Delayed post-irradiation bulbar palsy in nasopharyngeal carcinoma

Survival outcomes and toxicity profiles among patients with nonmetastatic nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT) versus IMRT + carbon-ion radiotherapy: A propensity score-matched analysis

OBJECTIVES

To compare survival outcomes and toxic effects among patients with newly diagnosed nonmetastatic nasopharyngeal carcinoma (NPC) when treated with intensity-modulated radiotherapy (IMRT) versus IMRT + carbon-ion radiotherapy (CIRT).

METHODS

We performed a retrospective propensity score matching analysis (1:1) of patients treated with IMRT and IMRT + CIRT. Descriptive statistics were used to examine the baseline characteristics of the patients. Survival was estimated using the Kaplan-Meier method. Univariate and multivariable logistic regression analysis were used to identify the independent predictors of survival. We examined the association between risk factors and adverse events (AEs) using chi-square tests. Cox model and logistic regression were used to analyze AEs.

RESULTS

Hundred and nine patients who received IMRT + CIRT were included and the median follow-up time was 20.6 months (range: 4.6-82 months). There were no statistically significant differences in locoregional failure-free survival, distant metastasis-free survival, disease-free survival, or overall survival between the two groups, but potentially better in IMRT + CIRT group (p > 0.05, respectively). Nodal boost was the only significant factor associated with LRFS and DFS on multivariable analysis. Thirty-seven patients (34.0%) developed grade 3 acute OMs and no grade 4 acute OMs were observed in IMRT + CIRT group. All patients in IMRT + CIRT group developed grade 1 dermatitis; while in the match group, 76 patients developed grade 1 dermatitis, 27 patients developed grade 2 dermatitis, 5 patients developed grade 3 dermatitis, 1 patient developed grade 4 dermatitis. IMRT + CIRT treatment was associated with a significant trend of lower grades of OM and dermatitis (p < 0.05, respectively). Any severe (i.e., grade 3) chronic AEs, such as xerostomia, skin fibrosis, temporal lobe necrosis, osteoradionecrosis, or radiation-induced optic neuropathy, was not observed.

CONCLUSIONS

In this study, IMRT + CIRT was associated with significantly reduced acute toxicity burden compared with full course of IMRT, with excellent survival outcomes. Patients with persistent disease after treatment and treated with nodal boost had a worse outcome. More accurate assessments of IMRT + CIRT to primary nonmetastatic NPC patients will be imperative.

Electromyography findings in radiation-induced unilateral tongue immobility

BACKGROUND

We used electromyography to characterize hypoglossal nerve function among radiation-treated head and neck cancer survivors with later onset unilateral tongue immobility.

METHODS

Patients with unilateral tongue immobility without evidence of recurrent cancer were seen at a tertiary academic institution between February and September 2021. All patients were at least 2 years post-treatment with radiation therapy for head and neck squamous cell carcinoma. Participants were under annual surveillance and displayed no evidence of operative injury to the hypoglossal nerve.

RESULTS

The median symptom-free interval for the 10 patients included in this study was 13.2 years (range 2-25 years). Myokymia alone was present in 3 of 10 patients, fibrillation potentials alone were present in 3 of 10 patients, and 1 subject displayed both fibrillation and myokymia. Three out of 10 patients had normal hypoglossal nerve function.

DISCUSSION

These findings highlight how disparate mechanisms may underlie similar clinical presentations of radiation-induced neuromuscular dysfunction.

Hypoglossal nerve delineation in nasopharyngeal carcinoma patients may reduce the radiation dose and damage to the nerve

This study aims to establish a delineation guideline for the contouring of the hypoglossal nerve by dividing the nerve into different segments, and to test the possibility of a radiation dose reduction to the hypoglossal nerve in NPC patients receiving radiotherapy. Twenty NPC patients were selected arbitrarily. The hypoglossal nerves were delineated using anatomic landmarks and divided into the cisternal, intracanalicular, carotid, and transverse segments. The tumor coverage by radiation and dose-volume parameters of the nerve with and without various dose constraints to the hypoglossal nerve were compared. The hypoglossal nerve, which is invisible on CT images, can be delineated accurately with the assistance of several anatomic landmarks. Without a dose constraint to the hypoglossal nerve, the carotid space, intracanalicular, and transverse segments had high radiation dose-volumes. The dose-volume to the nerve, however, can be reduced when the nerve was defined and a dose constraint was given. The delineation of the hypoglossal nerve with its different segments is feasible. The carotid space, intracanalicular, and transverse segments received the highest dose, where the nerve damage was most likely located. The dose to the nerve can be reduced to less than 70 Gy using the intensity-modulated radiotherapy technique.

