Proton therapy was performed to a total dose of 45 Grays physical dose delivered in eight fractions over two weeks. RESULTS: Ninety-two patients were included. The mean age was 63-year-old. 65.2% of patients had primary acquired melanosis. The mean tumor thickness and diameter was 2.5 mm and 7.0 mm respectively. The clinical stage was T1 in 71.6% of cases, with a quadrangular involvement of more than 90° in 69% of cases. Conjunctival melanomas were of epithelioid cell-type in 40% of cases. Mean follow-up was 4.7 years. Five-year local failure rate was 33.2%. Of 25 local recurrences, 14 were marginal/out-of-field, 4 in-field, others were undetermined. First surgery at expert center resulted in 24.3% of local failure at 5 years versus 38.7% if performed elsewhere (p = 0.41). Salvage exenteration was performed in 13 patients. Tumor stage and quadrangular involvement were significant factors for local failure. Five-year progression-free survival and cause-specific death rates were 61.5 and 3.6%. Stage and epithelioid type were associated with poorer progression-free survival. Trophic toxicity occurred in 22.9% of patients and was treated locally, with grafts in 7 patients. Glaucoma and cataract occurred in 13 and 22 patients respectively. Prognostic factors for visual deterioration were age, tumor extent (multifocality, quadrangular involvement > 180°) and cryotherapy. CONCLUSIONS: 5-year local failure rate after postoperative proton therapy for conjunctival melanoma was of 33.2%. Radiation-induced complications were overall manageable.

Proton therapy following induction chemotherapy for pediatric and adolescent nasopharyngeal carcinoma.

PURPOSE: In children treated for nasopharyngeal carcinoma, proton therapy and postchemotherapy target volumes can reduce the radiation dose to developing tissue in the brain and the skull base region. We analyzed outcomes in children with nasopharyngeal carcinoma treated with induction chemotherapy followed by moderate-dose proton therapy. METHODS/MATERIALS: Seventeen patients with nonmetastatic nonkeratinizing undifferentiated/poorly differentiated nasopharyngeal carcinoma underwent double-scattered proton therapy between 2011 and 2017. Median age was 15.3 years (range, 7-21). The American Joint Committee on Cancer T and N stage distribution included the following: T1, one patient; T2, five patients; T3, two patients; and T4, nine patients; and N1, six patients; N2, nine patients; and N3, two patients. Median radiation dose to the primary target volume and enlarged lymph nodes was 61.2 Gy (range, 59.4-61.2). Uninvolved cervical nodes received 45 Gy (range, 45-46.8). All radiation was delivered at 1.8 Gy/fraction daily using sequential plans. In 11 patients, photon-based intensity-modulated radiotherapy was used for elective neck irradiation to optimize dose homogeneity and improve target conformity. All patients received induction chemotherapy; all but one received concurrent chemotherapy. Five received adjuvant beta-interferon therapy. RESULTS: Median follow-up was 3.0 years (range, 1.6-7.9). No patients were lost to follow-up. Overall survival, progression-free survival, and local control rates were 100%. Fifteen patients developed mucositis requiring enteral feeding (n = 14) or total parenteral nutrition (n = 1) during radiotherapy. Serious late side effects included cataract (n = 1), esophageal stenosis requiring dilation (n = 1), sensorineural hearing loss requiring aids (n = 1), and hormone deficiency (n = 5, including three with isolated hypothyroidism). CONCLUSION: Following induction chemotherapy, moderate-dose proton therapy can potentially reduce toxicity in the brain and skull base region without compromising disease control. However, further follow-up is needed to fully characterize and evaluate any reduction in long-term complications.

Tumor bed proton irradiation in young children with localized medulloblastoma.

