Neurocognitive Function After (Chemo)-Radiotherapy for Head and Neck Cancer

"I couldn't connect the wires in my brain." Young adult cancer survivors' experience with cognitive functioning

OBJECTIVE

There is a dearth of literature describing young adult (YA) cancer survivors' experiences with cancer-related cognitive impairment (CRCI). We aimed to elucidate CRCI among YA cancer survivors and identify potentially modifiable risk factors.

METHODS

We conducted individual qualitative interviews with YA cancer survivors aged 18-30 years at study enrollment and used applied thematic analysis to identify themes across three topics (i.e., affected cognitive abilities, risk and protective factors influencing the impact of CRCI, and strategies for coping with CRCI).

RESULTS

YA cancer survivors (N = 20) were, on average, 23 years old at diagnosis and 26 years old when interviewed. Diverse cancer types and treatments were represented; most participants (85%) had completed cancer treatment. Participants described experiences across three qualitative topics: (1) affected cognitive abilities (i.e., concentration and attention, prospective memory, and long-term memory), (2) Risk factors (i.e., fatigue, sleep problems, mood, stress/distractions, and social isolation) and protective factors (i.e., social support), and (3) coping strategies, including practical strategies that helped build self-efficacy (e.g., writing things down, reducing distractions), beneficial emotion-focused coping strategies (e.g., focus on health, faith/religion), strategies with mixed effects (i.e., apps/games, medications/supplements, and yoga), and "powering through" strategies that exacerbated stress.

CONCLUSIONS

YA cancer survivors experience enduring cognitive difficulties after treatment. Specific concerns highlight the importance of attention and executive functioning impairments, long-term memory recall, and sensitivity to distractions. Future work is needed to improve assessment and treatment of CRCI among YA cancer survivors.

Volumetric brain assessment of long-term head and neck cancer survivors

BACKGROUND

Radiation therapy (RT) for locally advanced head and neck cancer (HNC) often exposes subcortical brain structures to radiation. We performed this study to assess region-specific brain volumetrics in a population of long term HNC survivors.

METHODS AND MATERIALS

Forty HNC survivors were enrolled at a mean of 6.4 years from completion of RT. Patients underwent a research MRI protocol that included a 3D T1- weighted whole-brain scan on a 3 Tesla MRI scanner. Voxel based morphometry was performed using the Computational Anatomy Toolbox with the Neuromorphometrics atlas. Healthy controls from the Human Connectome Project were used as a comparison cohort. Study participants also completed a comprehensive neurocognitive assessment.

RESULTS

The final study cohort consisted of 38 participants after excluding 2 participants due to image quality. HNC survivors displayed widespread reduction in gray matter (GM) brain region volumes that included bilateral medial frontal cortex, temporal lobe, hippocampus, supplemental motor area, and cerebellum. Greater radiation exposure was associated with reduced GM volume in the left ventral diencephalon (r = -0.512, p = 0.003). Associations between cognition and regional GM volumes were identified for motor coordination and bilateral cerebellum (left, r = 0.444, p = 0.009; right, r = 0.372, p = 0.030), confrontation naming and left amygdala (r = 0.382, p = 0.026), verbal memory and bilateral thalamus (left, r = 0.435, p = 0.010; right, r = 0.424, p = 0.012), right amygdala (r = 0.339, p = 0.050), and right putamen (r = 0.364, p = 0.034).

CONCLUSIONS

Reductions in GM were observed within this cohort of primarily non-nasopharyngeal HNC survivors as compared to a control sample. GM volumes were associated with performance in multiple cognitive domains. Results of this exploratory study support the need for investigation of anatomic brain changes as an important translational corollary to cognitive problems among HNC survivors.

Risk of temporal lobe necrosis between proton beam and volumetric modulated arc therapies in patients with different head and neck cancers

BACKGROUND

To investigate the frequency of temporal lobe necrosis (TLN) soon after radiotherapy (RT) and identify differences among patients with various types of head and neck cancer (HNC) and between different RT methods.

METHODS

We retrospectively reviewed 483 patients with HNC who had completed RT in our hospital after January, 2015. These patients were followed-up at the radio-oncology department and received contrast-enhanced magnetic resonance imaging (MRI) or computed tomography (CT) to identify metastases or recurrence of cancer at regular intervals. Meanwhile, the occurrence of TLN, graded according to the Common Terminology Criteria for Adverse Events V5.0, was recorded. We categorized the patients into nasopharyngeal carcinoma (NPC) and non-NPC groups and compared the cumulative occurrence of TLN between the groups using Kaplan-Meier and Cox regression analyses. We further compared the cumulative occurrence of TLN between proton beam therapy (PBT) and volumetric modulated arc therapy (VMAT) in patients with any HNC, NPC, and non-NPC HNC.

RESULTS

Compared with the non-NPC group, the NPC group had a higher frequency of TLN (5.6% vs. 0.4%,  p < 0.01) and were more commonly associated with TLN in the Kaplan-Meier analysis (p < 0.01) and the Cox regression model after covariates were adjusted for (adjusted hazard ratio: 13.35, 95% confidence interval: 1.37-130.61) during the follow-up period. Furthermore, the frequency of TLN was similar between patients receiving PBT and those receiving VMAT (PBT vs. VMAT: 4.7% vs. 6.3%, p = 0.76). Kaplan-Meier analysis revealed that the accumulated risks of TLN were similar between PBT and VMAT in patients with any HNC (p = 0.44), NPC (p = 0.84), and non-NPC HNC (p = 0.70).

CONCLUSION

Our study demonstrated that patients with NPC are susceptible to TLN during the early period after RT. In addition, PBT may be associated with an equivalent risk of TLN when compared with VMAT in patients with NPC or other HNCs.

Clinical implementation of standardized neurocognitive assessment before and after radiation to the brain

Background

Radiotherapy induced impairment of cognitive function can lead to a reduced quality of life. The aim of this study was to describe the implementation and compliance of standardized neurocognitive assessment. In addition, the first results of cognitive changes for patients receiving a radiation dose to the brain are described.

Materials and methods

Patients that received radiation dose to the brain (neuro, head and neck and prophylactic cranial irradiation between April-2019 and Dec-2021 were included. Three neuro cognitive tests were performed a verbal learning and memory test, the Hopkins Verbal Learning Test; a verbal fluency test, the Controlled Oral Word Association Test and a speed and cognitive flexibility test, the Trail Making Test A&B. Tests were performed before the start of radiation, 6 months (6 m) and 1 year (1y) after irradiation. The Reliable Change Index (RCI) between baseline and follow-up was calculated using reference data from literature.