EMG-Phänomene peripherer motorisch axonaler Übererregbarkeit

Bei der Nadel-Elektromyographie (EMG) besitzen Phänomene der vermehrten Erregbarkeit von Muskelfasern und von motorischen Axonen Bedeutung für die Diagnostik neuromuskulärer Erkrankungen. Zur motorisch axonalen Übererregbarkeit gehören spontane Phänomene wie Faszikulationen, spontane kontinuierliche Einzelentladungen der motorischen Einheit (SKEME), Myokymien, neuromyotone Entladungsserien und Krampi. Ferner gehören dazu reizinduzierte Phänomene wie manche A-Wellen, reizinduzierte komplex repetitive Entladungen oder tetanischen Spasmen bei Elektrolytstörungen. In der vorliegenden Übersicht wird der Kenntnisstand zu den verschiedenen Phänomenen motorisch axonaler Übererregbarkeit referiert. Ein Schwerpunkt liegt dabei auf den SKEME als neuem Mitglied der Gruppe spontaner Potenziale aus dem motorischen Axon.

Passively Scattered Proton Therapy for Nonmelanoma Skin Cancer with Clinical Perineural Invasion

Purpose

To report our experience with the delivery of passively scattered proton therapy in the management of nonmelanoma skin cancers with clinical perineural invasion.

Materials and Methods

We reviewed the medical records of patients who received definitive or postoperative proton therapy for nonmelanoma skin cancer with clinical perineural invasion at our institution and updated patient follow-up when possible. All patients were treated with curative intent with or without the delivery of concurrent systemic therapy. We report disease control rates and the rates of late toxicity among this cohort.

Results

Twenty-six patients treated between 2008 and 2017 were included in the analysis. Following proton therapy, the 3-year overall, cause-specific, and disease-free survival rates were 59%, 73%, and 60%, respectively. The 3-year local control, local regional control, and distant metastasis-free survival rates were 80%, 65%, and 96%, respectively. On univariate analysis, surgical resection before radiation therapy significantly improved local regional control rates at 3 years (55% versus 86%; P = .04). Grade 3+ late toxicities occurred in 13 patients (50%) and the most common toxicities included grade 3+ keratitis of the ipsilateral eye, which occurred in 4 patients (15%) and grade 3+ brain necrosis in 4 patients (15%).

Conclusion

Proton therapy is effective in the management of nonmelanoma skin cancer with clinical perineural invasion. Although disease control and complication rates compare favorably to those previously published for photon-based radiation therapy, the risk for late toxicity is significant and patients should be appropriately counseled.

Large German Multicenter Experience on the Treatment Outcome of 207 Patients With Adenoid Cystic Carcinoma of the Major Salivary Glands

Introdution

We aimed to evaluate treatment outcome of combined radiotherapy (RT) including photon intensity modulated radiotherapy (IMRT) and carbon ion boost for adenoid cystic carcinomas (ACCs) of the major salivary glands, the currently available largest German collective for this cohort.

Materials and Methods

Overall, 207 patients who were irradiated with combined RT between 2009 and 2019 at Heidelberg University Hospital were analyzed retrospectively for local control (LC), progression-free survival (PFS) and overall survival (OS) using Kaplan-Meier estimates. The majority of patients received postoperative RT (n=176/207, 85%) after previous surgery in large German hospitals mainly Mainz, Freiburg, Mannheim and Heidelberg University Hospitals and 15% received primary RT (n=31/207).

