Proton Therapy for Spinal Tumors: A Consensus Statement From the Particle Therapy Cooperative Group.

Purpose: Proton beam therapy (PBT) plays an important role in the management of primary spine tumors. The purpose of this consensus statement was to summarize safe and optimal delivery of PBT for spinal tumors.

Methods And Materials: The Particle Therapy Cooperative Group Skull Base/Central nervous system/Sarcoma Subcommittee consisting of radiation oncologists and medical physicists with specific expertise in spinal irradiation developed expert recommendations discussing treatment planning considerations and current approaches in the treatment of primary spinal tumors.

Practice Patterns of Spatially Fractionated Radiation Therapy: A Clinical Practice Survey.

Purpose: Spatially fractionated radiation therapy (SFRT) is increasingly used for bulky advanced tumors, but specifics of clinical SFRT practice remain elusive. This study aimed to determine practice patterns of GRID and Lattice radiation therapy (LRT)-based SFRT.

Methods And Materials: A survey was designed to identify radiation oncologists' practice patterns of patient selection for SFRT, dosing/planning, dosimetric parameter use, SFRT platforms/techniques, combinations of SFRT with conventional external beam radiation therapy (cERT) and multimodality therapies, and physicists' technical implementation, delivery, and quality procedures.

Overview and Recommendations for Prospective Multi-institutional Spatially Fractionated Radiation Therapy Clinical Trials.

Purpose: The highly heterogeneous dose delivery of spatially fractionated radiation therapy (SFRT) is a profound departure from standard radiation planning and reporting approaches. Early SFRT studies have shown excellent clinical outcomes. However, prospective multi-institutional clinical trials of SFRT are still lacking.

Characterization of Photon Intensity Modulated Radiation Therapy Robustness in Patients With Prostate Cancer as a Proposed Benchmark for Proton Therapy Robustness Evaluation.

Purpose: Robustness evaluation is increasingly used in particle therapy planning to assess clinical target volume (CTV) coverage in the setting of setup and range uncertainty. However, no clear standard exists as to an acceptable degree of plan robustness. The aim of this study is to quantify x-ray robustness parameters, as this could inform proton planning when held to a similar standard.

An International Consensus on the Design of Prospective Clinical-Translational Trials in Spatially Fractionated Radiation Therapy for Advanced Gynecologic Cancer.

Despite the unexpectedly high tumor responses and limited treatment-related toxicities observed with SFRT, prospective multi-institutional clinical trials of SFRT are still lacking. High variability of SFRT technologies and methods, unfamiliar complex dose and prescription concepts for heterogeneous dose and uncertainty regarding systemic therapies present major obstacles towards clinical trial development. To address these challenges, the consensus guideline reported here aimed at facilitating trial development and feasibility through a priori harmonization of treatment approach and the full range of clinical trial design parameters for SFRT trials in gynecologic cancer.

An International Consensus on the Design of Prospective Clinical-Translational Trials in Spatially Fractionated Radiation Therapy.

Purpose: Spatially fractionated radiation therapy (SFRT), which delivers highly nonuniform dose distributions instead of conventionally practiced homogeneous tumor dose, has shown high rates of clinical response with minimal toxicities in large-volume primary or metastatic malignancies. However, prospective multi-institutional clinical trials in SFRT are lacking, and SFRT techniques and dose parameters remain variable. Agreement on dose prescription, technical administration, and clinical and translational design parameters for SFRT trials is essential to enable broad participation and successful accrual to rigorously test the SFRT approach.

Work Outcomes after Intensity-Modulated Proton Therapy (IMPT) versus Intensity-Modulated Photon Therapy (IMRT) for Oropharyngeal Cancer.

Purpose: We compared work outcomes in patients with oropharyngeal cancer (OPC), randomized to intensity-modulated proton (IMPT) versus intensity-modulated photon therapy (IMRT) for chemoradiation therapy (CRT).

Patients And Methods: In 147 patients with stage II-IVB squamous cell OPC participating in patient-reported outcomes assessments, a prespecified secondary aim of a randomized phase II/III trial of IMPT (n = 69) versus IMRT (n = 78), we compared absenteeism, presenteeism (i.e.

Reproducibility of a novel, vacuum-assisted immobilization for breast stereotactic radiotherapy.

A novel, breast-specific stereotactic radiotherapy device has been developed for delivery of highly conformal, accelerated partial breast irradiation. This device employs a unique, vacuum-assisted, breast cup immobilization system that applies a gentle, negative pressure to the target breast with the patient in the prone position. A device-specific patient loader is utilized for simulation scanning and device docking.

Prospective Evaluation of Swallowing Symptoms in Human Papillomavirus-Associated Oropharynx Cancer.

To demonstrate that the lack of significant swallowing-related symptoms in patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is attributable to smaller mucosal primaries. A validated dysphagia symptom questionnaire and eating assessment tool was prospectively provided to patients presenting with untreated human papillomavirus-associated oropharyngeal cancer at the University of Maryland from July 2017 to December 2018. A 10-item Eating Assessment Tool (EAT-10) was completed by each patient prior to intervention.

Spatially Fractionated Radiotherapy (GRID) Prior to Standard Neoadjuvant Conventionally Fractionated Radiotherapy for Bulky, High-Risk Soft Tissue and Osteosarcomas: Feasibility, Safety, and Promising Pathologic Response Rates.

Spatially fractionated radiotherapy (GRID) has been utilized primarily in the palliative and definitive treatment of bulky tumors. Delivered in the modern era primarily with megavoltage photon therapy, this technique offers the promise of safe dose escalation with potential immunogenic, bystander and microvasculature effects that can augment a conventionally fractionated course of radiotherapy. At the University of Maryland, an institutional standard has arisen to incorporate a single fraction of GRID radiation in large (>8 cm), high-risk soft tissue and osteosarcomas prior to a standard fractionated course.