Results

644 patients performed the neurocognitive tests at baseline, 346 at 6 months and 205 at 1y after RT, with compliance rates of 90.4%, 85.6%, and 75.3%, respectively. Reasons for non-compliance were: 1. Patient did not attend appointment (49%), 2. Patient was unable to perform the test due to illness (12%), 3. Patient refused the test (8 %), 4. Various causes, (31%). A semi-automated analysis was developed to evaluate the test results. In total, 26% of patients showed a significant decline in at least one of variables at 1y and 11% on at least 2 variables at 1y. However, an increase in cognitive performance was observed in 49% (≥1 variable) and 22% (≥2 variables).

Conclusion

Standardized neurocognitive testing within the radiotherapy clinic was successfully implemented, with a high patient compliance. A semi-automatic method to evaluate cognitive changes after treatment was defined. Data collection is ongoing, long term follow-up (up to 5 years after treatment) and dose-effect analysis will be performed.

Betel Quid Dependence Effects on Working Memory and Remote Memory in Chewers with Concurrent Use of Cigarette and Alcohol

OBJECTIVE

The current study asked whether BQ dependence level could affect working memory (WM) and remote memory for the chewers with concurrent use of cigarettes and alcohol, a common phenomenon in Taiwan.

METHODS

The standardized neuropsychological tests (Wechsler Memory Scale III (WMS-III) and Remote Memory Test) were adopted to address the BQ chewers' verbal WM, spatial WM and remote memory. The Spatial Span Test and the Digit Span Test from WMS-III and the Remote Memory Test were adopted. The Betel Nut Dependency Scale (BNDS), the Fagerstrom Test for Nicotine Dependence (FTND), and the Alcohol Use Disorders Identification Test (AUDIT) were adopted to measure the dependence levels.

RESULTS

The BQ dependence level and Last BQ did not affect spatial WM, verbal WM, and remote memory. Last Cigarette is critical in affecting WM; namely, longer interval led to worse performance. Finally, higher alcohol dependence level could lead to better remote memory.

CONCLUSIONS

To our knowledge, there are no BQ studies addressing the effects of concurrent use of cigarettes and alcohol on memory. The current results suggest that cigarette smoking and alcohol drinking, rather than BQ chewing, are critical for memory performance.

Cognitive Decline following Radiotherapy of Head and Neck Cancer: Systematic Review and Meta-Analysis of MRI Correlates

Radiotherapy for head and neck cancers exposes small parts of the brain to radiation, resulting in radiation-induced changes in cerebral tissue. In this review, we determine the correlation between cognitive deterioration in patients with head and neck cancer after radiotherapy and magnetic resonance imaging (MRI) changes. Systematic searches were performed in PubMed, Scopus, and Cochrane databases in February 2021. Studies of head and neck cancer patients treated with radiotherapy and periodical cognitive and MRI assessments were included. Meta-analysis was performed to analyse the correlation of Montreal Cognitive Assessment (MoCA) scores to MRI structural and functional changes. Seven studies with a total of 404 subjects (irradiated head and neck patients, n = 344; healthy control, n = 60) were included. Most studies showed the significance of MRI in detecting microstructural and functional changes in association with neurocognitive function. The changes were seen in various brain areas, predominantly the temporal region, which also shows dose dependency (6/7 studies). An effect size (r = 0.43, p < 0.001) was reported on the correlation of MoCA scores to MRI structural and functional changes with significant correlations shown among patients treated with head and neck radiotherapy. However, the effect size appears modest.

Prevalence of neurocognitive and perceived speech deficits in patients with head and neck cancer before treatment: Associations with demographic, behavioral, and disease-related factors

Background

Neurocognition and speech, relevant domains in head and neck cancer (HNC), may be affected pretreatment. However, the prevalence of pretreatment deficits and their possible concurrent predictors are poorly understood.

Methods

Using an HNC prospective cohort (Netherlands Quality of Life and Biomedical Cohort Study, N ≥ 444) with a cross‐sectional design, we investigated the estimated prevalence of pretreatment deficits and their relationship with selected demographic, behavioral, and disease‐related factors.

Results

Using objective assessments, rates of moderate‐to‐severe neurocognitive deficit ranged between 4% and 8%. From patient‐reported outcomes, 6.5% of patients reported high levels of cognitive failures and 46.1% reported speech deficits. Patient‐reported speech functioning was worse in larynx compared to other subsites. Other nonspeech outcomes were unrelated to any variable. Patient‐reported neurocognitive and speech functioning were modestly correlated, especially in the larynx group.

Conclusions

These findings indicate that a subgroup of patients with HNC shows pretreatment deficits, possibly accentuated in the case of larynx tumors.

Chemo-brain: An activation likelihood estimation meta-analysis of functional magnetic resonance imaging studies

Adults with non-central nervous system (CNS) cancers frequently report problems in attention, memory and executive function during or after chemotherapy, referred to as cancer-related cognitive dysfunction (CRCD). Despite numerous studies investigating CRCD, there is no consensus regarding the brain areas implicated. We sought to determine if there are brain areas that consistently show either hyper- or hypo-activation in people treated with chemotherapy for non-CNS cancer (Chemo+). Using activation likelihood estimation on brain coordinates from 14 fMRI studies yielding 25 contrasts from 375 Chemo+ and 429 chemotherapy-naive controls while they performed cognitive tasks, the meta-analysis yielded two significant clusters which are part of the frontoparietal attention network, both showing lower activation in Chemo+. One cluster peaked in the left superior parietal cortex, extending into precuneus, inferior parietal lobule, and angular gyrus. The other peaked in the right superior prefrontal areas, extending into inferior prefrontal cortex. We propose that these observed lower activations reflect a dysfunction in mobilizing and/or sustaining attention due to depletion of cognitive resources. This could explain higher level of mental fatigue reported by Chemo+ and why cancer survivors report problems in a wide variety of cognitive domains.

