Baliga, Sujith

ABSTRACT Pediatric radiation therapy presents unique challenges compared to adult treatments, including those of immobilization, potential need for sedation, and the critical importance of accurate, reproducible positioning. Additionally, heightened attention to imaging doses is necessary to minimize long‐term toxicity in survivors. Many of these challenges must be addressed during the process of simulation. This report provides guidelines for pediatric radiotherapy simulation from the Children's Oncology Group. These guidelines cover all anatomic sites and include recommendations for photon and proton therapies, as well as specialized procedures such as stereotactic body radiation therapy, brachytherapy, and total body irradiation. These guidelines are presented as recommendations rather than prescriptive standards as the practice will vary depending on patient age, diagnosis, clinical judgment, and institutional resources.

Cisplatin, one of the most ototoxic anti-neoplastic agents, causes permanent hearing loss in up to 90% of patients. We assessed ototoxicity rates and prospectively collected audiologic outcomes of patients receiving low-dose or high-dose cisplatin with concurrent cochlear-sparing intensity-modulated radiation therapy (IMRT). Patients with head and neck squamous cell carcinoma (HNSCC) receiving definitive or adjuvant cisplatin-based chemoradiotherapy (CRT) were analyzed. Cisplatin was administered either in low doses weekly (40 mg/m2) for up to seven doses or in high doses triweekly (100 mg/m2) for up to three doses. Cochlear-sparing IMRT was delivered in all cases. Audiologic data were prospectively collected before, during, and after treatment completion. The primary endpoint was a hearing change grade of ≥3 after CRT completion. Of the 96 HNSCC patients evaluated, 69 received weekly cisplatin and 58 received definitive CRT. Of patients receiving weekly cisplatin, 13% developed ≥G3 ototoxicity vs. 56% of patients who received triweekly cisplatin (p < 0.001). In multivariable modeling, the cisplatin dose schedule remained significant (OR: 8.4, 95%CI: 2.8–27.8, p < 0.001) for risk of severe irreversible ototoxicity. Triweekly cisplatin CRT significantly increased the ≥G3 severe irreversible ototoxicity risk compared to low-dose weekly cisplatin, irrespective of the cumulative cisplatin dose, even with the use of cochlear-sparing IMRT. No significant difference in oncologic outcomes was observed between the two schedules.

e15045 Background: Human papillomavirus (HPV) is an oncogenic driver of several human cancers, including those of the anal canal, uterine cervix, and head and neck (predominantly oropharynx). Despite advancements in our understanding of HPV-related cancers, there remains an unmet need for a comprehensive biomarker-driven registry to establish correlations between biomarker detectability and clinicopathologic features in patients diagnosed and treated for HPV-driven cancers. To address this need, the NAVigate-HPV Registry has been established to systematically collect and analyze integrated biomarker and clinical data from many U.S. cancer centers. Methods: NavDx (Naveris, Inc.) is a clinically validated blood-based assay detecting circulating cell-free tumor tissue modified viral (TTMV)-HPV DNA. The NAVigate-HPV Registry is a web-based data platform based on a centrally IRB approved protocol. Participating investigators will include providers that order NavDx tests in the routine clinical care of their patients and agree to the terms and conditions for use of the registry. Eligible subjects will have or have had an HPV-driven cancer (with an initial focus on HPV-driven oropharynx cancer with confirmatory tissue testing) and have received one or more NavDx blood tests during routine clinical care. Clinical data and TTMV-HPV DNA scores will be collected at enrollment and defined intervals over five years or until death. Results: In the initial phase, the registry has enlisted participation and established a steering committee composed of a representative from each of 14 institutions. These institutions are geographically diverse centers ranging from community hospitals to clinics and academic medical facilities. An IRB protocol governing the registry will maintain ethical standards, ensuring compliance and ethical conduct throughout the registry process. Data extraction methods have been previously established to evaluate an initial cohort of 543 patients (Hanna GJ, Roof SA, et. al 2023). Conclusions: Naveris and collaborators have together successfully launched the NAVigate-HPV registry with the aim of creating a robust database linking tumor biomarker results from NavDx with clinical outcomes data for HPV-related cancers. The NAVigate-HPV database is expected to encompass more than 1,000 patients within 1 year and grow to > 5,000 patients within 5 years, serving as a powerful tool for precision cancer medicine in this patient cancer population. Establishing this registry will deepen insights into HPV-related cancers and advance diagnostic and therapeutic approaches to improve patient outcomes.