Results

After a median follow-up time of 50 months, 84% of the patients were still alive (n=174/207). Disease progression occurred in 32% of the patients (n=66/207) while local recurrence was diagnosed in 12% (n=25/207), and distant relapse in 27% (n=56/207). Estimated 5-year LC, PFS and OS rates were 84%, 56% and 83% for OS, respectively. In multivariate analysis, we could identify two prognostic subgroups: one subgroup resulting in decreased LC, PFS and OS rates and another subgroup having an additional survival disadvantage in PFS and OS. Patients with a macroscopic tumor disease (yes vs. no; p<0.001 for LC, p=0.010 for PFS and p=0.040 for OS) treated in a definitive setting (vs. postoperative setting; p=0.001 for LC, p=0.006 for PFS, p=0.049 for OS) and tumors of upper T stage (T1-4; p=0.004 for LC, p<0.001 for PFS, p<0.001 for OS) showed significantly more local relapses and a decreased PFS and OS. Upper Age (p<0.001 for both PFS and OS), lower Karnofsky Performance Score (<80% vs. ≥80%; p<0.001 for both PFS and OS) and solid histology (vs. non-solid; p=0.049 for PFS and p=0.003 for OS) were in addition associated with worse survival outcome. Toxicity was moderate with 18% late grade 2 and 3 toxicity.

Conclusions

Combined RT results in superior LC rates compared to photon data with moderate toxicity. In multivariate analysis, upper T stage, the existence of a macroscopic tumor before RT and definitive RT setting were identified as major prognostic factors affecting LC negatively.

Treatment Outcome of 227 Patients with Sinonasal Adenoid Cystic Carcinoma (ACC) after Intensity Modulated Radiotherapy and Active Raster-Scanning Carbon Ion Boost: A 10-Year Single-Center Experience

We aimed to evaluate the treatment outcome of primary and postoperative bimodal radiotherapy (RT) including intensity modulated photon radiotherapy (IMRT) and carbon ion radiotherapy (CIRT) for sinonasal adenoid cystic carcinoma (ACC) patients. Medical records of 227 consecutive patients who received either a primary (n = 90, 40%) or postoperative (n = 137, 60%; R2, n = 86, 63%) IMRT with doses between 48 and 56 Gy in 1.8 or 2 Gy fractions and active raster-scanning carbon ion boost with 18 to 24 Gy (RBE, relative biological effectiveness) in 3 Gy (RBE) fractions between 2009 and 2019 up to a median total dose of 80 Gy (EQD2, equivalent dose in 2 Gy single dose fractions, range 71–80 Gy) were reviewed. Results: Median follow-up was 50 months. In univariate and multivariate analysis, no significant difference in local control (LC) could be shown between the two treatment groups (p = 0.33). Corresponding 3-year LC rates were 79% for primary bimodal RT and 82% for postoperative bimodal RT, respectively. T4 stage (p = 0.002) and solid histology (p = 0.005) were identified as independent prognostic factors for decreased LC. Significant worse long-term treatment tolerance was observed for postoperatively irradiated patients with 17% vs. 6% late grade 3 toxicity (p < 0.001). Primary radiotherapy including IMRT and carbon ion boost for dose-escalation results in adequate LC with less long-term grade 3 toxicity compared to postoperative bimodal radiotherapy in sinonasal ACC patients. The high rate of macroscopic tumor disease in the postoperative group makes the interpretation of the beneficial results in LC for primary RT difficult.

The impact of age on the outcome of patients treated with radiotherapy for mucoepidermoid carcinoma (MEC) of the salivary glands in the head and neck: A 15-year single-center experience

INTRODUCTION

Data regarding treatment and survival outcome of patients with mucoepidermoid carcinoma of the head and neck are limited to case reports and case series. As a consequence of lacking evidence, treatment guidelines do not exist. We aimed to analyze the effect of modern radiotherapy in form of intensity modulated radiotherapy (IMRT) either with simultaneously integrated boost or carbon ion boost on local control and survival for a relatively large patient collective.

MATERIALS AND METHODS

Patient records of 62 consecutive patients treated with postoperative (n = 53, 85%) or definitive (n = 9, 15%) radiotherapy between 2004 and 2019 were analyzed retrospectively. Kaplan-Meier estimates for overall survival (OS), distant progression-free survival (PFS), local control (LC) and locoregional control (LRC) were statistically calculated and prognostic factors were identified using the log-rank test. Toxicity was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE).

