Emerging understanding of dosimetric factors impacting on dysphagia and nutrition following radiotherapy for oropharyngeal cancer

De-escalated radiation for human papillomavirus virus-related oropharyngeal cancer: evolving paradigms and future strategies

The incidence of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma has increased dramatically in recent years reaching epidemic-like proportions. Data has emerged not only showing that these cancers are a unique entity with distinct molecular characteristics but that they also have a significantly improved prognosis as a result of their exquisite radiosensitivity compared to their HPV-negative counterparts. This, it has been increasingly suggested that these tumors can be targeted with de-escalated approaches using reduced doses of radiation. The overriding goal of de-escalation is to maintain the high cure and survival rates associated with traditional approaches while reducing the incidence of both short- and long-term toxicity. Although the exact reason for the improved radiosensitivity of HPV-positive oropharyngeal carcinoma is unclear, prospective studies have now been published demonstrating that de-escalated radiation can successfully maintain the high rates of cure and preserve quality of life for appropriately selected patients with this disease. However, these studies have been complicated by such factors as the relatively limited sample sizes, as well as the variability in treatment, inclusion criteria, and follow-up. As the data continues to mature on de-escalation, it is unquestionable that treatment paradigms for this disease will evolve. The ongoing quest to define a standard regimen comprises the subject of this review.

Investigation of the Effect of Radiotherapy Dose on Chewing and Swallowing Structures in Head and Neck Cancer Patients Treated with Concomitant Chemoradiotherapy

Intensity-modulated radiotherapy (IMRT) is a treatment method that is used in the treatment of head and neck cancers. Impairment of chewing and swallowing functions in the early and late periods of radiotherapy is frequent. Therefore, revealing the dose-effect relationship is important. The main purpose of this study is to investigate the dose-effect relationship between chewing and swallowing structures objectively via a standardized videofluoroscopy protocol. The study included 35 participants treated with chemo-IMRT. A videofluoroscopic swallowing study (VFSS) was performed before IMRT, and 3 and 6 months after IMRT. VFSS results were scored according to the Modified Barium Swallow Impairment Profile (MBSImP) and the Penetration-Aspiration Scale (PAS). Maximum interincisor mouth opening, body mass index (BMI), and Functional Oral Intake Scale levels were determined in these cases. The quality of life of participants was evaluated. There was a significant increase in PAS and MBSImP scores and a significant decrease in BMI scores of the patients after treatment. Xerotomy and sticky saliva complaints increased after treatment. The dose to the mastication muscles (> 40 Gy) and the temporomandibular joint (> 46 Gy) were found to be associated with a decrease in BMI; the dose to the superior pharyngeal constructor muscle (> 58 Gy) was found to be associated with pharyngeal stripping wave. The presence of aspiration was associated with the inferior pharyngeal constructor muscle, glottic larynx, supraglottic larynx, and upper esophageal sphincter. Important findings to emerge from this study include detected toxic dose limits. These findings may guide physicians to minimize the side effects of IMRT.

Symptom Clusters in Head and Neck Cancer: A Systematic Review and Conceptual Model

OBJECTIVE

The two approaches to symptom-cluster research include grouping symptoms and grouping patients. The objective of this systematic review was to examine the conceptual approaches and methodologies used in symptom-cluster research in patients with head and neck cancer.

DATA SOURCES

Articles were retrieved from electronic databases (CINAHL, MEDLINE via Ovid, APA PsycINFO, Scopus, Embase, and Cochrane Central Register of Controlled Trials-CENTRAL), five grey literature portals, and Google Scholar. Seventeen studies met the eligibility criteria. Eight studies grouped symptoms to identify symptom clusters, of which two used qualitative methods. The number of symptom clusters ranged from two to five, and the number of symptoms in a cluster ranged from 2 to 11. Nine studies grouped patients based on their experiences with multiple symptoms. Cluster analysis and factor analysis were most commonly used. Despite variable names and composition of symptom clusters, synthesis revealed three prominent symptom clusters: general, head and neck cancer-specific, and gastrointestinal. Being female and quality of life were significantly associated with high symptom group or cluster severity. Biological mechanisms were sparsely examined.

CONCLUSION

Symptom cluster research in head and neck cancer is emerging. Consensus on nomenclature of a symptom cluster will facilitate deduction of core clinically relevant symptom clusters in head and neck cancer. Further research is required on understanding patients' subjective experiences, identifying predictors and outcomes, and underlying mechanisms for symptom clusters.

IMPLICATIONS FOR NURSING PRACTICE

Identification of clinically relevant symptom clusters would enable targeted symptom assessment and management strategies, thus improving treatment efficiencies and patient outcomes.

