Delineation of the primary tumour Clinical Target Volumes (CTV-P) in laryngeal, hypopharyngeal, oropharyngeal and oral cavity squamous cell carcinoma: AIRO, CACA, DAHANCA, EORTC, GEORCC, GORTEC, HKNPCSG, HNCIG, IAG-KHT, LPRHHT, NCIC CTG, NCRI, NRG Oncology, PHNS, SBRT, SOMERA, SRO, SSHNO, TROG consensus guidelines

Clinical and dosimetric feasibility of sparing submandibular gland in patients with oral cavity squamous cell carcinoma

BACKGROUND

To investigate the incidence of submandibular gland (SMG) involvement and explore the feasibility of sparing SMG in the oral cavity squamous cell carcinoma (OSCC).

METHODS

This study retrospectively analyzed patients between January 2018 to October 2022. Ten patients with tongue squamous cell carcinoma receiving postoperative radiotherapy were replanned to investigate the feasibility of sparing SMG. The dose constraint for the SMG was a mean dose (Dmean) <39 grey (Gy).

RESULTS

A total of 238 patients were identified and 105 had metastatic neck lymph nodes. Level II was the most common site of metastasis (n = 94, 89.5%), followed by level IB (n = 37, 35.2%), level III (n = 26, 24.8%), level IA (n = 3, 2.6%), and level IV (n = 2, 1.9%). A total of 50 metastatic lymph nodes were located at the level IB, of which 18 (36.0%), 29 (58.0%), and 3 (6%) were located in the lateral, anterior, and inferior aspect of the SMG. No metastatic lymph nodes were found within or on the medial aspect of the SMG. The Dmean of the SMG was <39 Gy in all patients with a Dmean of 38.8 Gy. The median dose of PTV54 D95% was 53.8 Gy, which met the prespecified allowable coverage goal.

CONCLUSIONS

Our study suggests that SMG involvement is rare in OSCC. With strict imaging and clinical evaluation, sparing SMG during radiotherapy is feasible.

Adaptive radiotherapy for oropharyngeal cancer with daily adapt-to-shape workflow on 1.5 T MRI-linac: Preliminary outcomes and comparison with helical tomotherapy

Introduction

MR-linac could offer several advantages for radical radiochemotherapy (RCHT) in oropharyngeal squamous cell carcinoma (OPSCC) patients. Currently, only a few case series have been published and no comparison with other techniques have been performed.

Methods

Data of 34 consecutive patients treated from September 2022 to May 2024 at a single Institution with RCHT on Unity® MR-linac for OPSCC with daily adaptive radiotherapy (RT) according to the adapt-to-shape (ATS) workflow were prospectively analyzed. A comparative cohort of 34 patients with similar characteristics treated with helical treatment on Radixact® was retrieved.

Results

Characteristics were well balanced across the two groups. Maximal toxicity grade ≥2 rate was borderline higher at RT end in MRI-linac group (p 0.049), but lower one month after RT (76.5 % vs 91.2 %; p = 0.257).Non-significantly lower rates of grade ≥2 xerostomia and dysgeusia were reported in Unity® group one and three months after RT. Higher rates of hospitalizations were reported in Radixact group at 20 fractions and at RT end (64.1 % vs 35.3 %; p = 0.015). Mean Karnofsky performance status (KPS) was higher in Unity group three months after RT (87.67 vs 83.87; p = 0.038).After a median follow up of 361.5 days, local complete response was reported for 93.6 % of patients treated with Unity® and 96.8 % of patients treated with Radixact®.

Conclusions

Results of this analysis support the feasibility of an ATS MR-linac workflow for RCHT in OPSCC. Compared with tomotherapy, treatment with Unity® resulted in significantly lower rates of hospitalization and higher KPS three months after RT. Grade 2 xerostomia and dysgeusia rates were non-significantly lower in Unity group. Optimal results in terms of local control were reported for both techniques.

Consensus for a postoperative atlas of sinonasal substructures from a modified Delphi study to guide radiotherapy in sinonasal malignancies

BACKGROUND

Sinonasal and skull base tumor surgery-related morbidity has been reduced by the use of endoscopic endonasal skull base surgery (EESBS). Postoperative radiation therapy (poRT) requires precise definition of target volumes. To enhance the accuracy of poRT planning, histological and radiological correlations are necessary to locate the tumor attachment on poRT CT scans. An accurate atlas of structures resected or identified during EESBS could serve for the interdisciplinary postoperative management of patients, personalizing poRT by adequate radiation dose delivery. The objective of this study was to achieve a consensual segmentation atlas on CT scan with surgeons practicing EESBS and radiation oncologists.

METHODS

The sinonasal structures relevant for poRT of sinonasal malignancies were determined by a two-round Delphi process. A rating group of 25 European experts in sinonasal malignancies was set up. Consensual structures emerged and were used to determine the anatomical limits of the retained structures to draft an atlas with expert based relevant structures. The atlas was then critically reviewed, discussed, and edited by another 2 skull base surgeons and 2 radiation oncologists.

RESULTS

After the two rating rounds, 46 structures obtained a strong agreement, 7 an agreement, 5 were rejected and 5 did not reach consensus. The atlas integrating all the selected structures is presented attached.

CONCLUSION

Consensual segmentation atlas on CT scan might allow, through careful poRT planning to limit the morbidity of poRT while maintaining good local control. Prospective studies are necessary to validate this potential precision medicine-based approach.

Prognostic Implications of HPV Cell-Free DNA Serial Testing During Follow-Up of p16 Positive Oropharyngeal Squamous Cell Carcinoma After Curative-Intent Treatment

INTRODUCTION

Plasma circulating HPV cell-free DNA has high sensitivity and specificity for the detection of HPV-mediated oropharyngeal squamous cell carcinoma. We investigated the clinical significance of serial testing after curative-intent treatments.

MATERIALS AND METHODS

Patients with concordant p16 positive tumour or neck node biopsy and positive high-risk HPV plasma cell-free DNA were prospectively recruited. HPV cell-free DNA were obtained using digital droplet polymerase chain reaction (ddPCR) and were collected at diagnosis and at every clinical follow-up. Three months after completion of curative-intent treatments, patients were stratified according to treatment response on computed tomography. Complete responders (CR) were followed-up clinically, partial responders (PR) underwent further imaging and surgical/medical management if appropriate, patients with progressive disease (PD) received palliative treatments.

RESULTS

A hundred and fourteen patients were included and 717 HPV cfDNA ddPCR samples were analysed during a median follow-up of 103 weeks (IQR, 40.2-147.8). Ninety (78.9%) patients were classified as CR, 18 (15.8%) as PR and all except one, who was rapidly diagnosed with PD, had negative HPV ddPCR at 12 weeks follow-up; 6 (5.3%) had PD and all except one had positive HPV ddPCR. Eleven had recurrent disease, 6 in the CR group (6.6%) and 5 among PR (27.7%). Ninety patients had consistently negative HPV ddPCR at all time points and one developed a recurrence (NPV 99%, 95% C.I., 93.2-99.8%). Eighteen patients developed positive HPV ddPCR and 10 developed recurrent disease (PPV 55%, 95% C.I., 38.6-71.4%). Ten patients had two consecutively positive HPV ddPCR and all had proven disease (PPV 100%, 95% C.I., 69.2-100%). Nine patients had transiently positive HPV ddPCR and none developed disease at that time.

CONCLUSIONS

Post-treatment HPV ddPCR reflected treatment response on imaging and serial testing had high PPV and NPV in detecting recurrent disease.

Tubarial gland sparing for oropharyngeal cancer: Feasibility with intensity modulated proton therapy & intensity modulated radiation therapy

The feasibility of sparing tubarial glands in oropharyngeal radiotherapy was assessed using IMPT and IMRT. Tubarial gland absolute mean dose differences of up to 18 Gy were observed between clinical and re-optimized plans without compromising target coverage. IMPT plans met tubarial gland mean dose constraints more often than IMRT plans.

Post-operative radiotherapy for oral cavity squamous cell carcinoma: Review of the data guiding the selection and the delineation of post-operative target volumes

BACKGROUND AND PURPOSE

To date, no consensus guidelines have been published that systematically guide delineation of primary and nodal Clinical Target Volumes (CTVs) in patients who require post-operative radiotherapy (PORT) for head and neck squamous cell carcinoma (HNSCC). As a result, significant individual, institutional and national variation exists in the way that CTVs are delineated in the post-operative setting, leading to considerable heterogeneity in radiotherapy treatment.

METHODS

A multi-disciplinary group of experts was convened by the European Society for Radiotherapy and Oncology (ESTRO), including radiation oncologists from Europe, North America and Asia, as well as surgery, radiology and pathology representatives. Oral cavity squamous cell carcinoma (OCSCC), where surgery followed by PORT is the standard of care, was first selected for focus. The indications for PORT, and the influence of tumour subsite and stage on post-operative treatment volumes, were considered with reference to current evidence, and clinical experience within the group.

RESULTS

We present clear recommendations regarding the indications for PORT in OCSCC, and propose a new classification of lateralised and non-lateralised OCSCC, to help guide the delineation of post-operative nodal CTVs.

CONCLUSIONS

The evidence and expert opinion summarised in this manuscript provides the background and context required to underpin new international consensus guidelines for the delineation of primary and nodal CTVs for OCSCC in the post-operative setting.

Personalising Nasopharyngeal Cancer: Systemic Therapy and Radiotherapy Treatment Volumes

Nasopharyngeal carcinoma (NPC) is sensitive to chemotherapy and radiotherapy, with current treatment recommendations largely based on TNM-stage. Radiotherapy remains the backbone of treatment for NPC. Over the past decades, the addition of concurrent chemotherapy to radiotherapy for early-stage disease, and the combination of induction chemotherapy (IC) or adjuvant chemotherapy (AC) with chemoradiotherapy vs chemoradiotherapy alone for advanced disease have led to substantial improvements in survival of patients with NPC. Nonetheless, in the era of precision oncology, there is growing recognition that patients with NPC are clinically heterogeneous even within the same stage-group, and future advances must focus on individualisation of systemic therapy and radiotherapy. In this review, we summarised the published evidence on EBV DNA as a biomarker for clinical stratification and treatment response in NPC, and discussed some of the ongoing clinical trials of EBV DNA-directed personalisation of systemic therapy in locoregionally-advanced disease. Next, we assessed the evidence concerning individualised radiotherapy strategies for target volume delineation of the primary tumour and cervical nodes that ought to be based on individual tumour extent and IC response (for locoregionally-advanced NPC) as opposed to the historical one-size fits all approach. In the same vein, radiotherapy dose de-escalation may be considered in good responders to IC, whereas for the poor responders, altered fractionation or dose escalation may be required to target resistant disease. These concepts are particularly relevant in the era of combinatorial immune checkpoint blockade therapy with radiotherapy, where preservation of circulating immune cells is crucial to evoke immune-mediated antitumour cytotoxicity.

