Outcomes and Pattern of Care for Spinal Myxopapillary Ependymoma in the Modern Era-A Population-Based Observational Study.

(1) Background: Myxopapillary ependymoma (MPE) is a rare tumor of the spine, typically slow-growing and low-grade. Optimal management strategies remain unclear due to limited evidence given the low incidence of the disease. (2) Methods: We analyzed data from 1197 patients with spinal MPE from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2020). Patient demographics, treatment modalities, and survival outcomes were examined using statistical analyses. (3) Results: Most patients were White (89.9%) with a median age at diagnosis of 42 years. Surgical resection was performed in 95% of cases. The estimated 10-year overall survival was 91.4%. Younger age (hazard ratio (HR) = 1.09, p < 0.001) and receipt of surgery (HR = 0.43, p = 0.007) were associated with improved survival. Surprisingly, male sex was associated with worse survival (HR = 1.86, p = 0.008) and a younger age at diagnosis compared to females. (4) Conclusions: This study, the largest of its kind, underscores the importance of surgical resection in managing spinal MPE. The unexpected association between male sex and worse survival warrants further investigation into potential sex-specific pathophysiological factors influencing prognosis. Despite limitations, our findings contribute valuable insights for guiding clinical management strategies for spinal MPE.

MR-guided stereotactic radiation therapy for head and neck cancers.

Purpose: MR-guided radiotherapy (MRgRT) has the advantage of utilizing high soft tissue contrast imaging to track daily changes in target and critical organs throughout the entire radiation treatment course. Head and neck (HN) stereotactic body radiation therapy (SBRT) has been increasingly used to treat localized lesions within a shorter timeframe. The purpose of this study is to examine the dosimetric difference between the step-and-shot intensity modulated radiation therapy (IMRT) plans on Elekta Unity and our clinical volumetric modulated arc therapy (VMAT) plans on Varian TrueBeam for HN SBRT. Method: Fourteen patients treated on TrueBeam sTx with VMAT treatment plans were re-planned in the Monaco treatment planning system for Elekta Unity MR-Linac (MRL). The plan qualities, including target coverage, conformity, homogeneity, nearby critical organ doses, gradient index and low dose bath volume, were compared between VMAT and Monaco IMRT plans. Additionally, we evaluated the Unity adaptive plans of adapt-to-position (ATP) and adapt-to-shape (ATS) workflows using simulated setup errors for five patients and assessed the outcomes of our treated patients. Results: Monaco IMRT plans achieved comparable results to VMAT plans in terms of target coverage, uniformity and homogeneity, with slightly higher target maximum and mean doses. The critical organ doses in Monaco IMRT plans all met clinical goals; however, the mean doses and low dose bath volumes were higher than in VMAT plans. The adaptive plans demonstrated that the ATP workflow may result in degraded target coverage and OAR doses for HN SBRT, while the ATS workflow can maintain the plan quality. Conclusion: The use of Monaco treatment planning and online adaptation can achieve dosimetric results comparable to VMAT plans, with the additional benefits of real-time tracking of target volume and nearby critical structures. This offers the potential to treat aggressive and variable tumors in HN SBRT and improve local control and treatment toxicity.

Addition of Metastasis-Directed Therapy to Intermittent Hormone Therapy for Oligometastatic Prostate Cancer: The EXTEND Phase 2 Randomized Clinical Trial.

Importance: Despite evidence demonstrating an overall survival benefit with up-front hormone therapy in addition to established synergy between hormone therapy and radiation, the addition of metastasis-directed therapy (MDT) to hormone therapy for oligometastatic prostate cancer, to date, has not been evaluated in a randomized clinical trial. Objective: To determine in men with oligometastatic prostate cancer whether the addition of MDT to intermittent hormone therapy improves oncologic outcomes and preserves time with eugonadal testosterone compared with intermittent hormone therapy alone. Design, Setting, Participants: The External Beam Radiation to Eliminate Nominal Metastatic Disease (EXTEND) trial is a phase 2, basket randomized clinical trial for multiple solid tumors testing the addition of MDT to standard-of-care systemic therapy. Men aged 18 years or older with oligometastatic prostate cancer who had 5 or fewer metastases and were treated with hormone therapy for 2 or more months were enrolled to the prostate intermittent hormone therapy basket at multicenter tertiary cancer centers from September 2018 to November 2020. The cutoff date for the primary analysis was January 7, 2022. Interventions: Patients were randomized 1:1 to MDT, consisting of definitive radiation therapy to all sites of disease and intermittent hormone therapy (combined therapy arm; n = 43) or to hormone therapy only (n = 44). A planned break in hormone therapy occurred 6 months after enrollment, after which hormone therapy was withheld until progression. Main Outcomes and Measures: The primary end point was disease progression, defined as death or radiographic, clinical, or biochemical progression. A key predefined secondary end point was eugonadal progression-free survival (PFS), defined as the time from achieving a eugonadal testosterone level (≥150 ng/dL; to convert to nanomoles per liter, multiply by 0.0347) until progression. Exploratory measures included quality of life and systemic immune evaluation using flow cytometry and T-cell receptor sequencing. Results: The study included 87 men (median age, 67 years [IQR, 63-72 years]). Median follow-up was 22.0 months (range, 11.6-39.2 months). Progression-free survival was improved in the combined therapy arm (median not reached) compared with the hormone therapy only arm (median, 15.8 months; 95% CI, 13.6-21.2 months) (hazard ratio, 0.25; 95% CI, 0.12-0.55; P < .001). Eugonadal PFS was also improved with MDT (median not reached) compared with the hormone therapy only (6.1 months; 95% CI, 3.7 months to not estimable) (hazard ratio, 0.32; 95% CI, 0.11-0.91; P = .03). Flow cytometry and T-cell receptor sequencing demonstrated increased markers of T-cell activation, proliferation, and clonal expansion limited to the combined therapy arm. Conclusions and Relevance: In this randomized clinical trial, PFS and eugonadal PFS were significantly improved with combination treatment compared with hormone treatment only in men with oligometastatic prostate cancer. Combination of MDT with intermittent hormone therapy may allow for excellent disease control while facilitating prolonged eugonadal testosterone intervals. Trial Registration: ClinicalTrials.gov Identifier: NCT03599765.