BACKGROUND: Radiotherapy is often deferred in very young children with medulloblastoma, in favor of more intense chemotherapy and stem cell rescue; however, posterior fossa radiation has been shown to improve overall survival (OS) and event-free survival compared with adjuvant chemotherapy alone. This study was performed to assess the OS, recurrence-free survival (RFS), patterns of failure, and clinical toxicity for children aged five and under who received focal proton radiation to the tumor bed alone. PROCEDURE: From 2010 to 2017, 14 patients with newly diagnosed medulloblastoma at one institution received tumor bed irradiation following surgery and chemotherapy. The median age of the patients was 40 months (range, 10.9-62.9 months). RESULTS: With a median follow-up of 54 months, four patients relapsed: three within the central nervous system (CNS) outside of the posterior fossa, and one within the tumor bed after subtotal resection. All relapses occurred within 28 months after the completion of radiation therapy. Five-year OS and RFS for this cohort of patients were 84% (95% CI, 48%-96%) and 70% (95% CI, 38%-88%), respectively. One patient experienced significant tumor regrowth soon after completion of radiation, autopsy showed viable tumor and necrosis near and within the brainstem, with relation to radiation unknown; however, no other acute clinical toxicities greater than grade 2 were observed in this group of patients. In the nine patients with available performance status follow-up, no significant changes in Lansky performance status were observed. CONCLUSIONS: Five-year OS and RFS following tumor bed irradiation in young children with medulloblastoma appear to be improved compared with other studies that forego the use of radiation therapy in this patient population. This approach should be further investigated in young children with medulloblastoma.

Proton Radiotherapy for Isolated Local Recurrence of Primary Resected Pancreatic Ductal Adenocarcinoma.

BACKGROUND: The optimal treatment for isolated local recurrence (ILR) of pancreatic adenocarcinoma (PDAC) after surgical resection remains unclear. This study aimed to evaluate the safety and efficacy of proton radiotherapy (PRT) for ILR of PDAC after surgery. METHODS: The medical records of patients with ILR of PDAC after surgery who underwent proton beam therapy between 2011 and 2015 at Hyogo Ion Beam Medical Center were retrospectively studied. RESULTS: The study analyzed 30 patients (14 women and 16 men) with a median age of 65 years (range 38-81 years) who had initially undergone pancreatoduodenectomy (n = 23) or distal pancreatectomy (n = 7) for their primary tumors. Upon ILR, PRT was administered with a median total cumulative dose of 67.5 gray equivalent (GyE) (range 50-67.5 GyE) using 19 to 25 fractions. For 25 patients, concurrent chemotherapy was administered using gemcitabine (n = 18) or S-1 (n = 7). Four patients (13.3%) experienced acute grade ≥ 3 gastrointestinal toxicities. After a median follow-up period of 17.6 months (range 2.1-50.4 months), 23 patients had experienced tumor progression and 10 had died. Nine patients (30%) experienced local tumor progression. The median overall, progression-free, and local progression-free survival rates were 26.1, 12.3, and 41.2 months, respectively. Pre-PRT serum levels of cancer antigen 19-9 higher than 100 U/mL and duke pancreatic monoclonal antigen type 2 higher than 150 U/mL were significantly associated with shorter progression-free survival rates. CONCLUSIONS: Proton radiotherapy for ILR of PDAC after surgery is well tolerated and produces good locoregional control and should be considered for eligible patients.

Early and late side effects, dosimetric parameters and quality of life after proton beam therapy and IMRT for prostate cancer: a matched-pair analysis.