Mid-treatment changes in intra-tumoural metabolic heterogeneity correlate to outcomes in oropharyngeal squamous cell carcinoma patients

BACKGROUND

This study evaluated mid-treatment changes in intra-tumoural metabolic heterogeneity and quantitative FDG-PET/CT imaging parameters and correlated the changes with treatment outcomes in oropharyngeal squamous cell cancer (OPSCC) patients. 114 patients from two independent cohorts underwent baseline and mid-treatment (week 3) FDG-PET. Standardized uptake value maximum (SUVmax), standardized uptake value mean (SUVmean), metabolic tumour volume (MTV), and total lesional glycolysis (TLG) were measured. Intra-tumoural metabolic heterogeneity was quantified as the area under a cumulative SUV-volume histogram curve (AUC-CSH). Baseline and relative change (%∆) in imaging features were correlated to locoregional recurrence free survival (LRRFS) using multivariate Cox regression analysis. Patients were stratified into three risk groups utilising ∆AUC-CSH and known prognostic features, then compared using Kaplan-Meier analysis.

RESULTS

Median follow up was 39 months. 18% of patients developed locoregional recurrence at 2 years. A decrease in heterogeneity (∆AUC-CSH: 24%) was observed mid-treatment. There was no statistically significant difference in tumour heterogeneity (AUC-CSH) at baseline (p = 0.134) and change at week 3 (p = 0.306) between p16 positive and p16 negative patients. Baseline imaging features did not correlate to LRRFS. However, ∆MTV (aHR 1.04; 95% CI 1.03-1.06; p < 0.001) and ∆AUC-CSH (aHR 0.96; 95% CI 0.94-0.98; p = 0.004) were correlated to LRRFS. Stratification using ∆AUC-CSH and p16 status into three groups showed significant differences in LRR (2 year LRRFS 94%, 79%, 17%; log rank p < 0.001). Stratification using ∆AUC-CSH and ∆MTV into three groups showed significant differences in LRR (2 year LRRFS 93%, 70%, 17%; log rank p < 0.001).

CONCLUSION

Mid-treatment changes in intra-tumoural FDG-PET/CT heterogeneity correlated with treatment outcomes in OPSCC and may help with response prediction. These findings suggest potential utility in designing future risk adaptive clinical trials.

Overview of the Head and Neck Tumor Segmentation for Magnetic Resonance Guided Applications (HNTS-MRG) 2024 Challenge

Magnetic resonance (MR)-guided radiation therapy (RT) is enhancing head and neck cancer (HNC) treatment through superior soft tissue contrast and longitudinal imaging capabilities. However, manual tumor segmentation remains a significant challenge, spurring interest in artificial intelligence (AI)-driven automation. To accelerate innovation in this field, we present the Head and Neck Tumor Segmentation for MR-Guided Applications (HNTS-MRG) 2024 Challenge, a satellite event of the 27th International Conference on Medical Image Computing and Computer Assisted Intervention. This challenge addresses the scarcity of large, publicly available AI-ready adaptive RT datasets in HNC and explores the potential of incorporating multi-timepoint data to enhance RT auto-segmentation performance. Participants tackled two HNC segmentation tasks: automatic delineation of primary gross tumor volume (GTVp) and gross metastatic regional lymph nodes (GTVn) on pre-RT (Task 1) and mid-RT (Task 2) T2-weighted scans. The challenge provided 150 HNC cases for training and 50 for final testing hosted on grand-challenge.org using a Docker submission framework. In total, 19 independent teams from across the world qualified by submitting both their algorithms and corresponding papers, resulting in 18 submissions for Task 1 and 15 submissions for Task 2. Evaluation using the mean aggregated Dice Similarity Coefficient showed top-performing AI methods achieved scores of 0.825 in Task 1 and 0.733 in Task 2. These results surpassed clinician interobserver variability benchmarks, marking significant strides in automated tumor segmentation for MR-guided RT applications in HNC.

Impact of Multiprofessional Radiotherapy Peer Review on Multidisciplinary Team Meeting Staging in Head and Neck Cancer

AIMS

Cancer staging is routinely done in a multidisciplinary team meeting (MDM). There is however no established quality assurance (QA) for MDM-recorded cancer staging. Conversely, radiotherapy peer review is a recommended QA process. This study aimed to compare the cancer staging of the multiprofessional radiotherapy peer review (with radiologists) against the referring MDMs.

MATERIALS AND METHODS

All head and neck intensity-modulated radiotherapy (IMRT) cases discussed in peer review between May 2023 to April 2024 were prospectively evaluated. Any radiological disease progression (PD) on IMRT-planning scan since the diagnostic scans, and patients' cancer staging, were prospectively recorded. These were compared with the MDM-recorded outcomes data.

RESULTS

A total of 235 IMRT cases were peer-reviewed: 166 definitive, 63 post-operative and 6 palliatives. Of the analysable definitive cases, 44/150 (29%) were found to have PD, with a mean interval from diagnostic to IMRT-planning scan of 51 days (Standard Deviation SD = 25), compared to 38 days (SD = 21) in the cohort without PD (p < 0.01). After the exclusion of 28 patients with the most advanced non-metastatic stage, 35 (30%) were upstaged with a mean interval from diagnostic to IMRT-planning of 49 days (SD = 26), compared to 39 days (SD = 23) in the cohort without upstage (p = 0.05). Twenty (57%) upstaged patients had evidence of PD, while the other 15 (43%) were upstaged despite the absence of PD. Two MDM-recorded T3-category larynx cancers were subsequently recommended for a primary laryngectomy due to T4a-category at peer review, and both were proven T4a pathologically. Three upstaged patients were recommended concomitant chemotherapy. The peer review recommended IMRT volume changes to 156 (66%) patients.

CONCLUSION

Discrepancies in MDM staging can occur, and a protracted diagnosis and treatment pathway too can affect final cancer staging. Routine radiologist input in peer review can provide crucial post-MDM outcome assurance and the recommended clinical management.

Deglutition preservation after swallowing (SWOARs)-sparing IMRT in head and neck cancers: definitive results of a multicenter prospective study of the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

BACKGROUND

To investigate changes of objective instrumental measures and correlate with patient reported outcomes (PROs) of radiation-induced dysphagia (RID) after swallowing organs at risk (SWOARs)-sparing IMRT.

METHODS

Patients (pts) underwent Fiberoptic Endoscopic Evaluation of Swallowing (FEES), Videofluoroscopy (VFS) and M.D. Anderson Dysphagia Inventory (MDADI) questionnaire at baseline, 6 and 12 months after treatment. They were categorized in two groups: MDADI-C ≥ 80 and MDADI-C < 80. Pharyngeal residue (PR) and penetration (P) or aspiration (A) were considered as surrogate of RID.

RESULTS

Between 2016 and 2022 we enrolled 75 pts, 40 (53 %) MDADI-C ≥ 80 and 35 (47 %) MDADI-C < 80 at baseline. Among MDADI-C ≥ 80 the mean baseline PR score at FEES was 0,42 rising to 1,36 at 6 months (p = 0,001) and stabilizing to 1,15 at 12 months (p = 0,21); indeed, the mean baseline PR score at VFS was 0,55 rising to 1 at 6 months (p = 0,069) and slightly dropping to 0,7 at 12 months (p = 0,069). Among MDADI-C < 80 the mean baseline PR score at FEES was 0,56 rising to 1,07 at 6 months (p = 0,012) and stabilizing to 1,07 at 12 months (p = 0,99); indeed the mean baseline PR score at VFS was 0,67 rising to 1,19 at 6 months (p = 0,04) and dropping to 0,78 at 12 months (p = 0,04). No correlation was found between PROs and objective measures.

CONCLUSION

Our results show optimal acceptable deglutition preservation from major complications after SWOARs-sparing IMRT by means of low objective scores in both MDADI-C groups. Lack of correlation between PROs and objective measures suggest that referred RID is likely associated to persistence of SWOARs inflammation rather than to a real impairment of function.

Optimising (re-)irradiation for locally recurrent head and neck cancer: impact of dose-escalation, salvage surgery, PEG tube and biomarkers on oncological outcomes-a single centre analysis

INTRODUCTION

Locoregional recurrence (LR) is common in locally advanced head and neck cancer (HNSCC), posing challenges for treatment. We analysed outcome parameters and toxicities for patients being treated with radiotherapy (RT) for LR-HNSCC and investigated patient and disease related prognostic factors in this prognostically unfavourable group.

METHODS

This analysis includes 101 LR-HNSCC patients treated with RT, radio-chemotherapy (RCT) or radio-immunotherapy (RIT) between 2010 and 2018 at a high-volume tertiary centre. Patient characteristics, tumour and treatment details were retrospectively collected. Overall survival (OS), progression-free survival (PFS) and toxicities according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0 were assessed.

RESULTS

62% of patients were radiotherapy-naïve (initial RT group) while 38% were re-irradiated at site of LR (re-RT group). Median OS for initial RT was 24 months, for re-RT 12 months (p < 0.01). In the RCT subgroup, patients with initial RT had significantly longer OS with 35 months compared to re-RT 12 months (p < 0.05). Patients with UICC grade IV tumours and percutaneous endoscopic gastrostomy (PEG) tube had significantly shorter OS in multivariate analysis: initial RT 13 vs. re-RT 32 months and initial RT 12 vs. re-RT 32 months respectively. Salvage surgery before RT at recurrence was a positive prognostic factor for OS (initial RT 35 vs. re-RT 12 months). Other significant factors for longer OS in univariate analysis included low inflammatory status (Glasgow Prognostic Score 0) and radiation doses ≥ 50 Gy. We detected 37 (15%) ≥ CTCAE Grade 3 events for initial RT and 19 (15%) for re-RT patients.