A spatial neighborhood methodology for computing and analyzing lymph node carcinoma similarity in precision medicine

Precision medicine seeks to tailor therapy to the individual patient, based on statistical correlates from patients who are similar to the one under consideration. These correlates can and should go beyond genetics, and in general, beyond tabular or array data that can be easily represented computationally and compared. For example, in many types of cancer, cancer treatment and toxicity depend in large measure on the spatial disease spread-e.g., metastasizes to regional lymph nodes in head and neck cancer. However, there is currently a lack of methodology for integrating spatial information when considering patient similarity. We present a novel modeling methodology for the comparison of cancer patients within a cohort, based on the spatial spread of the lymph nodes affected in each patient. The method uses a topological map, bigrams, and hierarchical clustering to group patients based on their similarity. We compare this approach against a nonspatial (categorical) similarity approach where patients are binned solely by their affected nodes. We present similarity results on a 582 head and neck cancer patient cohort, along with two visual abstractions for analysis of the results, and we present clinician feedback. Our novel methodology partitions a patient cohort into clinically meaningful groups more susceptible to treatment side-effects. Such spatially-aware similarity approaches can help maximize the effectiveness of each patient's treatment.

Deintensification of Adjuvant Treatment After Transoral Surgery in Patients With Human Papillomavirus-Positive Oropharyngeal Cancer: The Conception of the PATHOS Study and Its Development

PATHOS is a phase II/III randomized controlled trial (RCT) of risk-stratified, reduced intensity adjuvant treatment in patients undergoing transoral surgery (TOS) for human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC). The study opened in the UK in October 2015 and, after successful recruitment into the phase II, transitioned into phase III in the autumn of 2018. PATHOS aims to establish whether the de-intensification of adjuvant treatment in patients with favorable prognosis HPV-positive OPSCC will confer improved swallowing outcomes, whilst maintaining high rates of cure. In this article, we will outline the rationale for the study and how it aims to answer fundamentally important questions about the safety, effectiveness and functional outcomes of minimally invasive TOS techniques followed by adjuvant radiotherapy (RT) or chemo-radiotherapy (CRT) in this patient population.

Systematic review and meta-analysis of the impact of dosimetry to dysphagia and aspiration related structures

BACKGROUND

Technological advances in radiotherapy have allowed investigations into new methods to spare healthy tissue in those treated for head and neck cancer. This systematic review with meta-analysis demonstrates the effect that radiation has on swallowing.

METHODS

Selection and analysis of studies examining the effect of radiation to swallowing structures. A fixed effects meta-analysis calculated the pooled proportions for select outcomes of dysphagia, common across many studies.

RESULTS

The majority of the papers found a correlation between radiation dose to the swallowing structures and dysphagia, however a meta-analysis found the studies carried a significant degree of heterogeneity. The appraisal demonstrates the need for large-scale studies using a randomized design and instrumental dysphagia assessments.

CONCLUSIONS

Radiation dose to dysphagia and aspiration structures is correlated with incidence of dysphagia and aspiration. The variables in this population contribute to the heterogeneity within and cross studies and future studies should consider controlling for this.

Prospective in silico study of the feasibility and dosimetric advantages of MRI-guided dose adaptation for human papillomavirus positive oropharyngeal cancer patients compared with standard IMRT

PURPOSE

We aim to determine the feasibility and dosimetric benefits of a novel MRI-guided IMRT dose-adaption strategy for human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPC).

MATERIALS/METHODS

Patients with locally advanced HPV+ OPC underwent pre-treatment and in-treatment MRIs every two weeks using RT immobilization setup. For each patient, two IMRT plans were created (i.e. standard and adaptive). The prescription dose for the standard plans was 2.12 Gy/fx for 33 fractions to the initial PTV. For adaptive plans, a new PTVadaptive was generated based on serial MRIs in case of detectable tumor shrinkage. Prescription dose to PTVadaptive was 2.12 Gy/fx to allow for maximum dose to the residual disease. Any previously involved volumes received minimally a floor dose of 50.16 Gy. Uninvolved elective nodal volumes were prescribed 50.16 Gy in 1.52 Gy/fx. Dosimetric parameters of organs at risk (OARs) were recorded for standard vs. adaptive plans. Normal tissue complication probability (NTCP) for toxicity endpoints was calculated using literature-derived multivariate logistic regression models.

RESULTS

Five patients were included in this pilot study, 3 men and 2 women. Median age was 58 years (range 45-69). Three tumors originated at the tonsillar fossa and two at the base of tongue. The average dose to 95% of initial PTV volume was 70.7 Gy (SD,0.3) for standard plans vs. 58.5 Gy (SD,2.0) for adaptive plans. The majority of OARs showed decrease in dosimetric parameters using adaptive plans vs. standard plans, particularly swallowing related structures. The average reduction in the probability of developing dysphagia ≥ grade2, feeding tube persistence at 6-month post-treatment and hypothyroidism at 1-year post-treatment was 11%, 4%, and 5%, respectively. The probability of xerostomia at 6-month was only reduced by 1% for adaptive plans vs. standard IMRT.

