Stereotactic body radiotherapy for distant metastases to the head and neck.

PURPOSE: To report clinical outcomes for patients with metastatic disease to the head and neck (HN) treated with stereotactic body radiation therapy (SBRT). METHODS: A retrospective review of patients treated with SBRT to HN sites from 2012 to 2020 was conducted. Treatment indications included the following: oligometastases, oligoprogression, and control a dominant area of progression (DAP). Kaplan-Meier method was used to estimate local control (LC), regional control (RC), overall survival (OS), and progression-free survival (PFS). Univariable (UVA) and multivariable analyses (MVA) were performed. Grade 3-4 acute and late toxicities were reported by the Common Terminology Criteria for Adverse Events v5.0. RESULTS: Fifty-six patients (58 lesions) were analysed with a median follow-up of 16 months. Primary sites included lung (25.0%), kidney (19.6%), breast (19.6%) and other (35.8%). SBRT indications were as follows: oligometastases (42.9%), oligoprogression (19.6%) and local control of a dominant area of progression (37.5%). Most patients received SBRT to a single neck node (n = 47, 81.0%). Median SBRT dose was 40 Gy (range 25-50 Gy) in five fractions, with a median biologically effective dose (BED10) of 72 Gy (range 37.5-100 Gy). One- and 2-year LC and RC rates were 97.6% and 72.7% as well as 100% and 86.7%, respectively. Median OS was 19.2 months (95% [CI] 14.8-69.4), and median PFS was 7.4 months (95% [CI] 5.2-11.9). The 1-year OS and PFS rates for oligometastases, oligoprogression and DAP were 95.8%, 63.6% and 38.1% (p = 0.0039) as well as 56.5%, 27.3% and 19.1% (p = 0.0004), respectively. On MVA, treatment indication and histology were predictive for OS, while indication and prior systemic therapy were predictive for PFS. Cumulative late grade 3 + toxicity rate was 11.3%, without grade 5 events. CONCLUSION: The use of SBRT for metastatic disease to the HN provided excellent LC rates with low rates of regional failure and an acceptable toxicity profile, highlighting its utility in these patients. Patients with oligometastatic disease had better OS and PFS than others.

Transitions in oral and gut microbiome of HPV+ oropharyngeal squamous cell carcinoma following definitive chemoradiotherapy (ROMA LA-OPSCC study).

BACKGROUND: Oral and gut microbiomes have emerged as potential biomarkers in cancer. We characterised the oral and gut microbiomes in a prospective observational cohort of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) patients and evaluated the impact of chemoradiotherapy (CRT). METHODS: Saliva, oropharyngeal swabs over the tumour site and stool were collected at baseline and post-CRT. 16S RNA and shotgun metagenomic sequencing were used to generate taxonomic profiles, including relative abundance (RA), bacterial density, α-diversity and ß-diversity. RESULTS: A total of 132 samples from 22 patients were analysed. Baseline saliva and swabs had similar taxonomic composition (R2 = 0.006; p = 0.827). Oropharyngeal swabs and stool taxonomic composition varied significantly by stage, with increased oral RA of Fusobacterium nucleatum observed in stage III disease (p < 0.05). CRT significantly reduced the species richness and increased the RA of gut-associated taxa in oropharyngeal swabs (p < 0.05), while it had no effect in stool samples. These findings remained significant when adjusted by stage, smoking status and antibiotic use. CONCLUSIONS: Baseline oral and gut microbiomes differ by stage in this HPV+ cohort. CRT caused a shift towards a gut-like microbiome composition in oropharyngeal swabs. Stage-specific features and the transitions in oral microbiome might have prognostic and therapeutic implications.

Hypofractionated radiotherapy alone with 2.4 Gy per fraction for head and neck cancer during the COVID-19 pandemic: The Princess Margaret experience and proposal.

