Treatment Of Oropharyngeal Cancer Research Articles

Adaptive radiotherapy based on statistical process control for oropharyngeal cancer.

PurposeThe purpose of this study is to quantify dosimetric changes throughout the delivery of oropharyngeal cancer treatment and to investigate the application of statistical process control (SPC) for the management of significant deviations during the course of radiotherapy.MethodsThirteen oropharyngeal cancer patients with daily cone beam computed tomography (CBCT) were retrospectively reviewed. Cone beam computed tomography images of every other fraction were imported to the Velocity software and registered to planning CT using the 6 DOF (degrees of freedom) couch shifts generated during patient setup. Using Velocity “Adaptive Monitoring” module, the setup‐corrected CBCT was matched to planning CT using a deformable registration. Volumes and dose metrics at each fraction were calculated and rated with plan values to evaluate interfractional dosimetric variations using a SPC framework. T‐tests between plan and fraction volumes were performed to find statistically insignificant fractions. Average upper and lower process capacity limits (UCL, LCL) of each dose metric were derived from these fractions using conventional SPC guidelines.ResultsGross tumor volume (GTV) and organ at risk (OAR) volumes in the first 13 fractions had no significant changes from the pretreatment planning CT. The GTV and the parotid glands subsequently decreased by 10% at the completion of treatment. There were 3–4% increases in parotid mean doses, but no significant differences in dose metrics of GTV and other OARs. The changes were organ and patient dependent. Control charts for various dose metrics were generated to assess the metrics at each fraction for individual patient.ConclusionsDaily CBCT could be used to monitor dosimetric variations of targets and OARs resulting from volume changes and tissue deformation in oropharyngeal cancer radiotherapy. Treatment review with the guidance of a SPC tool allows for an objective and consistent clinical decision to apply adaptive radiotherapy.

A multicenter prospective phase II study of postoperative hypofractionated stereotactic body radiotherapy (SBRT) in the treatment of early-stage oropharyngeal and oral cavity cancers with high risk margins: the STEREO POSTOP GORTEC 2017-03 trial

BackgroundPrimary surgery is usually the mainstay treatment in early-stage oropharyngeal and oral cavity cancer. Typically, neck surgery is performed. Negative tumor margins are recommended (> 5 mm). If feasible, re-resection of any positive margin is preferred. Otherwise, postoperative radiotherapy is required. Adjuvant postoperative radiotherapy can be limited to the primary site for patients with pT1-T2 tumors and negative neck exploration. Currently, both fractionated external beam radiotherapy and brachytherapy can have a role in the postoperative management of early-stage oropharyngeal and oral cavity cancer with high risk margins. Another possible alternative could be postoperative stereotactic body radiotherapy (SBRT). The aim of this study is to evaluate postoperative SBRT in the treatment of early-stage oropharyngeal and oral cavity cancer with high risk margins.MethodsThe STEREO POSTOP study is a national, open-label, non-randomized phase II trial within the GORTEC network. Patients with early-stage oropharyngeal and oral cavity cancers with high risk margins indicating the need for postoperative radiation are eligible for enrollment. SBRT consists of a total dose of 36 Gy in 6 fractions over 2 weeks. The primary endpoint is severe late toxicity defined as 2-year toxicity of grade ≥ 3 according to CTCAE V4.03 classification. The secondary endpoints include acute toxicity (≤ 3 months), local and locoregional control, disease-free and overall survival, quality of life of patients, nutritional impact and predictive factors of toxicity. The experimental design chosen is a one-step Fleming plan design without interim analysis as the primary endpoint will be evaluated at a 2-year follow-up. Ninety patients will be recruited. The study was started in January 2018 with a 4-year enrollment period and an estimated completion in January 2024.DiscussionThis study is the first prospective trial to evaluate head and neck cancer postoperative SBRT in the setting of early-stage oropharyngeal and oral cavity cancers with high risk margins. SBRT is an attractive option because it delivers a highly conformal dose of radiation in a limited number of fractions (like brachytherapy but with less contraindication), with steep dose gradients resulting in reduced normal tissue irradiation and with a short overall treatment time.Trial registrationClinicaltrials.gov: NCT03401840, registered on 17-1-2018. Identifier in French National Agency for the Safety of Medicines and Health Products (ANSM): N°ID - RCB 2017-A02058–45, registered on July 2017.Protocol version: Version 3 dated from 25th November 2019.