CONCLUSION

These in silico results showed that the proposed MRI-guided adaptive approach is technically feasible and advantageous in reducing dose to OARs, especially swallowing musculature.

Is treatment de-escalation a reality in HPV related oropharyngeal cancer?

The incidence of HPV related oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing. It is now well recognised as a distinct clinical and biologic entity, compared to traditional OPSCC. The majority of these patients have an excellent prognosis due to the chemo-radiosensitive nature of these tumours. The de-escalation of current treatment regimens have therefore been proposed in an attempt to reduce the long term treatment related morbidity of this much younger patient cohort. Several of the more pertinent points regarding safe de-escalation strategies are considered within this manuscript.

Physiological changes to the swallowing mechanism following (chemo)radiotherapy for head and neck cancer: a systematic review

Emerging research suggests that preventative swallowing rehabilitation, undertaken before or during (chemo)radiotherapy ([C]RT), can significantly improve early swallowing outcomes for head and neck cancer (HNC) patients. However, these treatment protocols are highly variable. Determining specific physiological swallowing parameters that are most likely to be impacted post-(C)RT would assist in refining clear targets for preventative rehabilitation. Therefore, this systematic review (1) examined the frequency and prevalence of physiological swallowing deficits observed post-(C)RT for HNC, and (2) determined the patterns of prevalence of these key physiological deficits over time post-treatment. Online databases were searched for relevant papers published between January 1998 and March 2013. A total of 153 papers were identified and appraised for methodological quality and suitability based on exclusionary criteria. Ultimately, 19 publications met the study’s inclusion criteria. Collation of reported prevalence of physiological swallowing deficits revealed reduced laryngeal excursion, base-of-tongue (BOT) dysfunction, reduced pharyngeal contraction, and impaired epiglottic movement as most frequently reported. BOT dysfunction and impaired epiglottic movement showed a collective prevalence of over 75 % in the majority of patient cohorts, whilst reduced laryngeal elevation and pharyngeal contraction had a prevalence of over 50 %. Subanalysis suggested a trend that the prevalence of these key deficits is dynamic although persistent over time. These findings can be used by clinicians to inform preventative intervention and support the use of specific, evidence-based therapy tasks explicitly selected to target the highly prevalent deficits post-(C)RT for HNC.

Late radiation-associated dysphagia (late-RAD) with lower cranial neuropathy after oropharyngeal radiotherapy: a preliminary dosimetric comparison

BACKGROUND AND OBJECTIVES

Late radiation-associated dysphagia (late-RAD) is a rare delayed toxicity, in oropharyngeal cancer (OPC) survivors. Prevention of late-RAD is paramount because the functional impairment can be profound and refractory to standard therapies. The objective of this analysis is to identify candidate dosimetric predictors of late-RAD and associated lower cranial neuropathies after radiotherapy (RT) or chemo-RT (CRT) for OPC.

MATERIALS AND METHODS

An unmatched retrospective case-control analysis was conducted. Late-RAD cases were identified among OPC patients treated with definitive RT or CRT. Controls were selected with minimum of 6 years without symptoms of late-RAD. Dysphagia-aspiration related structures (DARS) and regions of interest containing cranial nerve paths (RCCNPs) were retrospectively contoured. Dose volume histograms were calculated. Non-parametric bivariate associations were analyzed with Bonferroni correction and multiple logistic regression models were fit.

RESULTS

Thirty-eight patients were included (12 late-RAD cases, 26 controls). Median latency to late-RAD was 5.8 years (range: 4.5-11.3 years). Lower cranial neuropathies were present in 10 of 12 late-RAD cases. Mean superior pharyngeal constrictor (SPC) dose was higher in cases relative to controls (median: 70.5 vs. 61.6 Gy). Mean SPC dose significantly predicted late-RAD (p = 0.036) and related cranial neuropathies (p = 0.019). RCCNPs did not significantly predict late-RAD or cranial neuropathies.

CONCLUSIONS

SPC dose may predict for late-RAD and related lower cranial neuropathies. These data, and those of previous studies that have associated SPC dose with classical dysphagia endpoints, suggest impetus to constrain dose to the SPCs when possible.

Weight and body mass index in relation to irradiated volume and to overall survival in patients with oropharyngeal cancer: a retrospective cohort study

Background

Weight loss is a common problem in patients with Squamous Cell Carcinoma of the Head and Neck (SCCHN) treated with radiotherapy (RT). The aims of the present study were to determine if treated volume (TV), as a measure of the radiation dose burden, can predict weight loss in patients with oropharyngeal cancer and to analyze weight loss and body mass index (BMI) in the same patient group in relation to 5-year overall survival.