Research progress on mechanism and imaging of temporal lobe injury induced by radiotherapy for head and neck cancer

Radiotherapy (RT) is an effective treatment for head and neck cancer (HNC). Radiation-induced temporal lobe injury (TLI) is a serious complication of RT. Late symptoms of radiation-induced TLI are irreversible and manifest as memory loss, cognitive impairment, and even temporal lobe necrosis (TLN). It is currently believed that the mechanism of radiation-induced TLI involves microvascular injury, neuron and neural stem cell injury, glial cell damage, inflammation, and the production of free radicals. Significant RT-related structural changes and dose-dependent changes in gray matter (GM) and white matter (WM) volume and morphology were observed through computed tomography (CT) and magnetic resonance imaging (MRI) which were common imaging assessment tools. Diffusion tensor imaging (DTI), dispersion kurtosis imaging (DKI), susceptibility-weighted imaging (SWI), resting-state functional magnetic resonance (rs-fMRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) can be used for early diagnosis and prognosis evaluation according to functional, molecular, and cellular processes of TLI. Early diagnosis of TLI is helpful to reduce the incidence of TLN and its related complications. This review summarizes the clinical features, mechanisms, and imaging of radiation-induced TLI in HNC patients. KEY POINTS: • Radiation-induced temporal lobe injury (TLI) is a clinical complication and its symptoms mainly include memory impairment, headache, and cognitive impairment. • The mechanisms of TLI include microvascular injury, cell injury, and inflammatory and free radical injury. Significant RT-related structural changes and dose-dependent changes in TL volume and morphology were observed through CT and MRI. • SWI, MRS, DTI, and DKI and other imaging examinations can detect anatomical and functional, molecular, and cellular changes of TLI.

Selenium-driven enhancement of synergistic cancer chemo-/radiotherapy by targeting nanotherapeutics

To overcome drug resistance in hypoxic tumors and the limitations of radiation impedance and radiation dose, we developed a nano-radiosensitizer to improve the efficacy of cancer radiotherapy. We used multifunctional mesoporous silica nanoparticles (MSNs) as the carriers for a novel anticancer selenadiazole derivative (SeD) and modified its surface with folic acid (FA) to enhance its cervical cancer-targeting effects, forming the nanosystem named SeD@MSNs-FA. Upon radiation, SeD@MSNs-FA inhibits the growth of cervical cancer cells by inducing apoptosis through the death receptor-mediated apoptosis pathway and S phase arrest, significantly improving the sensitivity of cervical cancer cells to X-ray radiation. The combined activity of SeD@MSN-FA and radiation can promote excessive production of intracellular reactive oxygen species (ROS) and induce cell apoptosis by affecting p53, protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) pathways. Furthermore, SeD@MSNs-FA can effectively inhibit tumor growth of xenografted HeLa tumors in nude mice. The toxicity analysis of SeD@MSNs-FA nanoparticles in vivo and the histological analysis performed in the mouse model showed that under the current experimental conditions, the nanoparticles induced no significant damage to the heart, liver, spleen, lungs, kidneys, or other major organs. Taken together, this study provides a translational nanomedicine-based strategy for the simultaneous chemo- and radiotherapy of cervical cancer and sheds light on potential mechanisms that can be used to overcome radiotherapeutic resistance.

The Hippocampus: A New Organ at Risk for Postoperative Radiation Therapy for Bucco-alveolar Cancer? A Dosimetric and Biological Analysis

PURPOSE

A significant proportion of patients with bucco-alveolar cancer are long-term survivors, warranting attention to survivorship issues. Decline in neurocognitive function after cranial irradiation for brain tumors correlates with a hippocampal maximum dose (Dmax) of more than 16 Gy, minimum dose (Dmin) of more than 9 Gy, and dose to 40% of the hippocampal volume (D40%) exceeding 7.3 Gy in 2-Gy equivalent dose (EQD2), respectively. We analyzed the utility of sparing the hippocampus in postoperative radiation therapy (PORT) for patients with bucco-alveolar cancer, given the proximity of target volumes to the hippocampus, by virtue of inclusion of the infratemporal fossa.

METHODS AND MATERIALS

We instituted hippocampal sparing for patients with bucco-alveolar cancer receiving PORT in March 2018. Ten prior and 10 subsequent consecutive patients with pathologically staged I-IVA cancers of the buccal mucosa, alveolus, and retromolar trigone formed the control group (no hippocampal sparing) and the study group (hippocampal sparing), respectively. The brain and temporal lobes were prescribed dose constraints in both groups. Patients received doses of 60 to 66 Gy at 2 Gy per fraction using the image-guided intensity modulated radiation therapy / volumetric modulated arc therapy technique. Treatment plans were evaluated for (1) hippocampal dosimetric parameters, (2) planning target volume dosimetry and plan-quality indices, and (3) biological indices of equivalent uniform dose (EUD) and normal-tissue complication probability (NTCP) for impaired neurocognitive function.

RESULTS

Hippocampal sparing significantly reduced the hippocampal DmaxEQD2, DmeanEQD2, and D40%EQD2 from 27 Gy to 10.9 Gy (P = .002), 14.3 Gy to 6.4 Gy (P = .002), and 15.5 Gy to 6.6 Gy (P = .005), respectively, with comparable plan-quality indices. The radiobiologically robust endpoints of ipsilateral hippocampal EUD (P = .005) and NTCP (P = .01) were statistically significantly improved.

CONCLUSIONS

Meaningful dosimetric benefit, corroborated with radiobiological indices, was observed with hippocampal sparing. The feasibility and benefit of hippocampal sparing supports our view that the hippocampus should be incorporated as an organ at risk and attention should be given to neurocognitive function in patients with bucco-alveolar cancer who are receiving PORT.

Proton therapy for selected low grade glioma patients in the Netherlands

Proton therapy offers an attractive alternative to conventional photon-based radiotherapy in low grade glioma patients, delivering radiotherapy with equivalent efficacy to the tumour with less radiation exposure to the brain. In the Netherlands, patients with favourable prognosis based on tumour and patient characteristics can be offered proton therapy. Radiation-induced neurocognitive function decline is a major concern in these long surviving patients. Although level 1 evidence of superior clinical outcome with proton therapy is lacking, the Dutch National Health Care Institute concluded that there is scientific evidence to assume that proton therapy can have clinical benefit by reducing radiation-induced brain damage. Based on this decision, proton therapy is standard insured care for selected low grade glioma patients. Patients with other intracranial tumours can also qualify for proton therapy, based on the same criteria. In this paper, the evidence and considerations that led to this decision are summarised. Additionally, the eligibility criteria for proton therapy and the steps taken to obtain high-quality data on treatment outcome are discussed.

Microglia Purinoceptor P2Y6: An Emerging Therapeutic Target in CNS Diseases

The purinergic receptor P2Y6 is expressed in immune cells, including the microglia that are implicated in neurological disorders. Its ligand, UDP, is a signaling molecule that can serve as an “find-me” signal when released in significant quantities by damaged/dying cells. The binding of UDP by P2Y6R leads to the activation of different biochemical pathways, depending on the disease context and the pathological environment. Generally, P2Y6R stimulates phagocytosis. However, whether or not phagocytosis coincides with cell activation or the secretion of pro-inflammatory cytokines needs further investigation. The current review aims to discuss the various functions of P2Y6R in some CNS disorders. We present evidence that P2Y6R may have a detrimental or beneficial role in the nervous system, in the context of neurological pathologies, such as ischemic stroke, Alzheimer’s disease, Parkinson’s disease, radiation-induced brain injury, and neuropathic pain.