Mechanisms of Impaired Swallowing on Thin Liquids Following Radiation Treatment for Oropharyngeal Cancer.

PurposeDysphagia is one of the most debilitating chronic symptoms experienced by patients who undergo radiation treatment for head and neck cancer. Despite the high prevalence of dysphagia in patients with head and neck cancer, we lack understanding of the specific changes in swallowing physiology that arise in the short-term following radiation therapy and how these changes impact the key functions of swallowing safety and efficiency. This study sought to identify pathophysiological mechanisms underlying impairments in swallowing safety and efficiency on thin liquids following (chemo)radiation for oropharyngeal cancer.MethodVideofluoroscopic swallowing studies were completed in 12 male patients within 6 months following completion of (chemo)radiation and in 12 healthy male controls. To compare swallowing function and physiology between groups, we analyzed three discrete sips of 20% w/v thin liquid barium per participant. The videofluoroscopic swallowing study recordings were rated for swallowing safety, efficiency, timing parameters, and pixel-based measures of structural area or movement.ResultsThe oropharyngeal cancer cohort displayed significantly higher frequencies of penetration–aspiration, incomplete laryngeal vestibule closure, prolonged time-to-laryngeal vestibule closure, and poor pharyngeal constriction. Incomplete or delayed laryngeal vestibule closure was associated with airway invasion, while poor pharyngeal constriction was associated with pharyngeal residue.ConclusionsThis study highlights the primary mechanisms behind impaired safety and efficiency of the swallow in patients following (chemo)radiation for oropharyngeal cancer.

Immunotherapy for cancer of the oral cavity and oropharynx. The use of monoclonal antibodies

The purpose is to review the literature and analyze the use of monoclonal antibodies in the treatment for cancer of the mouth and oropharynx.Conclusions. 1. Today, cetuximab is the only monoclonal antibody that has received FDA approval for the treatment for oral and oropharyngeal cancer. Clinically used for more than 10 years, and shows good results. 2. Clinical trials have confirmed the efficacy of moAbs targeting immune checkpoint receptors, including anti-CTLA-4 and anti-PD-1. Immune checkpoint blockade may improve the existing clinical effects of therapy on the background of low toxicity and may contribute to long-term effects through immunological memory. 3. The use of immune checkpoint inhibitors is currently only approved for advanced stages of cancer. 4. There is insufficient clinical data to demonstrate the feasibility of combining several different monoclonal antibody preparations and combining them with radiation therapy or chemotherapy.

Microbiology of wound infection after oral cancer surgery

IntroductionThe aim of present study is to investigate the most common infection pathogen found in the postoperative wounds, following surgical treatment of oral and oropharyngeal cancer, in order to identify the most suitable antibiotic treatment. Patients and methodsWe analyzed patients with squamous cell cancer of oral and oropharyngeal region. In patients who developed postoperative wound infection, wound swabs were taken from three different sites: the cannula, wounds on the neck and wounds in the oral cavity. ResultsIn total 195 patients were included. The postoperative wound infection was detected in 115 patients (59%). In average, the swabs were taken 8 days after the surgery. The similar bacterial species from all three sites were detected in 24 patients (12,3%). In comparison, we found that there was statistically significant difference in the bacteria abundance from all three sites (p=0,031). There were significantly more bacteria in the wounds of the neck than cannula (p=0,007) and in the wounds in the oral cavity than cannula (p=0,002). No statistically significant difference between the wound on the neck and in the oral cavity was found. The most frequently isolated bacterial family was Enterobacteriaceae. Other more commonly isolated bacteria species were Staphylococcus spp. (G+), Pseudomonas aeruginosa (G-), Corynebacteruim spp. (G +) and Acinetobacter baumanii (G-). ConclusionBased on the most commonly isolated groups of pathogens we concluded that probably the best empiric antibiotic treatment of wound infections until antibiogram is completed might be achieved from the group of aminoglycosides or quinolones. Antibiotic therapy should be reviewed if necessary when antibiogram is completed.

The investigation of salvage endoscopic laryngopharyngeal surgery after chemoradiotherapy.

