Estimates of cardiac implanted electronic device neutron dose for a pencil beam scanning proton therapy system.

Background: The presence of a cardiovascular implantable electronic device (CIED) is frequently viewed as a contraindication to proton therapy due to the creation of secondary neutrons that can potentially damage CIED electronics. As a result, photon therapy is typically recommended for patients with CIEDs.

Purpose: The study aims to provide a method for estimating neutron dose to a CIED by measuring equivalent neutron dose at varying distances from isocenter and field edge.

Beam angle optimization for proton therapy via group-sparsity based angle generation method.

Background: In treatment planning, beam angle optimization (BAO) refers to the selection of a subset with a given number of beam angles from all available angles that provides the best plan quality. BAO is a NP-hard combinatorial problem. Although exhaustive search (ES) can exactly solve BAO by exploring all possible combinations, ES is very time-consuming and practically infeasible.

Simultaneous dose and dose rate optimization (SDDRO) of the FLASH effect for pencil-beam-scanning proton therapy.

Purpose: Compared to CONV-RT (with conventional dose rate), FLASH-RT (with ultra-high dose rate) can provide biological dose sparing for organs-at-risk (OARs) via the so-called FLASH effect, in addition to physical dose sparing. However, the FLASH effect only occurs, when both dose and dose rate meet certain minimum thresholds. This work will develop a simultaneous dose and dose rate optimization (SDDRO) method accounting for both FLASH dose and dose rate constraints during treatment planning for pencil-beam-scanning proton therapy.

An adaptive spot placement method on Cartesian grid for pencil beam scanning proton therapy.

Pencil beam scanning proton radiotherapy (RT) offers flexible proton spot placement near treatment targets for delivering tumoricidal radiation dose to tumor targets while sparing organs-at-risk. Currently the spot placement is mostly based on a non-adaptive sampling (NS) strategy on a Cartesian grid. However, the spot density or spacing during NS is a constant for the Cartesian grid that is independent of the geometry of tumor targets, and thus can be suboptimal in terms of plan quality (e.

Pulmonary dose tolerance in hemithorax radiotherapy for Ewing sarcoma of the chest wall: Are we overestimating the risk of radiation pneumonitis?

Background: Children with chest wall Ewing sarcoma with malignant pulmonary effusion or pleural stranding require hemithorax radiation, often with plans that exceed lung constraints. We investigated disease control and pneumonitis in children requiring hemithorax radiation.

Procedure: Eleven children (median age 13 years) received hemithorax radiotherapy.

Proton therapy for adult medulloblastoma: Acute toxicity and disease control outcomes.

Purpose: We report disease control, survival outcomes, and treatment-related toxicity among adult medulloblastoma patients who received proton craniospinal irradiation (CSI) as part of multimodality therapy.

Methods: We reviewed 20 adults with medulloblastoma (≥ 22 years old) who received postoperative proton CSI ± chemotherapy between 2008 and 2020. Patient, disease, and treatment details and prospectively obtained patient-reported acute CSI toxicities were collected.

Proton radiotherapy for infant rhabdomyosarcoma: Rethinking young age as an adverse prognostic factor.

Background & Purpose: In infants with rhabdomyosarcoma, young age is considered an adverse prognostic factor and treatment is often attenuated to reduce side effects. Proton therapy may improve the therapeutic ratio in these patients. We report outcomes in infants with rhabdomyosarcoma treated with proton therapy.

Vision loss following high-dose proton-based radiotherapy for skull-base chordoma and chondrosarcoma.

Background & Purpose: Dose escalation for skull-based chordoma and chondrosarcoma can put critical adjacent structures at risk, specifically the anterior optic pathway. We report the incidence of vision loss following high-dose conformal proton-based radiotherapy.

Materials And Methods: We reviewed patients with skull-base chordoma or chondrosarcoma treated with proton-based therapy between 2007 and 2018.

Second tumor risk in children treated with proton therapy.

Background: Out-of-field neutron dissemination during double-scattered proton therapy has raised concerns of increased second malignancies, disproportionally affecting pediatric patients due to the proportion of body exposed to scatter dose and inherent radiosensitivity of developing tissue. We sought to provide empiric data on the incidence of early second tumors.

Methods: Between 2006 and 2019, 1713 consecutive children underwent double-scattered proton therapy.

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.

Visual decline in pediatric survivors of brain tumors following radiotherapy.

Purpose: Radiotherapy-related visual decline is a significant concern in survivors of childhood cancer; however, data establishing the dose-response relationship between dose to the optic apparatus and visual acuity decline in children are sparse. We aimed to determine this relationship in a cohort of children treated with proton therapy.

Material And Methods: We identified 458 children with 875 eyes at risk treated with proton therapy for intracranial malignancy between December 2006 and September 2018.

Treatment Outcomes After Proton Therapy for Ewing Sarcoma of the Pelvis.

Purpose: Ewing sarcoma of the pelvis is associated with inferior local control compared with those arising from other primary sites. Despite its increased use, outcome data for treatment with proton therapy remain limited. We report 3-year disease control and toxicity in pediatric patients treated with proton therapy.

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.

Outcomes Following Proton Therapy for Group III Pelvic Rhabdomyosarcoma.

Purpose: This study aimed to report on the institutional outcomes after proton therapy for pelvic rhabdomyosarcoma (RMS).

Methods And Materials: Thirty-one children (≤21 years old) with group III pelvic RMS were enrolled on a prospective outcome study and treated between 2007 and 2018. Patients with vaginal/cervical RMS were excluded.

Multidisciplinary Imaging Review Conference Improves Neuro-oncology Radiation Treatment Planning and Follow-up.

Purpose: To review the impact of a weekly multidisciplinary neuroradiology imaging review on the management of patients undergoing radiotherapy.

Methods: A prospective study of the management of 118 patients (30=head and neck, 40=skull base, central nervous system=48) was conducted over a 12-month period from January 2018 through January 2019. After review of each patient's history and relevant imaging, a radiation oncologist completed a form detailing the changes that were made in diagnosis and management.

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.

Dose-Effect Analysis of Early Changes in Orbital Bone Morphology After Radiation Therapy for Rhabdomyosarcoma.

Purpose: In survivors of orbital embryonal rhabdomyosarcoma (ERMS), late effects include facial deformation and asymmetry. We sought to quantify orbital asymmetry in ERMS survivors and characterize the dose effect of radiation to the orbital bones.

Methods And Materials: We evaluated the most recent follow-up magnetic resonance imaging (MRI) in 17 children (≤21 years old) with stage 1 group III orbital ERMS treated with proton therapy between 2007 and 2018.

45 GyRBE for group III orbital embryonal rhabdomyosarcoma.

Despite widespread concerns of radiotherapy toxicity in children with head and neck tumors, recent Children's Oncology Group (COG) findings suggest that the use of 45 Gy results in an unacceptably high rate of local recurrences in patients with low-risk orbital rhabdomyosarcoma. We therefore evaluated outcomes in our pediatric patients who received 45 GyRBE using proton therapy. To assess disease control and toxicity, we reviewed the medical records of 30 children (≤21 years old) with COG stage 1, group III embryonal orbital rhabdomyosarcoma enrolled on a prospective outcome study and treated with proton therapy between 2007 and 2018.

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.

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.