Initial psychometric testing of the Head and Neck Cancer Patient Self-Management Inventory (HNC-PSMI)

PURPOSE

Head and neck cancer (HNC) and its treatment are associated with significant symptom burden and functional impairment. HNC patients must engage in intensive and complex self-management protocols to minimize acute and late treatment effects. Self-management among HNC patients is understudied due to the limited availability of disease-specific self-management measures. This article describes the initial psychometric testing of the HNC Patient Self-Management Inventory (HNC-PSMI), an instrument that characterizes self-management tasks in the HNC population.

METHOD

A cross-sectional survey design was used. One hundred HNC patients completed the HNC-PSMI, the Vanderbilt Head and Neck Cancer Symptom Survey plus General Symptom Survey, and the Profile of Mood States-Short Form. To evaluate the psychometric properties of the HNC-PSMI, the relevance of items, internal consistency of domain item responses, and the direction and strength of associations between domain scores and other measures were examined.

RESULTS

There was variability both in the number of self-management tasks performed overall and in each domain as well as in the reported difficulty completing those tasks. Kuder-Richardson values for domains with > 3 items ranged from 0.61 to 0.86. Hypothesized associations were supported.

CONCLUSIONS

Overall, the psychometric properties for the HNC-PSMI were acceptable. The HNC-PSMI can be used to advance an understanding of self-management requirements and challenges in HNC patients.

Quality of Life, Anxiety, and Depression in the Head-and-Neck Cancer Patients, Undergoing Intensity-Modulated Radiotherapy Treatment

Aims:

The aim of this study is to investigate and compare distress and quality-of-life parameters among head-and-neck cancer patients who underwent intensity-modulated radiotherapy (IMRT).

Subjects and Methods:

The patients' sample consists of 55 individuals under IMRT treatment. Three questionnaires (Quality of Life Questionnaire [QLQ]-C30 and QLQ-H and N35) of the European Organization for the Research and Treatment of Cancer and the Greek Hospital Anxiety and Depression Scales were used.

Results:

Functioning and symptoms scales measured a week before the scheduled treatment worsen significantly until the end of the treatment and at the 3-month follow-up, tend to revert to their pretreatment values.

Conclusions:

Our results showed that all parameters (functioning scales, symptoms scales, and G-HAD subscales) worsen from the start to the end treatment and tend to revert to their pretreatment values after a 3-month period.

Temporal lobe microstructural abnormalities in patients with nasopharyngeal carcinoma quantitatively evaluated by high-resolution DWI and DKI after concurrent chemoradiotherapy

•

DKI could detect early radiation-induced microstructural abnormalities after CCRT.

•

The ADC, Dmean, and FA of temporal lobe showed a unique time-dependent trajectory.

•

Kmean might be more sensitive to detection of effects in the late delayed phases.

•

White and grey matter all underwent microstructural changes after radiotherapy.

Purpose

To investigate temporal lobe microstructural abnormalities and neurocognitive function impairment after concurrent chemoradiotherapy (CCRT) in patients with nasopharyngeal carcinoma (NPC).

Methods

NPC patients who underwent CCRT were enrolled. High-resolution diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI) and diffusion-kurtosis imaging (DKI) MRI, were performed 5 times per patient (once pre-CCRT, 1 week post-CCRT, 3 months post-CCRT, 6 months post-CCRT, and 12 months post-CCRT). Neurocognitive function was evaluated by Montreal Neurocognitive Assessment (MoCA) twice per patient, once pre-CCRT, and once 12-months after CCRT.

Results

Of 111 patients, 56 completed the entire protocol. The MRI derived apparent diffusion coefficient (ADC), mean of diffusion coefficient (Dmean) and fractional anisotropy (FA) values were significantly decreased (p < 0.05) over the 0–3 month period following CCRT and significantly increased (p < 0.05) over the 3–12 month period following CCRT. The mean of kurtosis coefficient (Kmean) continued to decline over a year post-CCRT. All parameters reveal more pronounced changes in white matter (WM) than in grey matter (GM). MoCA also declined after CCRT (p < 0.001). MoCA showed significant positive correlation with Kmean-WM-6 m, Kmean-WM-12 m and ΔKmean-WM.

Conclusions

High-resolution DWI and DKI should be considered as a promising method for the investigation of temporal lobe microstructural change in NPC patients after CCRT.

Radiotherapy-related quality of life in patients with head and neck cancers: a meta-analysis

OBJECTIVES

To compare effects of intensity-modulated radiotherapy (IMRT) with those of conventional radiotherapy on quality of life (QoL) and severity of xerostomia in patients with head and neck cancer.

MATERIAL AND METHODS

PubMed, Cochrane, and Embase databases were searched to July 1, 2019, to identify relevant studies, using the following terms: radiotherapy, head and neck cancer, quality of life, cognition, xerostomia, two-/three-dimensional conformal radiation therapy, IMRT, conformal proton beam radiation therapy, stereotactic radiosurgery, and volumetric modulated arc therapy. The outcomes of interest were QoL measured by global health status; emotional, social, and cognitive function; and severity of xerostomia.

RESULTS

Seven studies with a total of 761 patients (n = 369 with IMRT; n = 392 with conventional RT) were included in this study. Median patient age was 18-65 years. IMRT group patients had better global health status (pooled standardized mean difference [SMD] = 0.80, 95% CI 0.26 to 1.35, P = 0.004) and cognitive function (pooled SMD = 0.30, 95% CI 0.06 to 0.54, P = 0.013) than the conventional RT group. Patients receiving IMRT also had significantly lower scores for xerostomia than those receiving conventional RT (pooled SMD = - 0.60, 95% CI - 0.97 to - 0.24, P = 0.001). No differences were found in emotional function (P = 0.531) and social function (P = 0.348) between the two groups.

CONCLUSION

IMRT significantly improves QoL and reduces the severity of xerostomia in patients with head and neck cancer. Results of this study provide clinicians with guidelines for decisions on the use of IMRT versus conventional RT.

Assessment of Neurocognitive Impairment and Speech Functioning Before Head and Neck Cancer Treatment

Importance

Head and neck cancer (HNC) and its treatment may negatively alter neurocognitive and speech functioning. However, the prevalence of neurocognitive impairment among patients with HNC before treatment is poorly studied, and the association between neurocognitive and speech functioning is unknown, which hampers good interpretability of the effect of HNC treatment on neurocognitive and speech function.