BACKGROUND: The objective of this study was to identify a subgroup of patients with head and neck squamous cell carcinoma (HNSCC) who might be suitable for hypofractionated radiotherapy (RT-hypo) during the COVID-19 pandemic. METHODS: HNSCC cases (oropharynx/larynx/hypopharynx) treated with definitive RT-hypo (60 Gy in 25 fractions over 5 weeks), moderately accelerated radiotherapy (RT-acc) alone (70 Gy in 35 fractions over 6 weeks), or concurrent chemoradiotherapy (CCRT) during 2005-2017 were included. Locoregional control (LRC) and distant control (DC) after RT-hypo, RT-acc, and CCRT were compared for various subgroups. RESULTS: The study identified 994 human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma cases (with 61, 254, and 679 receiving RT-hypo, RT-acc, and CCRT, respectively) and 1045 HPV- HNSCC cases (with 263, 451, and 331 receiving RT-hypo, RT-acc, and CCRT, respectively). The CCRT cohort had higher T/N categories, whereas the radiotherapy-alone patients were older. The median follow-up was 4.6 years. RT-hypo, RT-acc, and CCRT produced comparable 3-year LRC and DC for HPV+ T1-2N0-N2a disease (seventh edition of the TNM system [TNM-7]; LRC, 94%, 100%, and 94%; P = .769; DC, 94%, 100%, and 94%; P = .272), T1-T2N2b disease (LRC, 90%, 94%, and 97%; P = .445; DC, 100%, 96%, and 95%; P = .697), and T1-2N2c/T3N0-N2c disease (LRC, 89%, 93%, and 95%; P = .494; DC, 89%, 90%, and 87%; P = .838). Although LRC was also similar for T4/N3 disease (78%, 84%, and 88%; P = .677), DC was significantly lower with RT-hypo or RT-acc versus CCRT (67%, 65%, and 87%; P = .005). For HPV- HNSCC, 3-year LRC and DC were similar with RT-hypo, RT-acc, and CCRT in stages I and II (LRC, 85%, 89%, and 100%; P = .320; DC, 99%, 98%, and 100%; P = .446); however, RT-hypo and RT-acc had significantly lower LRC in stage III (76%, 69%, and 91%; P = .006), whereas DC rates were similar (92%, 85%, and 90%; P = .410). Lower LRC in stage III predominated in patients with laryngeal squamous cell carcinoma receiving RT-acc (62%) but not RT-hypo (80%) or CCRT (92%; RT-hypo vs CCRT: P = .270; RT-acc vs CCRT: P = .004). CCRT had numerically higher LRC in comparison with RT-hypo or RT-acc in stage IV (73%, 65%, and 66%; P = .336). CONCLUSIONS: It is proposed that RT-hypo be considered in place of CCRT for HPV+ T1-T3N0-N2c (TNM-7) HNSCCs, HPV- T1-T2N0 HNSCCs, and select stage III HNSCCs during the COVID-19 outbreak.

Treatment de-escalation for HPV-associated oropharyngeal squamous cell carcinoma with radiotherapy vs. trans-oral surgery (ORATOR2): study protocol for a randomized phase II trial.

BACKGROUND: Patients with human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPC) have substantially better treatment response and overall survival (OS) than patients with HPV-negative disease. Treatment options for HPV+ OPC can involve either a primary radiotherapy (RT) approach (± concomitant chemotherapy) or a primary surgical approach (± adjuvant radiation) with transoral surgery (TOS). These two treatment paradigms have different spectrums of toxicity. The goals of this study are to assess the OS of two de-escalation approaches (primary radiotherapy and primary TOS) compared to historical control, and to compare survival, toxicity and quality of life (QOL) profiles between the two approaches. METHODS: This is a multicenter phase II study randomizing one hundred and forty patients with T1-2 N0-2 HPV+ OPC in a 1:1 ratio between de-escalated primary radiotherapy (60 Gy) ± concomitant chemotherapy and TOS ± de-escalated adjuvant radiotherapy (50-60 Gy based on risk factors). Patients will be stratified based on smoking status (< 10 vs. ≥ 10 pack-years). The primary endpoint is OS of each arm compared to historical control; we hypothesize that a 2-year OS of 85% or greater will be achieved. Secondary endpoints include progression free survival, QOL and toxicity. DISCUSSION: This study will provide an assessment of two de-escalation approaches to the treatment of HPV+ OPC on oncologic outcomes, QOL and toxicity. Results will inform the design of future definitive phase III trials. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03210103. Date of registration: July 6, 2017, Current version: 1.3 on March 15, 2019.

Radiotherapy versus transoral robotic surgery and neck dissection for oropharyngeal squamous cell carcinoma (ORATOR): an open-label, phase 2, randomised trial.

BACKGROUND: Transoral robotic surgery (TORS) with concurrent neck dissection has supplanted radiotherapy in the USA as the most common treatment for oropharyngeal squamous cell carcinoma (OPSCC), yet no randomised trials have compared these modalities. We aimed to evaluate differences in quality of life (QOL) 1 year after treatment. METHODS: The ORATOR trial was an investigator-initiated, multicentre, international, open-label, parallel-group, phase 2, randomised study. Patients were enrolled at six hospitals in Canada and Australia. We randomly assigned (1:1) patients aged 18 years or older, with Eastern Cooperative Oncology Group scores of 0-2, and with T1-T2, N0-2 (≤4 cm) OPSCC tumour types to radiotherapy (70 Gy, with chemotherapy if N1-2) or TORS plus neck dissection (with or without adjuvant chemoradiotherapy, based on pathology). Following stratification by p16 status, patients were randomly assigned using a computer-generated randomisation list with permuted blocks of four. The primary endpoint was swallowing-related QOL at 1 year as established using the MD Anderson Dysphagia Inventory (MDADI) score, powered to detect a 10-point improvement (a clinically meaningful change) in the TORS plus neck dissection group. All analyses were done by intention to treat. This study is registered with ClinicalTrials.gov (NCT01590355) and is active, but not currently recruiting. FINDINGS: 68 patients were randomly assigned (34 per group) between Aug 10, 2012, and June 9, 2017. Median follow-up was 25 months (IQR 20-33) for the radiotherapy group and 29 months (23-43) for the TORS plus neck dissection group. MDADI total scores at 1 year were mean 86·9 (SD 11·4) in the radiotherapy group versus 80·1 (13·0) in the TORS plus neck dissection group (p=0·042). There were more cases of neutropenia (six [18%] of 34 patients vs none of 34), hearing loss (13 [38%] vs five [15%]), and tinnitus (12 [35%] vs two [6%]) reported in the radiotherapy group than in the TORS plus neck dissection group, and more cases of trismus in the TORS plus neck dissection group (nine [26%] vs one [3%]). The most common adverse events in the radiotherapy group were dysphagia (n=6), hearing loss (n=6), and mucositis (n=4), all grade 3, and in the TORS plus neck dissection group, dysphagia (n=9, all grade 3) and there was one death caused by bleeding after TORS. INTERPRETATION: Patients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change. Toxicity patterns differed between the groups. Patients with OPSCC should be informed about both treatment options. FUNDING: Canadian Cancer Society Research Institute Grant (#701842), Ontario Institute for Cancer Research Clinician-Scientist research grant, and the Wolfe Surgical Research Professorship in the Biology of Head and Neck Cancers grant.