CONCLUSION

In this analysis, we identified key prognostic factors including PEG tube and inflammation status that could guide treatment decision. Our findings suggest salvage surgery as preferred treatment option with postoperative RT at LR. Adverse events due to re-RT were acceptable. A radiation dose of ≥ 50 Gy should be administered to achieve better outcomes.

Adjuvant Intensity Modulated Radiation Therapy With a Pedicled Flap Reconstruction in Oral Cavity Squamous Cell Carcinomas: Implications on Target Delineation

OBJECTIVES

To address controversies regarding target volume delineation for adjuvant intensity-modulated radiation therapy for oral cavity squamous cell carcinoma with pedicled flap reconstruction and elective nodal irradiation (ENI).

MATERIALS AND METHODS

During target volume delineation, the primary tumor bed was the pre-surgical gross tumor volume with an additional isotropic margin of 5-10 mm. Additionally, the flap and body tissue junction were given a margin of 5-10 mm (if not already given). An effort was not made to trace the flap for inclusion in the clinical target volume (CTV), except when it traversed through the involved nodal regions. Contralateral ENI was carried out only in tumors crossing the midline when there was a heavy nodal burden at Ia/Ib.

RESULTS

In the 143 patients analyzed, the most common sub-site was buccal mucosa (78, 54.5%). Contralateral ENI was done in 63 patients (36 Tongue, 23 Buccoalveolar). The median follow-up of surviving patients was 24 months. The 2-year Locoregional Control, Disease-Free Survival, and Overall Survival were 77.4%, 64.5%, and 79% respectively. Overall, there were 55 (38.5%) recurrences, of which 35 (24.5%) were either local, regional, or combined locoregional failures, 13 (9.1%) were distant failures alone, and 7 (4.9%) had both locoregional and distant failures. The elective nodal regions had 3 (2.1%) contralateral nodal failures.

CONCLUSION

The entire flap need not be intentionally covered in the target volume. Contralateral ENI should be considered only for patients with heavy nodal burden at ipsilateral level Ia/Ib, in tumors crossing the midline, or in tumors having a high propensity for contralateral lymph nodal involvement.

Correlation of degree of acute radiation dermatitis (RD) with skin dose distribution in head and neck squamous cell carcinoma patients treated with definitive concurrent chemoradiation

Background

Radiation dermatitis (RD) or skin toxicity is one of the most common acute side effects of radiation in head and neck cancer patients. This study aims to correlate the pattern of volumetric-modulated arc therapy (VMAT) dose distribution to the skin with the grades of RD.

Materials and methods

80 plans of histopathologically proven squamous cell carcinoma head and neck patients already treated with definitive concurrent chemoradiation [66-70 Gy in 33-35# or 66 Gy in 30# in simultaneous integrated boost (SIB), with concurrent Cisplatin 100 mg/m2 3 weekly] at our institution between November 2022 and November 2023 were retrieved from our digital archives. For each plan, 1 ring structure was created 3mm below the external skin surface, and the parameters V40, V50, V60 and Dmax were collected from the same. These parameters were correlated with grades of RD as per Common Terminology Criteria for Adverse Events (CTCAE) v5.0. The statistical analysis was done using MedCalc software version 22.021.

Results

The incidence of G2/G3 RD was 52.5%, and its incidence was significantly correlated with all of the four parameters. Statistically significant (p < 0.001) dosimetric predictive accuracy was provided by 71.66 cc, 29.98 cc and 7.624 cc of the 3mm skin ring V40, V50 and V60, respectively.

Conclusion

The dose distribution pattern to a skin layer stationed 3mm below the surface may help predict the development of severe RD in head and neck cancer patients receiving concurrent chemoradiation.

Radiologist Involvement in Radiation Oncology Peer Review: A Systematic Review and Meta-Analysis

Importance

Radiotherapy (RT) plan quality is an established predictive factor associated with cancer recurrence and survival outcomes. The addition of radiologists to the peer review (PR) process may increase RT plan quality.

Objective

To determine the rate of changes to the RT plan with and without radiology involvement in PR of radiation targets.

Data Sources

PubMed, Scopus, and Web of Science were queried for peer-reviewed articles published from inception up to March 6, 2024. Search terms included key words associated with PR of contoured targets for the purposes of RT planning with or without radiology involvement.

Study Selection

Studies reporting PR of contoured radiation targets with or without radiology involvement. Studies were excluded if they lacked full text, reported clinical trial-specific quality assurance, or reported PR without dedicated review of RT targets.

Data Extraction and Synthesis

Data were extracted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Titles and abstracts were screened by 2 reviewers. In the case of discordance, discussion was used to reach consensus regarding inclusion for full-text review. RT plan changes were characterized as major when the change was expected to have a substantial clinical impact, as defined by the original study. Pooled outcomes were estimated using random-effects models.

Main Outcomes and Measures

Primary outcome was pooled rate of RT plan changes. Secondary outcomes included pooled rates of major and minor changes to RT targets or organs at risk.

Results

Of 4185 screened studies, 31 reporting 39 509 RT plans were included (390 with radiology and 39 119 without). The pooled rate of plan changes was 29.0% (95% CI, 20.7%-37.2%). Radiologist participation in PR was associated with significant increases in plan change rates (49.4% [95% CI, 28.6%-70.1%] vs 25.0% [95% CI, 17.0%-33.1%]; P = .02) and in clinically relevant major changes (47.0% [95% CI, 34.1%-59.8%] vs 10.2% [95% CI, 4.6%-15.8%]; P < .001). There was no difference in minor changes (15.2% [95% CI, 9.7%-20.6%] vs 13.8% [95% CI, 9.3%-18.3%]; P = .74). Subgroup analyses identified increases in the rates of changes to the gross tumor and planning target volumes with radiology-based PR. The highest rates of plan changes were observed in head and neck or lung cancer studies, studies performing PR prior to RT planning, and prospective studies.

Conclusions and Relevance

In this systematic review and meta-analysis of radiation oncology PR of contoured targets, radiologist involvement in peer review was associated with a significant increase in the rate of total and clinically meaningful changes to the RT targets with no change in minor change rates. These results support the value of interdisciplinary collaboration with radiology during RT planning.

Global assessment of swallow function (GASF) following VMAT radiotherapy for head and neck squamous cell carcinoma

Aim

This study aimed to conduct a global assessment of swallow function (GASF) using a range of swallow outcome tools, in a cohort of patients pre- and post-treatment with image-guided volumetric modulated arc therapy (VMAT) radiotherapy.

Materials and methods

All patients receiving radical (chemo)radiation for SCC of the larynx, oro-, hypo- or nasopharynx between October 2016 - 2021 were eligible for inclusion.Patients were treated with VMAT radiotherapy according to institutional and national protocols.Patients underwent GASF pre- and 6 months post-treatment. Data were collated from the MD Anderson Dysphagia Inventory (MDADI), the Functional Oral Intake Scale (FOIS), the Performance Status Scale-Head and Neck: Normalcy of Diet scale (PSS-NoD), the 100 ml water swallow test (WST) for capacity and maximal interincisal opening (MIO).

Results

One hundred and seventy-five patients were included. 55.2 % of patients experienced a fall in MDADI-Composite score greater than the published meaningful clinical important difference (MCID).A trend for a decrease in FOIS score reflects a decrease in range of diet textures and increase in reliance on enteral feeding at 6 months post-treatment.Mean PSS-NoD score decreased reflecting increased restriction in diet textures.20 patients' WST capacity improved by the minimal clinically important difference of > 4mls whilst 37 % of patients experienced a decrease in WST capacity of 4mls or more. 12.6 % of patients developed trismus following radiotherapy.

Conclusions

This paper adds new detail to the understanding of the decline in measured eating, drinking and swallowing function that patients treated with VMAT radiotherapyexperience at 6 months post treatment. However, gaps are highlighted in the evidence base in terms of interpretation of swallow outcomes tool scores; future research in HNC should include ongoing discussion and development around robust outcomes tools and data collection.

The role of upfront neck dissection in definitive radiotherapy for locally advanced hypopharyngeal squamous cell carcinoma: A single-center retrospective analysis

BACKGROUND

Hypopharyngeal cancer, constituting 3%-5% of head and neck cancers, predominantly presents as squamous cell carcinoma, with a 5-year overall survival rate of approximately 40%. Treatment modalities for locally advanced cases include chemoradiotherapy; however, the role of upfront neck dissection (UND) remains controversial. This study aimed to investigate the effect of UND on definitive radiotherapy in locally advanced hypopharyngeal carcinoma.

METHODS

This retrospective analysis included consecutive patients with locally advanced hypopharyngeal squamous cell carcinoma who were treated in our department between January 2007 and June 2023. All patients underwent definitive radiotherapy (dRT) at a total dose of 70 Gy in 35 fractions. The patients were categorized into two groups: dRT (radiotherapy with or without chemotherapy) and UND-dRT (surgical neck dissection followed by radiotherapy). Univariate Cox models and multivariate analyses were conducted to investigate the independent prognostic factors for overall survival and locoregional control rate.

RESULTS

This study included 115 patients, predominantly male (109/115), with a median age of 66 years. Clinical stage and chemotherapy distribution differed significantly between the dRT and UND-dRT groups. The 3-year overall survival and locoregional control rates for all patients were 63.8% and was 63.3%, respectively. The UND-dRT group exhibited a trend toward improved locoregional control, although this difference was not statistically significant. The multivariate analysis revealed that UND was an independent factor significantly associated with improved overall survival and locoregional control.

CONCLUSION

This study provided evidence supporting the effectiveness of UND in conjunction with definitive radiotherapy for locally advanced hypopharyngeal carcinoma. Future research should focus on validating and refining these findings through well-designed prospective multicenter trials.

Interobserver Variability in a Spanish Society of Radiation Oncology (SEOR) Head and Neck Course. Is Current Contouring Training Sufficient?

Purpose

External beam radiation therapy has grown significantly, incorporating advanced techniques like intensity modulation or stereotactic treatments, which enhance precision and accuracy. Nevertheless, variability in target volume delineation by radiation oncologists remains a challenge, influencing dose distribution. This study analyzes an online training course by the Spanish Society of Radiation Oncology, focusing on head and neck tumor contouring, to evaluate interobserver variability.

Material and Methods

Eight instructors provided clinical directives for 8 head and neck pathologies. Participants contoured structures using their own treatment planning systems, emphasizing gross tumor volume and high-, medium-, and low-risk clinical target volumes (CTV) contouring. Delineation variability was evaluated using the Dice similarity coefficient and volume relative change.

