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.

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.

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.

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.

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.

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.

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.

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.

Assessment of Toxic Effects and Survival in Treatment Deescalation With Radiotherapy vs Transoral Surgery for HPV-Associated Oropharyngeal Squamous Cell Carcinoma: The ORATOR2 Phase 2 Randomized Clinical Trial.

Importance: The optimal approach for treatment deescalation in human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCCs) is unknown. Objective: To assess a primary radiotherapy (RT) approach vs a primary transoral surgical (TOS) approach in treatment deescalation for HPV-related OPSCC. Design, Setting, and Participants: This international, multicenter, open-label parallel-group phase 2 randomized clinical trial was conducted at 9 tertiary academic cancer centers in Canada and Australia and enrolled patients with T1-T2N0-2 p16-positive OPSCC between February 13, 2018, and November 17, 2020. Patients had up to 3 years of follow-up. Interventions: Primary RT (consisting of 60 Gy of RT with concurrent weekly cisplatin in node-positive patients) vs TOS and neck dissection (ND) (with adjuvant reduced-dose RT depending on pathologic findings). Main Outcomes and Measures: The primary end point was overall survival (OS) compared with a historical control. Secondary end points included progression-free survival (PFS), quality of life, and toxic effects. Results: Overall, 61 patients were randomized (30 [49.2%] in the RT arm and 31 [50.8%] in the TOS and ND arm; median [IQR] age, 61.9 [57.2-67.9] years; 8 women [13.6%] and 51 men [86.4%]; 31 [50.8%] never smoked). The trial began in February 2018, and accrual was halted in November 2020 because of excessive toxic effects in the TOS and ND arm. Median follow-up was 17 months (IQR, 15-20 months). For the OS end point, there were 3 death events, all in the TOS and ND arm, including the 2 treatment-related deaths (0.7 and 4.3 months after randomization, respectively) and 1 of myocardial infarction at 8.5 months. There were 4 events for the PFS end point, also all in the TOS and ND arm, which included the 3 mortality events and 1 local recurrence. Thus, the OS and PFS data remained immature. Grade 2 to 5 toxic effects occurred in 20 patients (67%) in the RT arm and 22 (71%) in the TOS and ND arm. Mean (SD) MD Anderson Dysphagia Inventory scores at 1 year were similar between arms (85.7 [15.6] and 84.7 [14.5], respectively). Conclusions and Relevance: In this randomized clinical trial, TOS was associated with an unacceptable risk of grade 5 toxic effects, but patients in both trial arms achieved good swallowing outcomes at 1 year. Long-term follow-up is required to assess OS and PFS outcomes. Trial Registration: Clinicaltrials.gov Identifier: NCT03210103.

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

PURPOSE: The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has risen rapidly, because of an epidemic of human papillomavirus infection. The optimal management of early-stage OPSCC with surgery or radiation continues to be a clinical controversy. Long-term randomized data comparing these paradigms are lacking. METHODS: We randomly assigned patients with T1-T2, N0-2 (≤ 4 cm) OPSCC to radiotherapy (RT) (with chemotherapy if N1-2) versus transoral robotic surgery plus neck dissection (TORS + ND) (with or without adjuvant therapy). The primary end point was swallowing quality of life (QOL) at 1-year using the MD Anderson Dysphagia Inventory. Secondary end points included adverse events, other QOL outcomes, overall survival, and progression-free survival. All analyses were intention-to-treat. Herein, we present long-term outcomes from the trial. RESULTS: Sixty-eight patients were randomly assigned (n = 34 per arm) between August 10, 2012, and June 9, 2017. Median follow-up was 45 months. Longitudinal MD Anderson Dysphagia Inventory analyses demonstrated statistical superiority of RT arm over time (P = .049), although the differences beyond 1 year were of smaller magnitude than at the 1-year timepoint (year 2: 86.0 ± 13.5 in the RT arm v 84.8 ± 12.5 in the TORS + ND arm, P = .74; year 3: 88.9 ± 11.3 v 83.3 ± 13.9, P = .12). These differences did not meet the threshold to qualify as a clinically meaningful change at any timepoint. Certain differences in QOL concerns including more pain and dental concerns in the TORS + ND arm seen at 1 year resolved at 2 and 3 years; however, TORS patients started to use more nutritional supplements at 3 years (P = .015). Dry mouth scores were higher in RT patients over time (P = .041). CONCLUSION: On longitudinal analysis, the swallowing QOL difference between primary RT and TORS + ND approaches persists but decreases over time. Patients with OPSCC should be informed about the pros and cons of both treatment options (ClinicalTrials.gov identifier: NCT01590355).

Contralateral nodal failures in oropharyngeal cancers after TORS and unilateral neck management: a retrospective study.