Osteoradionecrosis of the mandible in patients with oropharyngeal carcinoma treated with intensity-modulated radiotherapy.

BACKGROUND: Osteoradionecrosis (ORN) of the mandible is a late toxicity affecting patients treated with radiotherapy for head and neck malignancies. To the authors' knowledge, ORN has no standardized grading system and its reporting is based on retrospective findings in heterogeneous patient populations. The rate of ORN in the era of intensity-modulated radiotherapy (IMRT) still is unknown. METHODS: The authors report the incidence of ORN from prospectively collected data regarding 1196 patients who were diagnosed with squamous cell carcinoma of the oropharynx and treated with curative-intent IMRT, with or without concomitant systemic treatment, from January 2005 to December 2014. Each case of ORN was graded according to its severity. Clinical and dosimetric comparisons were performed between patients with ORN and a matched control cohort of patients without ORN. RESULTS: The actuarial rate of ORN of the mandible was 3% at 1 year, 5% at 3 years, and 7% at 5 years. On multivariable analysis, smoking (hazard ratio, 1.9; 95% confidence interval, 1.07-3.4 [P = .03]) and T classification (hazard ratio, 1.78; 95% confidence interval, 1.02-3.1 [P = .041]) were found to be statistically significant risk factors. The presence of cardiovascular comorbidities, use of bisphosphonates, and pre-IMRT dental extractions were found to be different between the matched cohorts. The mandibular volume receiving 50 grays (Gy) (in cm3 ) and the volume receiving 60 Gy (in cm3 ) were found to be associated with ORN on multivariable analysis in the matched cohort patients receiving an IMRT regimen of 2 Gy per fraction. CONCLUSIONS: ORN is relatively uncommon among patients with oropharyngeal carcinoma who are treated with IMRT, but continues to occur beyond 5 years after treatment. Modifiable risk factors that are associated with higher rates of ORN include smoking and the use of bisphosphonates. Minimizing the volumes of the mandible receiving >50 Gy or > 60 Gy also may have an effect on the ORN rate. Cancer 2017;123:3691-3700. © 2017 American Cancer Society.

PMH 9907: Long-term outcomes of a randomized phase 3 study of short-term bicalutamide hormone therapy and dose-escalated external-beam radiation therapy for localized prostate cancer.

BACKGROUND: The role of hormone therapy (HT) with dose-escalated external-beam radiotherapy (DE-EBRT) in the treatment of intermediate-risk prostate cancer (IRPC) remains controversial. The authors report the long-term outcome of a phase 3 study of DE-EBRT with or without HT for patients with localized prostate cancer (LPC). METHODS: From 1999 to 2006, 252 of an intended 338 patients with LPC were randomized to receive DE-EBRT with or without 5 months of neoadjuvant and concurrent bicalutamide 150 mg once daily. The study was closed early because of contemporary concerns surrounding bicalutamide. The primary outcome was biochemical failure (BF) incidence, and the secondary endpoints were overall survival (OS), local control (LC), and quality of life. The BF and OS rates were estimated using the cumulative incidence function and Kaplan-Meier methods and were compared using the Gray test and the log-rank test. RESULTS: Eleven patients were excluded from analysis. Characteristics were well balanced in each treatment arm. Ninety-five percent of patients had IRPC. The prescribed dose increased from 75.6 grays (Gy) in 42 fractions to 78 Gy in 39 fractions over the period. At a median follow-up of 9.1 years, 98 BFs occurred, with no significant effect of HT versus no HT on the BF rate (40% vs 47%; P = .32), the OS rate (82% vs 86%; P = .37), the LC rate (52% vs 48 %; P = .32) or quality of life, in the patients who completed the questionnaires. Dose escalation to 75.6 Gy versus >75.6 Gy reduced the BF rate by 26% (P = .004). CONCLUSIONS: For patients who predominantly have IRPC, the addition of HT to DE-EBRT did not significantly affect BF, OS, or LC. Bicalutamide appeared to be well tolerated. The conclusions from the study are limited by incomplete recruitment. Cancer 2016;122:2595-603. © 2016 American Cancer Society.

Phase I trial of dacomitinib, a pan-human epidermal growth factor receptor (HER) inhibitor, with concurrent radiotherapy and cisplatin in patients with locoregionally advanced squamous cell carcinoma of the head and neck (XDC-001).