Objectives

To document neurocognitive functioning in patients with HNC before treatment and to investigate the association between neurocognitive and speech functioning.

Design, Setting, and Participants

Prospective cohort study of newly diagnosed patients with HNC before treatment using a large sample obtained in a nationwide, multicenter setting (Netherlands Quality of Life and Biomedical Cohort Study in Head and Neck Cancer [NET-QUBIC] project).

Main Outcome and Measures

Objective neuropsychological measures of delayed recall, letter fluency, and executive functioning, as well as patient-reported outcome measures on neurocognitive speech and functioning, were collected before treatment.

Results

In total, 254 patients with HNC participated (71.7% male), with a mean (SD) age of 62 (10) years. The response rate ranged from 81.9% (208 of 254) to 84.6% (215 of 254). Objective neurocognitive measures indicated that 4.7% (10 of 212) to 15.0% (32 of 214) of patients were initially seen with moderate to severe cognitive impairment. Mild to moderate impairment was found in 12.3% (26 of 212) to 26.2% (56 of 214) of patients. The most altered domains were delayed recall and letter fluency. Seven percent (15 of 208) of the patients reported high levels of everyday neurocognitive failure, and 42.6% (89 of 209) reported speech problems. Objective neurocognitive function was not significantly associated with patient-reported neurocognitive or speech functioning, but the results from patient-reported outcome measures were significantly correlated.

Conclusions and Relevance

Results of this study demonstrate a high prevalence of impaired speech functioning among patients with HNC before treatment, which is in line with previous findings. A novel finding is that neurocognitive impairment is also highly prevalent as objectively measured and as self-perceived. Understanding the reason why patients with HNC are initially seen with neurocognitive impairment before the start of treatment is important because this impairment may complicate patient-clinician interaction and alter treatment adherence and because treatment itself may further worsen cognitive functioning. In addition, low self-perceived neurocognitive and speech functioning before treatment may decrease a patient's confidence in communicative participation and perceived quality of life. Disentangling the associations between objective and patient-reported neurocognitive and speech functions is an important area for future research.

Evolution and predictive factors of quality of life in patients undergoing oncologic surgery for head and neck cancer: A prospective multicentric study

OBJECTIVES

The purposes of this study were to assess the evolution of quality of life (QoL) in patients with head and neck squamous cell carcinoma (HNSCC) undergoing oncologic surgery and to determine the predictive factors of post-therapeutic QoL.

METHODS

All HNSCC patients who underwent primary surgery, between 2012 and 2014, were enrolled in this prospective multicentric study. Patients completed the EORTC QLQ-C30 and QLQ-H&N35 questionnaires before surgery and at 6 months after treatment. Predictive factors of post-therapeutic QoL scores were determined.

RESULTS

A total of 200 patients were included in this study. There was no significant deterioration of global QoL and no significant increase in general symptoms between the pre- and post-therapeutic periods, but a significant deterioration in role and social functioning, and an increase of most head and neck symptoms. Tumor stage, tumor site and treatment modalities (type of surgery, adjuvant therapy) were the main predictors of QoL scores. We found a negative correlation between satisfaction with the information received and global QoL score or several functioning scales.

CONCLUSION

HNSCC surgical treatment affects patients QoL mainly by increasing head and neck symptoms, which results in social and role functioning deterioration. These results are of great interest to improve multidisciplinary care of HNSCC patients.

Dynamic contrast-enhanced magnetic resonance imaging may act as a biomarker for vascular damage in normal appearing brain tissue after radiotherapy in patients with glioblastoma

Background

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising perfusion method and may be useful in evaluating radiation-induced changes in normal-appearing brain tissue.

Purpose

To assess whether radiotherapy induces changes in vascular permeability (K^trans) and the fractional volume of the extravascular extracellular space (V_e) derived from DCE-MRI in normal-appearing brain tissue and possible relationships to radiation dose given.

Material and Methods

Seventeen patients with glioblastoma treated with radiotherapy and chemotherapy were included; five were excluded because of inconsistencies in the radiotherapy protocol or early drop-out. DCE-MRI, contrast-enhanced three-dimensional (3D) T1-weighted (T1W) images and T2-weighted fluid attenuated inversion recovery (T2-FLAIR) images were acquired before and on average 3.3, 30.6, 101.6, and 185.7 days after radiotherapy. Pre-radiotherapy CE T1W and T2-FLAIR images were segmented into white and gray matter, excluding all non-healthy tissue. K^trans and V_e were calculated using the extended Kety model with the Parker population-based arterial input function. Six radiation dose regions were created for each tissue type, based on each patient’s computed tomography-based dose plan. Mean K^trans and V_e were calculated over each dose region and tissue type.

Results

Global K^trans and V_e demonstrated mostly non-significant changes with mean values higher for post-radiotherapy examinations in both gray and white matter compared to pre-radiotherapy. No relationship to radiation dose was found.

Conclusion

Additional studies are needed to validate if K^trans and V_e derived from DCE-MRI may act as potential biomarkers for acute and early-delayed radiation-induced vascular damages. No dose-response relationship was found.

Baseline Cognition Assessment Among Patients With Oropharyngeal Cancer Using PROMIS and NIH Toolbox

Importance

Cognitive dysfunction (CD) is recognized by the American Cancer Society as a treatment effect in head and neck cancer, but the extent of this problem at baseline in oropharyngeal cancer (OPC), the most common subsite in current practice, to our knowledge has never been studied.

Objective

To assess the baseline cognition of patients with OPC using National Institutes of Health (NIH)-sponsored instruments of Patient-Reported Outcomes Measurement Information System (PROMIS) and NIH Toolbox Cognitive Battery (NIHTB-CB).

Design, Setting, and Participants

This was a prospective cohort study conducted at a tertiary academic center. Of 83 consecutive patients, newly diagnosed as having OPC from September 2016 to May 2017, 16 were ineligible, 8 refused to participate, and 3 were lost to follow-up after screening, resulting in 56 study participants.

Main Outcomes and Measures

Self-perceived and objective cognition with PROMIS and NIHTB-CB standardized T scores, respectively, were main outcomes. Impairment was defined as (1) T scores less than 0.5 SD for PROMIS; (2) T score less than 1.5 SD in at least 1 cognitive domain or less than 1 SD in 2 or more domains for NIHTB-CB total cognition; and (3) T score per previously published criteria for NIHTB-CB intelligence-stratified cognition.