BACKGROUND: Report the incidence of contralateral nodal failure rates in well-lateralized oropharyngeal carcinoma treated with upfront surgery and unilateral neck management. METHODS: Lateralized oropharyngeal carcinomas treated with upfront surgery using transoral robotic surgery (TORS) and unilateral neck management (unilateral neck dissection ± unilateral radiation treatment) were identified. Primary endpoint was contralateral regional control (CRC). Secondary endpoints were local control (LC), and overall survival (OS). RESULTS: Thirty-two patients were included. Pathologic T categories included 66% pT1, 31% pT2 and 3% pT3. Nodal diseases comprised 41% N0 and 47% N1 (AJCC 8th). Twenty-three (72%) patients had HPV related tumors. 3-years CRC, LC and OS were 100%, 96% (89-100) and 96% (CI 89-100). One patient developed a second primary with contralateral nodal disease. Only one patient died from another primary cancer. CONCLUSION: In selected patients with lateralized oropharyngeal cancer, treatment with TORS and ipsilateral management of the neck may be oncologically safe without significant risk of contralateral failure. LEVEL OF EVIDENCE: Level 2.

Regional Recurrences and Hyams Grade in Esthesioneuroblastoma.

Objective The aim of this study is to determine if Hyams grade may help predict which patients with esthesioneuroblastoma (ENB) tumors are likely to develop regional recurrences, and to determine the impact of tumor extent on regional failure in ENB patients without evidence of nodal disease at presentation. Design The study was designed as a retrospective review for ENB patients. Settings The study was prepared at tertiary care academic center for ENB patients. Participants Patients with ENB were included in the study. Main Outcome Measures Oncologic outcomes (5-year regional and locoregional control (LRC) and overall survival) in patients with Hyams low grade versus high grade. Oncologic outcomes based on radiographic disease extent. Results A total of 43 patients were included. Total 25 patients (58%) had Hyams low-grade tumor, and 18 (42%) had high-grade tumor. Of the 34 patients without regional disease at presentation, 8 (24%) were treated with elective nodal radiation. There were no statistically significant differences in 5-year regional control in the Hyams low-grade versus high-grade groups (78 vs. 89%; p = 0.4). The 5-year LRC rates in patients with low grade versus high grade were 73 versus 89% ( p = 0.6). The 5-year overall survival rates in patients with low-grade versus high-grade tumors were 86 versus 63% ( p = 0.1). Radiographic extension of disease into the olfactory groove, olfactory nerve, dura, and periorbita were statistically associated with decreased 5-year overall survival (5-year OS 49 vs. 91% [ p = 0.04], 49 vs. 91% [ p = 0.04], 44 vs. 92% [ p = 0.02], and 44 vs. 80% [ p = 0.04], respectively). Conclusion ENBs are associated with a risk of regional failure. The current analysis suggests that Hyams low-grade and high-grade malignancies have comparable rates of early and delayed regional recurrences, although small sample size may limit our conclusions.

Stereotactic body radiotherapy for head and neck skin cancer.

AIM: To report outcomes of Stereotactic Body Radiotherapy (SBRT) for head and neck skin cancer (HNSC) patients treated at a high-volume center. MATERIALS: A retrospective review of HNSC SBRT patients from 2012 to 2019 was conducted. Kaplan-Meier method was used to estimate local control (LC), locoregional control (LRC) outside of SBRT field, overall survival (OS), progression-free survival (PFS) and late toxicity (LT). Univariate and multivariate analyses were performed. Grade 3-4 acute and late toxicities were reported by the Common Terminology Criteria for Adverse Events v5.0. RESULTS: One hundred and six medically unfit HNSC patients (112 lesions) were included. Median follow-up was 8 months. Median patient age at diagnosis was 86 years (range: 56-102 years). The majority of patients had advanced disease (overall stage III-IV [n = 90, 85%]) with median gross tumor volumes (GTV) of 31 cm3 (range: 17-56 cm3). Treated sites were: primary (n = 51), nodal (n = 47) or primary plus nodal (n = 8). SBRT doses ranged from 32-50 Gy delivered twice weekly in 4-6 fractions to the gross tumor volume (GTV). One and 2-year LC rates were 78% (69-88) and 67% (53-82), respectively. One-year LRC outside of SBRT field, OS, PFS and LT rates were 72% (62-84), 53% (43-65), 52% (40-62), and 7% (2-17), respectively. Thirty-three patients (31%) developed acute grade ≥ 3 treatment-related toxicity, most commonly dermatitis (n = 31). Nine patients (8%) experienced late grade ≥ 3 toxicity, including 7 grade 3 fibrosis, 1 grade 3 bone radionecrosis and 1 grade 4 skin ulceration. No treatment-related deaths (grade 5) were observed. CONCLUSION: SBRT provides durable disease control with acceptable toxicity for medically unfit high-risk HNSC patients unable to undergo standard of care curative treatment approaches.