Methods

The ARTSCAN trial is a prospective, randomized, multicenter trial in patients with SCCHN. Nutritional data from the ARTSCAN trial were analyzed retrospectively using univariate and multivariate statistical methods based on information on percentage weight loss from the start of RT up to five months after the termination of RT (study cohort 1, n = 232) and information on patients’ BMI at the start of RT (study cohort 2, n = 203). TV was defined as the volume of the patient receiving at least 95% of the prescribed dose. TV_{64.6 Gy} encompasses macroscopic tumor and TV_{43.7 Gy} elective lymph nodes of the neck.

Results

TV_{64.6 Gy} and TV_{43.7 Gy} were both significantly correlated with higher weight loss up to five months after the termination of RT in study cohort 1 (p < 0.001 for both). BMI at the start of RT was shown to be a prognostic factor for 5-year overall survival in study cohort 2 but weight loss was not. The hazard ratios and 95% confidence intervals were 3.78 (1.46–9.75) and 2.57 (1.43–4.62) in patients with underweight and normal weight, respectively.

Conclusions

TV can predict weight loss during RT in patients with oropharyngeal cancer regardless of clinical stage. A high BMI (>25 kg/m²) at the start of RT is positively associated with survival in patients with oropharyngeal cancer.

Assessment of early and late dysphagia using videofluoroscopy and quality of life questionnaires in patients with head and neck cancer treated with radiation therapy

Backgorund

The aim of this study was to evaluate dysphagia in patients with head and neck cancer (HNC) undergoing three-dimensional conformal radiation therapy using objective and subjective tools simultaneously and to associate the clinical correlates of dysphagia with dosimetric parameters.

Methods

Twenty patients were included in the study. The primary tumor and the involved lymph nodes (LN) were treated with 66-70 Gy, the uninvolved LN were treated with 46-50 Gy. Six swallowing structures were identified: the superior pharyngeal constrictor muscle (SPCM), the middle pharyngeal constrictor muscle (MPCM), the inferior pharyngeal constrictor muscle (IPCM), the base of tongue (BOT), the larynx and the proximal esophageal sphincter (PES). Dysphagia was evaluated using videofluoroscopy and European Organization for Research and Treatment of Cancer (EORTC) QoL questionnaire (QLQ-C30) and supplemental EORTC QoL module for HNC (QLQ-H&N35). The evaluations were performed before treatment, at 3 months and at 6 months following treatment.

Results

On objective evaluation, the D_max for the larynx and the sub-structures of the PCM were correlated with impaired lingual movement, BOT weakness and proximal esophageal stricture at 3 months, whereas the V₆₅, the V₇₀and the D_max for the larynx was correlated with BOT weakness and the V₆₅, the V₇₀, the D_max or the D_mean for the sub-structures of the PCM were correlated with impaired lingual movement, BOT weakness, reduced laryngeal elevation, reduced epiglottic inversion and aspiration at 6 months following treatment. On subjective evaluation, the V₆₀, the D_max and the D_mean for SPCM were correlated with QoL scores for HNSO at 3 months, whereas the V₇₀ for SPCM were correlated with QoL scores for HNPA and the V₆₀, the V₆₅, the V₇₀, the D_max and the D_mean for SPCM were correlated with QoL scores for HNSO at 6 months following treatment.

Conclusions

The use of multiple dysphagia-related endpoints to complement eachother rather than to overlap with one another, as well as the use of multiple evaluations over time to represent a scale of early to late findings might provide a better insight in terms of the association of the clinical correlates of dysphagia with the dose-volume data for the dysphagia-related anatomical structures.

Pretreatment weight status and weight loss among head and neck cancer patients receiving definitive concurrent chemoradiation therapy: implications for nutrition integrated treatment pathways

PURPOSE

The purpose was to examine the effect of pretreatment weight status on loco-regional progression for patients with squamous cell carcinoma of the head and neck (SCCHN) after receiving definitive concurrent chemoradiation therapy (CCRT).

METHODS

In an expanded cohort of 140 patients, we retrospectively reviewed weight status and loco-regional progression of SCCHN patients treated with CCRT between 2004 and 2010.

RESULTS

Pretreatment ideal body weight percentage (IBW%) was statistically significantly different for patients with disease progression than for those without progression (p = 0.02) but was not an independent predictor of progression. Median pretreatment IBW% was 118 (72-193) for the progression-free group and was 101.5 (73-163) for the group with progression. Both groups suffered clinically severe weight loss of approximately 9 % from baseline to end treatment.

CONCLUSIONS

Pretreatment weight status, a very crude indicator of nutrition status, may have prognostic value in patients with SCCHN undergoing definitive CCRT. Inadequate nutritional status in these patients has been associated with poor clinical outcomes and decreased quality of life. Based on this report and others, the best next steps include routine validated malnutrition screening and the testing of evidence-based nutrition care protocols with the goals of minimizing weight loss and improvement of quality of life.