Optimizing Preventive Adjuvant Linac-Based (OPAL) Radiation: A Phase 2 Trial of Daily Partial Breast Irradiation.

PURPOSE: Evidence supports use of partial-breast irradiation (PBI) in the management of early breast cancer, but the optimal dose-fractionation remains unsettled. METHODS AND MATERIALS: We conducted a phase 2 clinical trial (OPAL trial) to evaluate a novel PBI dosing schedule of 35 Gy in 10 daily fractions. Patients with close (<2 mm) margins also received a boost of 9 Gy in 3 fractions. Eligible patients underwent margin-negative lumpectomy for ductal carcinoma in situ or estrogen receptor-positive invasive breast cancer, up to 3 cm, pTis-T2 N0. The primary outcome was any grade ≥2 toxic effect occurring from the start of radiation through 6 months of follow-up. Secondary outcomes included patient-reported cosmesis, breast pain, and functional status, measured using the Breast Cancer Treatment Outcomes Scale, and physician-reported cosmesis, measured using the Radiation Therapy and Oncology Group scale. The Cochran-Armitage trend test and multivariable mixed-effects longitudinal growth curve models compared outcomes for the OPAL study population with those for a control group of similar patients treated with whole-breast irradiation (WBI) plus boost. RESULTS: All 149 patients enrolled on the OPAL trial received the prescribed dose, and 17.4% received boost. The median age was 64 years; 83.2% were White, and 73.8% were overweight or obese. With median follow-up of 2.0 years, 1 patient (0.7%) experienced in-breast recurrence. Prevalence of the primary toxicity outcome was 17.4% (26 of 149 patients) in the OPAL trial compared with 72.7% (128 of 176 patients) in the control WBI-plus-boost cohort (P < .001). In longitudinal multivariable analysis, treatment on the OPAL trial was associated with improved patient-reported cosmesis (P < .001), functional status (P = .004), breast pain (P = .004), and physician-reported cosmesis (P < .001). CONCLUSIONS: Treatment with daily PBI was associated with substantial reduction in early toxicity and improved patient- and physician-reported outcomes compared with WBI plus boost. Daily external-beam partial-breast irradiation with 13 or fewer fractions merits further prospective evaluation.

Temporal characterization of acute pain and toxicity kinetics during radiation therapy for head and neck cancer. A retrospective study.

Objectives: Pain during Radiation Therapy (RT) for oral cavity/oropharyngeal cancer (OC/OPC) is a clinical challenge due to its multifactorial etiology and variable management. The objective of this study was to define complex pain profiles through temporal characterization of pain descriptors, physiologic state, and RT-induced toxicities for pain trajectories understanding. Materials and methods: Using an electronic health record registry, 351 OC/OPC patients treated with RT from 2013 to 2021 were included. Weekly numeric scale pain scores, pain descriptors, vital signs, physician-reported toxicities, and analgesics were analyzed using linear mixed effect models and Spearman's correlation. Area under the pain curve (AUCpain) was calculated to measure pain burden over time. Results: Median pain scores increased from 0 during the weekly visit (WSV)-1 to 5 during WSV-7. By WSV-7, 60% and 74% of patients reported mouth and throat pain, respectively, with a median pain score of 5. Soreness and burning pain peaked during WSV-6/7 (51%). Median AUCpain was 16% (IQR (9.3-23)), and AUCpain significantly varied based on gender, tumor site, surgery, drug use history, and pre-RT pain. A temporal increase in mucositis and dermatitis, declining mean bodyweight (-7.1%; P < 0.001) and mean arterial pressure (MAP) 6.8 mmHg; P < 0.001 were detected. Pulse rate was positively associated while weight and MAP were negatively associated with pain over time (P < 0.001). Conclusion: This study provides insight on in-depth characterization and associations between dynamic pain, physiologic, and toxicity kinetics. Our findings support further needs of optimized pain control through temporal data-driven clinical decision support systems for acute pain management.