RESULTS

The median follow-up was 47 months (range, 4-188 months). The 3-year OS, DPFS, LC and LRC, estimated by Kaplan-Meier curves, were 82%, 87%, 89% and 92%, the estimated 5-year OS, DPFS, LC and LRC were 78%, 87%, 84% and 88%, respectively. In univariate analysis, age >56 years (vs. age ≤56 years) was identified as the only independent negative prognostic factor for decreased OS (HR = 1.078; 95%-CI = 1.029-1.130; p = 0.001), DPFS (HR = 1.055; 95%-CI = 1.000-1.114; p = 0.051) and LC (HR = 1.087; 95%-CI = 1.022-1.157; p = 0.008). Treatment was well tolerated without any grade ≥4 toxicity. Acute and late grade 3 toxicities were rare with 16% acute (n = 10) and 13% late toxicities (n = 8).

CONCLUSION

Radiotherapy with intensity modulated radiotherapy including either simultaneously integrated photon boost or active raster-scanning carbon ion boost for mucoepidermoid carcinomas of the head and neck resulted in excellent survival outcome and locoregional control with moderate toxicity. However, patients older than 56 years seem to have a disadvantage in all calculated endpoints (OS, DPFS, LRC) due to frequent local and distant relapses.

CONDENSED ABSTRACT

Modern radiotherapy with intensity modulated radiotherapy including either a simultaneously integrated photon boost or carbon ion boost for mucoepidermoid carcinoma results in excellent survival outcome and locoregional control with moderate toxicity. The 5-year OS, DPFS, LC and LRC, estimated by Kaplan-Meier curves, were 89%, 75%, 84% and 80%, respectively. Patients older than 56 years seem to have a disadvantage in all calculated endpoints (OS, DPFS, LRC).

Chemotherapy Potentially Facilitates the Occurrence of Radiation Encephalopathy in Patients With Nasopharyngeal Carcinoma Following Radiotherapy: A Multiparametric Magnetic Resonance Imaging Study

Radiation encephalopathy (RE) is deemed to be a disease induced only by radiotherapy (RT), with the effects of chemotherapeutic agents on the brains of nasopharyngeal carcinoma (NPC) patients being largely overlooked. In this study, we investigated structural and functional brain alterations in NPC patients following RT with or without chemotherapy. Fifty-six pre-RT, 37 post-RT, and 108 post-CCRT (concomitant chemo-radiotherapy) NPC patients were enrolled in this study. A surface-based local gyrification index (LGI) was obtained from high resolution MRI and was used to evaluate between-group differences in cortical folding. Seed-based functional connectivity (FC) analysis of resting-state fMRI data was also conducted to investigate the functional significance of the cortical folding alterations. Compared with the Pre-RT group, patients in the Post-CCRT group showed LGI reductions in widespread brain regions including the bilateral temporal lobes, insula, frontal lobes, and parietal lobes. Compared with the Post-RT group, patients in the Post-CCRT group showed LGI reductions in the right insula, which extended to the adjacent frontal lobe. Seed-based FC analysis showed that patients in the Post-CCRT group had lower FC between the insula and the left middle frontal gyrus than patients in the Pre-RT group. The follow-up results showed that patients in the Post-CCRT group had a much higher RE incidence rate (20.4%) than patients in the Post-RT group (2.7%; P = 0.01). These findings indicate that chemotherapy potentially facilitated the occurrence of RE in NPC patients who underwent radiotherapy.

Dosimetric comparison of protons vs photons in re-irradiation of intracranial meningioma

OBJECTIVES

Re-irradiation of recurrent intracranial meningiomas represents a major challenge due to dose limits of critical structures and the necessity of sufficient dose coverage of the recurrent tumor for local control. The aim of this study was to investigate dosimetric differences between pencil beam scanning protons (PBS) and volumetric modulated arc therapy (VMAT) photons for intracranial re-irradiation of meningiomas.