Purpose: To compare early and late toxicities, dosimetric parameters and quality of life (QoL) between conventionally fractionated proton beam therapy (PBT) and intensity-modulated radiation therapy (IMRT) in prostate cancer (PCA) patients. Methods: Eighty-eight patients with localized PCA treated between 2013 and 2017 with either definitive PBT (31) or IMRT (57) were matched using propensity score matching on PCA risk group, transurethral resection of the prostate, prostate volume, diabetes mellitus and administration of anticoagulants resulting in 29 matched pairs. Early and late genitourinary (GU) and gastrointestinal (GI) toxicities according to Common Terminology Criteria for Adverse Events (CTCAE) and QoL based on EORTC-QLQ-C30/PR25 questionnaires were collected prospectively until 12 months after radiotherapy (RT). Associations between toxicities and dose-volume parameters in corresponding organs at risk (OARs) were modeled by logistic regression. Results: There were no significant differences in GI and GU toxicities between both treatment groups except for late urinary urgency, which was significantly lower after PBT (IMRT: 25.0%, PBT: 0%, p = .047). Late GU toxicities and obstruction grade ≥2 were significantly associated with the relative volume of the anterior bladder wall receiving 70 Gy and the entire bladder receiving 60 Gy, respectively. The majority of patients in both groups reported high functioning and low symptom scores for the QoL questionnaires before and after RT. No or little changes were observed for most items between baseline and 3 or 12 months after RT, respectively. Global health status increased more at 12 months after IMRT (p = .040) compared to PBT, while the change of constipation was significantly better at 3 months after PBT compared to IMRT (p = .034). Conclusions: Overall, IMRT and PBT were well tolerated. Despite the superiority of PBT in early constipation and IMRT in late global health status compared to baseline, overall QoL and the risks of early and late GU and GI toxicities were similar for conventionally fractionated IMRT and PBT.

Proton therapy for skull-base chondrosarcoma, a single-institution outcomes study.

BACKGROUND: We sought to evaluate the effectiveness of definitive or adjuvant external-beam proton therapy on local control and survival in patients with skull-base chondrosarcoma. METHODS: We reviewed the medical records of 43 patients with a median age of 49 years (range, 23-80 years) treated with double-scattered 3D conformal proton therapy for skull-base chondrosarcomas between January 2007 and February 2016. Proton therapy-related toxicities were scored using CTCAE v4.0. RESULTS: The median radiotherapy dose was 73.8 Gy(RBE) (range, 64.5-74.4 Gy[RBE]). Thirty-six (84%) and 7 (16%) patients underwent surgical resection or biopsy alone. Tumor grade distribution included: grade 1, 19 (44%) patients; grade 2, 22 (51%); and grade 3, 2 (5%). Forty patients had gross disease at the time of radiotherapy and 7 patients were treated for locally recurrent disease following surgery. The median follow-up was 3.7 years (range, 0.7-10.1 years). There were no acute grade 3 toxicities related to RT. At 4 years following RT, actuarial rates of overall survival, cause-specific survival, local control, and RT-related grade 3 toxicity-free survival were 95%, 100%, 89%, and 95%. CONCLUSION: High-dose, double-scattered 3D conformal proton therapy alone or following surgical resection for skull-base chondrosarcoma is an effective treatment with a high rate of local control with no acute grade 3 radiation-related toxicity. Further follow-up of this cohort is necessary to better characterize long-term disease control and late toxicities.

The role of dose escalation and proton therapy in perioperative or definitive treatment of chondrosarcoma and chordoma: An analysis of the National Cancer Data Base.

BACKGROUND: Chordomas and chondrosarcomas are a rare but challenging subset of tumors to treat; however, previous studies have shown benefits from proton therapy, which are thought to be primarily driven by prescription conformality permitting homogeneous tumor dosing and the allowance of higher doses. No retrospective studies to date have directly compared the outcomes of conventional and particle therapy or examined the role of high doses (specifically ≥70 Gy) in definitive radiotherapy (DRT) or perioperative radiotherapy (PRT) for both types of malignancies. METHODS: A total of 863 patients with chondrosarcoma and 715 patients with chordoma treated with nonpalliative proton or conventional radiation therapy with a dose range of 20 to 80 Gy and at least 15 months of follow-up were identified from the National Cancer Data Base for the years 2003-2014. The primary endpoint of overall survival (OS) was evaluated, and clinical features, including age, sex, grade, clinical stage, and Charlson-Deyo comorbidity index, were compared. RESULTS: Patients receiving DRT were older and had more advanced disease. In DRT for chondrosarcoma, a high dose (40.6% vs 16.9%; P = .006) and proton therapy (75.0% vs 19.1%; P = .046) were associated with improved OS at 5 years in a multivariate analysis. In DRT for chordoma, proton therapy was associated with improved OS at 5 years in a multivariate analysis (100% vs 34.1%; P = .031), and a high dose for chordoma was significant for improved OS in a univariate analysis with both DRT (79.0% vs 54.1%; P = .027) and PRT (83.3% vs 77.4%; P = .007). CONCLUSIONS: In the largest retrospective series to date, dose escalation and proton radiotherapy were associated with improved OS in patients with chondrosarcoma and chordoma despite limited follow-up and access to particle therapy.