Adhering to Eat and Exercise Status During Radiotherapy for Oropharyngeal Cancer for Prevention and Mitigation of Radiotherapy-Associated Dysphagia.

Importance: Previously published work reported independent benefit of maintenance of oral intake (eat) and swallowing exercise adherence (exercise) during radiotherapy (RT) on diet and functional outcomes. The current study seeks to validate the authors' previously published findings in a large contemporary cohort of patients with oropharynx cancer (OPC) and address limitations of the prior retrospective study using prospective, validated outcome measures. Objective: To examine the longitudinal association of oral intake and swallowing exercise using validated, clinician-graded and patient-reported outcomes. Design, Setting, and Participants: Secondary analysis of a prospective OPC registry including patients who underwent primary RT/chemoradiotherapy (CRT) or primary transoral robotic surgery plus RT/CRT for OPC at a single-institution comprehensive cancer center. Exposures: Adherence to speech pathology swallowing intervention during RT coded as (1) eat: oral intake at end of RT (nothing by mouth [NPO]; partial oral intake [PO], with feeding tube [FT] supplement; full PO); and (2) exercise: swallowing exercise adherence (nonadherent vs partial/full adherence). Main Outcomes and Measures: Feeding tube and diet (Performance Status Scale for Head and Neck Cancer) patient-reported swallowing-related quality of life (MD Anderson Dysphagia Inventory; MDADI) and clinician-graded dysphagia severity grade (videofluoroscopic Dynamic Imaging Grade of Swallowing Toxicity; DIGEST) were collected at baseline, 3 to 6 months, and 18 to 24 months post-RT. Results: A total of 595 patients (mean [SD] age, 65 [10] years; 532 [89%] male) who underwent primary RT (111 of 595 [19%]), CRT (434 of 595 [73%]), or primary transoral robotic surgery plus RT/CRT (50 of 595 [8%]) were included in this cohort study. At the end of RT, 55 (9%) patients were NPO, 115 (19%) were partial PO, 425 (71%) were full PO, and 340 (57%) reported exercise adherence. After multivariate adjustment, subacute return to solid diet and FT were independently associated with oral intake (odds ratio [OR], 2.0; 95% CI, 1.0-4.1; OR, 0.1; 95% CI, 0.0-0.2, respectively) and exercise (OR, 2.9; 95% CI, 1.9-4.5; OR, 0.3; 95% CI, 0.1-0.5, respectively). Subacute MDADI (ß = 6.5; 95% CI, 1.8-11.2), FT duration (days; ß = -123.4; 95% CI, -148.5 to -98.4), and less severe dysphagia per DIGEST (OR, 0.6; 95% CI, 0.3-1.0) were independently associated with oral intake, while exercise was independently associated with less severe laryngeal penetration/aspiration per DIGEST-safety (OR, 0.7; 95% CI, 0.4-1.0). DIGEST grade associations with oral intake were not preserved long-term; however, exercise was associated with a higher likelihood of solid diet intake and better swallow safety per DIGEST. Conclusions and Relevance: The findings of this cohort study extend the authors' previously published findings that oral intake and swallowing exercise during RT are associated with favorable functional outcomes, now demonstrated with broader domains of function using validated measures. Patterns of benefit differed in this study. Specifically, better subacute recovery of swallow-related quality of life and less severe dysphagia were found among patients who maintained oral intake independent of exercise adherence, and shorter FT utilization and better long-term diet and swallowing safety were found among those who exercised independent of oral intake.

Definitive Local Consolidative Therapy for Oligometastatic Solid Tumors: Results From the Lead-in Phase of the Randomized Basket Trial EXTEND.