METHODS

Nine patients who received an initial dose >50 Gy for intracranial meningioma and who were re-irradiated for recurrence were selected for plan comparison. A volumetric modulated arc therapy photon and a pencil beam scanning proton plan were generated (prescription dose: 15 × 3 Gy) based on the targets used in the re-irradiation treatment.

RESULTS

In all cases, where the cumulative dose exceeded 100 or 90 Gy, these high dose volumes were larger for the proton plans. The integral doses were significantly higher in all photon plans (reduction with protons: 48.6%, p < 0.01). In two cases (22.2%), organ at risk (OAR) sparing was superior with the proton plan. In one case (11.1%), the photon plan showed a dosimetric advantage. In the remaining six cases (66.7%), we found no clinically relevant differences in dose to the OARs.

CONCLUSIONS

The dosimetric results of the accumulated dose for a re-irradiation with protons and with photons were very similar. The photon plans had a steeper dose falloff directly outside the target and were superior in minimizing the high dose volumes. The proton plans achieved a lower integral dose. Clinically relevant OAR sparing was extremely case specific. The optimal treatment modality should be assessed individually.

ADVANCES IN KNOWLEDGE

Dose sparing in re-irradiation of intracranial meningiomas with protons or photons is highly case specific and the optimal treatment modality needs to be assessed on an individual basis.

Bimodal Radiotherapy with Active Raster-Scanning Carbon Ion Radiotherapy and Intensity-Modulated Radiotherapy in High-Risk Nasopharyngeal Carcinoma Results in Excellent Local Control

Background: In this analysis, we aimed to present the first results of carbon ion radiotherapy (CIRT), which is known for its conformal dose distribution and increased biological effectiveness in the treatment of high-risk nasopharyngeal carcinoma (NPC). Methods: We retrospectively analyzed twenty-six consecutive patients who had been treated at our center with CIRT for high-risk NPC between 2009 and 2018. Carbon ion (C12) boost was applied in a bimodal setting combined with intensity-modulated radiotherapy (IMRT) base plan. The median cumulative total dose was 74 Gy (RBE), and patients with inoperable (n = 17, 65%) or incompletely resected (n = 7, 27%) tumors were included in the analysis. Overall, 81% received concomitant chemotherapy (n = 21). Results: The median follow-up time was 40 months (range 10–97 months) for all patients. At the last follow-up, 92% of the patients were still alive. We could identify excellent tumor response with complete tumor remission (CR) in 60% (n = 15/25), partial tumor remission (PR) in 20% (n = 5/25), and stable disease (SD) in 12% (n = 3/25) of the patients according to the RECIST (Response Evaluation Criteria in Solid Tumors) criteria. Despite unfavorable tumor characteristics, only one patient showed a locally in-field recurrence after 56 months (4%) and another patient a locoregional recurrence in the unilateral cervical lymph nodes after 21 months (4%). The 2-year local control (LC), distant progression-free survival (DPFS), and overall survival (OS) were 95%, 93%, and 100% and the estimated 5-year LC, DPFS, and OS were 90%, 86%, and 86%, respectively. Overall, treatment was tolerated well with 20% acute and 16% chronic grade 3 side effects. No toxicity greater than grade 3 occurred. Conclusion: Bimodal radiotherapy including IMRT and active raster-scanning CIRT for high-risk nasopharyngeal cancer is a safe treatment method resulting in moderate toxicity and excellent local control. A larger patient number and longer follow-up time would be necessary to strengthen the current findings.

Results of a combination treatment with intensity modulated radiotherapy and active raster-scanning carbon ion boost for adenoid cystic carcinoma of the minor salivary glands of the nasopharynx

OBJECTIVES

We aimed to present the first clinical results for adenoid cystic carcinoma (ACC) of the nasopharynx after primary radiotherapy (RT) with the focus on local control (LC) and patterns of recurrence.

MATERIALS AND METHODS

We retrospectively analyzed 59 patients with ACC of the nasopharynx, who were treated with bimodal radiotherapy (RT) consisting of intensity modulated radiotherapy and carbon ion boost at the Heidelberg Ion-Beam Therapy Center between 2009 and 2018. The patients had predominantly inoperable (n = 42, 72%) or incompletely resected (n = 17, 29%) tumors. Kaplan-Meier estimates and the log-rank (Mantel-Cox) test were used for univariate and multivariate analyses.