Background Curative-intent, non-surgical treatment options for locoregionally advanced squamous cell carcinoma of the head and neck (LA-SCCHN) include radiotherapy with/without chemotherapy or radiotherapy with cetuximab. This single institution phase I dose escalation trial tested the pan-human epidermal growth factor receptor (HER) oral tyrosine kinase inhibitor, dacomitinib, in combination with standard cisplatin-based chemoradiotherapy. Methods Patients received oral dacomitinib once daily at 3 protocol-defined dose levels (15 mg, 30 mg, and 45 mg). Cisplatin was given intravenously at 100 mg/m(2) every 3 weeks. Radiotherapy was delivered using intensity modulated radiation therapy (IMRT) to a dose of 70Gy in 35 daily fractions to the primary and nodal disease. Dose escalation was performed using a standard 3 + 3 design. Results Twelve patients with LA-SCCHN were enrolled between January 2013 and August 2014. No dose limiting toxicities (DLTs) were observed in the 15 mg and 30 mg dose levels. In the 45 mg dose level, one of four evaluable patients developed a DLT with intolerable grade 2 diarrhea requiring discontinuation of therapy. Adverse events (AEs) attributed to dacomitinib alone include diarrhea, hypertension, and acneiform and maculopapular rash. The most common non-hematological AEs include weight loss, diarrhea, dry mouth, mucositis, nausea, hypoalbuminemia, and hyponatremia. Frequency and severity of AEs did not increase with increasing dose levels of dacomitinib. All patients completed the full course of radiotherapy on schedule and the median dose of cisplatin was 200 mg/m(2), which is comparable to historical standards. Of the 10 patients evaluable for response, 1 patient relapsed with metastatic disease. Conclusions The triple combination has a tolerable side effect profile and dose levels 15 mg and 30 mg were cleared safely. The addition of dacomitinib did not preclude delivery of standard chemoradiotherapy. Studies testing the addition of other HER-targeted therapies to platinum-based concurrent chemo-radiotherapy in LA-SCCHN have failed to demonstrate improved patient outcomes and have reported trends towards excessive toxicities. These results generated uncertainty regarding the future of these agents in combination with chemo-radiation for the treatment of LA-SCCHN, which ultimately led to the early termination of this study.

Prognostic value of pretreatment circulating neutrophils, monocytes, and lymphocytes in oropharyngeal cancer stratified by human papillomavirus status.

BACKGROUND: The objective of this study was to investigate the prognostic value of the pretreatment circulating neutrophil count (CNC), circulating monocyte count (CMC), and circulating lymphocyte count (CLC) in human papillomavirus (HPV)-related (HPV+) and HPV-unrelated (HPV-) oropharyngeal cancer (OPC). METHODS: All p16-confirmed HPV+ and HPV- OPC cases treated with chemoradiotherapy from 2000 to 2010 were included. Overall survival (OS) and recurrence-free survival (RFS) were compared for high and low CNCs, CMCs, and CLCs (dichotomized by median values). A multivariate analysis (MVA) confirmed their prognostic value in HPV+ and HPV- tumors, respectively. RESULTS: Five hundred ten HPV+ OPC cases and 192 HPV- OPC cases were included. The HPV+ cohort had lower CNC and CMC values but a CLC similar to that of the HPV- patients (P < .01). The median follow-up was 4.8 years. In the HPV+ cohort, a high CNC or CMC correlated with reduced OS and RFS in comparison with a low CNC or CMC (P < .01 for all), but no difference was evident in OS (P = .30) or RFS (P = .10) with the CLC. MVA confirmed that a higher CNC or CMC independently predicted lower OS (hazard ratio [HR] for CNC, 1.14, P < .01; HR for CMC, 2.95, P < .01) and lower RFS (HR for CNC, 1.11, P < .01; HR for CMC, 3.39, P < .01), whereas a higher CLC was associated with higher RFS (HR, 0.66, P = .03) and marginally higher OS (HR, 0.80, P = .08). In the HPV- cohort, CNC, CMC, and CLC were not predictive of OS (P = .16, P = .86, and P = .14) or RFS (P = .61, P = .59, and P = .62). CONCLUSIONS: This relatively large cohort study demonstrates that a high CNC and a high CMC independently predict inferior OS and RFS, whereas a high CLC predicts better RFS and marginally better OS in HPV+ OPC patients. This association was not apparent in HPV- patients.

MR-guided prostate biopsy for planning of focal salvage after radiation therapy.