IntroductionEndoscopic laryngopharyngeal surgery (ELPS) is an effective treatment for early-stage oropharyngeal and hypopharyngeal cancers. Since 2007, we have performed ELPS on 14 patients with early-stage cancer who had undergone radiation therapy (salvage ELPS). We discuss the beneficial effects and issues with salvage ELPS compared with those of fresh patients since we experienced some severe complications, such as ruptured pseudoaneurysm with salvage ELPS.AimTo our knowledge, the efficacy and safety of ELPS following radiation therapy have not yet been evaluated, and several unknown factors exist. An evaluation was performed for assessing whether ELPS following radiation therapy is safe, similar to findings in fresh cases previously reported by us, and whether this treatment method can be efficacious.Material and methodsWe studied the cases of 14 patients who had undergone salvage ELPS after radiation therapy for head and neck cancer at Akita University Hospital between 2007 and 2018.ResultsThe rate of recurrence of head and neck cancer at different sites after salvage ELPS was 48.9% at 2 years. Furthermore, deformation of the pharyngolarynx made it extremely difficult to perform surgery. We also experienced extremely severe complications of ruptured pseudoaneurysms.ConclusionsIf salvage ELPS is performed after radiation therapy, patients should be followed up on an outpatient basis to monitor the onset of subsequent cancers. Complications may become severe; therefore, postoperative management should be performed cautiously. In particular, vulnerable sites, such as the piriform sinus, may not be indicated for surgery. At this stage, the expectation is that patients need to be methodically selected.

Total glossectomy in multimodal treatment of oropharyngeal cancer: immediate results

The study objective is to analyze the results of combined antitumor therapy, which included glossectomy, to treat locally advanced and recurrent oropharyngeal squamous cell cancer.Materials and methods. We performed a retrospective analysis of multimodal antitumor therapy of 19 patients, who were treated in the Nizhny Novgorod Regional Clinical Oncologic Dispensary within 2009–2019. All patients underwent segmental resection of the mandible due to massive tumor invasion into the periosteum. After total glossectomy the defect was filled using pectoralis musculocutaneous flap. Due to the wide local tumor spread, a neck dissection (n = 7) or radical cervical lymphadenectomy (n = 12) were performed. During preventive surgery, metastases that were not detected before surgery were revealed in 2 patients in 1 neck lymph node. Results. Eleven patients had local purulent-necrotic postoperative complications. It was noted that after surgery but without radiation therapy complications developed in fewer patients (n = 4) and were less severe: of I degree – in 3 patients, of III degree – in 1 patient. Radiation therapy before surgery resulted in more severe purulent-necrotic complications in 7 patients: of I degree – in 2 patients, of II degree – in 1, of III degree – in 4. Mortality rates: 30-day, 60-day and 90-day – 10.5 %, 21 % and 37 %, respectively. The causes of death were complications of gastrostomy: profuse bleeding from the stomach wall (n = 1), acute psychosis complicated by cerebral edema (n = 1), increased heart failure (n = 1), necrosis of the anterior abdominal wall and cachexia, developed after gastrostomy (n = 1), continued tumor growth between chemotherapy courses (n = 3). Twelve patients survived more than 90 days after surgery, 3 patients – more than 2 years. As most of the patients could not swallow, they were administered a nasogastric tube, since a simultaneous gastrostomy increases the duration of a traumatic operation and aggravates the postoperative period.Conclusion. Multicomponent surgery after radiation therapy results in more often local purulent-necrotic postoperative complications than if the surgery is performed before radiation therapy. High mortality in the first 90 days after surgery (n = 7) due to local cancer spread is generally determined by the severe condition of patients with advanced cancer and the concomitant diseases. However, rejection of gastrostomy in favor of nasogastric tube seems reasonable, since several deaths in the early postoperative period may be occurred due to complications associated with gastrostomy.

Deintensification of treatment for human papillomavirus-related oropharyngeal cancer: Current state and future directions.

Human papillomavirus (HPV)-related oropharyngeal squamous cell cancer (OPSCC) has emerged as a distinct clinical entity of head and neck cancer with expected high survival. This recognition has led to the investigation of whether a population of patients can be identified who can safely undergo treatment de-escalation, in an effort to minimize long-term treatment toxicity while maintaining excellent survival. The purpose of this review is to describe the rationale for treatment deintensification for HPV-related OPSCC, summarize available results from published clinical trials, explore the methods by which risk groups are assigned, and provide context for the multitude of clinical trials that are currently underway.