RESULTS

The median follow-up was 32 months. At last follow-up, 67% of the patients were still alive (n = 39/58), of whom 74% were free of progression (n = 29/39). The 2-year LC, distant progression-free survival (DPFS) and overall survival (OS) were 83%, 81%, 87% and the estimated 5-year LC, DPFS and OS were 49%, 54%, 69%, respectively. LC was significantly inferior in patients with large tumor volumes (gross tumor volume, GTV > 100 cc, p = 0.020) and T4 tumors (p = 0.021). The majority of the recurrences occurred at the margin, where critical structures were spared (n = 11/19, 58%). Overall, grade 3 toxicity was moderate with 12% acute and 8% late side effects.

CONCLUSION

Bimodal RT including active raster-scanning carbon ion boost for nasopharyngeal ACC resulted in adequate LC and OS rates with moderate toxicity. T4 stage, large tumor volume and the necessary dose sparing in critical structures, i.e. optic nerves, brain stem and orbit, negatively affected LC.

Carbon-ion radiotherapy in accelerated hypofractionated active raster-scanning technique for malignant lacrimal gland tumors: feasibility and safety

Introduction

We evaluated treatment outcomes of CIRT in an active raster-scanning technique alone or in combination with IMRT for lacrimal gland tumors.

Methods

A total of 24 patients who received CIRT for a malignant lacrimal gland tumor at the HIT between 2009 and 2018 were analyzed retrospectively for LC, OS, and distant progression-free survival (DPFS) using Kaplan-Meier estimates. Toxicity was assessed according to the CTCAE version 5.

Results

Median follow-up was 30 months and overall median LC, OS, and DPFS 24 months, 36 months, and 31 months, respectively. Two-year LC, OS, and DPFS of 93%, 96%, and 87% with CIRT was achieved for all patients. Local failure occurred only in patients with ACC and after a median follow-up of 30 months after the completion of RT (n=5, 21%; P=0.09). We identified a significant negative impact of a macroscopic tumor disease, which was diagnosed on planning CT or MRI before RT, on LC (P=0.026). In contrast, perineural spread (P=0.661), T stage (P=0.552), and resection margins in operated patients (P=0.069) had no significant impact on LC. No grade ≥3 acute or grade >3 chronic toxicity occurred. Late grade 3 side effects were identified in form of a wound-healing disorder 3 months after RT in one patient and temporal lobe necrosis 6 months after RT in another (n=2, 8%).

Conclusion

Accelerated hypofractionated active raster-scanning CIRT for relative radio-resistant malignant lacrimal gland tumors results in adequate LC rates and moderate acute and late toxicity. Nevertheless, LC for ACC histology remains challenging and risk factors for local recurrence are still unclear. Further follow-up is necessary to evaluate long-term clinical outcome.

Radiation-induced functional connectivity alterations in nasopharyngeal carcinoma patients with radiotherapy

The study aims to investigate the radiation-induced brain functional alterations in nasopharyngeal carcinoma (NPC) patients who received radiotherapy (RT) using functional magnetic resonance imaging (fMRI) and statistic scale.The fMRI data of 35 NPC patients with RT and 24 demographically matched untreated NPC patients were acquired. Montreal Cognitive Assessment (MoCA) was also measured to evaluate their global cognition performance. Multivariate pattern analysis was performed to find the significantly altered functional connections between these 2 groups, while the linear correlation level was detected between the altered functional connections and the MoCA scores.Forty-five notably altered functional connections were found, which were mainly located between 3 brain networks, the cerebellum, sensorimotor, and cingulo-opercular. With strictly false discovery rate correction, 5 altered functional connections were shown to have significant linear correlations with the MoCA scores, that is, the connections between the vermis and hippocampus, cerebellum lobule VI and dorsolateral prefrontal cortex, precuneus and dorsal frontal cortex, cuneus and middle occipital lobe, and insula and cuneus. Besides, the connectivity between the vermis and hippocampus was also significantly correlated with the attention score, 1 of the 7 subscores of the MoCA.The present study provides new insights into the radiation-induced functional connectivity impairments in NPC patients. The results showed that the RT may induce the cognitive impairments, especially the attention alterations. The 45 altered functional connections, especially the 5 altered functional connections that were significantly correlated to the MoCA scores, may serve as the potential biomarkers of the RT-induced brain functional impairments and provide valuable targets for further functional recovery treatment.