PURPOSE: To determine if the integration of diagnostic magnetic resonance (MR) imaging and MR-guided biopsy would improve target delineation for focal salvage therapy in men with prostate cancer. MATERIALS AND METHODS: Between September 2008 and March 2011, 30 men with biochemical failure after radiation therapy for prostate cancer provided written informed consent and were enrolled in a prospective clinical trial approved by the institutional research ethics board. An integrated diagnostic MR imaging and interventional biopsy procedure was performed with a 1.5-T MR imager by using a prototype table and stereotactic transperineal template. Multiparametric MR imaging (T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted sequences) was followed by targeted biopsy of suspicious regions and systematic sextant sampling. Biopsy needle locations were imaged and registered to diagnostic images. Two observers blinded to clinical data and the results of prior imaging studies delineated tumor boundaries. Area under the receiver operating characteristic curve (Az) was calculated based on generalized linear models by using biopsy as the reference standard to distinguish benign from malignant lesions. RESULTS: Twenty-eight patients were analyzed. Most patients (n = 22) had local recurrence, with 82% (18 of 22) having unifocal disease. When multiparametric volumes from two observers were combined, it increased the apparent overall tumor volume by 30%; however, volumes remained small (mean, 2.9 mL; range, 0.5-8.3 mL). Tumor target boundaries differed between T2-weighted, dynamic contrast-enhanced, and diffusion-weighted sequences (mean Dice coefficient, 0.13-0.35). Diagnostic accuracy in the identification of tumors improved with a multiparametric approach versus a strictly T2-weighted or dynamic contrast-enhanced approach through an improvement in sensitivity (observer 1, 0.65 vs 0.35 and 0.44, respectively; observer 2, 0.82 vs 0.64 and 0.53, respectively; P < .05) and improved further with a 5-mm expansion margin (Az = 0.85 vs 0.91 for observer 2). After excluding three patients with fewer than six informative biopsy cores and six patients with inadequately stained margins, MR-guided biopsy enabled more accurate delineation of the tumor target volume be means of exclusion of false-positive results in 26% (five of 19 patients), false-negative results in 11% (two of 19 patients) and by guiding extension of tumor boundaries in 16% (three of 19 patients). CONCLUSION: The integration of guided biopsy with diagnostic MR imaging is feasible and alters delineation of the tumor target boundary in a substantial proportion of patients considering focal salvage.

Oropharyngeal Cancer Staging Health Record Extraction Using Artificial Intelligence.

Importance: Accurate, timely, and cost-effective methods for staging oropharyngeal cancers are crucial for patient prognosis and treatment decisions, but staging documentation is often inaccurate or incomplete. With the emergence of artificial intelligence in medicine, data abstraction may be associated with reduced costs but increased efficiency and accuracy of cancer staging. Objective: To evaluate an algorithm using an artificial intelligence engine capable of extracting essential information from medical records of patients with oropharyngeal cancer and assigning tumor, nodal, and metastatic stages according to American Joint Committee on Cancer eighth edition guidelines. Design, Setting, and Participants: This retrospective diagnostic study was conducted among a convenience sample of 806 patients with oropharyngeal squamous cell carcinoma. Medical records of patients with staged oropharyngeal squamous cell carcinomas who presented to a single tertiary care center between January 1, 2010, and August 1, 2020, were reviewed. A ground truth cancer stage dataset and comprehensive staging rule book consisting of 135 rules encompassing p16 status, tumor, and nodal and metastatic stage were developed. Subsequently, 4 distinct models were trained: model T (entity relationship extraction) for anatomical location and invasion state, model S (numerical extraction) for lesion size, model M (sequential classification) for metastasis detection, and a p16 model for p16 status. For validation, results were compared against ground truth established by expert reviewers, and accuracy was reported. Data were analyzed from March to November 2023. Main Outcomes and Measures: The accuracy of algorithm cancer stages was compared with ground truth. Results: Among 806 patients with oropharyngeal cancer (mean [SD] age, 63.6 [10.6] years; 651 males [80.8%]), 421 patients (52.2%) were positive for human papillomavirus. The artificial intelligence engine achieved accuracies of 55.9% (95% CI, 52.5%-59.3%) for tumor, 56.0% (95% CI, 52.5%-59.4%) for nodal, and 87.6% (95% CI, 85.1%-89.7%) for metastatic stages and 92.1% (95% CI, 88.5%-94.6%) for p16 status. Differentiation between localized (stages 1-2) and advanced (stages 3-4) cancers achieved 80.7% (95% CI, 77.8%-83.2%) accuracy. Conclusion and Relevance: This study found that tumor and nodal staging accuracies were fair to good and excellent for metastatic stage and p16 status, with clinical relevance in assigning optimal treatment and reducing toxic effect exposures. Further model refinement and external validation with electronic health records at different institutions are necessary to improve algorithm accuracy and clinical applicability.

Radiation enhancement using focussed ultrasound-stimulated microbubbles for head and neck cancer: A phase 1 clinical trial.

BACKGROUND AND PURPOSE: Preclinical research demonstrated that the exposure of microbubbles (intravascular gas microspheres) to focussed ultrasound within the targeted tumour upregulates pro-apoptotic pathways and enhances radiation-induced tumour cell death. This study aimed to assess the safety and efficacy of magnetic resonance (MR)-guided focussed ultrasound-stimulated microbubbles (MRgFUS-MB) for head and neck cancers (HN). MATERIALS AND METHODS: This prospective phase 1 clinical trial included patients with newly diagnosed or recurrent HN cancer (except nasopharynx malignancies) for whom locoregional radiotherapy with radical- or palliative-intent as deemed appropriate. Patients with contraindications for microbubble administration or contrast-enhanced MR were excluded. MR-coupled focussed ultrasound sonicated intravenously administered microbubbles within the MR-guided target volume. Patients receiving 5-10 and 33-35 radiation fractions were planned for 2 and 3 MRgFUS-MB treatments, respectively. Primary endpoint was toxicity per CTCAEv5.0. Secondary endpoint was tumour response at 3 months per RECIST 1.1 criteria. RESULTS: Twelve patients were enrolled between Jun/2020 and Nov/2023, but 1 withdrew consent. Eleven patients were included in safety analysis. Median follow-up was 7 months (range, 0.3-38). Most patients had oropharyngeal cancer (55 %) and received 20-30 Gy/5-10 fractions (63 %). No systemic toxicity or MRgFUS-MB-related adverse events occurred. The most severe acute adverse events were radiation-related grade 3 toxicities in 6 patients (55 %; dermatitis in 3, mucositis in 1, dysphagia in 6). No radiation necrosis or grade 4/5 toxicities were reported. 8 patients were included in the 3-month tumour response assessment: 4 had partial response (50 %), 3 had complete response (37.5 %), and 1 had progressive disease (12.5 %). CONCLUSIONS: MRgFUS-MB treatment was safe and associated with high rates of tumour response at 3 months.