Results

The results reveal significant variability in contouring, with mean Dice similarity coefficient values ranging from 0.57 to 0.69. High-risk CTV demonstrated higher variability compared with medium-risk CTV. The presence of a gross tumor volume and supporting positron emission tomography/computed tomography or magnetic resonance imaging studies did not significantly improve the concordance. Parotid cases exhibited the greatest differences.

Conclusions

Despite the introduction of new automatic tools, this study points to the need for uniform contouring criteria. Training and standardization efforts are essential to enhance radiation therapy treatment consistency and quality.

Usefulness of using the superficial temporal pedicle as the recipient site for microvascular anastomosis in facial reconstruction: A retrospective study of 94 cases

In cranio-cervico-facial reconstructive surgery, it is accepted that the use of free flaps is the treatment of choice. The multiple antecedents can place the surgeon in situations of vascular deserts. The aim of our study is to report and analyse our experience of the use of temporal vessels in primary and secondary reconstructive surgery. A retrospective study was conducted between 01/01/2010 and 31/03/2023. Patients who underwent cranio-cervico-facial reconstruction using free flaps, with use of the superficial temporal pedicle as the recipient site for the vascular anastomosis were included. Early and late complication and failure rates were analysed according to type of reconstruction, location and risk factors for free flap failure. A total of 94 patients underwent craniocervical-facial reconstruction using a free flap anastomosed to the superficial temporal pedicle (in primary or secondary situations). Ten patients underwent reconstruction of the upper third, 58 the middle third and 26 the lower third. With an overall complication rate of 28.7% (21.3% minor complications and 7.4% major complications). Our study proves the reliability of the superficial temporal pedicle, both in the primary situation (with a success rate of 93.9%) and in the secondary situation (with a success rate of 89.3%), as well as its versatility whatever the cranio-cervico-facial level to be reconstructed. This study demonstrates the value of preserving the superficial temporal pedicle in craniofacial reconstruction surgery. This is because it is a preferred recipient site for reconstructions of the upper and middle thirds in the primary situation or in the event of recourse.

Multi-modal segmentation with missing image data for automatic delineation of gross tumor volumes in head and neck cancers

BACKGROUND

Head and neck (HN) gross tumor volume (GTV) auto-segmentation is challenging due to the morphological complexity and low image contrast of targets. Multi-modality images, including computed tomography (CT) and positron emission tomography (PET), are used in the routine clinic to assist radiation oncologists for accurate GTV delineation. However, the availability of PET imaging may not always be guaranteed.

PURPOSE

To develop a deep learning segmentation framework for automated GTV delineation of HN cancers using a combination of PET/CT images, while addressing the challenge of missing PET data.

METHODS

Two datasets were included for this study: Dataset I: 524 (training) and 359 (testing) oropharyngeal cancer patients from different institutions with their PET/CT pairs provided by the HECKTOR Challenge; Dataset II: 90 HN patients(testing) from a local institution with their planning CT, PET/CT pairs. To handle potentially missing PET images, a model training strategy named the "Blank Channel" method was implemented. To simulate the absence of a PET image, a blank array with the same dimensions as the CT image was generated to meet the dual-channel input requirement of the deep learning model. During the model training process, the model was randomly presented with either a real PET/CT pair or a blank/CT pair. This allowed the model to learn the relationship between the CT image and the corresponding GTV delineation based on available modalities. As a result, our model had the ability to handle flexible inputs during prediction, making it suitable for cases where PET images are missing. To evaluate the performance of our proposed model, we trained it using training patients from Dataset I and tested it with Dataset II. We compared our model (Model 1) with two other models which were trained for specific modality segmentations: Model 2 trained with only CT images, and Model 3 trained with real PET/CT pairs. The performance of the models was evaluated using quantitative metrics, including Dice similarity coefficient (DSC), mean surface distance (MSD), and 95% Hausdorff Distance (HD95). In addition, we evaluated our Model 1 and Model 3 using the 359 test cases in Dataset I.

RESULTS

Our proposed model(Model 1) achieved promising results for GTV auto-segmentation using PET/CT images, with the flexibility of missing PET images. Specifically, when assessed with only CT images in Dataset II, Model 1 achieved DSC of 0.56 ± 0.16, MSD of 3.4 ± 2.1 mm, and HD95 of 13.9 ± 7.6 mm. When the PET images were included, the performance of our model was improved to DSC of 0.62 ± 0.14, MSD of 2.8 ± 1.7 mm, and HD95 of 10.5 ± 6.5 mm. These results are comparable to those achieved by Model 2 and Model 3, illustrating Model 1's effectiveness in utilizing flexible input modalities. Further analysis using the test dataset from Dataset I showed that Model 1 achieved an average DSC of 0.77, surpassing the overall average DSC of 0.72 among all participants in the HECKTOR Challenge.

CONCLUSIONS

We successfully refined a multi-modal segmentation tool for accurate GTV delineation for HN cancer. Our method addressed the issue of missing PET images by allowing flexible data input, thereby providing a practical solution for clinical settings where access to PET imaging may be limited.

Impact of annotation imperfections and auto-curation for deep learning-based organ-at-risk segmentation

Background and purpose

Segmentation imperfections (noise) in radiotherapy organ-at-risk segmentation naturally arise from specialist experience and image quality. Using clinical contours can result in sub-optimal convolutional neural network (CNN) training and performance, but manual curation is costly. We address the impact of simulated and clinical segmentation noise on CNN parotid gland (PG) segmentation performance and provide proof-of-concept for an easily implemented auto-curation countermeasure.

Methods and Materials

The impact of segmentation imperfections was investigated by simulating noise in clean, high-quality segmentations. Curation efficacy was tested by removing lowest-scoring Dice similarity coefficient (DSC) cases early during CNN training, both in simulated (5-fold) and clinical (10-fold) settings, using our full radiotherapy clinical cohort (RTCC; N = 1750 individual PGs). Statistical significance was assessed using Bonferroni-corrected Wilcoxon signed-rank tests. Curation efficacies were evaluated using DSC and mean surface distance (MSD) on in-distribution and out-of-distribution data and visual inspection.

Results

The curation step correctly removed median(range) 98(90-100)% of corrupted segmentations and restored the majority (1.2 %/1.3 %) of DSC lost from training with 30 % corrupted segmentations. This effect was masked when using typical (non-curated) validation data. In RTCC, 20 % curation showed improved model generalizability which significantly improved out-of-distribution DSC and MSD (p < 1.0e-12, p < 1.0e-6). Improved consistency was observed in particularly the medial and anterior lobes.

Conclusions

Up to 30% case removal, the curation benefit outweighed the training variance lost through curation. Considering the notable ease of implementation, high sensitivity in simulations and performance gains already at lower curation fractions, as a conservative middle ground, we recommend 15% curation of training cases when training CNNs using clinical PG contours.

Radiation Therapy for HPV-Positive Oropharyngeal Squamous Cell Carcinoma: An ASTRO Clinical Practice Guideline

PURPOSE

Human Papilloma Virus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is a distinct disease from other head and neck tumors. This guideline provides evidence-based recommendations on the critical decisions in its curative treatment, including both definitive and postoperative radiation therapy (RT) management.

METHODS

ASTRO convened a task force to address 5 key questions on the use of RT for management of HPV-associated OPSCC. These questions included indications for definitive and postoperative RT and chemoradiation; dose-fractionation regimens and treatment volumes; preferred RT techniques and normal tissue considerations; and posttreatment management decisions. The task force did not address indications for primary surgery versus RT. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Concurrent cisplatin is recommended for patients receiving definitive RT with T3-4 disease and/or 1 node >3 cm, or multiple nodes. For similar patients who are ineligible for cisplatin, concurrent cetuximab, carboplatin/5-fluorouracil, or taxane-based systemic therapy are conditionally recommended. In the postoperative setting, RT with concurrent cisplatin (either schedule) is recommended for positive surgical margins or extranodal extension. Postoperative RT alone is recommended for pT3-4 disease, >2 nodes, or a single node >3 cm. Observation is conditionally recommended for pT1-2 disease and a single node ≤3 cm without other risk factors. For patients treated with definitive RT with concurrent systemic therapy, 7000 cGy in 33 to 35 fractions is recommended, and for patients receiving postoperative RT without positive surgical margins and extranodal extension, 5600 to 6000 cGy is recommended. For all patients receiving RT, intensity modulated RT over 3-dimensional techniques with reduction in dose to critical organs at risk (including salivary and swallowing structures) is recommended. Reassessment with positron emission tomography-computed tomography is recommended approximately 3 months after definitive RT/chemoradiation, and neck dissection is recommended for convincing evidence of residual disease; for equivocal positron emission tomography-computed tomography findings, either neck dissection or repeat imaging is recommended.

CONCLUSIONS

The role and practice of RT continues to evolve for HPV-associated OPSCC, and these guidelines inform best clinical practice based on the available evidence.

Enhanced head and neck radiotherapy target definition through multidisciplinary delineation and peer review: A prospective single-center study

This study evaluates the benefit of weekly delineation and peer review by a multidisciplinary team (MDT) of radiation oncologists (ROs), radiologists (RXs), and nuclear medicine (NM) physicians in defining primary and lymph node tumor volumes (GTVp and GTVn) for head and neck cancer (HNC) radiotherapy. This study includes 30 consecutive HNC patients referred for definitive curative (chemo)-radiotherapy. Imaging data including head and neck MRI, [18F]-FDG-PET and CT scan were evaluated by the MDT. The RO identified the 'undeniable' tumor as GTVp_core and determined GTVp_max, representing the maximum tumoral volume. The MDT delineation (MDT-D) by RX and NM physicians outlined their respective primary GTVs (GTVp_RX and GTVp_NM). During the MDT meeting (MDT-M), these contours were discussed to reach a consensus on the final primary GTV (GTVp_final). In the comparative analysis of various GTVp delineations, we performed descriptive statistics and assessed two MDT-M factors: 1) the added value of MDT-M, which includes the section of GTVp_final outside GTVp_core but within GTVp_RX or GTVp_NM, and 2) the part of GTVp_final that deviates from GTVp_max, representing the area missed by the RO. For GTVn, discussions evaluated lymph node extent and malignancy, documenting findings and the frequency of disagreements. The average GTVp core and max volumes were 19.5 cc (range: 0.4-90.1) and 22.1 cc (range: 0.8-106.2), respectively. Compared to GTVp_core, MDT-D to GTVp_final added an average of 3.3 cc (range: 0-25.6) and spared an average of 1.3 cc (0-15.6). Compared to GTVp_max, MDT-D and -M added an average of 2.7 cc (range: 0-20.3) and removed 2.3 cc (0-21.3). The most frequent GTVn discussions included morphologically suspicious nodes not fixing on [18F]-FDG-PET and small [18F]-FDG-PET negative retropharyngeal lymph nodes. Multidisciplinary review of target contours in HNC is essential for accurate treatment planning, ensuring precise tumor and lymph node delineation, potentially improving local control and reducing toxicity.