HPV-Positive Oropharyngeal Cancer: The Nurse's Role in Patient Management of Treatment-Related Sequelae.

Patients diagnosed with oropharyngeal cancer (OPC) make up about 3% of all new cancer cases in the United States, with increasing numbers of these patients being diagnosed aged younger than 45 years and with human papillomavirus (HPV)-positive disease. Treatment effects may alter patients' physical and mental states during and after treatment. This article provides an overview of possible OPC treatment long-term effects to equip oncology nurses with information needed to empower patients with OPC to perform self-care. The OPC literature was reviewed to identify incidence, survival, risk factors, symptoms, treatment options, and treatment effects. This article provides a foundation for the plan of care for patients with OPC and strategies for patients to contribute to their self-care.

Comparative analysis of acute toxicities and patient reported outcomes between intensity-modulated proton therapy (IMPT) and volumetric modulated arc therapy (VMAT) for the treatment of oropharyngeal cancer

Background and purposeIMPT improves normal tissue sparing compared to VMAT in treating oropharyngeal cancer (OPC). Our aim was to assess if this translates into clinical benefits. Materials and methodsOPC patients treated with definitive or adjuvant IMPT or VMAT from 2013 to 2018 were included. All underwent prospective assessment using patient-reported-outcomes (PROs) (EORTC-QLQ-H&N35) and provider-assessed toxicities (CTCAEv4.03). End-of-treatment and pretreatment scores were compared. PEG-tube use, hospitalization, and narcotic use were retrospectively collected. Statistical analysis used the Wilcoxon Rank-Sum Test with propensity matching for PROs/provider-assessed toxicities, and t-tests for other clinical outcomes. Results46 IMPT and 259 VMAT patients were included; median follow-up was 12 months (IMPT) and 30 months (VMAT). Baseline characteristics were balanced except for age (p = 0.04, IMPT were older) and smoking (p < 0.01, 10.9% IMPT >20PYs, 29.3% VMAT). IMPT was associated with lower PEG placement (OR = 0.27; 95% CI: 0.12–0.59; p = 0.001) and less hospitalization ≤60 days post-RT (OR = 0.21; 95% CI:0.07–0.6, p < 0.001), with subgroup analysis revealing strongest benefits in patients treated definitively or with concomitant chemoradiotherapy (CRT). IMPT was associated with a relative risk reduction of 22.3% for end-of-treatment narcotic use. Patients reported reduced cough and dysgeusia with IMPT (p < 0.05); patients treated definitively or with CRT also reported feeling less ill, reduced feeding tube use, and better swallow. Provider-assessed toxicities demonstrated less pain and mucositis with IMPT, but more mucosal infection. ConclusionIMPT is associated with improved PROs, reduced PEG-tube placement, hospitalization, and narcotic requirements. Mucositis, dysphagia, and pain were decreased with IMPT. Benefits were predominantly seen in patients treated definitively or with CRT.

Systematic Review and Meta-analysis of Quality of Life Outcomes Based on Type of Treatment for HPV-associated Oropharyngeal Cancer

In the era of HPV-associated oropharyngeal cancer survival outcomes are generally good and functional outcomes after treatment are critical. The literature is limited with a paucity of randomized trials. In this study, we synthesize existing studies to examine the impact of treatment modality on functional outcomes in HPV-associated oropharyngeal cancer.

Functional results after soft palate reconstruction in oropharyngeal cancer patients

Surgery of the soft palate in patients with oropharyngeal cancer can result in functional deficiencies of swallowing and speech. Reconstruction of the resected structures can contribute to regaining sufficient functionality after therapy. The current study used frequency analysis to evaluate the change in speech characteristics after resection and reconstruction of the soft palate during post-therapeutic follow-up. In 18patients with oropharyngeal carcinoma and involvement of the soft palate, resection and reconstruction by free radial forearm graft (FRFG) and adjuvant chemoradiotherapy was conducted. The spoken German numbers "eins", "zwei", "drei", "vier", "fünf" were recorded during follow-up and objectively assessed by frequency analysis. Additionally, food intake status and the necessity of atracheostomy were evaluated. The maximum peak frequencies of the numbers analysed increased from 150-300 Hz before up to 1000 Hz after therapy. Two years post therapy, the peak frequencies again declined to levels comparable to those before tumour therapy. One year after therapy, complete oral nutrition was possible in two thirds of patients and the tracheostomy was closed in 80%. Reconstruction of the soft palate by FRFG during the course of oropharyngeal cancer treatment allows function to be regained with respect to speech and swallowing. In the majority of patients, it is possible to reach alevel of function comparable to the state before tumour treatment.