Lymph node yield: Impact on oncologic outcomes in oral cavity cancer.

BACKGROUND: Lymph node metastases are associated with poor prognosis in oral cavity squamous cell carcinoma (OCSCC). In other cancers, clinical guidelines on the number of lymph nodes removed during primary surgery, lymph node yield (LNY), exist. Here, we evaluated the prognostic capacity of LNY on regional failure, locoregional recurrence, and disease-free survival (DFS) in patients with OCSCC treated by primary neck surgery. METHODS: This retrospective cohort study took place at Sunnybrook Health Sciences Centre in Toronto, Canada and involved a chart review of all adult patients with treatment-naive OCSCC undergoing primary neck dissection. For each outcome, we first used the maximally selected rank statistics and an optimism-corrected concordance to identify an optimal threshold of LNY. We then used a multivariable Cox proportional hazards model to assess the association between high LNY (>threshold) and each outcome. RESULTS: Among the 579 patients with OCSCC receiving primary neck dissection, 61.7% (n = 357) were male with a mean age of 62.9 years (standard deviation: 13.1) at cancer diagnosis. When adjusting for sociodemographic and clinical factors, LNY >15 was significantly associated with improved DFS (adjusted HR [aHR]: 0.73, 95% CI: 0.54-0.98), locoregional recurrence (aHR: 0.68, 95% CI: 0.49-0.95), and regional failure (aHR: 0.61, 95% CI: 0.39-0.93). CONCLUSIONS: Our study findings suggested high LNY to be a strong independent predictor of various patient-level quality of surgical care metrics. The optimal LNY we found (15) was lower than the conventionally recommended (18), which calls for further research to establish validity in practice.

Radiotherapy Versus Transoral Robotic Surgery for Oropharyngeal Squamous Cell Carcinoma: Final Results of the ORATOR Randomized Trial.

Radiotherapy (RT) and transoral robotic surgery (TORS) are both curative-intent treatment options for oropharyngeal squamous cell carcinoma (OPSCC). Herein, we report the final outcomes of the ORATOR trial comparing these modalities, 5 years after enrollment completion. We randomly assigned 68 patients with T1-2N0-2 OPSCC to RT (with chemotherapy if node-positive) versus TORS plus neck dissection (± adjuvant RT/chemoradiation). The primary end point was swallowing quality of life (QOL) assessed with the MD Anderson Dysphagia Inventory (MDADI). Secondary end points included overall and progression-free survival (OS, PFS), adverse events (AEs), and other QOL metrics. The primary end point has been previously reported (Nichols 2019). In this report, the median follow-up was 5.1 years (IQR, 5.0-5.3 years). MDADI total scores converged by 5 years and were not significantly different across the follow-up period (P = .11). EORTC QLQ-C30 and H&N35 scores demonstrated differing profiles, including worse dry mouth in the RT arm (P = .032) and worse pain in the TORS arm (P = .002). Grade 2-5 AE rates did not differ between arms (91% [n = 31] v 97% [n = 33] respectively, P = .61), with more neutropenia and hearing loss in the RT arm, and more dysphagia and other pain in the TORS arm based on grades 2-5 (all P < .05). There were no differences in OS or PFS. In conclusion, toxicity and QOL profiles differ in some domains between RT and TORS, but oncologic outcomes were excellent in both arms. Choice of treatment should remain a shared decision between the patient and their providers.

Changes in apparent diffusion coefficient and T2 relaxation during radiotherapy for prostate cancer.

PURPOSE: To evaluate regional and temporal changes in apparent diffusion coefficient (ADC) and T2 relaxation during radiation therapy (RT) in patients with low and intermediate risk localized prostate cancer. MATERIALS AND METHODS: Seventeen patients enrolled on a prospective clinical trial where MRI was acquired every 2 weeks throughout eight weeks of image-guided prostate IMRT (78 Gy/39 fractions). ADC and T2 quantification used entire prostate, central gland, benign peripheral zone, and tumor-dense regions-of-interest, and mean values were evaluated for common response trends. RESULTS: Overall, the RT responses were greater than volunteer measurement repeatability, and week 6 appeared to be an optimum time-point for early detection. RT effects on the entire prostate were best detected using ADC (5-7% by week 2, P < 0.0125), effects on peripheral zone were best detected using T2 (19% reduction at week 6; P = 0.004) and effects on tumors were best detected using ADC (14% elevation at week 6; P = 0.004). CONCLUSION: ADC and T2 may be candidate biomarkers of early response to RT warranting further investigation against clinical outcomes.