PURPOSE: The benefit of local consolidative therapy (LCT) for oligometastasis across histologies remains uncertain. EXTernal beam radiation to Eliminate Nominal metastatic Disease (EXTEND; NCT03599765) is a randomized phase 2 basket trial evaluating the effectiveness of LCT for oligometastatic solid tumors. We report here the prospective results of the single-arm "lead-in" phase intended to identify histologies most likely to accrue to histology-specific endpoints in the randomized phase. METHODS AND MATERIALS: Eligible histologies included colorectal, sarcoma, lung, head and neck, ovarian, renal, melanoma, pancreatic, prostate, cervix/uterine, breast, and hepatobiliary. Patients received LCT to all sites of active metastatic disease and primary/regional disease (as applicable) plus standard-of-care systemic therapy or observation. The primary endpoint in EXTEND was progression-free survival (PFS), and the primary endpoint of the lead-phase was histology-specific accrual feasibility. Adverse events were graded by Common Terminology Criteria for Adverse Events version 4.0. RESULTS: From August 2018 through January 2019, 50 patients were enrolled and 49 received definitive LCT. Prostate, breast, and kidney were the highest enrolling histologies and identified for independent accrual in the randomization phase. Most patients (73%) had 1 or 2 metastases, most often in lung or bone (79%), and received ablative radiation (62%). Median follow-up for censored patients was 38 months (range, 16-42 months). Median PFS was 13 months (95% confidence interval, 9-24), 3-year overall survival rate was 73% (95% confidence interval, 57%-83%), and local control rate was 98% (93 of 95 tumors). Two patients (4%) had Common Terminology Criteria for Adverse Events grade 3 toxic effects related to LCT; no patient had grade 4 or 5 toxic effects. CONCLUSIONS: The prospective lead-in phase of the EXTEND basket trial demonstrated feasible accrual, encouraging PFS, and low rates of severe toxic effects at mature follow-up. The randomized phase is ongoing with histology-based baskets that will provide histology-specific evidence for LCT in oligometastatic disease.

Unilateral Radiation Therapy for Tonsillar Cancer: Treatment Outcomes in the Era of Human Papillomavirus, Positron-Emission Tomography, and Intensity Modulated Radiation Therapy.

PURPOSE: The goal of this study was to evaluate disease, survival, and toxic effects after unilateral radiation therapy treatment for tonsillar cancer. METHODS AND MATERIALS: A retrospective study was performed of patients treated at our institution within the period from 2000 to 2018. Summary statistics were used to assess the cohort by patient characteristics and treatments delivered. The Kaplan-Meier method was used to determine survival outcomes. RESULTS: The cohort comprised 403 patients, including 343 (85%) with clinical and/or radiographic evidence of ipsilateral cervical nodal disease and 181 (45%) with multiple involved nodes. Human papillomavirus was detected in 294 (73%) tumors. Median follow-up time was 5.8 years. Disease relapse was infrequent with local recurrence in 9 (2%) patients, neck recurrence in 13 (3%) patients, and recurrence in the unirradiated contralateral neck in 9 (2%) patients. Five- and 10-year overall survival rates were 94% and 89%, respectively. Gastrostomy tubes were needed in 32 (9%) patients, and no patient had a feeding tube 6 months after therapy. CONCLUSIONS: For patients with well-lateralized tonsillar tumors and no clinically evident adenopathy of the contralateral neck, unilateral radiation therapy offers favorable rates of disease outcomes and a relatively low toxicity profile.

Adoption of Ultrahypofractionated Radiation Therapy in Patients With Breast Cancer.

Introduction: The first high-quality clinical trial to support ultrahypofractionated whole-breast irradiation (ultra-HF-WBI) for invasive early-stage breast cancer (ESBC) was published in April 2020, coinciding with the beginning of the COVID-19 pandemic. We analyzed adoption of ultra-HF-WBI for ductal carcinoma in situ (DCIS) and ESBC at our institution after primary trial publication. Methods and Materials: We evaluated radiation fractionation prescriptions for all patients with DCIS or ESBC treated with WBI from March 2020 to May 2021 at our main campus and regional campuses. Demographic and clinical characteristics were extracted from the electronic medical record. Treating physician characteristics were collected from licensure data. Hierarchical logistic regression models identified factors correlated with adoption of ultra-HF-WBI (26 Gy in 5 daily factions [UK-FAST-FORWARD] or 28.5 Gy in 5 weekly fractions [UK-FAST]). Results: Of 665 included patients, the median age was 61.5 years, and 478 patients (71.9%) had invasive, hormone-receptor-positive breast cancer. Twenty-one physicians treated the included patients. In total, 249 patients (37.4%) received ultra-HF-WBI, increasing from 4.3% (2 of 46) in March-April 2020 to a high of 45.5% (45 of 99) in July-August 2020 (P < .001). Patient factors associated with increased use of ultra-HF-WBI included older age (≥50 years old), low-grade WBI without inclusion of the low axilla, no radiation boost, and farther travel distance (P < .03). Physician variation accounted for 21.7% of variance in the outcome, with rate of use of ultra-HF-WBI by the treating physicians ranging from 0% to 75.6%. No measured physician characteristics were associated with use of ultra-HF-WBI. Conclusions: Adoption of ultra-HF-WBI at our institution increased substantially after the publication of randomized evidence supporting its use. Ultra-HF-WBI was preferentially used in patients with lower risk disease, suggesting careful selection for this new approach while long-term data are maturing. Substantial physician-level variation may reflect a lack of consensus on the evidentiary standards required to change practice.

Contemporary Outcomes After Multimodality Therapy in Patients With Breast Cancer Presenting With Ipsilateral Supraclavicular Node Involvement.