Immunotherapy for cancer of the oral cavity and oropharynx

Purpose: To review the scientific articles which cover types and methods of immunotherapy of patients with oral cancer and oropharynx. Analyze the research results in treatment of oral and oropharyngeal cancer using immunopreparations and their feasibility.Conclusions. 1. Immunomodulatory therapies that overcome immunosuppressive signals in patients with oral and oropharyngeal cancer are scientifically and therapeutically reasonable. 2. Immunological therapy has the potential to solve clinical problems in patients with oral and oropharynx cancer by combination with specific therapies. 3. The inclusion of immunotherapeutic drugs in the scheme of complex treatment of patients with oral and oropharynx cancer significantly improve survival rates.

Return to work after oropharyngeal cancer treatment—Highlighting a growing working‐age population

To describe the frequency of patients returning to work after treatment for oropharyngeal cancer and to identify predictors and physical barriers that might interfere with the return to work process. Cross-sectional study including 295 patients. Data were collected regarding work/sick leave situation at 1 month before diagnosis and 15 months after diagnosis. The situation before diagnosis was retrospectively recalled by the patients. Two subscales and two single items from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-H&N35 were used. Data were analyzed with multivariate logistic regression. Fifteen months after diagnosis, 212 patients (72%) were working. To be working 15 months after diagnosis was associated with working before diagnosis. Swallowing difficulties, problems talking on the telephone, and physical appearance were negatively associated with returning to work. The large number of individuals returning to work is encouraging for patients diagnosed with oropharyngeal cancer.

Современная концепция использования лучевой терапии при раке полости рта и орофарингеальной зоны

In the world, there is a rise of cancer incidence, including cancer of the head and neck. The incidence cancer of the head and neck is 4.8 cases per 100 000 population. Oral and oropharyngeal cancers are the most frequently forms cancer of the head and neck – 4,8–27 % of all cancer with this location. Among the causes of oral and oropharyngeal cancer noted alcohol abuse, tobacco and infection with human papilloma virus (HPV-16). Mortality from oral and oropharyngeal cancer is on 8 rank among patients with all tumors. Now when deciding about treatment of oral and oropharyngeal cancer is applied a new classification АJCC8th, the main differences from the previous version are the inclusion of data on the depth of tumor invasion and the presence of extranodal growth of lymphogenic metastasis.&#x0D; The chemoradiotherapy to a total dose 60–74 Gy is the most common treatment used in oral and oropharyngeal cancer. When planning irradiation, both the tumor itself (or its residual component) and lymphogenic metastases or lymph nodes with a high risk of metastatic lesions are included in the target volume. The most commonly used chemotherapy drug is cisplatin. The duration of life of patients is significantly influenced by the stage of the tumor process. So 5-year relapse-free survival among patients with oral cancer is 91 % at T1–2, 83 % – at T3 and 12 % – at T4. During the first 5 years after completion of treatment, the probability of locoregional recurrence in patients with oropharyngeal cancer is much shorter in infected HPV-16 – 28.9 % and 54.9 %, respectively. &#x0D; The effective multimodal treatment of oral and oropharyngeal cancer can be only if the evaluation of the tumor process under the current classification, comply with the requirements of treatment standards and clinical guidelines as well as take into account the latest achievements of the relevant field of medical science.

3D Exoscopic Surgery (3Des) for Transoral Oropharyngectomy.