A feasibility study of adaptive radiation therapy for postprostatectomy prostate cancer.

Postoperative prostate radiotherapy requires large planning target volume (PTV) margins to account for motion and deformation of the prostate bed. Adaptive radiation therapy (ART) can incorporate image-guidance data to personalize PTVs that maintain coverage while reducing toxicity. We present feasibility and dosimetry results of a prospective study of postprostatectomy ART. Twenty-one patients were treated with single-adaptation ART. Conventional treatments were delivered for fractions 1 to 6 and adapted plans for the remaining 27 fractions. Clinical target volumes (CTVs) and small bowel delineated on fraction 1 to 4 CBCT were used to generate adapted PTVs and planning organ-at-risk (OAR) volumes for adapted plans. PTV volume and OAR dose were compared between ART and conventional using Wilcoxon signed-rank tests. Weekly CBCT were used to assess the fraction of CTV covered by PTV, CTV D99, and small bowel D1cc. Clinical metrics were compared using a Student's t-test (p < 0.05 significant). Offline adaptive planning required 1.9 ± 0.4 days (mean ± SD). ART decreased mean adapted PTV volume 61 ± 37 cc and bladder wall D50 compared with conventional treatment (p < 0.01). The CTV was fully covered for 96% (97%) of fractions with ART (conventional). Reconstructing dose on weekly CBCT, a nonsignificant reduction in CTV D99 was observed with ART (94%) compared to conventional (96%). Reduced CTV D99 with ART was significantly correlated with large anterior-posterior rectal diameter on simulation CT. ART reduced the number of fractions exceeding our institution's small bowel D1c limit from 14% to 7%. This study has demonstrated the feasibility of offline ART for post-prostatectomy cancer. ART facilitates PTV volume reduction while maintaining reasonable CTV coverage and can reduce the dose to adjacent normal tissues.

Long-term oncologic outcomes of low dose-rate brachytherapy compared to hypofractionated external beam radiotherapy for intermediate -risk prostate cancer.

PURPOSE: To compare the long-term oncologic outcomes of intermediate risk (IR) prostate cancer (PCa) patients treated with low dose-rate brachytherapy (LDR-BT) or moderate hypofractionated external beam radiotherapy (HF-EBRT). METHODS AND MATERIALS: Patients diagnosed with IR PCa and treated with LDR-BT or HF-EBRT between January 2005 and December 2013 were included. Brachytherapy treatment involved a transperineal implant of iodine-125 to a dose of 145 Gy to the PTV, while HF-EBRT was delivered using intensity modulated radiotherapy with 60 Gy in 20 fractions. The Phoenix ''nadir +2'' threshold was used to define biochemical relapse (BR). The cumulative incidence function (CIF) of BR and metastases was reported for each group and compared using the Gray's test to account for the competing risk of death. The Kaplan-Meier (KM) method was used to estimate overall survival (OS) and prostate cancer specific survival (PCSS). Univariate (UVA) and multivariable (MVA) analysis of the CIF of BR and metastases were performed. A 2-tailed p-value ≤ 0.05 was considered statistically significant. RESULTS: Overall, 122 and 124 patients were treated with LDR-BT and HF-EBRT respectively. Median follow-up was 95 months [interquartile range (IQR): 79-118] in the LDR-BT group and 96 months (IQR: 63-123) in the HF-EBRT group. BR was observed in 5 patients treated with LDR-BT and 34 treated with HF-EBRT. At 60 and 90 months, the CIF of BR was 0.9% and 3.5% in the LDR-BT group vs. 16.6% and 23.7% in the HF-EBRT (p < 0.001). The CIF of metastases at 90 and 108 months, was 0% and 1.6% vs. 3.4% and 9.1% in the LDR-BT and HF-EBRT groups (p = 0.003), respectively. At the last follow-up, 3 patients treated with HF-EBRT died from their cancer [PCSS of 97.5% at 8 years and none died in the LDR-BT group (p = 0.09). On UVA and MVA risk group and treatment modality were independently associated with CIF of BR. On UVA HF-EBRT and ISUP grade group 3 were associated with metastases. CONCLUSION: LDR-BT was associated with higher biochemical and metastases control in our cohort when compared to moderately HF-EBRT. In the absence of a randomized trial, LDR-BT when feasible should be offered to patients with a life expectancy of >8 years.

Cine MRI-based analysis of intrafractional motion in radiation treatment planning of head and neck cancer patients.