Multicriteria optimization of radiation therapy: Towards empowerment and standardization of reverse planning for head and neck squamous cell carcinoma

PURPOSE

The purpose of this study was to assess if multicriteria optimization could limit interoperator variability in radiation therapy planning and assess if this method could contribute to target volume coverage and sparing of organ at risk for intensity-modulated curative radiation therapy of head and neck cancers.

MATERIAL AND METHODS

We performed a retrospective analysis on 20 patients treated for an oropharyngeal or oral cavity squamous cell carcinoma. We carried out a comparative dosimetric study of manual plans produced with Precision® software, compared with the plans proposed using the multicriteria optimization method (RayStation®). We assessed interoperator reproducibility on the first six patients, and dosimetric contribution in sparing organs at risk using the multicriteria optimization method.

RESULTS

Median age was 69 years, most lesions were oropharyngeal carcinoma (65%), and 35% lesions were stage T3. First, we obtained a high degree of similarity between the four operator measurements for each patient at the level of each organ. Intraclass correlation coefficients were greater than 0.85. Second, we observed a significant dosimetric benefit for contralateral parotid gland, homolateral and contralateral masseter muscles, homolateral and contralateral pterygoid muscles and for the larynx (P<0.05). For the contralateral parotid gland, the mean dose difference between the multicriteria optimization and manual plans was -2.0Gy (P=0.01). Regarding the larynx, the mean dose difference between the two plans was -4.6Gy (P<0.001).

CONCLUSION

Multicriteria optimization is a reproducible technique and faster than manual optimization. It allows dosimetric advantages on organs at risk, especially for those not usually taken into consideration in manual dosimetry. This may lead to improved quality of life.

Early-stage hypopharyngeal squamous cell carcinoma treated with radical radiotherapy at a uniform dose of 70 Gy in 35 fractions: a single-center study

INTRODUCTION

Hypopharyngeal squamous cell carcinoma (HSCC) is often undetected until advanced stages, which contributes to poor survival rates. Recent advances in diagnostic techniques have enhanced the feasibility of early detection, and this study evaluated the efficacy and safety of radical radiotherapy that specifically targets early stage HSCC.

METHODS

This retrospective cohort study consecutively analyzed patients with clinical stage I or II HSCC between December 2008 and February 2023. These patients underwent radical radiotherapy with a uniform dose of 70 Gy delivered in 35 fractions to the primary site, followed by elective nodal irradiation. We assessed clinical outcomes, including overall survival (OS), disease-free survival (DFS), and 5-year locoregional control (LRC). Multivariate analyses were performed to identify the independent prognostic factors for OS.

RESULTS

The 5-year OS rate of the entire cohort was 80.7% (95% confidence interval [CI] = 66.5-89.4%), with no significant difference between patients with clinical stage I and II HSCC. Stratified by subsite, the 5-year OS for pyriform sinus, posterior pharyngeal wall, and postcricoid region were 81.6, 68.2, and 100%, respectively. The ECOG-Performance status (PS) was identified as an independent risk factor for OS (hazard ratio [HR] = 8.457; 95% CI 1.325-53.970; p = 0.024). DFS at 5 years was 66.4%, with local recurrence being the most frequent, and LRC rate at 5 years was 79.3%. Acute and late-phase toxicities were predominantly mild to moderate, with no grade 3 or higher toxicities reported.

CONCLUSION

This study supports radical radiotherapy as an effective approach for optimal tumor control in patients with early stage HSCC. Despite the limitations of this study, including its retrospective design and single-center confinement, our results revealed the effectiveness and feasibility of radical radiotherapy in the management of early stage HSCC.

The Evolving Role of Novel Imaging Techniques for Radiotherapy Planning

The ability to visualise cancer with imaging has been crucial to the evolution of modern radiotherapy (RT) planning and delivery. And as evolving RT technologies deliver increasingly precise treatment, the importance of accurate identification and delineation of disease assumes ever greater significance. However, innovation in imaging technology has matched that seen with RT delivery platforms, and novel imaging techniques are a focus of much research activity. How these imaging modalities may alter and improve the diagnosis and staging of cancer is an important question, but already well served by the literature. What is less clear is how novel imaging techniques may influence and improve practical and technical aspects of RT planning and delivery. In this review, current gold standard approaches to integration of imaging, and potential future applications of bleeding-edge imaging technology into RT planning pathways are explored.

Association of low adherence to weekly cisplatin with outcomes in patients with head and neck squamous cell carcinoma: a retrospective cohort study

BACKGROUND

The National Comprehensive Cancer Network (NCCN) guideline recommends consideration of weekly cisplatin as an alternative option for patients with head and neck cancer undergoing definitive chemoradiation. However, in a recent phase III trial (ConCERT), 20% of patients treated with weekly cisplatin could not receive a total of 200 mg/m2, and the association of low adherence to weekly cisplatin and cancer control outcomes remains unclear. To fill this knowledge gap, we performed an observational cohort study of patients with head and neck cancer undergoing definitive chemoradiation with weekly cisplatin.

METHODS

Our institutional database was queried for patients with non-metastatic head and neck cancer who underwent definitive chemoradiation with weekly cisplatin (40 mg/m2) between November 2007 and April 2023. Adherence to weekly cisplatin was defined as receiving at least 5 cycles with a total cumulative dose of 200 mg/m2. Survival outcomes were evaluated using Kaplan-Meier method, log-rank tests, Cox proportional hazard multivariable (MVA) analyses. Logistic MVA was performed to identify variables associated with low adherence to weekly cisplatin. Fine-Gray MVA was performed to analyze failure outcomes with death as a competing event.

RESULTS

Among 119 patients who met our criteria, 51 patients (42.9%) had low adherence to weekly cisplatin. Median follow up was 19.8 months (interquartile range 8.8-65.6). Low adherence to weekly cisplatin was associated with worse overall survival (adjusted hazards ratio [aHR] 2.94, 95% confidence interval [CI] 1.58-5.47, p < 0.001) and progression-free survival (aHR 2.32, 95% CI 1.29-4.17, p = 0.005). It was also associated with worse distant failure (aHR 4.55, 95% CI 1.19-17.3, p = 0.03), but not locoregional failure (aHR 1.61, 95% CI 0.46-5.58, p = 0.46). KPS < 90 was the only variable associated with low adherence to weekly cisplatin (adjusted odds ratio [aOR] 2.67, 95% CI 1.10-6.65, p = 0.03).

CONCLUSION

Our study suggested that over 40% of patients underwent fewer than 5 weekly cisplatin cycles and that low adherence to weekly cisplatin was an independent, adverse prognostic factor for worse survival and distant failure outcomes. Those with reduced adherence to weekly cisplatin were more likely to have poor performance status. Further studies are warranted to improve the adherence to chemotherapy and outcomes.

Modelling the lymphatic metastatic progression pathways of OPSCC from multi-institutional datasets

The elective clinical target volume (CTV-N) in oropharyngeal squamous cell carcinoma (OPSCC) is currently based mostly on the prevalence of lymph node metastases in different lymph node levels (LNLs) for a given primary tumor location. We present a probabilistic model for ipsilateral lymphatic spread that can quantify the microscopic nodal involvement risk based on an individual patient's T-category and clinical involvement of LNLs at diagnosis. We extend a previously published hidden Markov model (HMM), which models the LNLs (I, II, III, IV, V, and VII) as hidden binary random variables (RVs). Each represents a patient's true state of lymphatic involvement. Clinical involvement at diagnosis represents the observed binary RVs linked to the true state via sensitivity and specificity. The primary tumor and the hidden RVs are connected in a graph. Each edge represents the conditional probability of metastatic spread per abstract time-step, given disease at the edge's starting node. To learn these probabilities, we draw Markov chain Monte Carlo samples from the likelihood of a dataset (686 OPSCC patients) from three institutions. We compute the model evidence using thermodynamic integration for different graphs to determine which describes the data best.The graph maximizing the model evidence connects the tumor to each LNL and the LNLs I through V in order. It predicts the risk of occult disease in level IV is below 5% if level III is clinically negative, and that the risk of occult disease in level V is below 5% except for advanced T-category (T3 and T4) patients with clinical involvement of levels II, III, and IV. The provided statistical model of nodal involvement in OPSCC patients trained on multi-institutional data may guide the design of clinical trials on volume-deescalated treatment of OPSCC and contribute to more personal guidelines on elective nodal treatment.

Adenoid Cystic carcinoma of minor salivary glands (AdCCmSG): a multidisciplinary update

INTRODUCTION

Adenoid cystic carcinoma of minor salivary glands (AdCCmSG) represents a 'rarity in the rarity,' posing a clinical challenge in lack of standardized, evidence-based recommendations. At present, AdCCmSG management is mostly translated from major salivary gland cancers (MSGCs). Ideally, AdCCmSG diagnostic-therapeutic workup should be discussed and carried out within a multidisciplinary, high-expertise setting, including pathologists, surgeons, radiation oncologists and medical oncologists.

AREAS COVERED

The present review provides an overview of epidemiology and pathologic classification. Moreover, the most recent, clinically relevant updates in the treatment of AdCCmSG (Pubmed searches, specific guidelines) are critically discussed, aiming to a better understanding of this rare pathologic entity, potentially optimizing the care process, and offering a starting point for reflection on future therapeutic developments.

EXPERT OPINION

The management of rare cancers is often hindered by limited data and clinical trials, lack of evidence-based guidelines, and hardly represented disease heterogeneity, which cannot be successfully tackled with a 'one-size-fits-all' approach. Our goal is to address these potential pitfalls, providing an easy-to-use, updated, multidisciplinary collection of expert opinions concerning AdCCmSG management as of today's clinical practice. We will also cover the most promising future perspectives, based on the potential therapeutic targets highlighted within AdCCmSG's molecular background.