Results

Of the 56 study participants (52 men, 4 women; median age, 59 years [range, 42-77 years]), 19 (34%) had a college degree, and 20 (36%) had a professional or technical occupation. Thirty (about 53%) were never-smokers, 26 (46%) were never-drinkers, 29 (52%) were obese, 13 (23%) had a moderate to severe comorbidity, 3 (5%) used antidepressants, and 25 (52%) had hearing loss. Impaired self-reported, NIHTB-CB total, and intelligence-stratified cognition scores were observed in 6 (11%), 18 (32%), and 12 (21%), respectively. Among all variables, objective impairment was more common in men (23% vs 0%) and those with p16-negative OPC (33% vs 20%), moderate to severe comorbidity (31% vs 18%), and hearing loss (31% vs 12%).

Conclusions and Relevance

Impaired objective cognition was more common at baseline than self-reported, and was more frequent in men, participants with p16-negative OPC, moderate to severe comorbidity, and hearing loss. NIHTB-CB allowed immediate scoring of demographically adjusted cognitive function. In clinical practice, these scores can be used to identify patients with impaired cognition at baseline who may be susceptible to developing further impairment after treatment. Identification of impairment at baseline will help to institute early cognitive interventions, which may lead to an improved posttreatment quality of life.

A cross sectional study in cognitive and neurobehavioral impairment in long-term nasopharyngeal cancer survivors treated with intensity-modulated radiotherapy

PURPOSE/OBJECTIVES

To determine neurocognitive and neurobehavioral impairment in long-term nasopharyngeal cancer survivors (NPC) treated with intensity-modulated radiotherapy (IMRT).

MATERIALS/METHODS

A cross-sectional cohort of NPC ≥4 years (y) following IMRT was assessed. Objective cognitive function was measured using the Montreal Cognitive Assessment (MoCA) and patient-reported memory was assessed with the MDASI-HN problems remembering item. Patient and family ratings of patients' neurobehavioral symptoms of apathy, disinhibition and executive dysfunction were assessed with the Frontal Systems Behavior Scale (FrSBe). Other patient-reported symptoms (MDASI-HN), mood (HADS), and quality of life (FACT-H&N) were also collected.

RESULTS

Among 102 participants: M:F = 66:36; median age 56y (32-77); median time since IMRT 7.5y (4.2-11.1). Impaired MoCA scores (<23) were observed in 33 (32%). Patient and family ratings of pre-illness neurobehavioral symptoms were in the normal range (total FrSBe T-scores 53.3 and 59.0 respectively). In contrast, post-treatment patient and family T-scores were clinically impaired (64.7, 71.3 respectively), with apathy, disinhibition and executive dysfunction post-treatment ratings all significantly worse than pre-treatment (p < 0.001). Prevalence of clinically significant post-treatment disturbance was high by patient and family ratings (48%/66% apathy, 35%/53% disinhibition, 39%/56% executive dysfunction). Post-treatment neurobehavioral symptoms strongly correlated with lower quality of life (r = -0.62) and higher anxiety (r = 0.62) and depression scores (r = 0.67, all p < 0.001). Total MoCA scores did not correlate with RT dose. However, greater declines in apathy, disinhibition and executive dysfunction were associated with receiving >75 Gy to temporal lobes.

CONCLUSION

NPC treated with IMRT had moderate to high rates of neurocognitive impairment and clinically significant apathy, disinhibition, and executive dysfunction.

Prevalence of Comorbidities among Older Head and Neck Cancer Survivors in the United States

Objective

The aim of this study was to evaluate the prevalence of comorbidities among patients with head and neck squamous cell carcinoma (HNSCC) at the time of their cancer diagnosis and during their survivorship trajectory. The second aim was to evaluate the differences in comorbidities developed according to treatment type received.

Study Design

Retrospective cross-sectional.

Setting

SEER (Surveillance, Epidemiology, and End Results)–Medicare linked database.

Subjects and Methods

Individuals with a first-incident primary diagnosis of HNSCC from 2004 to 2011 per the SEER-Medicare database were included in analysis. The presence or absence of 30 comorbid conditions of interest was identified during distinct periods and analyzed according to treatment with surgery alone, primary (chemo)radiation, or surgery with (chemo)radiation.

Results

The study population consisted of 10,524 individuals diagnosed with HNSCC, with a mean age of 74.8 years. At diagnosis, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, and diabetes were the most prevalent comorbidities, and they increased over time. The probability of developing treatment-related comorbidities such as pneumonia, dysphagia, weight loss, malnutrition, and dental issues rose significantly in the short and long term following treatment ( P < .05). By 5 years from cancer diagnosis, patients were most likely to have newly diagnosed hypertension, dysphagia, anemia, and weight loss. Primary surgery alone was associated with a lower risk of diagnosis with these treatment-related comorbidities, as compared with treatments involving radiation therapy and/or chemotherapy in the primary or adjuvant settings ( P < .05).

Conclusions

There is a large burden of comorbidities among patients following HNSCC treatment, which warrant clinical attention during surveillance.

Association of Neurocognitive Deficits With Radiotherapy or Chemoradiotherapy for Patients With Head and Neck Cancer

Importance

Neurocognitive deficits (NCD) have been observed in noncentral nervous system cancers, yet short- and long-term neurocognitive data on patients treated for head and neck cancer (HNC) are lacking.

Objective

To assess objective neurocognitive function before and after definitive radiation therapy for HNC.

Design, Setting, and Participants

In a prospective, longitudinal study, neurocognitive function and self-reported symptoms were assessed in 80 patients with histologically proven HNC requiring definitive chemoradiotherapy or radiotherapy and in 40 healthy controls 4 times (baseline, 6, 12, and 24 months after baseline) prior to commencing treatment at Princess Margaret Cancer Centre, Toronto, Canada.

Main Outcomes and Measures

Neurocognitive test scores were converted to age-corrected z scores (mean, 0; standard deviation, 1) and reported as mean scores, standardized regression-based scores, and frequencies of impairments in intellectual capacity, concentration, memory, executive function, processing speed, and motor dexterity. Multivariable analysis was used to identify factors associated with NCD 2 years after treatment.

