Importance Standard adjuvant therapy for human papillomavirus–associated oropharyngeal squamous cell carcinoma (HPV-OPSCC) is radiation therapy 60 Gy with or without cisplatin delivered in 30 fractions during 6 weeks. A phase 3 randomized clinical trial demonstrated decreased toxic effects and improved patient-reported outcomes with de-escalated adjuvant radiation therapy (DART) compared with standard therapy; however, outcomes for patients treated in the clinical practice setting following trial adoption remain unknown. Objective To compare characteristics and oncologic outcomes of patients treated with DART during clinical trials (on study) and in clinical practice settings (off study) and report progression-free survival (PFS) by risk category. Design, Setting, and Participants This retrospective cohort study included patients treated with DART in the MC1273 and MC1675 trials and in clinical practice after study completion at a multisite tertiary care center. Patients with surgically resectable HPV-OPSCC who underwent margin-negative resection between August 20, 2013, and March 21, 2023, and were treated with DART were included in the analysis. Those with prior head and neck cancer, pT0 or pT4 disease, unknown HPV status, metastatic disease at presentation, synchronous primary tumors, induction chemotherapy, or treatment at an outside institution were excluded. Data were analyzed from July 1, 2024, to July 18, 2025. Interventions DART consisting of 30 to 36 Gy in 1.5- to 1.8-Gy fractions twice daily with docetaxel 15 mg/m 2 on days 1 and 8. Main Outcomes and Measures Progression-free survival as measured via Kaplan-Meier analysis. Results A total of 282 patients were included in the analysis: 176 (62.4%) in the on-study group and 106 (37.6%) in the off-study group (252 [89.4%] male; mean [SD] age, 59.1 [9.3] years). Both groups were predominantly male (157 [89.2%] and 95 [89.6%], respectively) and consisted mostly of never smokers (118 [67.0%] and 62 [58.5%], respectively). Pathologic features were similar between groups except for nodal stage (pN1: 155 [88.1%] on study vs 102 [96.2%] off study; pN2: 21 [11.9%] on study vs 4 [3.8%] off study; P = .02). The median follow-up times were 5.2 years (95% CI, 5.2-5.8 years) in the on-study group and 2.2 years (95% CI, 1.9-2.4 years) in the off-study group. Two-year PFS was similar (93% [95% CI, 88%-97%] on study vs 93% [95% CI, 88%-99%] off study). For patients with pN1 and no extranodal extension (ENE), 2- and 5-year PFS were 97% (95% CI, 93%-100%) and 96% (95% CI, 92%-100%), respectively. Patients with pN1 and ENE had a 2- and 5-year PFS of 93% (95% CI, 89%-98%) and 87% (95% CI, 81%-94%), respectively. Conclusions and Relevance In this retrospective cohort study of patients receiving DART on and off study, oncologic outcomes were similar between the 2 groups. Fewer patients with pN2 received DART off study, given the interim results of MC1675. Patients with pN1 and no ENE treated with DART had excellent 2- and 5-year PFS, supporting DART as a compelling treatment option in well-selected patients. An additional study that is currently underway will evaluate biomarker risk-stratified treatment of patients with pN1 and ENE receiving DART.
Immunotherapy and Radiation for Clinical Perineural Invasion in Cutaneous Squamous Cell Carcinoma
Localized cutaneous squamous cell carcinoma (cSCC) has a favorable prognosis, unlike advanced disease, especially with clinical perineural invasion (PNI), which poses substantial management challenges due to aggressivity and higher recurrence, metastasis, and mortality risks. PNI, a high-risk staging feature, has worse outcomes, particularly when clinically evident rather than incidental. Clinical PNI (cPNI) is evident by clinical symptoms (such as pain, paresthesia, or motor deficits) or radiologic findings, whereas incidental PNI (iPNI) is identified only histologically without associated symptoms or radiologic evidence. PNI remains a novel area with varying practice patterns across institutions. Improving risk stratification and tailoring multidisciplinary approaches are critical for optimizing outcomes. Our review outlines clinical practice patterns at our institution, providing insights into managing cSCC with PNI, focusing on diagnosis, imaging, staging, and emerging immunotherapies. A structured search was conducted using the terms “perineural invasion,” “cutaneous squamous cell carcinoma,” and “immunotherapy.” cPNI has a poor prognosis and requires nuanced clinical decision-making. Surgery and radiation remain central to management. Adjuvant therapy offers substantial survival benefit in cSCC with PNI, with improved disease-free and overall survival compared with surgery alone, supporting its use in appropriately selected high-risk patients. Traditional systemic therapies, including cisplatin and cetuximab, remain foundational but have shown only moderate response rates and limited durability in advanced or neurotropic cSCC. In contrast, immunotherapy—now preferred for advanced or unresectable cases—has transformed management, with programmed cell death protein-1 (PD-1) inhibitors showing promising results (up to 69% response rate) and disease stabilization. Neoadjuvant immunotherapy may enable tumor downstaging, improve radiation planning, and reduce surgical morbidity. Imaging for squamous cell carcinoma (SCC) with PNI aids staging and surveillance, but symptoms remain key for detecting recurrence. Our multidisciplinary approach emphasizes personalized care. Larger trials are needed to define the optimal role and sequencing of immunotherapy in this high-risk patient population.