Can dysphagia aspiration related structures (DARS) be spared in patients with oropharyngeal cancers? Dosimetric evaluation in a prospective study of DARS optimized intensity modulated radiation therapy

PURPOSE

To evaluate the feasibility of sparing the dysphagia-aspiration-related structures (DARS) in various head and neck cancer sites treated with definitive DARS-optimized intensity modulated radiation therapy (IMRT) and concurrent chemotherapy.

MATERIALS AND METHODS

Target volumes, organs at risk, and in addition, individual DARS were delineated, including the superior, middle, and inferior pharyngeal constrictor muscles, supraglottic and glottic larynx, the base of the tongue, esophageal inlet muscles and cervical esophagus in 35 patients with head and neck squamous cell carcinoma. Volume-based dose constraints were applied to the DARS outside the planning target volume (PTV). An IMRT plan was then generated to limit doses to DARS without compromising PTV dose coverage.

RESULTS

Twelve (34.3%) patients had an oropharyngeal primary (OPX), 18 (51.4%) had a laryngeal, and 5 (14.3%) patients had hypopharyngeal primary. The mean dose to the DARS was 47.93 Gy for the entire group, while it was 54.6 Gy in oropharyngeal primaries and 44.4 Gy in laryngopharyngeal primaries. DARS mean dose of ≤45 Gy could be achieved in a significantly lesser number of patients with oropharyngeal primaries (P < 0.02). Similarly, DARS mean dose was 42.25 Gy in patients with N0 disease, 49.6 Gy with ipsilateral involved nodes, and 55 Gy with bilateral disease. Sparing of DARS was feasible when the volume of PTV was ≤150 cc (P < 0.025).

CONCLUSION

Sparing of DARS structures appears to be challenging in patients with oropharyngeal cancers without compromising the dose to the PTVs while it is feasible in laryngopharyngeal cancers. DARS sparing is feasible when the PTV volume is < 150 cc and in patients with negative or unilateral nodal disease.

Comparison of 3-year local control using DAHANCA radiotherapy guidelines before and after implementation of five millimetres geometrical GTV to high-dose CTV margin

INTRODUCTION

Treatment planning using a five-millimetre geometrical margin from GTV to high-dose CTV (CTV1) has been used in DAHANCA treatment centres since 2013. We aimed to evaluate changes in CTV1 volumes, local control (LC), and recurrence pattern after the implementation of five-millimetre geometrical margins nationally.

MATERIALS AND METHODS

1,948 patients with pharyngeal, and laryngeal squamous cell carcinomas completed definitive IMRT-based treatment in 2010-2012 and 2013-2015 in three centres. The patient-specific margin was calculated as median surface distance from primary tumour GTV (GTV-T) to CTV1. Radiologically verified local recurrences were analysed using a centre of mass (COM) of the delineated recurrence volume, measuring the shortest distance between COM to GTV-T and CTV1 boundaries.

RESULTS

Median GTV-CTV1 was 0.9 (0.0-0.97) and 0.47 cm (0.4-0.5) for 2010-2012 and 2013-2015, respectively. Median CTV1 changed in three centres from 76, 28, 42 cm3 to 61, 53, 62 cm3 for 2010-2012 and 2013-2015, respectively. Local failures occurred at 247 patients during first three years after radiotherapy. The 3-year LC rate for 2010-2012 and 2013-2015 was 0.84 and 0.87 (p = 0.06). Out of 146 radiology-verified analysable local recurrences, 102 (69.9%) were inside the CTV1. In 74.6% and 91% of cases, the LRs were covered by 95% isodose in 2010-2012 and 2013-2015, respectively.

CONCLUSION

DAHANCA radiotherapy guidelines based on a geometrically generated isotropic CTV1 margin led to less variation in treatment volumes and between centres than previous guidelines. The transition towards consensus GTV-CTV1 margins did not influence local tumour control. The majority of local recurrences were inside CTV1 and covered by the prescription dose.

Individualized 3D-printed applicators for magnetic resonance imaging-guided brachytherapy in nasal vestibule cancer

Background and purpose

Brachytherapy is treatment of choice for early stage nasal vestibule cancer. Over the years improvements were achieved by means of image guided target definition, interstitial implant techniques and also individual mold techniques. The aim of this study was to improve the technique of the implant so that the need for interstitial catheters can be limited by making use of patient individualized 3D-printed applicators.

Materials and Methods

In 19 patients 3D-printed applicators were used to deliver pulse dose rate (PDR) brachytherapy. All patients underwent computed tomography (CT) and magnetic resonance imaging (MRI). A pre-plan with tumor delineation and manually optimized catheter positions to achieve tumor coverage was made. Based on the pre-plan a 3D-printed applicator was manufactured. Dose was evaluated by several indices: Conformity Index, Healthy Tissues Conformity Index, Dose Homogeneity Index, Dose non-uniformity ratio, Conformal index and high dose (HD) index.

Results

A high target coverage was achieved, with a median V100%CTV of 99.1 % (range, 81.8-100 %) and median CI of 0.99 (range, 0.82-1.00), as well as a median V0.7GyGTV of 100 % (range, 93.0-100 %). The median HD was 0.39 (range, 0.20-0.83). Interstitial catheters were needed in 12 patients. None of the patients developed grade ≥ II toxicity within the median follow up of 18 months.

Conclusions

This study shows that using 3D-printed applicators limits the need for interstitial catheters and also limits the high doses in normal tissue.

Organs-at-risk dose and normal tissue complication probability with dynamic trajectory radiotherapy (DTRT) for head and neck cancer

We compared dynamic trajectory radiotherapy (DTRT) to state-of-the-art volumetric modulated arc therapy (VMAT) for 46 head and neck cancer cases. DTRT had lower dose to salivary glands and swallowing structure, resulting in lower predicted xerostomia and dysphagia compared to VMAT. DTRT is deliverable on C-arm linacs with high dosimetric accuracy.

Reducing Salivary Toxicity with Adaptive Radiotherapy (ReSTART): A Randomized Controlled Trial Comparing Conventional IMRT to Adaptive IMRT in Head and Neck Squamous Cell Carcinomas

BACKGROUND

The utility of Adaptive Radiotherapy (ART) in Head and Neck Squamous Cell Carcinoma (HNSCC) remains to be ascertained. While multiple retrospective and single-arm prospective studies have demonstrated its efficacy in decreasing parotid doses and reducing xerostomia, adequate randomized evidence is lacking.

METHODS AND ANALYSIS

ReSTART (Reducing Salivary Toxicity with Adaptive Radiotherapy) is an ongoing phase III randomized trial of patients with previously untreated, locally advanced HNSCC of the oropharynx, larynx, and hypopharynx. Patients are randomized in a 1:1 ratio to the standard Intensity Modulated Radiotherapy (IMRT) arm {Planning Target Volume (PTV) margin 5 mm} vs. Adaptive Radiotherapy arm (standard IMRT with a PTV margin 3 mm, two planned adaptive planning at 10th and 20th fractions). The stratification factors include the primary site and nodal stage. The RT dose prescribed is 66Gy in 30 fractions for high-risk PTV and 54Gy in 30 fractions for low-risk PTV over six weeks, along with concurrent chemotherapy. The primary endpoint is to compare salivary toxicity between arms using salivary scintigraphy 12 months' post-radiation. To detect a 25% improvement in the primary endpoint at 12 months in the ART arm with a two-sided 5% alpha value and a power of 80% (and 10% attrition ratio), a sample size of 130 patients is required (65 patients in each arm). The secondary endpoints include acute and late toxicities, locoregional control, disease-free survival, overall survival, quality of life, and xerostomia scores between the two arms.

DISCUSSION

The ReSTART trial aims to answer an important question in Radiation Therapy for HNSCC, particularly in a resource-limited setting. The uniqueness of this trial, compared to other ongoing randomized trials, includes the PTV margins and the xerostomia assessment by scintigraphy at 12 months as the primary endpoint.

Determining the library size for the optimal output plan in the RapidPlan knowledge-based planning system using multicriteria optimization

OBJECTIVES

The aim of this study was to determine the number of trade-off explored (TO) library plans required for building a RapidPlan (RP) library that would generate the optimal clinical treatment plan.

METHODS

We developed 2 RP models, 1 each for the 2 clinical sites, head and neck (HN) and cervix. The models were created using 100 plans and were validated using 70 plans (VP) for each site respectively. Each of the 2 libraries comprising 100 TO plans was divided into 5 different subsets of library plans comprising 20, 40, 60, 80, and 100 plans, leading to 5 different RP models for each site. For every validation patient, a TO plan (TO_VP) was created. For every patient, 5 RP plans were automatically generated using RP models. The dosimetric parameters of the 6 plans (TO_VP + 5 RP plans) were compared using Pearson correlation and Greenhouse-Geisser analysis.

RESULTS

Planning target volume (PTV) dose volume parameters PTVD95% in 6 competing plans varied between 97.6 ± 0.7% and 98.1 ± 0.6% in HN cases and 98.8 ± 0.3% and 99.0 ± 0.4% in cervix cases. Overall, for both sites, the mean variations in organ at risk (OAR) doses or volumes were within 50 cGy, 0.5%, and 0.2 cc between library plans, and if TO_VP was included the variations deteriorated to 180 cGy, 0.4%, and 15 cc. All OARs in both sites, except D0.1 ccspine, showed a statistically insignificant variation between all plans.

CONCLUSIONS

Dosimetric variation among various output plans generated from 5 RP libraries is minimal and clinically insignificant. The optimal output plan can be derived from the least-weighted library consisting of 20 plans.

ADVANCES IN KNOWLEDGE

This article shows that, when the constituent plans are subjected to trade-off exploration, the number of constituent plans for a knowledge-based planning module is not relevant in terms of its dosimetric output.