Background: Salivary duct carcinomas (SDC) are a rare and aggressive subtype of salivary gland neoplasm. They can present with distinct immunoprofiles, such as androgen receptor (AR) and HER-2/Neu-positivity. To date, no consensus exists on how to best manage this entity. Methods: All patients diagnosed with nonmetastatic AR+ SDC of the parotid from 2013 to 2019 treated with curative intent were included. Immunologic tumor profiling was conducted using 24 distinct markers. Kaplan–Meier analyses were used to estimate locoregional recurrence (LRR), distant control, and overall survival (OS). Results: Fifteen patients were included. Nine (60%) patients presented with T4 disease and eight (53%) had positive ipsilateral cervical lymphadenopathy. Ten (67%) patients underwent trimodality therapy, including surgery followed by adjuvant radiation and concurrent systemic therapy. The median follow-up was 5.5 years (interquartile range, 4.8–6.1). The estimated 5-year rates of LRR, distant progression, and OS were 6%, 13%, and 87%, respectively. Conclusion: Despite only including AR+ SDC of the parotid, immunoprofiles, such as expression of HER-2, were highly variable, highlighting the potential to tailor systemic regimens based on individual histologic profiles in the future. Studies with larger patient numbers using tumor-specific molecular profiling and tumor heterogeneity analyses are justified to better understand the biology of these tumors. Molecularly informed treatment approaches, including the potential use of AR- and HER-2/Neu-directed therapies upfront in the definitive setting, may hold future promise to further improve outcomes for these patients.

Objectives: Patients with recurrent and metastatic head and neck cancer (HNC) have limited treatment options. ‘QuadShot’ (QS), a hypofractionated palliative radiotherapy regimen, can provide symptomatic relief and local control and may potentiate the effects of immune checkpoint inhibitors (ICIs). We compared outcomes of QS ± concurrent ICIs in the palliative treatment of HNC. Materials and Methods: We identified patients who received ≥three cycles of QS from 2017 to 2022 and excluded patients without post-treatment clinical evaluation or imaging. Outcomes for patients who received QS alone were compared to those treated with ICI concurrent with QS, defined as receipt of ICI within 4 weeks of QS. Results: Seventy patients were included, of whom 57% received concurrent ICI. Median age was 65.5 years (interquartile range [IQR]: 57.9–77.8), and 50% patients had received prior radiation to a median dose of 66 Gy (IQR: 60–70). Median follow-up was 8.8 months. Local control was significantly higher with concurrent ICIs (12-month: 85% vs. 63%, p = 0.038). Distant control (12-month: 56% vs. 63%, p = 0.629) and median overall survival (9.0 vs. 10.0 months, p = 0.850) were similar between the two groups. On multivariable analysis, concurrent ICI was a significant predictor of local control (HR for local failure: 0.238; 95% CI: 0.073–0.778; p = 0.018). Overall, 23% patients experienced grade 3 toxicities, which was similar between the two groups. Conclusions: The combination of QS with concurrent ICIs was well tolerated and significantly improved local control compared to QS alone. The median OS of 9.4 months compares favorably to historical controls for patients with HNC treated with QS. This approach represents a promising treatment option for patients with HNC unsuited for curative-intent treatment and warrants prospective evaluation.