Results

Eighty patients and 40 healthy controls enrolled. Analyses revealed significant differences between patient and control mean performance in some domains, with patient deficits increasing over time: intellectual capacity (Cohen d, effect sizes [95% CIs] of -0.46 [-0.64 to 0.30], -0.51 [-0.72 to -0.30], and -0.70 [-0.92 to -0.49] for time points 6, 12, and 24 months, respectively); concentration/short-term attention span (-0.19 [-0.37 to 0.00], -0.38 [-0.55 to -0.21], -0.54 [-0.71 to -0.37]); verbal memory (-0.16 [-0.33 to 0.02], -0.38 [-0.64 to -0.12], -0.53 [-0.74 to -0.32]); executive function (-0.14 [-0.27 to 0.00], -0.34 [-0.52 to -0.16], -0.43 [-0.64 to -0.22]), and global cognitive function composite (-0.38 [-0.55 to -0.22], -0.75 [-0.92 to -0.58], -1.06 [-1.26 to -0.86]). There was an increased rate of impaired global neurocognitive functioning among patients (38%) at 24 months compared with controls (0%). Neurocognitive deficits were not associated with baseline cytokines.

Conclusions and Relevance

Head and neck cancer survivors have neurocognitive sequelae up to 2 years after definitive chemoradiotherapy or radiation treatment. Patients and health care teams should know about such potential risks. Further research is warranted in search of strategies to avoid, reduce, and compensate for declines.

The Older Adult With Locoregionally Advanced Head and Neck Squamous Cell Carcinoma: Knowledge Gaps and Future Direction in Assessment and Treatment

Older adults with head and neck squamous cell carcinoma (HNSCC) pose unique treatment and supportive care challenges to oncologists and other cancer care providers. The majority of patients with HNSCC present with locoregionally advanced disease, for which combined-modality treatment integrating chemotherapy and radiation therapy is often necessary to maximize tumor control. However, applying these approaches to an older population with concomitant comorbidities and a higher risk of functional impairments remains challenging and is exacerbated by the paucity of studies involving older adults. The purpose of this article is to identify knowledge gaps in the evaluation and management of older adults with HNSCC-particularly those undergoing concurrent chemoradiation therapy-and their caregivers through a review of the literature conducted by clinicians, researchers, and patient advocates. The findings highlight the importance of a geriatric assessment and the therapeutic paradigms and challenges relevant to this population. Furthermore, we identify the need for additional research and interventions related to key supportive care issues that arise during and after treatment in older adults with locoregionally advanced HNSCC. On the basis of our findings, we prioritize these issues to guide future patient-oriented research endeavors to address these knowledge gaps and thus better serve this growing patient population.

Radiation-induced neurocognitive dysfunction in head and neck cancer patients

It might seem odd that a special issue about Gianni Bonadonna would publish a review on radiation-induced neurocognitive dysfunction. Dr. Gianni Bonadonna is considered a pioneer in medical oncology history, mainly due to new and revolutionary treatment approaches proposed in breast cancer and Hodgkin lymphoma. He had an active role in the field of medical oncology, especially through lectures and textbooks. He shared his considerable insight of understanding cancer behavior and evaluating research advances over the years to prevent tumor recurrence and preserve patients from unnecessary toxicity. From a theoretical point of view, this complex vision is valid for all malignancies and can be indirectly shifted to every primary cancer, including head and neck cancer (HNC). During the last decades, multidisciplinary treatment for HNC has improved clinical outcomes but makes acute and late toxicity challenging. This article highlights the main central nervous structures that have a major impact on the development of neurocognitive dysfunction after radiotherapy for HNC. We briefly summarize the specific structure contouring instructions and the dose-volume histogram parameters. The aim is to raise awareness in clinicians in defining normal tissues to optimize radiotherapy regimens.

Clinical Assessment of Cognitive Function in Patients with Head and Neck Cancer: Prevalence and Correlates

Objective Identify the prevalence and clinical correlates of cognitive impairment in patients presenting for treatment of head and neck cancer (HNC) using brief screening within a multidisciplinary care team. Study Design A case series with planned data collection of cognitive function, quality of life (QoL), and psychosocial variables. Setting Urban Midwest academic medical center. Subjects and Methods In total, 209 consecutive patients with a diagnosis of HNC between August 2015 and September 2016 who had a pretreatment assessment with a clinical health psychologist. At pretreatment assessment, the Montreal Cognitive Assessment (MoCA), a brief screening tool for cognitive function, was administered along with a semistructured interview to gather information on psychiatric symptoms, social support, and substance use. Patient information, including demographics, clinical variables, and psychosocial variables, was extracted via chart review. A subset of patients with HNC completed the Functional Assessment of Cancer Therapy-Head and Neck Cancer at pretreatment assessment and was included in the QoL analyses. Results Cognitive impairment was associated with current alcohol use, past tobacco use and number of pack years, time in radiotherapy, and adherence to treatment recommendations. Social, emotional, and functional QoL scales were associated with cognitive impairment, including executive function, language, and memory. Conclusion Cognitive impairment is common in patients with HNC, and there are important associations between cognitive impairment and psychosocial, QoL, and treatment adherence variables. The results argue for the incorporation of cognitive screening as part of pretreatment assessment for patients, as well as further research into more direct, causal relationships via longitudinal, prospective studies.

The Benefit of Adjuvant Radiation in Surgically-Treated T1-2 N1 Oropharyngeal Squamous Cell Carcinoma

Importance

The benefit of adjuvant radiation in surgically treated T1‐2N1 oropharyngeal cancer without adverse pathologic features remains unclear

Objectives

To compare population‐level survival outcomes in surgically‐treated T1‐2N1 oropharyngeal squamous cell carcinoma (OPSCC) with and without the use of adjuvant radiation.

Study Design

Retrospective population‐based study using the Surveillance, Epidemiology, and End Results (SEER) registry data from 1998–2011.

Setting

Population‐level study.

Participants

Patients with T1‐2N1 OPSCC treated with surgical resection and neck dissection with or without adjuvant radiation.

Intervention(s) for Clinical Trials or Exposure(s) for observational studies

The use of postoperative adjuvant radiation.

Main Outcome(s) and Measures

Overall and disease‐specific survival.

Results

Radiation was utilized in 74% of patients and was positively associated with extracapsular extension and well‐differentiated histology. The use of radiation was associated with improved mean overall survival (124 v. 108 months, p=0.023) and a non‐significant increase in mean disease‐specific survival (138 v. 131 months, p=0.053).

Conclusions and Relevance

The use of adjuvant radiation is associated with improved survival in surgically‐treated T1‐2N1 squamous cell carcinoma of the oropharynx with unknown HPV status.

Level of Evidence

IV

Euflammation Attenuates Central and Peripheral Inflammation and Cognitive Consequences of an Immune Challenge after Tumor Development

OBJECTIVE

Repeated subthreshold bacterial exposures in rodents cause novel euflammation that attenuates neuroinflammation and sickness behaviors upon subsequent infectious challenges to the host without eliciting illness behavior. The investigation of bacterial exposure effects on brain and behavior is clinically relevant because bacterial-based antitumor treatments are used successfully, but are suboptimal due to their illness side effects. In addition, behavioral consequences (depression, cognitive impairments) to homeostatic challenges that are associated with inflammation are prevalent and reduce the quality of life in cancer patients and survivors. Therefore, this study tested the potential for euflammation to attenuate behavioral consequences of an immune challenge in tumor-bearing mice.