Clinical integration of machine learning for curative-intent radiation treatment of patients with prostate cancer.

Machine learning (ML) holds great promise for impacting healthcare delivery; however, to date most methods are tested in 'simulated' environments that cannot recapitulate factors influencing real-world clinical practice. We prospectively deployed and evaluated a random forest algorithm for therapeutic curative-intent radiation therapy (RT) treatment planning for prostate cancer in a blinded, head-to-head study with full integration into the clinical workflow. ML- and human-generated RT treatment plans were directly compared in a retrospective simulation with retesting (n = 50) and a prospective clinical deployment (n = 50) phase. Consistently throughout the study phases, treating physicians assessed ML- and human-generated RT treatment plans in a blinded manner following a priori defined standardized criteria and peer review processes, with the selected RT plan in the prospective phase delivered for patient treatment. Overall, 89% of ML-generated RT plans were considered clinically acceptable and 72% were selected over human-generated RT plans in head-to-head comparisons. RT planning using ML reduced the median time required for the entire RT planning process by 60.1% (118 to 47 h). While ML RT plan acceptability remained stable between the simulation and deployment phases (92 versus 86%), the number of ML RT plans selected for treatment was significantly reduced (83 versus 61%, respectively). These findings highlight that retrospective or simulated evaluation of ML methods, even under expert blinded review, may not be representative of algorithm acceptance in a real-world clinical setting when patient care is at stake.

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.

Curative-intent Metastasis-directed Therapies for Molecularly-defined Oligorecurrent Prostate Cancer: A Prospective Phase II Trial Testing the Oligometastasis Hypothesis.

BACKGROUND: The hypothesis of a curable oligometastatic prostate cancer (PCa) state remains to be clinically-proven. Conventional imaging often fails to localize early recurrences, hampering the potential for radical approaches. OBJECTIVE: We hypothesize that prostate-specific membrane antigen (PSMA)-targeted PET-MR/CT allows for earlier detection and localization of oligorecurrent-PCa, unveiling a molecularly-defined state amenable to curative-intent metastasis-directed treatment (MDT). DESIGN/SETTING/PARTICIPANTS: Single-institution single-arm phase-two study. Patients with rising PSA (0.4-3.0 ng/mL) after maximal local therapy (radical prostatectomy and post-operative radiotherapy), negative conventional staging, and no prior salvage hormonal therapy (HT) were eligible. INTERVENTIONS: All patients underwent [18F]DCFPyL PET-MR/CT. Patients with molecularly-defined oligorecurrent-PCa had MDT (stereotactic ablative body radiotherapy [SABR] or surgery) without HT. OUTCOME MEASUREMENTS/STATISTICAL ANALYSIS: Primary endpoint was biochemical response (complete, i.e. biochemical 'no evidence of disease' [bNED], or partial response [100% or ≥50% PSA decline from baseline, respectively]) after MDT. Simon's two-stage design was employed (null and alternate hypotheses <5% and >20% response rate, respectively), with α and ß of 0.1. RESULTS: Seventy-two patients were enrolled (May/2017-July/2019). Thirty-eight (53%) had PSMA-detected oligorecurrent-PCa amenable for MDT. Thirty-seven (51%) agreed to MDT: 10 and 27 underwent surgery and SABR, respectively. Median follow-up was 15.9 months (IQR 9.8-19.1). Of patients receiving MDT, the overall response rate was 60%, including 22% rendered bNED. One (2.7%) grade 3 toxicity (intra-operative ureteric injury) was observed. CONCLUSIONS: PSMA-defined oligorecurrent-PCa can be rendered bNED, a necessary step towards cure, in 1 of 5 patients receiving MDT alone. Randomized trials are justified to determine if MDT +/- systemic agents can expand the curative therapeutic armamentarium for PCa. PATIENT SUMMARY: We studied men treated for prostate cancer with rising PSA. We found PSMA imaging detected recurrent cancer in three-quarters of patients, and targeted treatment to these areas significantly decreased PSA in half of patients.

Prognostic value of clinical and radiologic extranodal extension and their role in the 8th edition TNM cN classification for HPV-negative oropharyngeal carcinoma.