Neurological complications of modern radiotherapy for head and neck cancer

Radiotherapy is one of the mainstay treatment modalities for the management of non-metastatic head and neck cancer (HNC). Notable improvements in treatment outcomes have been observed in the recent decades. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and charged particle therapy, have significantly improved tumor target conformity and enabled better preservation of normal structures. However, because of the intricate anatomy of the head and neck region, multiple critical neurological structures such as the brain, brainstem, spinal cord, cranial nerves, nerve plexuses, autonomic pathways, brain vasculature, and neurosensory organs, are variably irradiated during treatment, particularly when tumor targets are in close proximity. Consequently, a diverse spectrum of late neurological sequelae may manifest in HNC survivors. These neurological complications commonly result in irreversible symptoms, impair patients' quality of life, and contribute to a substantial proportion of non-cancer deaths. Although the relationship between radiation dose and toxicity has not been fully elucidated for all complications, appropriate application of dosimetric constraints during radiotherapy planning may reduce their incidence. Vigilant surveillance during the course of survivorship also enables early detection and intervention. This article endeavors to provide a comprehensive review of the various neurological complications of modern radiotherapy for HNC, summarize the current incidence data, discuss methods to minimize their risks during radiotherapy planning, and highlight potential strategies for managing these debilitating toxicities.

NRG Oncology Assessment of Artificial Intelligence Deep Learning-Based Auto-segmentation for Radiation Therapy: Current Developments, Clinical Considerations, and Future Directions

Deep learning neural networks (DLNN) in Artificial intelligence (AI) have been extensively explored for automatic segmentation in radiotherapy (RT). In contrast to traditional model-based methods, data-driven AI-based models for auto-segmentation have shown high accuracy in early studies in research settings and controlled environment (single institution). Vendor-provided commercial AI models are made available as part of the integrated treatment planning system (TPS) or as a stand-alone tool that provides streamlined workflow interacting with the main TPS. These commercial tools have drawn clinics' attention thanks to their significant benefit in reducing the workload from manual contouring and shortening the duration of treatment planning. However, challenges occur when applying these commercial AI-based segmentation models to diverse clinical scenarios, particularly in uncontrolled environments. Contouring nomenclature and guideline standardization has been the main task undertaken by the NRG Oncology. AI auto-segmentation holds the potential clinical trial participants to reduce interobserver variations, nomenclature non-compliance, and contouring guideline deviations. Meanwhile, trial reviewers could use AI tools to verify contour accuracy and compliance of those submitted datasets. In recognizing the growing clinical utilization and potential of these commercial AI auto-segmentation tools, NRG Oncology has formed a working group to evaluate the clinical utilization and potential of commercial AI auto-segmentation tools. The group will assess in-house and commercially available AI models, evaluation metrics, clinical challenges, and limitations, as well as future developments in addressing these challenges. General recommendations are made in terms of the implementation of these commercial AI models, as well as precautions in recognizing the challenges and limitations.

Systematic Implementation of Effective Quality Assurance Processes for the Assessment of Radiation Target Volumes in Head and Neck Cancer

PURPOSE

Significant heterogeneity exists in clinical quality assurance (QA) practices within radiation oncology departments, with most chart rounds lacking prospective peer-reviewed contour evaluation. This has the potential to significantly affect patient outcomes, particularly for head and neck cancers (HNC) given the large variance in target volume delineation. With this understanding, we incorporated a prospective systematic peer contour-review process into our workflow for all patients with HNC. This study aims to assess the effectiveness of implementing prospective peer review into practice for our National Cancer Institute Designated Cancer Center and to report factors associated with contour modifications.

METHODS AND MATERIALS

Starting in November 2020, our department adopted a systematic QA process with real-time metrics, in which contours for all patients with HNC treated with radiation therapy were prospectively peer reviewed and graded. Contours were graded with green (unnecessary), yellow (minor), or red (major) colors based on the degree of peer-recommended modifications. Contours from November 2020 through September 2021 were included for analysis.

RESULTS

Three hundred sixty contours were included. Contour grades were made up of 89.7% green, 8.9% yellow, and 1.4% red grades. Physicians with >12 months of clinical experience were less likely to have contour changes requested than those with <12 months (8.3% vs 40.9%; P < .001). Contour grades were significantly associated with physician case load, with physicians presenting more than the median number of 50 cases having significantly less modifications requested than those presenting <50 (6.7% vs 13.3%; P = .013). Physicians working with a resident or fellow were less likely to have contour changes requested than those without a trainee (5.2% vs 12.6%; P = .039). Frequency of major modification requests significantly decreased over time after adoption of prospective peer contour review, with no red grades occurring >6 months after adoption.

CONCLUSIONS

This study highlights the importance of prospective peer contour-review implementation into systematic clinical QA processes for HNC. Physician experience proved to be the highest predictor of approved contours. A growth curve was demonstrated, with major modifications declining after prospective contour review implementation. Even within a high-volume academic practice with subspecialist attendings, >10% of patients had contour changes made as a direct result of prospective peer review.

The role of the soft palate dose regarding normal tissue toxicities in older adults with head and neck cancer undergoing definitive radiotherapy

PURPOSE

The number of older adults with head and neck squamous cell carcinoma (HNSCC) is continuously increasing. Older HNSCC patients may be more vulnerable to radiotherapy-related toxicities, so that extrapolation of available normal tissue complication probability (NTCP) models to this population may not be appropriate. Hence, we aimed to investigate the correlation between organ at risk (OAR) doses and chronic toxicities in older patients with HNSCC undergoing definitive radiotherapy.

METHODS

Patients treated with definitive radiotherapy, either alone or with concomitant systemic treatment, between 2009 and 2019 in a large tertiary cancer center were eligible for this analysis. OARs were contoured based on international consensus guidelines, and EQD2 doses using α/ß values of 3 Gy for late effects were calculated based on the radiation treatment plans. Treatment-related toxicities were graded according to Common Terminology Criteria for Adverse Events version 5.0. Logistic regression analyses were carried out, and NTCP models were developed and internally validated using the bootstrapping method.

RESULTS

A total of 180 patients with a median age of 73 years fulfilled the inclusion criteria and were analyzed. Seventy-three patients developed chronic moderate xerostomia (grade 2), 34 moderate dysgeusia (grade 2), and 59 moderate-to-severe (grade 2-3) dysphagia after definitive radiotherapy. The soft palate dose was significantly associated with all analyzed toxicities (xerostomia: OR = 1.028, dysgeusia: OR = 1.022, dysphagia: OR = 1.027) in the multivariable regression. The superior pharyngeal constrictor muscle was also significantly related to chronic dysphagia (OR = 1.030). Consecutively developed and internally validated NTCP models were predictive for the analyzed toxicities (optimism-corrected AUCs after bootstrapping: AUCxerostomia=0.64, AUCdysgeusia=0.60, AUCdysphagia=0.64).

CONCLUSIONS

Our data suggest that the dose to the soft palate is associated with chronic moderate xerostomia, moderate dysgeusia and moderate-to-severe dysphagia in older HNSCC patients undergoing definitive radiotherapy. If validated in external studies, efforts should be undertaken to reduce the soft palate dose in these patients.

Streptococcus salivarius K12 Alleviates Oral Mucositis in Patients Undergoing Radiotherapy for Malignant Head and Neck Tumors: A Randomized Controlled Trial

PURPOSE

Oral mucositis (OM) is a common debilitating toxicity associated with radiotherapy (RT) for malignant head and neck tumors. This prospective, randomized, double-blind, placebo-controlled trial aimed to evaluate the efficacy and safety of Streptococcus salivarius K12 (SsK12) in reducing the incidence, duration, and severity of severe OM (SOM).

METHODS

A total of 160 patients with malignant head and neck tumors undergoing definitive or postoperative adjuvant RT were randomly assigned (1:1) to receive SsK12 probiotic (n = 80) or placebo (n = 80) at West China Hospital, Sichuan University, Chengdu, China. Patients were instructed to suck SsK12 or placebo lozenges thrice daily from the initiation to the end of RT. OM was evaluated twice a week during RT and once a week thereafter for up to 8 weeks. The primary end point was the incidence of SOM. Adverse events were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0.

RESULTS

Baseline patient characteristics were similar in the SsK12 and placebo groups. The incidence of SOM was significantly lower in the SsK12 group as compared with the placebo group (36.6% v 54.2%; P = .0351). The duration (median, 0.0 days v 7.0 days; mean, 8.9 days v 18.3 days; P = .0084) and time to develop SOM (median, not estimable v 42.0 days; hazard ratio, 0.55 [95% CI, 0.34 to 0.89]; log-rank test: P = .0123) were also improved in the case of the SsK12 group. Adverse events were similar between the groups, and mild or moderate gastrointestinal reactions (flatulence or dyspepsia) associated with the lozenges were observed in two patients in the SsK12 group. High-throughput sequencing results indicated that SsK12 inhibited opportunistic pathogens and enriched oral commensals during RT.

CONCLUSION

In this prospective, randomized clinical trial, SsK12 probiotic significantly reduced the incidence, onset, and duration of SOM with a good safety profile.

Intensity-Modulated Radiation Therapy Alone Versus Intensity-Modulated Radiation Therapy and Brachytherapy for Early-Stage Oropharyngeal Cancers: Results From a Randomized Controlled Trial

PURPOSE

The objective of this study was to compare clinical outcomes of intensity-modulated radiation therapy (IMRT) alone versus IMRT + brachytherapy (BT) in patients with T1-T2N0M0 oropharyngeal squamous cell cancers (OPSCC).

METHODS AND MATERIALS

This open-label randomized controlled trial was conducted at Tata Memorial Hospital, Mumbai, India. Patients with stage I and II OPSCC were considered for IMRT to a dose of 50 Gy/25 fractions/5 weeks in phase I followed by randomization (1:1) to further treatment with IMRT (20 Gy/10 fractions/2 weeks) or BT (192Ir high dose rate, 21 Gy/7 fractions/2 fractions per day). The primary endpoint of the trial was the reduction in xerostomia at 6 months evaluated using 99mTc salivary scintigraphy. Severe salivary toxicity (xerostomia) was defined as posttreatment salivary excretion fraction ratio <45%. Secondary endpoints were local control, disease-free survival, and overall survival.

RESULTS

Between November 2010 and February 2020, 90 patients were randomized to IMRT (n = 46) alone or IMRT + BT (n = 44). Eleven patients (8 residual/recurrent disease, 2 lost to follow-up, 1 second primary) in the IMRT arm and 9 patients (8 residual/recurrence, 1 lost to follow-up) in the BT arm were not evaluable at 6 months for the primary endpoint. At 6 months, xerostomia rates using salivary scintigraphy were 14% (5/35: 95% CI, 5%-30%) in the BT arm while it was seen in 44% (14/32: 95% CI, 26%-62%) in the IMRT arm (P = .008). Physician-rated Radiation Therapy Oncology Group grade ≥2 xerostomia at any time point was observed in 30% of patients (9/30) in the IMRT arm and 6.7% (2/30) in the BT arm (P = .02). At a median follow-up of 42.5 months, the 3-year local control in the IMRT arm was 56.4% (95% CI, 43%-73%) while it was 66.2% (95% CI, 53%-82%) in the BT arm (P = .24).