Understanding High-Dose, Ultra-High Dose Rate, and Spatially Fractionated Radiation Therapy.

The National Cancer Institute's Radiation Research Program, in collaboration with the Radiosurgery Society, hosted a workshop called Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy on August 20 and 21, 2018 to bring together experts in experimental and clinical experience in these and related fields. Critically, the overall aims were to understand the biological underpinning of these emerging techniques and the technical/physical parameters that must be further defined to drive clinical practice through innovative biologically based clinical trials.

Sticky stuff: xerostomia in patients undergoing head and neck radiotherapy-prevalence, prevention, and palliative care.

Xerostomia remains one of the most common and impactful side effects associated with radiotherapy for head and neck malignancies. With improvements in oncologic therapy and an improved prognosis for patients with head and neck squamous cell carcinoma (HNSCC) overall, the long-standing effects of therapy have become even more significant. Recent efforts have primarily focused on prevention of this morbidity through technological advances, reductions in radiotherapy fields, and radioprotectants.

When saliva becomes a problem: the challenges and palliative care for patients with sialorrhea.

Sialorrhea, or relative excess of salivary excretion, is a vexing problem for many patients. This symptom is precipitated by dysfunction in one of two interrelated processes-salivary production and oropharyngeal clearance. While medications primarily precipitate the former, dysphagia, often due to neurologic dysfunction, often causes the latter.

Prognostic factors for spinal chordomas and chondrosarcomas treated with postoperative pencil-beam scanning proton therapy: a large, single-institution experience.

Objective: The aim of this paper was to evaluate the prognostic factors in surgical and adjuvant care for spinal chordomas and chondrosarcomas after surgery followed by high-dose pencil-beam scanning proton therapy (PBS-PT).

Methods: From 1997 to 2016, 155 patients (61 female patients; median age 55 years) with spinal (cervical, n = 61; thoracic, n = 29; lumbar, n = 13; sacral, n = 46; pelvic, n = 6) classic chordomas (n = 116) and chondrosarcomas (n = 39; most were low grade) were treated with maximal safe resection followed by PBS-PT (median dose prescribed: 74 Gy [relative biological effectiveness], range 48.6-77 Gy).

Optimal Target Delineation and Treatment Techniques in the Era of Conformal Photon and Proton Breast and Regional Nodal Irradiation.

Purpose: Regional nodal irradiation improves disease-free and distant disease-free survival in patients with high-risk breast cancer (BC). Trials demonstrating this used 2- or 3-dimensional conformal radiation therapy (2-dimensional or 3-dimensional [3D] conformal radiotherapy [CRT]) fields based on bony anatomy. Modern volumetric-modulated arc therapy (VMAT) and pencil beam scanning proton therapy (PBSPT) may underdose regional nodes (RNs) not contoured but covered by 3D CRT.

Multicriteria optimization: Site-specific class solutions for VMAT plans.

Multicriteria optimization (MCO), a novel commercially available optimization method for IMRT and VMAT has the potential to improve treatment planning techniques and workflows. MCO allows planners and physicians to assess in real time the impact and tradeoffs between all clinical goals and organ constraints. We investigate the feasibility of a universal set of objectives and constraints for VMAT plans in different anatomical sites and the impact of involving the Physician in the navigation of the generated Pareto plans.

Optimizing immobilization, margins, and imaging for lung stereotactic body radiation therapy.

The simultaneous advancement of technologies for the delivery of precisely targeted radiation therapy and the paradigm shift to substantial hypofractionation have led to significant improvements in the treatment of early stage non-small cell lung cancer (ES-NSCLC). Stereotactic body radiation therapy (SBRT) has become a well-established option for the treatment of ES-NSCLC and is now becoming widely available within the radiation oncology community. Implementation of this technique, however, requires highly accurate target delineation, thorough evaluation of tumor motion, and improved on-board imaging at the time of treatment for patient alignment, each of which is critical for successful tumor control and mitigation of risks to normal tissues.

Advances in the use of motion management and image guidance in radiation therapy treatment for lung cancer.

The development of advanced radiation technologies, including intensity-modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT) and proton therapy, has resulted in increasingly conformal radiation treatments. Recent evidence for the importance of minimizing dose to normal critical structures including the heart and lungs has led to incorporation of these advanced treatment modalities into radiation therapy (RT) for non-small cell lung cancer (NSCLC). While such technologies have allowed for improved dose delivery, implementation requires improved target accuracy with treatments, placing increasing importance on evaluating tumor motion at the time of planning and verifying tumor position at the time of treatment.

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.

Excellent Pathologic Response and Atypical Clinical Course of High-Grade Extremity Sarcoma to Neoadjuvant Pencil Beam Scanning Proton Therapy.

Neoadjuvant radiation therapy, followed by definitive surgical resection, remains the standard of care for resectable high-grade and unresectable soft tissue sarcomas. Proton therapy offers the promise of highly conformal dose distributions with improved sparing of neighboring normal tissues as compared with conformal and intensity modulated photon techniques. It is unclear whether proton therapy may offer an improved tumoral response, especially with dose escalation, in this relatively radio-insensitive tumor type.

Dramatic Response of a Large Sacral Chordoma to Intensity Modulated Proton Beam Therapy.

Sacral chordomas are slow-growing, indolent, and locally invasive tumors that typically present with pain and neurologic dysfunction. Wide en-bloc surgical excision is the primary treatment, but achieving adequate margins is difficult and surgery is often associated with significant morbidity. Adjuvant radiation therapy (RT) is utilized to decrease the risk of local recurrence or as definitive treatment for nonsurgical candidates.

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.