METHODS

Mice with and without oral tumors in their flank underwent the established peripheral euflammatory protocol or vehicle treatment, followed by an acute peripheral immune challenge (lipopolysaccharide [LPS] injection) or PBS. Cognitive function and sickness behavior were assessed after the challenge, and peripheral and central inflammatory responses were measured.

RESULTS

Euflammation reduced LPS-induced peripheral and central inflammation in all mice; however, neuroinflammation was less attenuated in tumor-bearing mice compared with tumor-free controls. LPS-induced lethargy and cognitive impairments were more pronounced among tumor-bearing mice and were effectively attenuated with euflammation. Cognitive changes were independent of brain-derived growth factor gene expression in the hippocampus.

CONCLUSION

These results suggest that induction of euflammation may be useful in alleviating the negative side effects of bacterial-based tumor treatments and in potentially attenuating common behavioral comorbidities associated with cancer or other chronic diseases.

Clinical application of computed tomography-guided (125)I seed interstitial implantation for head and neck cancer patients with unmanageable cervical lymph node metastases

Background

To assess clinical application of computed tomography (CT)-guided ¹²⁵I seed implantation for patients who cannot endure or unwillingly receive repeated surgery, chemotherapy, or radiotherapy for unmanageable cervical lymph node metastases in head and neck cancer (HNC).

Methods

Thirty-one consecutive patients received CT-guided ¹²⁵I seed implantation between February 2010 and December 2013. To evaluate the clinical efficiency, karnofsky performance score (KPS), numeric rating scale (NRS), and tumor volume at 3-, and 6-month post-implantation were compared with pre-implantation, along with local control rate (LCR), overall survival rate (OSR), and complications at 3, 6 months, 1, and 2 years.

Results

The tumor volume was obviously decreased at 3-, and 6-month post-implantation (21.23 ± 8.83 versus 9.19 ± 7.52 cm²; 21.23 ± 8.83 versus 6.42 ± 9.79 cm²; P < 0.05) compared with pre-implantation. The NRS was statistically reduced (3.06 ± 1.06 versus 7.77 ± 0.92; 2.39 ± 1.15 versus 7.77 ± 0.92; P < 0.05), while KPS was significantly improved (83.18 ± 5.97 versus 73.60 ± 7.90; 82.86 ± 5.43 versus 73.60 ± 7.90; P < 0.05) postoperatively at 3 and 6 months, respectively. The LCR at 3, 6 months, 1, and 2 years was 96.30, 83.87, 64.51, and 45.16 %, respectively. The OSR was 100, 100, 67.74, and 45.16 %, respectively. Three cases experienced grade I and two had grade II acute radiation toxicity.

Conclusions

CT-guided seed implantation may be feasible and safe for HNC patients whose neck nodes are not manageable by routine strategies with fewer complications, higher LCR, and significant pain relief.

P2Y6 Receptor-Mediated Microglial Phagocytosis in Radiation-Induced Brain Injury

Microglia are the resident immune cells and the professional phagocytic cells of the CNS, showing a multitude of cellular responses after activation. However, how microglial phagocytosis changes and whether it is involved in radiation-induced brain injury remain unknown. In the current study, we found that microglia were activated and microglial phagocytosis was increased by radiation exposure both in cultured microglia in vitro and in mice in vivo. Radiation increased the protein expression of the purinergic receptor P2Y6 receptor (P2Y6R) located on microglia. The selective P2Y6 receptor antagonist MRS2578 suppressed microglial phagocytosis after radiation exposure. Inhibition of microglial phagocytosis increased inhibitory factor Nogo-A and exacerbated radiation-induced neuronal apoptosis and demyelination. We also found that the levels of protein expression for phosphorylated Ras-related C3 botulinum toxin substrate 1 (Rac1) and myosin light chain kinase (MLCK) were elevated, indicating that radiation exposure activated Rac1 and MLCK. The Rac1 inhibitor NSC23766 suppressed expression of MLCK, indicating that the Rac1-MLCK pathway was involved in microglial phagocytosis. Taken together, these findings suggest that the P2Y6 receptor plays a critical role in mediating microglial phagocytosis in radiation-induced brain injury, which might be a potential strategy for therapeutic intervention to alleviate radiation-induced brain injury.

Brain-sparing methods for IMRT of head and neck cancer

PURPOSE

Radical radiotherapy for head and neck cancer (HNC) may deliver significant doses to brain structures. There is evidence that this may cause a decline in neurocognitive function (NCF). Radiation dose to the medial temporal lobes, and particularly to the hippocampi, seems to be critical in determining NCF outcomes. We evaluated the feasibility of two alternative intensity-modulated radiotherapy (IMRT) techniques to generate hippocampus- and brain-sparing HNC treatment plans to preserve NCF.

METHODS AND MATERIALS

A planning study was undertaken for ten patients with HNC whose planning target volume (PTV) included the nasopharynx. Patients had been previously treated using standard (chemo)-IMRT techniques. Bilateral hippocampi were delineated according to the RTOG atlas, on T1w MRI co-registered to the RT planning CT. Hippocampus-sparing plans (HSRT), and whole-brain/hippocampus-sparing fixed-field non-coplanar IMRT (BSRT) plans, were generated. DVHs and dose difference maps were used to compare plans. NTCP calculations for NCF impairment, based on hippocampal dosimetry, were performed for all plans.

RESULTS

Significant reductions in hippocampal doses relative to standard plans were achieved in eight of ten cases for both HSRT and BSRT. EQD2 D40% to bilateral hippocampi was significantly reduced from a mean of 23.5 Gy (range 14.5-35.0) in the standard plans to a mean of 8.6 Gy (4.2-24.7) for HSRT (p = 0.001) and a mean of 9.0 Gy (4.3-17.3) for BSRT (p < 0.001). Both HSRT and BSRT resulted in a significant reduction in doses to the whole brain, brain stem, and cerebellum.

CONCLUSION

We demonstrate that IMRT plans for HNC involving the nasopharynx can be successfully optimised to significantly reduce dose to the bilateral hippocampi and whole brain. The magnitude of the achievable dose reductions results in significant reductions in the probability of radiation-induced NCF decline. These results could readily be translated into a future clinical trial.