PURPOSE: Patients with breast cancer and ipsilateral supraclavicular (SCV) node involvement at the time of diagnosis (TNM cN3c) have historically had poor outcomes. Radiation therapy (RT) has an important role because SCV nodes are not routinely surgically dissected. However, optimal locoregional management, contemporary outcomes, and prognostic factors are not well defined. METHODS AND MATERIALS: We reviewed the data of patients with cN3c breast cancer treated at our institution between 2014 and 2019 with curative intent, including neoadjuvant chemotherapy, surgery, and adjuvant RT. All patients received comprehensive regional RT, including to the SCV nodes. Institutional guidelines recommend a 10-Gy or 16-Gy boost to resolved and unresolved N3 nodes, respectively. Overall survival (OS), recurrence-free survival (RFS), locoregional recurrence-free survival (LRRFS), and supraclavicular recurrence-free survival (SCRFS) were analyzed. RESULTS: Data from 173 consecutive patients were analyzed with a median follow-up time of 2.8 years. The median age was 54 years, 76 patients (44%) were estrogen receptor positive/human epidermal growth factor receptor 2 negative, 100 patients (58%) had T3/4 disease, and 10 patients (6%) underwent a neck dissection. In addition, 156 patients (90%) received a cumulative SCV dose of ≥60 Gy. The 5-year OS, SCRFS, LRRFS, and RFS rates were 73%, 95%, 86%, and 50%, respectively. The 5-year OS rate for a cumulative SCV dose of ≥60 Gy versus <60 Gy was 75% versus 39% (P = .04). In the multivariable analysis, a cumulative SCV dose of ≥60 Gy, extranodal extension, receptor status, and Eastern Cooperative Oncology Group performance status were associated with OS. The 5-year SCRFS rates with and without neck dissection were 100% versus 95% (P = .57). Among patients with a postchemotherapy SCV node size of ≥1 cm without neck dissection, the 5-year SCRFS rate was 83%. CONCLUSIONS: In one of the largest series of patients with cN3c breast cancer, multimodality therapy using adjuvant RT with a SCV boost resulted in a 5-year LRRFS rate of 86%. There is a limited role for neck dissection as the 5-year SCRFS rate was 95% overall and 83% for residual SCV disease ≥1 cm after chemotherapy with RT alone. A cumulative SCV dose of ≥60 Gy was associated with improved OS, but not SCRFS, LRRFS, or RFS. A SCV boost should be considered in these patients as treatment was well-tolerated. Despite advances in systemic therapy, nearly half of patients developed distant metastases, highlighting the need for close observation after treatment.

Stereotactic body ablative radiotherapy for reirradiation of small volume head and neck cancers is associated with prolonged survival: Large, single-institution, modern cohort study.

BACKGROUND: Recurrent head and neck cancer has poor prognosis. Stereotactic body radiotherapy (SBRT) may improve outcomes by delivering ablative radiation doses. METHODS: We reviewed patients who received definitive-intent SBRT reirradiation at our institution from 2013 to 2020. Patterns of failure, overall survival (OS), and toxicities were analyzed. RESULTS: One hundred and thirty-seven patients were evaluated. The median OS was 44.3 months. The median SBRT dose was 45 Gy and median target volume 16.9 cc. The 1-year local, regional, and distant control was 78%, 66%, and 83%, respectively. Systemic therapy improved regional (p = 0.004) and distant control (p = 0.04) in nonmetastatic patients. Grade 3+ toxicities were more common at mucosal sites (p = 0.001) and with concurrent systemic therapy (p = 0.02). CONCLUSIONS: In a large cohort of SBRT reirradiation for recurrent, small volume head and neck cancers, a median OS of 44.3 months was observed. Systemic therapy improved regional and distant control. Toxicities were modulated by anatomic site and systemic therapy.

Proton Therapy for Head and Neck Cancer: A 12-Year, Single-Institution Experience.

PURPOSE: To characterize our experience and the disease control and toxicity of proton therapy (PT) for patients with head and neck cancer (HNC). PATIENTS AND METHODS: Clinical outcomes for patients with HNC treated with PT at our institution were prospectively collected in 2 institutional review board-approved prospective studies. Descriptive statistics were used to summarize patient characteristics and outcomes. Overall survival, local-regional control, and disease-free survival were estimated by the Kaplan-Meier method. Treatment-related toxicities were recorded according to the Common Terminology Criteria for Adverse Events (version 4.03) scale. RESULTS: The cohort consisted of 573 patients treated from February 2006 to June 2018. Median patient age was 61 years. Oropharynx (33.3%; n = 191), paranasal sinus (11%; n = 63), and periorbital tissues (11%; n = 62) were the most common primary sites. Patients with T3/T4 or recurrent disease comprised 46% (n = 262) of the cohort. The intent of PT was definitive in 53% (n = 303), postoperative in 37% (n = 211), and reirradiation in 10% (n = 59). Median dose was 66 Gy (radiobiological equivalent). Regarding systemic therapy, 43% had received concurrent (n = 244), 3% induction (n = 19), and 15% (n = 86) had both. At a median follow-up of 2.4 years, 88 patients (15%) had died and 127 (22%) developed disease recurrence. The overall survival, local-regional control, and disease-free survival at 2 and 5 years were, respectively, 87% and 75%, 87% and 78%, and 74% and 63%. Maximum toxicity (acute or late) was grade 3 in 293 patients (51%), grade 2 in 234 patients (41%), and grade 1 in 31 patients (5%). There were 381 acute grade 3 and 190 late grade 3 unique toxicities across 212 (37%) and 150 (26%) patients, respectively. There were 3 late-grade 4 events across 2 patients (0.3%), 2 (0.3%) acute-grade 5, and no (0%) late-grade 5 events. CONCLUSIONS: The overall results from this prospective study of our initial decade of experience with PT for HNC show favorable disease control and toxicity outcomes in a multidisease-site cohort and provide a reference benchmark for future comparison and study.