Over the past three decades, the incidence of oropharyngeal squamous cell carcinoma has increased, primarily related to the spread of human papillomavirus. Treatment has always been preferentially unimodal (surgery or radiotherapy) for early stage disease and multimodal (surgery with adjuvant therapy or concomitant chemoradiotherapy) for advanced stages. Recently, the surgical approach has gained renewed interest due to the morbidity of non-surgical treatments and also to technical innovations. We have coined the term 3Des (3D exoscope surgery) to describe the use of the 3D Vitom Exoscope System for transoral surgery of oropharyngeal cancers. During the period from June 2017 to May 2018, 10 patients with oropharyngeal cancer were treated by oropharyngeal surgery with the 3Des approach at FPO IRCCS Institute of Candiolo. The aim of the present prospective study was to evaluate the utility of 3Des for the treatment of early-stage oropharyngeal cancer. 3Des could represent a viable alternative to the operating microscope and robotic surgery thanks to its excellent ability to provide 3D visual information, depth of field, magnification, image contrast, color imaging, and low running costs. It promises great utility in the learning process, with the possibility of recording in high definition.

Reduced radiation-induced toxicity by using proton therapy for the treatment of oropharyngeal cancer

Patients with squamous cell carcinoma of the oropharynx are generally treated with (chemo) radiation. Patients with oropharyngeal cancer have better survival than patients with squamous cell carcinoma of other head and neck subsites, especially when related to human papillomavirus. However, radiotherapy results in a substantial percentage of survivors suffering from significant treatment-related side-effects. Late radiation-induced side-effects are mostly irreversible and may even be progressive, and particularly xerostomia and dysphagia affect health-related quality of life. As the risk of radiation-induced side-effects highly depends on dose to healthy normal tissues, prevention of radiation-induced xerostomia and dysphagia and subsequent improvement of health-relatedquality of life can be obtained by applying proton therapy, which offers the opportunity to reduce the dose to both the salivary glands and anatomic structures involved in swallowing.This review describes the results of the first cohort studies demonstrating that proton therapy results in lower dose levels in multiple organs at risk, which translates into reduced acute toxicity (i.e. up to 3 months after radiotherapy), while preserving tumour control. Next to reducing mucositis, tube feeding, xerostomia and distortion of the sense of taste, protons can improve general well-being by decreasing fatigue and nausea. Proton therapy results in decreased rates of tube feeding dependency and severe weight loss up to 1 year after radiotherapy, and may decrease the risk of radionecrosis of the mandible. Also, the model-based approach for selecting patients for proton therapy in the Netherlands is described in this review and future perspectives are discussed.

Primary surgery for locoregional advanced oropharyngeal cancer: prognostic factors

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Oropharyngeal squamous cell carcinoma (OPSCC) incidence is rising in developed countries. These malignancies usually present in advanced stages and are associated with poor outcome. This work aims to ascertain the clinical and histopathological prognostic factors of locoregional advanced OPSCC treated with primary surgery in a tertiary oncology centre.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Retrospective chart review of all patients with advanced OPSCC who underwent primary surgery from 2011 to 2016. Overall and disease-free survivals were estimated using Kaplan-Meier method. Clinical and histopathological prognostic factors were determined by univariate (Log Rank tests) and multivariate (Cox models) analyses. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; 89 patients (89.9% male) with a mean age of 57.6±10.0 years were included in the study. Five-year overall and disease-free survivals were 53.9% and 57.7%, respectively. Pathologic N stage (HR=2.65 95% IC 1.32-5.32, p&amp;lt;0.01), distant metastasis (HR= 3.26 95% IC 1.24-8.62, p=0.01) and postoperative radiotherapy (HR=0.02 95% IC 0.01-0.12, p&amp;lt;0.01) were significantly correlated with overall survival. Pathologic N stage (HR=2.41, 95% IC 1.04-5.63, p=0.04) perineural infiltration (2.45, 95% IC 1.01-5.95 p=0.04), distant metastasis (HR=5.24, 95% IC 2.31-11.89, p&amp;lt;0.01) and postoperative radiotherapy (HR=0.02 95% IC 0.00-0.18, p&amp;lt;0.01), were significantly correlated with locoregional disease-free survival.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Knowledge of survival prognostic factors is crucial for selection of the appropriate treatment of oropharyngeal cancer. Pathological nodal stage, postoperative radiotherapy and the occurrence of distant metastasis were the main prognostic factors for overall and disease-free survivals in the present series. These findings may help to provide proper stratification in future randomized trials.&lt;/p&gt;

Knowledge-based automated planning with three-dimensional generative adversarial networks.