CONCLUSIONS

The addition of BT to IMRT for T1-T2N0M0 OPSCC results in a significant reduction in xerostomia. This strongly supports the addition of BT to IMRT in suitable cases.

A proposed framework for the implementation of head and neck cancer treatment at a new cancer center from a radiation oncology perspective

BACKGROUND

Establishing a new head and neck cancer (HNC) treatment center requires multidisciplinary team management and expertise. To our knowledge, there are no clear recommendations or guidelines in the literature for the commencement of HNC radiation therapy (RT) at a new cancer center. We propose a novel framework outlining the necessary components required to set-up a new radiation therapy HNC treatment.

METHODS

We reviewed the infrastructure and methodology in the commencement of HNC radiation therapy in our cancer care center and invited several external, experienced metropolitan head and neck radiation oncologists to develop a novel consensus guideline that may be used by new RT centers to treat HNC. Recommendations were presented to our internal and external staff specialists using a survey questionnaire with ratings utilized to determine consensus using pre-defined thresholds as per the American Society of Clinical Oncology Guidelines Methodology Manual.

CONCLUSION

This consensus recommendation aims to improve RT utilization whilst advocating for optimal patient outcomes by presenting a framework for new radiation therapy centers ready to step up and manage the treatment of head and neck cancer patients. We propose these evidence-based consensus guidelines endorsed by external HNC radiation oncologists.

Latin American Consensus on the Treatment of Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is well known as a serious health problem worldwide, especially in low-income countries or those with limited resources, such as most countries in Latin America. International guidelines cannot always be applied to a population from a large region with specific conditions. This study established a Latin American guideline for care of patients with head and neck cancer and presented evidence of HNSCC management considering availability and oncologic benefit. A panel composed of 41 head and neck cancer experts systematically worked according to a modified Delphi process on (1) document compilation of evidence-based answers to different questions contextualized by resource availability and oncologic benefit regarding Latin America (region of limited resources and/or without access to all necessary health care system infrastructure), (2) revision of the answers and the classification of levels of evidence and degrees of recommendations of all recommendations, (3) validation of the consensus through two rounds of online surveys, and (4) manuscript composition. The consensus consists of 12 sections: Head and neck cancer staging, Histopathologic evaluation of head and neck cancer, Head and neck surgery-oral cavity, Clinical oncology-oral cavity, Head and neck surgery-oropharynx, Clinical oncology-oropharynx, Head and neck surgery-larynx, Head and neck surgery-larynx/hypopharynx, Clinical oncology-larynx/hypopharynx, Clinical oncology-recurrent and metastatic head and neck cancer, Head and neck surgery-reconstruction and rehabilitation, and Radiation therapy. The present consensus established 48 recommendations on HNSCC patient care considering the availability of resources and focusing on oncologic benefit. These recommendations could also be used to formulate strategies in other regions like Latin America countries.

[Proposal for the delineation of postoperative primary clinical target volumes in maxillary sinus and nasal cavity cancers]

In this article, we propose a consensus delineation of postoperative clinical target volumes for the primary tumour in maxillary sinus and nasal cavity cancers. These guidelines are developed based on radioanatomy and the natural history of those cancers. They require the fusion of the planning CT with preoperative imaging for accurate positioning of the initial GTV and the combined use of the geometric and anatomical concepts for the delineation of clinical target volume for the primary tumour. This article does not discuss the indications of external radiotherapy (nor concurrent systemic treatment) but focuses on target volumes when there is an indication for radiotherapy.

Efficacy and safety of FDG-PET for determining target volume during intensity-modulated radiotherapy for head and neck cancer involving the oral level

PURPOSE

To determine the efficacy and safety of target volume determination by 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) for intensity-modulated radiation therapy (IMRT) for locally advanced head and neck squamous cell carcinoma (HNSCC) extending into the oral cavity or oropharynx.

METHODS

We prospectively treated 10 consecutive consenting patients with HNSCC using IMRT, with target volumes determined by PET-CT. Gross tumor volume (GTV) and clinical target volume (CTV) at the oral level were determined by two radiation oncologists for CT, magnetic resonance imaging (MRI), and PET-CT. Differences in target volume (GTVPET, GTVCT, GTVMRI, CTVPET, CTVCT, and CTVMRI) for each modality and the interobserver variability of the target volume were evaluated using the Dice similarity coefficient and Hausdorff distance. Clinical outcomes, including acute adverse events (AEs) and local control were evaluated.

RESULTS

The mean GTV was smallest for GTVPET, followed by GTVCT and GTVMRI. There was a significant difference between GTVPET and GTVMRI, but not between the other two groups. The interobserver variability of target volume with PET-CT was significantly less than that with CT or MRI for GTV and tended to be less for CTV, but there was no significant difference in CTV between the modalities. Grade ≤ 3 acute dermatitis, mucositis, and dysphagia occurred in 55%, 88%, and 22% of patients, respectively, but no grade 4 AEs were observed. There was no local recurrence at the oral level after a median follow-up period of 37 months (range, 15-55 months).

CONCLUSIONS

The results suggest that the target volume determined by PET-CT could safely reduce GTV size and interobserver variability in patients with locally advanced HNSCC extending into the oral cavity or oropharynx undergoing IMRT. Trial registration UMIN, UMIN000033007. Registered 16 jun 2018, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037631.

Differences in geometric patterns of failure in human papillomavirus (HPV)-associated and HPV-non-associated oropharyngeal cancer after definitive radiotherapy

INTRODUCTION

The aim of this study was to evaluate and compare the spatial pattern of locoregional recurrences in patients diagnosed with HPV-associated and HPV-non-associated oropharyngeal SCC (OPSCC) treated with definitive radiotherapy.

METHODS AND MATERIALS

Patients who had locoregional recurrence following definitive intensity-modulated radiation therapy were identified at a single tertiary institution. Target volumes were delineated according to the latest consensus international guidelines. Recurrences were classified into five categories based on radiotherapy dose distribution and target volume, using a previously validated methodology; type A (central high dose), type B (peripheral high dose), type C (central elective dose), type D (peripheral elective dose), and type E (extraneous dose). The types of failure were compared between p16-positive and p16-negative tumors using the Pearson chi-square test.

RESULTS

Fifty-eight locoregional recurrences were observed in 36 patients. The majority of recurrences were in nodal locations (66%, 38/58). Among these, 34 (59%) were classified as type A, 6 (10%) as type B, 9 (15%) as type C, 5 (9%) as type D, and 4 (7%) as type E failure. A significant difference was found in the types of failure between p16-positive and p16-negative tumors (X2 9.52, p = 0.044). p16-negative tumors were more likely to have recurrences in a peripheral location compared to p16-positive tumors (32% vs. 7%). p16-positive tumor were more likely to have extraneous recurrences (17% vs. 0%).

CONCLUSION

Our study results identified a significant difference in patterns of locoregional failure among patients diagnosed with oropharyngeal cancer following consensus-based tumor delineation and modern radiotherapy. Further confirmatory pattern of failure studies are required to enable greater individualization of radiotherapy for patients diagnosed with oropharyngeal malignancy in the future.

Clinical Outcomes of Curative Intent Radiotherapy by Helical Tomotherapy for Laryngeal Squamous Cell Carcinoma: A Retrospective Analysis in a Tertiary Referral Center

Background

The management of laryngeal cancer involves balancing curative treatment with preserving essential functions. This study aimed to evaluate the clinical outcomes of helical tomotherapy, an advanced form of radiation therapy, as a primary treatment modality for laryngeal squamous cell carcinoma (LSCC).

Methods

A retrospective analysis of data obtained from a tertiary referral center was performed to assess treatment response rates, survival outcomes, disease control, and treatment-related adverse events.

Results

The study included 45 patients with LSCC treated with helical tomotherapy between May 2015 and September 2022. The 5-year overall survival (OS) rate and disease-free survival (DFS) rate were 89.2% and 71.1%, respectively. Local control and laryngeal preservation rates at 5 years were 79.7% and 84.7%, respectively. Subgroup analysis revealed higher DFS rates in early-stage patients (84.2%) compared to advanced-stage patients (58.9%).

Conclusions

The results indicate that helical tomotherapy offers effective tumor control and potential for laryngeal preservation in LSCC. Further prospective studies and longer follow-up are needed to validate these findings and optimize treatment strategies for LSCC patients.

Segmentation of 71 Anatomical Structures Necessary for the Evaluation of Guideline-Conforming Clinical Target Volumes in Head and Neck Cancers

The delineation of the clinical target volumes (CTVs) for radiation therapy is time-consuming, requires intensive training and shows high inter-observer variability. Supervised deep-learning methods depend heavily on consistent training data; thus, State-of-the-Art research focuses on making CTV labels more homogeneous and strictly bounding them to current standards. International consensus expert guidelines standardize CTV delineation by conditioning the extension of the clinical target volume on the surrounding anatomical structures. Training strategies that directly follow the construction rules given in the expert guidelines or the possibility of quantifying the conformance of manually drawn contours to the guidelines are still missing. Seventy-one anatomical structures that are relevant to CTV delineation in head- and neck-cancer patients, according to the expert guidelines, were segmented on 104 computed tomography scans, to assess the possibility of automating their segmentation by State-of-the-Art deep learning methods. All 71 anatomical structures were subdivided into three subsets of non-overlapping structures, and a 3D nnU-Net model with five-fold cross-validation was trained for each subset, to automatically segment the structures on planning computed tomography scans. We report the DICE, Hausdorff distance and surface DICE for 71 + 5 anatomical structures, for most of which no previous segmentation accuracies have been reported. For those structures for which prediction values have been reported, our segmentation accuracy matched or exceeded the reported values. The predictions from our models were always better than those predicted by the TotalSegmentator. The sDICE with 2 mm margin was larger than 80% for almost all the structures. Individual structures with decreased segmentation accuracy are analyzed and discussed with respect to their impact on the CTV delineation following the expert guidelines. No deviation is expected to affect the rule-based automation of the CTV delineation.