Proton Therapy for Major Salivary Gland Cancer: Clinical Outcomes.

PURPOSE: To report clinical outcomes in terms of disease control and toxicity in patients with major salivary gland cancers (SGCs) treated with proton beam therapy. MATERIALS AND METHODS: Clinical and dosimetric characteristics of patients with SGCs treated from August 2011 to February 2020 on an observational, prospective, single-institution protocol were abstracted. Local control and overall survival were calculated by the Kaplan-Meier method. During radiation, weekly assessments of toxicity were obtained, and for patients with ≥ 90 days of follow-up, late toxicity was assessed. RESULTS: Seventy-two patients were identified. Median age was 54 years (range, 23-87 years). Sixty-three patients (88%) received postoperative therapy, and nine patients (12%) were treated definitively. Twenty-six patients (36%) received concurrent chemotherapy. Nine patients (12%) had received prior radiation. All (99%) but one patient received unilateral treatment with a median dose of 64 GyRBE (relative biological effectiveness) (interquartile range [IQR], 60-66), and 53 patients (74%) received intensity-modulated proton therapy with either single-field or multifield optimization. The median follow-up time was 30 months. Two-year local control and overall survival rates were 96% (95% confidence interval [CI] 85%-99%) and 89% (95% CI 76%-95%], respectively. Radiation dermatitis was the predominant grade-3 toxicity (seen in 21% [n = 15] of the patients), and grade ≥ 2 mucositis was rare (14%; n = 10 patients). No late-grade ≥ 3 toxicities were reported. CONCLUSION: Proton beam therapy for treatment of major SGCs manifests in low rates of acute mucosal toxicity. In addition, the current data suggest a high rate of local control and minimal late toxicity.

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., the extent to which an employee is not fully functional at work), and work productivity losses. We used the work productivity and activity impairment questionnaire at baseline (pre-CRT), at the end of CRT, and at 6 months, 1 year, and 2 years. A one-sided Cochran-Armitage test was used to analyze within-arm temporal trends, and a χ2 test was used to compare between-arm differences. Among working patients, at each follow-up point, a 1-sided Wilcoxon rank-sum test was used to compare work-productivity scores. RESULTS: Patient characteristics in IMPT versus IMRT arms were similar. In the IMPT arm, within-arm analysis demonstrated that an increasing proportion of patients resumed working after IMPT, from 60% (40 of 67) pre-CRT and 71% (30 of 42) at 1 year to 78% (18 of 23) at 2 years (P = 0.025). In the IMRT arm, the proportion remained stable, with 57% (43 of 76) pre-CRT, 54% (21 of 39) at 1 year, and 52% (13 of 25) working at 2 years (P = 0.47). By 2 years after CRT, the between-arm difference between patients who had IMPT and those who had IMRT trended toward significance (P = 0.06). Regardless of treatment arm, among working patients, the most severe work impairments occurred from treatment initiation to the end of CRT, with significant recovery from absenteeism, presenteeism, and productivity impairments by the 2-year follow-up (P < 0.001 for all). Higher magnitudes of recovery from absenteeism (at 1 year, P = 0.05; and at 2 years, P = 0.04) and composite work impairment scores (at 1 year, P = 0.04; and at 2 years, P = 0.04) were seen in patients treated with IMPT versus those treated with IMRT. CONCLUSION: In patients with OPC receiving curative CRT, patients randomized to IMPT demonstrated increasing work and productivity recovery trends. Studies are needed to identify mechanisms underlying head and neck CRT treatment causing work disability and impairment.

Proton Therapy for HPV-Associated Oropharyngeal Cancers of the Head and Neck: a De-Intensification Strategy.