PURPOSE/OBJECTIVE(S): To investigate intrafraction motion of (HN) target volumes and to determine patient-specific planning target volume (PTV) margins. MATERIALS/METHODS: MR-cine imaging was performed for radiation treatment planning in HN cancer patients treated with definitive EBRT (n = 62) or SBRT (n = 4) on a 1.5 T MRI between 2017-2019. Dynamic MRI scans (sagittal orientation, 2 × 82 × 7 mm3 resolution), ranging from 3-5 min and 900-1500 images, were acquired. The position of the maximum tumor displacement along each direction in the anterior/posterior (A/P) and superior/inferior (S/I) position was recorded and analyzed to determine average PTV margins. RESULTS: Primary tumor sites (n = 66) were oropharynx (n = 39), larynx (n = 24) and hypopharynx (n = 3). PTV margins for A/P/S/I positions were 4.1/4.4/5.0/6.2 mm and 4.9/4.3/6.7/7.7 mm for oropharyngeal and laryngeal/hypopharyngeal cancers when accounting for all motion. V100 for PTV was calculated and compared to the original plans. The mean drop in PTV coverage was in most cases under 5%. For a subset of patients with 3 mm plans available, V100 for PTV had more substantial decreases in coverage averaging 8.2% - and 14.3% for oropharyngeal and laryngeal/hypopharynx plans, respectively. CONCLUSION: The use of MR-cine in treatment planning allows for quantification of tumor motion during swallow and resting periods and should be accounted for during treatment planning. With motion considered, the derived margins may exceed the commonly used 3-5 mm PTV margins. Quantification and analysis of tumor and patient-specific PTV margins is a step towards real-time MRI guidance adaptive radiotherapy.

Evaluating contralateral neck failure in patients with lateralized OPSCC treated with transoral robotic surgery and neck management based on pre-operative SPECT-CT lymphatic mapping.

BACKGROUND: Risk of contralateral nodal metastases in oropharyngeal squamous cell carcinoma (OPSCC) is relatively low, however, many OPSCC patients receive bilateral neck treatment. This study evaluates the oncological outcomes with management of the contralateral cN0 neck based on lymphatic mapping with single photon emission computed tomography (SPECT-CT). METHODS: Retrospective evaluation of patients with lateralized cT1-2 and contralateral cN0 OPSCC treated with primary surgery between December 2017 and October 2019. All patients underwent pre-operative lymphatic mapping using SPECT-CT. Clinical parameters including demographics, tumor characteristics and oncological outcomes were recorded. RESULTS: Thirteen patients underwent primary site resection with transoral robotic surgery (TORS) and ipsilateral neck dissection with or without adjuvant therapy. Twelve patients (92.3%) had ipsilateral drainage on SPECT-CT, whereas 1 (7.7%) patient had bilateral neck lymphatic drainage. Four patients (30.8%) underwent post-operative radiation therapy (PORT). Three patients with unilateral drainage on SPECT-CT underwent PORT with unilateral neck irradiation, and 1 patient with bilateral drainage underwent PORT with bilateral neck irradiation. Seven (53.8%) patients were staged as pT1, 6 (46.2%) patients as pT2, 6 (46.2%) patients were pN0, 3 (23.1%) patients were pN1, 1 (7.7%) patient was pN2a for and 3 (23.1%) patients were N2b. The median distance of the tumor from midline was 1.05 cm (0.0-1.58). Primary sites included tonsil (n = 10, 76.9%) and tongue base (n = 3, 23.1%). The median follow-up time was 15.4 months. All patients were disease free at the latest follow-up with no contralateral neck failures. CONCLUSIONS: Pre-operative mapping of lymphatic drainage in early stage OPSCC with SPECT-CT is a promising tool which can reduce treatment to the contralateral neck potentially without compromising oncological outcomes.

Extended Results and Independent Validation of a Phase 2 Trial of Metastasis-Directed Therapy for Molecularly Defined Oligometastatic Prostate Cancer.

PURPOSE: The role of metastasis-directed therapy (MDT) in molecularly defined oligorecurrent prostate cancer (PCa) remains irresolute. We present extended follow-up and an independent validation cohort of a prospective trial. METHODS AND MATERIALS: This study consists of 2 sequential single-arm phase-2 trials of patients with biochemical recurrence (prostate specific antigen [PSA] 0.4-3.0 ng/mL) and negative conventional imaging after radical prostatectomy and postoperative radiation therapy. All patients underwent [18F]DCFPyL positron emission tomography/computed tomography. Patients with molecularly defined oligorecurrent prostate cancer underwent MDT with stereotactic body radiation therapy or surgery, without androgen deprivation therapy (ADT). The primary end point was biochemical response (≥50% PSA decline from baseline). Secondary end points included PSA progression-free survival and ADT-free survival. The sample size of 37 MDT patients was determined based on a Simon's 2-stage design with biochemical response rate >20%, and this design was also applied for the subsequent independent validation cohort. RESULTS: Seventy-four patients underwent MDT: 37 each in the initial and validation cohorts. Both cohorts met the prespecified biochemical response rate and completed the planned 2-stages of accrual. For the pooled cohort, the median number of prostate specific membrane antigen positron emission tomography avid lesions was 2 and most (87%) recurrences were nodal. Sixty-four (87%) had stereotactic body radiation therapy and 10 (13%) had surgery. Median follow-up (interquartile range [IQR]) for the initial, validation and combined cohorts were 41 (35-46) months, 14 months (7-21), and 24 months (14-41), respectively. The biochemical response rates for the initial, validation and combined cohorts were 59%, 43%, and 51%, respectively. For the combined cohort, median biochemical progression-free survival was 21 months (95% confidence interval, 13-not reached), and median ADT-free survival was 45 months (95% confidence interval, 31-not reached). CONCLUSIONS: Half of patients treated with MDT for molecularly defined-only oligorecurrent prostate cancer exhibited a biochemical response. This study provides necessary and validated evidence to support randomized trials aiming to determine whether MDT (alone or with systemic therapy) can affect clinically meaningful end points.