To develop a knowledge-based automated planning pipeline that generates treatment plans without feature engineering, using deep neural network architectures for predicting three-dimensional (3D) dose. Our knowledge-based automated planning (KBAP) pipeline consisted of a knowledge-based planning (KBP) method that predicts dose for a contoured computed tomography (CT) image followed by two optimization models that learn objective function weights and generate fluence-based plans, respectively. We developed a novel generative adversarial network (GAN)-based KBP approach, a 3D GAN model, which predicts dose for the full 3D CT image at once and accounts for correlations between adjacent CT slices. Baseline comparisons were made against two state-of-the-art deep learning-based KBP methods from the literature. We also developed an additional benchmark, a two-dimensional (2D) GAN model which predicts dose to each axial slice independently. For all models, we investigated the impact of multiplicatively scaling the predictions before optimization, such that the predicted dose distributions achieved all target clinical criteria. Each KBP model was trained on 130 previously delivered oropharyngeal treatment plans. Performance was tested on 87 out-of-sample previously delivered treatment plans. All KBAP plans were evaluated using clinical planning criteria and compared to their corresponding clinical plans. KBP prediction quality was assessed using dose-volume histogram (DVH) differences from the corresponding clinical plans. The best performing KBAP plans were generated using predictions from the 3D GAN model that were multiplicatively scaled. These plans satisfied 77% of all clinical criteria, compared to the clinical plans, which satisfied 67% of all criteria. In general, multiplicatively scaling predictions prior to optimization increased the fraction of clinical criteria satisfaction by 11% relative to the plans generated with nonscaled predictions. Additionally, these KBAP plans satisfied the same criteria as the clinical plans 84% and 8% more frequently as compared to the two benchmark methods, respectively. We developed the first knowledge-based automated planning framework using a 3D generative adversarial network for prediction. Our results, based on 217 oropharyngeal cancer treatment plans, demonstrated superior performance in satisfying clinical criteria and generated more realistic plans as compared to the previous state-of-the-art approaches.

Stability analysis of CT radiomic features with respect to segmentation variation in oropharyngeal cancer

IntroductionAccurate segmentation of tumors and quantification of tumor features are important for cancer detection, diagnosis, monitoring, and planning therapeutic intervention. Due to inherent noise components in multi-parametric imaging and inter-observer and intra-observer variations, it is common that various segmentation methods may produce large segmentation errors in tumor volumes and their associated radiomic features. The purpose of this study is to carry out the stability analysis for radiomic features with respect to segmentation variation in oropharyngeal cancer (OPC). MethodsIn this study, 436 contrast-enhanced computed tomography (CT) axial images were collected from patients with OPC. In order to derive various segmentations of tumor volumes, two additional segmentations were obtained via resizing the original segmented regions of interest (ROIs) based on their geometric information on the boundary. For three ROI image groups, we calculated 109 radiomic features. Then, a logistic regression model was built to investigate the correlation between the radiomic features extracted from GTVp and the response to chemotherapy and radiation in terms of overall survival (OS). Finally, in order to evaluate the stability of each feature with respect to segmentation results, based on the prediction probabilities, we assessed the inter-rater reliability and reproducibility by calculating the intra-class correlation coefficients (ICC) and concordance correlation coefficients (CCC). ResultsMost radiomic features in this study varied a lot when the ROIs were not well segmented. For both the representation agreement and predictive agreement, the ICC and CCC were below 0.5 for all the features. We still found some robust features with relatively high ICC and CCC compared to most features. For example, 25percentile (ICC = 0.38, CCC = 0.37 in representation agreement and ICC = CCC = 0.27 in predictive agreement) is a quantile based feature, which is robust to the extremely high or low values; and Hu_1_std (ICC = 0.31, CCC = 0.31 in representation agreement) is a feature calculated based on the first Hu moment, which is invariant to the transformation of ROIs. ConclusionIn OPC studies, the tumor segmentation variation affects the radiomic features from CT images in terms of both representation and prediction. Some features that are robust to the extreme values or invariant to the transformation of ROIs may be treated as radiomic markers to assist with OPC treatment monitoring and prognostic prediction.