OPINION STATEMENT: The rise in the incidence of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPC), the relatively young age at which it is diagnosed, and its favorable prognosis necessitate the use of treatment techniques that reduce the likelihood of side effects during and after curative treatment. Intensity-modulated proton therapy (IMPT) is a form of radiotherapy that de-intensifies treatment through dose de-escalation to normal tissues without compromising dose to the primary tumor and involved, regional lymph nodes. Preclinical studies have demonstrated that HPV-positive squamous cell carcinoma is more sensitive to proton radiation than is HPV-negative squamous cell carcinoma. Retrospective studies comparing intensity-modulated photon (X-ray) radiotherapy to IMPT for OPC suggest comparable rates of disease control and lower rates of pain, xerostomia, dysphagia, dysgeusia, gastrostomy tube dependence, and osteoradionecrosis with IMPT-all of which meaningfully affect the quality of life of patients treated for HPV-associated OPC. Two phase III trials currently underway-the "Randomized Trial of IMPT versus IMRT for the Treatment of Oropharyngeal Cancer of the Head and Neck" and the "TOxicity Reduction using Proton bEam therapy for Oropharyngeal cancer (TORPEdO)" trial-are expected to provide prospective, level I evidence regarding the effectiveness of IMPT for such patients.

Longitudinal characterization of the tumoral microbiome during radiotherapy in HPV-associated oropharynx cancer.

PURPOSE: To describe the baseline and serial tumor microbiome in HPV-associated oropharynx cancer (OPC) over the course of radiotherapy (RT). METHODS: Patients with newly diagnosed HPV-associated OPC treated with definitive radiotherapy +/- concurrent chemotherapy were enrolled in this prospective study. Using 16S rRNA gene sequencing, dynamic changes in the tumor site microbiome during RT were investigated. Surface tumor samples were obtained before RT and at week 1, 3 and 5 of RT. Radiological primary tumor response at mid-treatment was categorized as complete (CR) or partial (PR). RESULTS: Ten patients were enrolled, but 9 patients were included in the final analysis. Mean age was 62 years (range: 51-71). As per AJCC 8th Ed, 56%, 22% and 22% of patients had stage I, II and III, respectively. At 4-weeks, 6 patients had CR and 3 patients had PR; at follow-up imaging post treatment, all patients had CR. The baseline diversity of the tumoral versus buccal microbiome was not statistically different. For the entire cohort, alpha diversity was significantly decreased over the course of treatment (p = 0.04). There was a significant alteration in the bacterial community within the first week of radiation. Baseline tumor alpha diversity of patients with CR was significantly higher than those with PR (p = 0.03). While patients with CR had significant reduction in diversity over the course of radiation (p = 0.01), the diversity remained unchanged in patients with PR. Patients with history of smoking had significantly increased abundance of  Kingella (0.05) and lower abundance of Stomatobaculum (p = 0.03) compared to never smokers. CONCLUSIONS: The tumor microbiome of HPV-associated OPC exhibits reduced alpha diversity and altered taxa abundance over the course of radiotherapy. The baseline bacterial profiles of smokers vs. non-smokers were inherently different. Baseline tumor alpha diversity of patients with CR was higher than patients with PR, suggesting that the microbiome deserves further investigation as a biomarker of radiation response.

Outcomes after salvage for HPV-positive recurrent oropharyngeal cancer treated with primary radiation.

PURPOSE: HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) carries a favorable prognosis for patients, yet nearly 30% of patients will experience disease relapse. We sought to detail patterns of failure, associated salvage therapy, and outcomes for patients with recurrent HPV-positive OPSCC. METHODS AND MATERIALS: This is a single institution retrospective study of patients with recurrent HPV-positive OPSCC irradiated from 2002 to 2014. The primary study outcome was overall survival (OS, calculated using the Kaplan-Meier method). Secondary aims included patterns of first failure with descriptive details of salvage therapy. Solitary recurrences were defined as initial presentation of recurrence in a single site (primary, neck or oligometastatic), and multi-site was defined as local and regional and/or multiple sites of distant recurrence. Survival outcomes were compared using the log-rank test. RESULTS: The cohort consisted of 132 patients. The median follow-up was 59 months for surviving patients. Estimated 2-year and 5-year OS rates were 47% and 32%, respectively. Comparative 2-year and 5-year OS rates were 65% and 46% versus 19% and 9% for the solitary group and multi-site group, respectively (p < .001). CONCLUSIONS: Patients with recurrent HPV-positive OPSCC experience 5-year survival of approximately 32%. However, patients with a "solitary" recurrence including disease at the primary site, neck or oligometastatic site have more favorable long-term outcomes.

Defining the dose-volume criteria for laryngeal sparing in locally advanced oropharyngeal cancer utilizing split-field IMRT, whole-field IMRT and VMAT.

