The Effect of Radiation and Chemoradiation Therapy on the Head and Neck Mucosal Microbiome: A Review.

Radiation (RT) and chemoradiation therapy (CRT) play an essential role in head and neck cancer treatment. However, both cause numerous side effects in the oral cavity, paranasal sinuses, and pharynx, having deleterious consequences on patients' quality of life. Concomitant with significant advances in radiation oncology, much attention has turned to understanding the role of the microbiome in the pathogenesis of treatment-induced tissue toxicity, to ultimately explore microbiome manipulation as a therapeutic intervention. This review sought to discuss current publications investigating the impact of RT and CRT-induced changes on the head and neck microbiome, using culture-independent molecular methods, and propose opportunities for future directions. Based on 13 studies derived from a MEDLINE, EMBASE, and Web of Science search on November 7, 2021, use of molecular methods has uncovered various phyla and genera in the head and neck microbiome, particularly the oral microbiome, not previously known using culture-based methods. However, limited research has investigated the impact of RT/CRT on subsites other than the oral cavity and none of the studies aimed to examine the relationship between the head and neck microbiome and treatment effectiveness. Findings from this review provide helpful insights on our current understanding of treatment-induced oral mucositis, dental plaque, and caries formation and highlight the need for future research to examine the effect of RT/CRT on the sinonasal and oropharyngeal microbiome. In addition, future research should use larger cohorts, examine the impact of the microbiome on treatment response, and study the effect of manipulating the microbiome to overcome therapy resistance.

Radiomics strategies for risk assessment of tumour failure in head-and-neck cancer.

Quantitative extraction of high-dimensional mineable data from medical images is a process known as radiomics. Radiomics is foreseen as an essential prognostic tool for cancer risk assessment and the quantification of intratumoural heterogeneity. In this work, 1615 radiomic features (quantifying tumour image intensity, shape, texture) extracted from pre-treatment FDG-PET and CT images of 300 patients from four different cohorts were analyzed for the risk assessment of locoregional recurrences (LR) and distant metastases (DM) in head-and-neck cancer. Prediction models combining radiomic and clinical variables were constructed via random forests and imbalance-adjustment strategies using two of the four cohorts. Independent validation of the prediction and prognostic performance of the models was carried out on the other two cohorts (LR: AUC = 0.69 and CI = 0.67; DM: AUC = 0.86 and CI = 0.88). Furthermore, the results obtained via Kaplan-Meier analysis demonstrated the potential of radiomics for assessing the risk of specific tumour outcomes using multiple stratification groups. This could have important clinical impact, notably by allowing for a better personalization of chemo-radiation treatments for head-and-neck cancer patients from different risk groups.

Palliative Radiation Therapy for Advanced Head and Neck Carcinomas: A Phase 2 Study.

PURPOSE: Incurable head and neck cancer is hard to manage with usual palliative care. Radiation therapy (RT) in this setting is sometimes omitted because there is an apprehension that the side effects in the head and neck region might counterbalance the benefits. The objective of this phase 2 study was to evaluate whether highly conformal RT could improve the therapeutic ratio with this comprehensive Quality of Life (QOL) and toxicity evaluation. METHODS AND MATERIALS: Patients from 2 academic centers, deemed unfit for radical treatment because of their poor medical condition or advanced cancer stage by an experienced tumor board, were offered 25 Gy in 5 daily intensity modulated RT fractions over 1 week to the symptomatic tumor volume. QOL was evaluated with the European Organization for Research and Treatment of Cancer QLQ-C15-PAL and QLQ-H&N35 questionnaires, and toxicities with the Common Terminology Criteria for Adverse Events version 4.0. Survival and time to tumor progression were calculated with the Kaplan-Meier method. RESULTS: Thirty-two patients were recruited, of whom 66% had at least T4, N3, or M1 disease. The QOL questionnaires completion rate was 86%. Eighty-eight percent of patients received the planned dose. The median overall survival and progression-free survival times were, respectively, 6.5 and 3.2 months. No grade 4 or 5 toxicity was seen. Only 13% of patients had any grade 3 toxicities, and 17% of patients reported no toxicity at all. The QOL was equal or improved, and head and neck symptoms remained equal to or lower than the baseline values for most patients at up to 6 months. Eighty-five percent of patients would have chosen to receive this RT regimen again when asked. CONCLUSIONS: This palliative RT regimen was highly tolerable and effective in preserving or improving self-reported QOL in most patients for up to 6 months, which corresponds to this population's median overall survival. Given the minimal side effects, intensification could be considered to achieve longer locoregional control.

Simultaneous integrated boost using intensity-modulated radiotherapy compared with conventional radiotherapy in patients treated with concurrent carboplatin and 5-fluorouracil for locally advanced oropharyngeal carcinoma.

PURPOSE: To compare, in a retrospective study, the toxicity and efficacy of simultaneous integrated boost using intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (CRT) in patients treated with concomitant carboplatin and 5-fluorouracil for locally advanced oropharyngeal cancer. METHODS AND MATERIALS: Between January 2000 and December 2007, 249 patients were treated with definitive chemoradiation. One hundred patients had 70 Gy in 33 fractions using IMRT, and 149 received CRT at 70 Gy in 35 fractions. Overall survival, disease-free survival, and locoregional control were estimated using the Kaplan-Meier method. RESULTS: Median follow-up was 42 months. Three-year actuarial rates for locoregional control, disease-free survival, and overall survival were 95.1% vs. 84.4% (p = 0.005), 85.3% vs. 69.3% (p = 0.001), and 92.1% vs. 75.2% (p < 0.001) for IMRT and CRT, respectively. The benefit of the radiotherapy regimen on outcomes was also observed with a Cox multivariate analysis. Intensity-modulated radiotherapy was associated with less acute dermatitis and less xerostomia at 6, 12, 24, and 36 months. CONCLUSIONS: This study suggests that simultaneous integrated boost using IMRT is associated with favorable locoregional control and survival rates with less xerostomia and acute dermatitis than CRT when both are given concurrently with chemotherapy.