BACKGROUND/OBJECTIVES: We evaluate the performance between the TNM-8 versus TNM-7 cN-classification and explore the relative prognostic contribution of radiologic extranodal extension (rENE) for HPV-negative oropharyngeal cancer (HPV-OPC). MATERIALS/METHODS: All HPV- OPC treated with IMRT between 2005 and 2016 were included. cENE was defined as unambiguous "fixation" of a neck mass or "skin involvement" on clinical examination. rENE was recorded by re-reviewing pre-treatment CT/MR. Disease-free survival (DFS) stratified by cENE or rENE were compared. Multivariable analyses (MVA) calculated the adjusted hazard ratio (aHR) for the separate cENE and rENE attributes and their combination. A refined cN-category incorporating both cENE and rENE parameters was proposed. The performance of the revision was compared to TNM-8 and TNM-7. RESULTS: Of 361 HPV- OPC, 97 were cN0 and 264 were cN+ with 48 cENE+ and 72 rENE+ respectively. Median follow-up was 5.4 years. The 3-year DFS was lower in cENE+ vs cENE-negative (cENE-) (23% vs 45%; aHR = 1.68, p = 0.008) and rENE+ vs rENE-negative (rENE-) patients (29% vs 45%; aHR = 1.44, p = 0.037). The cENE+/rENE+ subset had the worse DFS vs cENE-/rENE+ or cENE-/rENE- (24%/37%/46%, p = 0.005). We propose a refined cN-category wherein any cENE-/rENE+ case is reclassified one N-stratum higher while any cENE+ case remains cN3b. The stage schema with the refined N-categorization outperformed TNM-8, and both outperformed TNM-7. CONCLUSIONS: cENE and rENE are both prognostic but the cENE+/rENE+ subset has the worst outcome. The TNM-8 cN-categories improves outcome prediction compared to the TNM-7. Incorporation of rENE into TNM-8 cN-categories may further augment performance.

Short-term and long-term unstimulated saliva flow following unilateral vs bilateral radiotherapy for oropharyngeal carcinoma.

BACKGROUND: We aimed to compare unstimulated saliva flow using 3-minute modified Schirmer test (MST) following bilateral vs unilateral radiotherapy (RT) in oropharyngeal carcinoma (OPC). METHODS: We reviewed OPC patients treated with definitive intensity-modulated radiation therapy (IMRT) between 2011 and 2017. MST was measured at baseline, 1-/6-/12-/24-month post-RT. MST values were compared between bilateral-RT vs unilateral-RT groups. Multivariable logistic regression analysis (MVA) identified predictors of hyposalivation (MST < 25 mm). RESULTS: Total 498 bilateral-RT and 36 unilateral-RT patients were eligible. The MST values at 1-/6-/12-/24-month post-RT were all significantly reduced from baseline for the entire cohort. Baseline unilateral-RT and bilateral-RT MST values (in mm) were similar (P = .2), but much higher for unilateral-RT 1-month (mean: 19.1 vs 13.0, P = .03), 6-month (20.5 vs 9.3, P < .001), 12-month (20.1 vs 11.9, P < .01), and 24-month post-RT (22.2 vs 13.9, P = .04). MVA confirmed that unilateral RT reduced the likelihood of hyposalivation vs bilateral RT (OR 2.36, P = .006). CONCLUSION: Unilateral RT reduces unstimulated salivary flow in OPC patients.

Non-operative management for oral cavity carcinoma: Definitive radiation therapy as a potential alternative treatment approach.

PURPOSE: To determine the outcomes of oral cavity squamous cell cancer (OSCC) patients treated with non-surgical approach i.e. definitive intensity-modulated radiation therapy (IMRT). METHODS: All OSCC patients treated radically with IMRT (without primary surgery) between 2005-2014 were reviewed in a prospectively collected database. OSCC patients treated with definitive RT received concurrent chemotherapy except for early stage patients or those who declined or were unfit for chemotherapy. The 5-year local, and regional, distant control rates, disease-free, overall, and cancer-specific survival, and late toxicity were analyzed. RESULTS: Among 1316 OSCC patients treated with curative-intent; 108 patients (8%) received non-operative management due to: medical inoperability (n = 14, 13%), surgical unresectability (n = 8, 7%), patient declined surgery (n = 15, 14%), attempted preservation of oral structure/function in view of required extensive surgery (n = 53, 49%) or extensive oropharyngeal involvement (n = 18, 17%). Sixty-eight (63%) were cT3-4, 38 (35%) were cN2-3, and 38 (35%) received concurrent chemotherapy. With a median follow-up of 52 months, the 5-year local, regional, distant control rate, disease-free, overall, and cancer-specific survival were 78%, 92%, 90%, 42%, 50%, and 76% respectively. Patients with cN2-3 had higher rate of 5-year distant metastasis (24% vs 3%, p = 0.001), with detrimental impact on DFS (p = 0.03) and OS (p < 0.02) on multivariable analysis. Grade ≥ 3 late toxicity was reported in 9% of patients (most common: grade 3 osteoradionecrosis in 6%). CONCLUSIONS: Non-operative management of OSCC resulted in a meaningful rate of locoregional control, and could be an alternative curative approach when primary surgery would be declined, unsuitable or unacceptably delayed.