PURPOSE: To determine the optimal dose-volume constraint for laryngeal sparing using three commonly employed intensity modulated radiation therapy (IMRT) approaches in patients with oropharyngeal cancer treated to the bilateral neck. MATERIALS AND METHODS: Thirty patients with stage II-IVA oropharynx cancers received definitive radiotherapy with split-field IMRT (SF-IMRT) to the bilateral neck between 2008 and 2013. Each case was re-planned using whole-field IMRT (WF-IMRT) and volumetric modulated arc therapy (VMAT) and plan quality metrics and dose to laryngeal structures was evaluated. Two larynx volumes were defined and compared on the current study: the Radiation Therapy Oncology Group (RTOG) larynx as defined per the RTOG 1016 protocol and the MDACC larynx defined as the components of the larynx bounded by the superior and inferior extent of the thyroid cartilage. RESULTS: Target coverage, conformity, and heterogeneity indices were similar in all techniques. The RTOG larynx mean dose was lower with WF-IMRT than SF-IMRT (22.1 vs 25.8 Gy; P < 0.01). The MDACC larynx mean dose was 17.5 Gy ± 5.4 Gy with no differences between the 3 techniques. WF-IMRT and VMAT plans were associated with lower mean doses to the supraglottic larynx (42.1 vs 41.2 vs 54.8 Gy; P < 0.01) and esophagus (18.1 vs 18.2 vs 36 Gy; P < 0.01). CONCLUSIONS: Modern whole field techniques can provide effective laryngeal sparing in patients receiving radiotherapy to the bilateral neck for advanced oropharyngeal cancers. SUMMARY: We evaluated laryngeal dose in patients with locally advanced oropharyngeal cancer treated to the bilateral neck using split-field IMRT (SF-IMRT), whole-field IMRT (WF-IMRT) and volumetric arc therapy (VMAT). All three techniques provided good sparing of laryngeal structures and were able to achieve a mean larynx dose < 33 Gy. There were no significant differences in dose to target structures or non-laryngeal organs at risk among techniques.

Development and validation of a contouring guideline for the taste bud bearing tongue mucosa.

PURPOSE: To introduce a contouring guideline for the taste bud bearing tongue mucosa for head and neck cancer patients receiving radiotherapy. METHODS AND MATERIALS: CT simulation images of oropharyngeal cancer patients were used to delineate both the whole tongue (extrinsic/intrinsic tongue muscles, floor of mouth) and the taste bud bearing tongue mucosa (method A: adaptation of the whole tongue structure; method B: axial adaptation of a mid-sagittal contour). Volumetric and dosimetric parameters of the whole tongue and the two methods of mucosal delineation, spatial overlap between methods A and B, and inter-observer variability for method B were calculated. RESULTS: The study cohort was comprised of 70 patients with T1-4 N0-1 tonsillar (83%) and base of tongue (17%) cancers. Most of the comparative parameters between the whole tongue and mucosa (method A) significantly differed (mean, minimum, and maximum dose, V5-V70, D40-D90). The mean dose calculated for the whole tongue deviated on average 3.77 Gy compared to method A. No significant differences were found between methods A and B of the taste bud bearing tongue mucosa structure, and none of the dosimetric parameters differed more than 1.03 Gy on average. The mean Dice similarity coefficient for both mucosal structures was 0.79 ± 0.05, and 0.63 ± 0.12 for the inter-observer analysis of method B. CONCLUSIONS: We defined two methods for delineating the taste bud bearing mucosa and both are equally satisfactory procedures. Either method is preferable over delineation of the whole tongue as organ at risk for taste impairment.

A Dosimetric Comparison of Oral Cavity Sparing in the Unilateral Treatment of Early Stage Tonsil Cancer: IMRT, IMPT, and Tongue-Deviating Oral Stents.

INTRODUCTION: Tongue-deviating oral stents (TDOS) are commonly used during unilateral neck radiation therapy to reduce unnecessary dose to nontarget oral structures. Their benefit in the setting of highly conformal treatment techniques, however, is not defined. The goal of this study was to investigate the potential benefit of TDOS use on dosimetric parameters in unilateral intensity modulated radiation therapy (IMRT) and intensity modulated proton therapy (IMPT). METHODS: A total of 16 patients with T1-2 tonsil cancer treated at a single institution were selected, of which 8 were simulated/treated with a TDOS and 8 without a TDOS. All received definitive unilateral IMRT to a dose of 66 Gy in 30 fx. IMPT plans were generated for each patient for study purposes and optimized according to standard institutional practice. RESULTS: For IMRT plans, the presence of a TDOS (vs without) was associated with a significantly lower oral mucosa mean dose (31.4 vs 35.3 Gy; P = .020) and V30 (42.7% vs 57.1%; P = .025). For IMPT plans, the presence of TDOS (vs without) was not associated with any improvement in oral mucosa mean dose (18.3 vs 19.9 Gy; P = .274) or V30 (25.0% vs 26.2%; P = .655). IMPT plans without TDOS compared with IMRT plans with TDOS demonstrated reduced oral mucosa mean dose (P < .001) and V30 (P < .001). CONCLUSION: The use of a TDOS for the unilateral treatment of well-lateralized tonsil cancers was associated with oral mucosa sparing for IMRT, but not for IMPT. Moreover, mucosa sparing was improved for IMPT plans without a TDOS compared to IMRT plans with a TDOS.