Novel Assessment of Advanced Practice Provider‐Led Head and Neck Cancer Survivorship Clinic: Quality‐of‐Care Metric Analysis and
HOUSES
Index Application
ABSTRACT Background As head and neck cancer survival rates improve, there is growing demand for quality survivorship care and tools to predict patient adherence; this study aims to evaluate an advanced practice provider ( APP )‐led survivorship clinic and assess these key metrics. Methods We performed a retrospective review of 213 head and neck cancer patients treated with curative radiation therapy between 2016 and 2023, to assess follow‐up adherence in an advanced practice provider–led survivorship clinic. Results With a median follow‐up of 2.4 years, follow‐up care metrics identified high completion percentages (> 90%) for lung cancer screening, smoking cessation, thyroid screening, dental evaluation, xerostomia, dysphagia, and dysgeusia. The HOUsing ‐based SocioEconomic Status ( HOUSES ) index at diagnosis showed a significant adherence difference (median percentile, 78% vs. 55%, adherent vs. nonadherent; p = 0.03). Conclusions High adherence rates with guideline‐defined care metrics are achievable in an advanced practice provider‐led head and neck cancer survivorship clinic. The HOUSES index may assist in predicting nonadherence; however, further studies are needed.
Artificial Intelligence Measured Tumor Burden and Pre‐Treatment Circulating Tumor DNA in Human Papilloma Virus‐Associated Oropharynx Cancer
ABSTRACTBackgroundArtificial intelligence (AI)‐based imaging analysis and circulating tumor‐associated DNA (ctDNA) are both being used diagnostically in HPV‐driven oropharynx squamous cell carcinoma (HPV‐OPSCC). We evaluated associations between AI‐measured tumor burden and ctDNA.MethodsWe analyzed 170 patients treated definitively for HPV‐OPSCC. All had pre‐treatment serum tumor‐tissue modified viral (TTMV) ctDNA levels. An AI algorithm measured tumor and lymph nodes on CT scans. Linear regressions detected associations between ctDNA (fragments/mL) and automated volumes, clinical tumor (T) and nodal (N) stage, and disease factors.ResultsAutomated tumor volume (coeff = 39.43, p < 0.001), nodal volume (coeff = 39.54, p < 0.001), T stage (coeff = 1031.09, p = 0.009), and N stage (coeff = 1840, p = 0.018) were associated with ctDNA. On multivariable analysis, tumor (coeff = 34.79, p = 0.001) and nodal volumes (coeff = 24.68, p = 0.022) were associated with ctDNA; T and N stage were not.ConclusionsAutomated volumetrics are independently and more strongly associated with ctDNA, compared with clinical stage. Automated volumetrics provide a practical correlate to ctDNA.
Carbon Radiotherapy for Rare Tumors: Electronic Consent and Follow-up
ABSTRACTBackgroundIn sinonasal cancer (SNC), treatment with proton therapy (PT) provides excellent local control, especially after gross total resection. Because of the heterogeneity and rarity of this disease site, a comprehensive assessment of toxicity, survival, and control rates is lacking. Our primary objective was to assess the toxicity outcomes of PT in SNC patients, with a secondary aim of assessing survival and tumor control after PT.MethodsPubMed, Embase, EBSCO, Scopus, Science Direct, Web of Science, Ovid, Proquest, and Cochrane Library were searched from inception to August 2024 reporting PT acute and late toxicity, survival, and tumor control outcomes in SNC patients. A random‐effect meta‐analysis was used to assess the pooled safety, survival, and tumor control outcomes. The primary analysis was to report acute and late toxicity. The secondary aims included overall survival (OS), disease‐free survival (DFS), local control (LC), regional control (RC), and distant metastasis control (DMC) rate.ResultsFourteen studies were included for qualitative analysis. We pooled data from 756 patients who received PT for SNC. Among acute toxicity (AT), there was a 31.9% occurrence rate of grade ≥ 3 events, whereas within late toxicity (LT), grade ≥ 3 events occurred at a rate of 35.3%. Most LT (62.1%) were classified as grade 2, with the most frequent being ocular (24.8%) or neurological (18.4%) toxicities. The most common grade ≥ 3 toxicities were mucositis (15.3%) in AT and ocular toxicity (9.6%) in LT. The pooled 5‐year OS, DFS, LC, RC, and DMC were 36.8%, 34.2%, 35.6%, 28.6%, and 54.3%, respectively.ConclusionOur analysis demonstrates that PT‐treated SNC patients experience acceptable rates of acute and LT consistent with other published outcomes with highly conformal radiation techniques. PT demonstrates favorable OS and DFS. Further prospective and comparative effectiveness research is needed to better quantify the magnitude of the benefit of PT or other forms of radiation modalities.
Impact of Relative Biologic Effectiveness for Proton Therapy for Head and Neck and Skull-Base Tumors: A Technical and Clinical Review
Proton therapy has emerged as a crucial tool in the treatment of head and neck and skull-base cancers, offering advantages over photon therapy in terms of decreasing integral dose and reducing acute and late toxicities, such as dysgeusia, feeding tube dependence, xerostomia, secondary malignancies, and neurocognitive dysfunction. Despite its benefits in dose distribution and biological effectiveness, the application of proton therapy is challenged by uncertainties in its relative biological effectiveness (RBE). Overcoming the challenges related to RBE is key to fully realizing proton therapy’s potential, which extends beyond its physical dosimetric properties when compared with photon-based therapies. In this paper, we discuss the clinical significance of RBE within treatment volumes and adjacent serial organs at risk in the management of head and neck and skull-base tumors. We review proton RBE uncertainties and its modeling and explore clinical outcomes. Additionally, we highlight technological advancements and innovations in plan optimization and treatment delivery, including linear energy transfer/RBE optimizations and the development of spot-scanning proton arc therapy. These advancements show promise in harnessing the full capabilities of proton therapy from an academic standpoint, further technological innovations and clinical outcome studies, however, are needed for their integration into routine clinical practice.
Predictors for survival after radium-223 (R223) treatment for castration-resistant metastatic prostate cancer.