Background and purpose: A bolus is required when treating scalp lesions with photon radiation therapy. Traditional bolus materials face several issues, including air gaps and setup difficulty due to irregular, convex scalp geometry. A 3D-milled bolus is custom-formed to match individual patient anatomy, allowing improved dose coverage and homogeneity. Here, we describe the creation process of a 3D-milled bolus and report the outcomes for patients with scalp malignancies treated with Volumetric Modulated Arc Therapy (VMAT) utilizing a 3D-milled bolus. Materials and methods: Twenty-two patients treated from 2016 to 2022 using a 3D-milled bolus and VMAT were included. Histologies included squamous cell carcinoma (n = 14, 64%) and angiosarcoma (n = 8, 36%). A total of 7 (32%) patients were treated in the intact and 15 (68%) in the postoperative setting. The median prescription dose was 66.0 Gy (range: 60.0–69.96). Results: The target included the entire scalp for 8 (36%) patients; in the remaining 14 (64%), the median ratio of planning target volume to scalp volume was 35% (range: 25–90%). The median dose homogeneity index was 1.07 (range: 1.03–1.15). Six (27%) patients experienced acute grade 3 dermatitis and one (5%) patient experienced late grade 3 skin ulceration. With a median follow-up of 21.4 months (range: 4.0–75.4), the 18-month rates of locoregional control and overall survival were 75% and 79%, respectively. Conclusions: To our knowledge, this is the first study to report the clinical outcomes for patients with scalp malignancies treated with the combination of VMAT and a 3D-milled bolus. This technique resulted in favorable clinical outcomes and an acceptable toxicity profile in comparison with historic controls and warrants further investigation in a larger prospective study.

Background: Racial/ethnic (R/E) minorities with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes compared to White patients. While disparities in patient outcomes for R/E minorities have been well documented, the specific drivers of the inferior outcomes remain poorly understood. Patients and Methods: This was a population-based retrospective cohort study that analyzed HNSCC patients using the National Cancer Database (NCDB) from 2000–2016. Patient outcomes were stratified by R/E groups including White, Black, Hispanic, Native American/Other, and Asian. The main outcome in this study was overall survival (OS). Univariate time-to-event survival analyses were performed using the Kaplan–Meier product limit estimates and the log-rank test to evaluate the differences between strata. Results: There were 304,138 patients with HNSCC identified in this study, of which 262,762 (86.3%) were White, 32,528 (10.6%) were Black, 6191 were Asian (2.0%), and 2657 were Native American/Other (0.9%). Black R/E minorities were more likely to be uninsured (9% vs. 5%, p < 0.0001), have Medicaid insurance (22% vs. 8%, p < 0.0001), be in a lower income quartile (<30,000, 42% vs. 13%, p < 0.0001), have metastatic disease (5% vs. 2%, p < 0.001), and have a total treatment time 6 days longer than White patients (median 107 vs. 101 days, p < 0.001). The 5-year OS for White, Black, Native American/Other, and Asian patients was 50.8%, 38.6%, 51.1%, and 55.8%, respectively. Among the oropharynx HNSCC patients, the 5-year OS rates in p16+ White, Black, and Asian patients were 65.7%, 39.4%%, and 55%, respectively. After a multivariate analysis, Black race was still associated with an inferior OS (HR:1.09, 95% CI: 1.03–1.15, p = 0.002). Conclusions: This large cohort study of HNSCC patients demonstrates that Black race is independently associated with worse OS, in part due to socioeconomic, clinical, and treatment-related factors.