Protons versus Photons for Unresectable Hepatocellular Carcinoma: Liver Decompensation and Overall Survival.

PURPOSE: Ablative radiation therapy is increasingly being used for hepatocellular carcinoma (HCC) resulting in excellent local control rates; however, patients without evidence of disease progression often die from liver failure. The clinical benefit of proton- over photon-based radiation therapy is unclear. We therefore sought to compare clinical outcomes of proton versus photon ablative radiation therapy in patients with unresectable HCC. METHODS AND MATERIALS: This is a single-institution retrospective study of patients treated during 2008 to 2017 with nonmetastatic, unresectable HCC not previously treated with liver-directed radiation therapy and who did not receive further liver-directed radiation therapy within 12 months after completion of index treatment. The primary outcome, overall survival (OS), was assessed using Cox regression. Secondary endpoints included incidence of non-classic radiation-induced liver disease (defined as increase in baseline Child-Pugh score by ≥2 points at 3 months posttreatment), assessed using logistic regression, and locoregional recurrence, assessed using Fine-Gray regression for competing risks. All outcomes were measured from radiation start date. RESULTS: The median follow-up was 14 months. Of 133 patients with median age 68 years and 75% male, 49 (37%) were treated with proton radiation therapy. Proton radiation therapy was associated with improved OS (adjusted hazard ratio, 0.47; P = .008; 95% confidence interval [CI], 0.27-0.82). The median OS for proton and photon patients was 31 and 14 months, respectively, and the 24-month OS for proton and photon patients was 59.1% and 28.6%, respectively. Proton radiation therapy was also associated with a decreased risk of non-classic radiation-induced liver disease (odds ratio, 0.26; P = .03; 95% CI, 0.08-0.86). Development of nonclassic RILD at 3 months was associated with worse OS (adjusted hazard ratio, 3.83; P < .001; 95% CI, 2.12-6.92). There was no difference in locoregional recurrence, including local failure, between protons and photons. CONCLUSIONS: Proton radiation therapy was associated with improved survival, which may be driven by decreased incidence of posttreatment liver decompensation. Our findings support prospective investigations comparing proton versus photon ablative radiation therapy for HCC.

Proton beam therapy is a safe and feasible treatment for patients with second primary lung cancer after lung resection.

BACKGROUND: The purpose of the present study was to retrospectively evaluate the safety and efficacy of proton beam therapy (PBT) in patients with second primary lung cancer after lung resection. METHODS: Patients who were diagnosed with second primary lung cancer after lung resection and underwent PBT between January 2009 and February 2015 were retrospectively recruited. Toxicities were evaluated using Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Nineteen patients were eligible for inclusion in this study. All of the patients completed the treatment. The median age was 75 (range: 63-82) years, and the median follow-up time of living patients was 60 months. The median dose of PBT was 76.8 Gy relative biological effectiveness (range: 66.0-80.0 Gy). The three-year overall survival rate was 63.2% and the three-year local control rate was 84.2%. No grade 4 or 5 toxicities were observed after PBT. CONCLUSIONS: Our results suggest that PBT is a safe and feasible treatment for second primary lung cancer compared to surgery or X-ray radiotherapy. PBT may become a treatment choice for patients with second primary lung cancer after lung resection.