Enteral feeding during chemoradiotherapy for advanced head-and-neck cancer: a single-institution experience using a reactive approach.

PURPOSE: The optimal method for providing enteral nutrition to patients with head-and-neck cancer is unclear. The purpose of the present study was to evaluate the safety and efficacy of our reactive policy, which consists of the installation of a nasogastric (NG) feeding tube only when required by the patient's nutritional status. METHODS AND MATERIALS: The records of all patients with Stage III and IV head-and-neck cancer treated with concomitant chemotherapy and radiotherapy between January 2003 and December 2006 were reviewed. The overall and disease-free survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test. RESULTS: The present study included 253 patients, and the median follow-up was 33 months. At 3 years, the estimated overall survival and disease-free survival rate was 82.8% and 77.8%, respectively, for the whole population. No survival difference was observed when the patients were compared according to the presence and absence of a NG tube or stratified by weight loss quartile. The mean weight loss during treatment for all patients was 10.4%. The proportion of patients requiring a NG tube was 49.8%, and the NG tube remained in place for a median duration of 40 days. No major complications were associated with NG tube installation. Only 3% of the patients were still dependent on enteral feeding at 6 months. CONCLUSION: These results suggest that the use of a reactive NG tube with an interdisciplinary team approach is a safe and effective method to manage malnutrition in patients treated with concomitant chemotherapy and radiotherapy for head-and-neck cancer.

Organ preservation with concurrent chemoradiation for advanced laryngeal cancer: are we succeeding?

PURPOSE: To determine the rates of organ preservation and function in patients with advanced laryngeal and hypopharyngeal carcinomas treated with concurrent chemoradiotherapy (CRT). METHODS AND MATERIALS: Between April 1999 and September 2005, 82 patients with advanced laryngeal (67%) and hypopharyngeal carcinomas (33%) underwent conventional radiotherapy and concurrent platinum-based chemotherapy with curative intent. Sixty-two patients were male (75.6%). The median age was 59 years. Eighteen patients (22%) were in Stage III and 64 (78%) were in Stage IV. The median radiation dose was 70 Gy. The median potential follow-up was 3.9 years. RESULTS: Overall survival and disease-free survival were respectively 63% and 73% at 3 years. Complete response rate from CRT was 75%. Nineteen patients (23%) experienced significant long-term toxicity after CRT: 6 (7.3%) required a percutaneous endoscopic gastrostomy, 5 (6%) had persistent Grade 2 or 3 dysphagia, 2 (2.4%) had pharyngoesophageal stenosis requiring multiple dilations, 2 (2.4%) had chronic lung aspiration, and 7 (8.5%) required a permanent tracheostomy. Four patients (4.9%) underwent laryngectomy without pathologic evidence of disease. At last follow-up, 5 (6%) patients were still dependent on a gastrostomy. Overall, 42 patients (52%) were alive, in complete response, with a functional larynx and no other major complications. CONCLUSIONS: In our institution, CRT for advanced hypopharyngeal and laryngeal carcinoma has provided good overall survival and locoregional control in the majority of patients, but a significant proportion did not benefit from this approach because of either locoregional failure or late complications. Better organ preservation approaches are necessary to improve locoregional control and to reduce long-term toxicities.

Automated radiation targeting in head-and-neck cancer using region-based texture analysis of PET and CT images.

PURPOSE: A co-registered multimodality pattern analysis segmentation system (COMPASS) was developed to automatically delineate the radiation targets in head-and-neck cancer (HNC) using both (18)F-fluoro-deoxy glucose-positron emission tomography (PET) and computed tomography (CT) images. The performance of the COMPASS was compared with the results of existing threshold-based methods and radiation oncologist-drawn contours. METHODS AND MATERIALS: The COMPASS extracted texture features from corresponding PET and CT voxels. Using these texture features, a decision-tree-based K-nearest-neighbor classifier labeled each voxel as either "normal" or "abnormal." The COMPASS was applied to the PET/CT images of 10 HNC patients. Automated segmentation results were validated against the manual segmentations of three radiation oncologists using the volume, sensitivity, and specificity. The performance of the COMPASS was compared with three PET-based threshold methods: standard uptake value of 2.5, 50% maximal intensity, and signal/background ratio. RESULTS: The tumor delineations of the COMPASS were both quantitatively and qualitatively more similar to those of the radiation oncologists than the delineations from the other methods. The specificity was 95% +/- 2%, 84% +/- 9%, 98% +/- 3%, and 96% +/- 4%, and the sensitivity was 90% +/- 12%, 93% +/- 10%, 48% +/- 20%, and 68% +/- 25% for the COMPASS, for a standard uptake value of 2.5, 50% maximal intensity, and signal/background ratio, respectively. The COMPASS distinguished HNC from adjacent normal tissues with high physiologic uptake and consistently defined tumors with large variability in (18)F-fluoro-deoxy glucose uptake, which are often problematic with the threshold-based methods. CONCLUSION: Automated segmentation using texture analysis of PET/CT images has the potential to provide accurate delineation of HNC. This could lead to reduced interobserver variability, reduced uncertainty in target delineation, and improved treatment planning accuracy.