Abstract Patients with human papillomavirus‐associated oropharyngeal squamous cell carcinoma (HPV‐OPSCC) have a favorable prognosis and excellent overall survival (OS), and studies have demonstrated these findings in cohorts of predominantly White patients. Racial/ethnic (R/E) minorities, particularly Black patients, with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes compared with White patients. In this study, we aimed to determine if Black patients with HPV‐OPSCC have a similar favorable prognosis to the White population. This was a population‐based retrospective cohort study that analyzed HNSCC patients using the National Cancer Database from 2010 to 2016. We identified patients with Stage I–IV HPV‐ OPSCC who were treated with radiation, surgery, chemotherapy, or a combination of modalities. Patient outcomes were stratified by R/E groups including White Versus Black patients. The main outcome in this study was OS. Analyses for proportions of categorical variables were performed using a χ 2 or Fisher's exact test. Univariate and multivariate time‐to‐event survival analyses were performed using Kaplan–Meier product limit estimates and log‐rank test to test the differences between strata. A Cox proportional hazards regression model was used to assess the association between covariates and risk of death (OS). We identified 9256 OPSCC patients who met inclusion criteria and were treated between 2010 and 2016, of which 7912 were White (85.5%) and 1344 were Black (14.5%). A total of 1727 were HPV‐OPSCC, of which 1598 were White (92.5%) and 129 (7.5%) were Black. By race, the 5‐year OS for White versus Black OPSCC patients was 42% versus 23%, respectively (log‐rank, p < 0.0001). Among HPV‐positive OPSCC patients, the 5‐year OS for White versus Black patients was 65% versus 39% (log‐rank, p < 0.0001). Among HPV‐negative patients, the 5‐year OS for White versus Black patients was 36% versus 13% (log‐rank, p < 0.0001). On multivariate analysis, after accounting for age, sex, insurance status, income, Charlson–Deyo score, receipt of surgery, distance from facility, and total treatment time, Black race trended toward, but was not associated with worse survival. Hazard ratio (HR:1.24, 95% confidence interval [CI] 0.85–1.81, p = 0.255). This national cohort study of OPSCC patients demonstrates that Black patients with HPV‐OPSCC have a poor prognosis and OS similar to HPV‐negative White patients. This may be partly due to socioeconomic barriers such as insurance and income. Further work is needed to better understand the specific drivers of inferior survival outcomes in this specific patient population.

Purpose/Objective(s): Microbiome has been shown to affect tumorigenesis by promoting inflammation. However, the association between the upper aerodigestive microbiome and head and neck squamous cell carcinoma (HNSCC) is not well established. Hypoxia is a modifiable factor associated with poor radiation response. Our study analyzed the HNSCC tumor samples from The Cancer Genome Atlas (TCGA) to investigate the relationship between different HNSCC tumor subsites, hypoxia, and local tumor microbiome composition. Results: A total of 357 patients were included [Oral cavity (OC) = 226, Oropharynx (OPx) = 53, and Larynx/Hypopharynx (LHPx) = 78], of which 12.8%, 71.7%, and 10.3%, respectively, were HPV positive. The mean (SD) hypoxia scores were 30.18 (11.10), 24.31 (14.13), and 29.53 (12.61) in OC, OPx, and LHPx tumors, respectively, with higher values indicating greater hypoxia. The hypoxia score was significantly higher for OC tumors compared to OPx (p = 0.044) and LHPx (p = 0.002). There was no significant correlation between hypoxia and HPV status. Pseudomonas sp. in OC, Actinomyces sp. and Sulfurimonas sp. in OPx, and Filifactor, Pseudomonas and Actinomyces sp. in LHPx had the strongest association with the hypoxia score. Materials/Methods: Tumor RNAseq samples from TCGA were processed, and the R package “tmesig” was used to calculate gene expression signature, including the Buffa hypoxia (BH) score, a validated hypoxia signature using 52 hypoxia-regulated genes. Microbe relative abundances were modeled with primary tumor location and a high vs. low tertile BH score applying a gamma-distributed generalized linear regression using the “stats” package in R, with adjusted p-value < 0.05 considered significant. Conclusions: In our study, oral cavity tumors were found to be more hypoxic compared to other head and neck subsites, which could potentially contribute to their radiation resistance. For each subsite, distinct microbial populations were over-represented in hypoxic tumors in a subsite-specific manner. Further studies focusing on an association between microbiome, hypoxia, and patient outcomes are warranted.