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.

Delayed cervicobulbar neuronopathy and myokymia after head and neck radiotherapy for nasopharyngeal carcinoma: a case report

INTRODUCTION

Delayed progressive cervicobulbar palsy with secondary lingual, facial, and neck myokymia after radiation therapy to the head and neck is a known but rare event with few reported case descriptions.

CASE PRESENTATION

We report a case with a video description of a young Asian woman who developed progressive dysarthria and dysphagia after approximately 1 year after radiation treatment for nasopharyngeal carcinoma. Her symptoms, clinical, and electromyographic findings are discussed and were felt to be secondary to a cervicobulbar neuronopathy secondary to the previous radiation she received. A brief literature review was performed and pathophysiological mechanisms and treatment options are discussed.

CONCLUSION

Delayed progressive cervicobulbar neuronopathy with myokymia is an uncommon complication of radiotherapy for nasopharyngeal carcinoma. Clinicians should be aware of this entity to prevent misdiagnosis with other neuromuscular and nonneuromuscular diseases.

Neurotoxicity of radiation therapy

Direct or incidental exposure of the nervous system to therapeutic irradiation carries the risk of symptomatic neurologic injury. Central nervous system toxicity from radiation includes focal cerebral necrosis, neurocognitive deficits, and less commonly cerebrovascular disease, myelopathy, or the occurrence of a radiation-induced neoplasm. Brachial or lumbosacral plexopathy are the most common syndromes of radiation toxicity affecting the peripheral nervous system. This article focuses on the clinical features, diagnosis, and management options for patients with radiation neurotoxicity.

Radiation-induced cranial neuropathies manifesting as baroreflex failure and progressive bulbar impairment

INTRODUCTION

Baroreflex failure and bulbar palsy have been rarely reported as potential complications of radiotherapy for head and neck tumors. However, the occurrence of both disorders in the same patient has not been well described. We present a unique patient with radiation-induced cranial neuropathies, resulting in bulbar palsy and baroreflex failure.

CASE REPORT

A 67-year-old man underwent surgical resection of tonsillar squamous cell carcinoma and postoperative radiation therapy. Six years later, he developed severe orthostatic hypotension with syncope, followed later by progressive bulbar impairment. EMG showed myokymic discharges in the tongue, and marked orthostatic hypotension was noted on tilt-table testing.

CONCLUSION

Progressive bulbar impairment and baroreflex failure can occur following radiotherapy for head and neck cancers. Furthermore, these manifestations of radiation injury can occur in the same patient.

Botulinum toxin for radiation-induced facial pain and trismus

OBJECTIVE

To report the efficacy of botulinum toxin A for radiation-induced pain, trismus, and masticator spasm in head and neck cancer.

PATIENTS AND METHODS

This prospective nonrandomized study included patients in complete remission with radiation-induced pain and trismus with or without masticator spasms. Fifty units of Botox (Allergan) or 250 units of Dysport (Ipsen) were injected transcutaneously into the masseter muscles. Jaw opening was measured and patients answered 20 questions about jaw opening, pain, and cramps, before injection at 1 month.

RESULTS

Nineteen patients (7 women, 12 men) were included. Median time after radiation therapy was 5 years (range, 11 months to 22 years). At 1 month, no significant increase in jaw opening was recorded. Improvement was noted in the functional domain (P = 0.004), for pain (P = 0.002) and cramps (P = 0.004), but not in the social (P = 0.83) or emotional (P = 0.43) domains. No side effects occurred.

CONCLUSIONS

Botulinum toxin did not improve trismus but significantly improved pain scores and masticator spasms (oromandibular dystonia).

Neurologic Complications of Head and Neck Cancers

Despite the physical proximity of head and neck cancers to neurologic structures there have been few reviews of the neurologic complications of these cancers. This article reviews the neurologic manifestations of primary cancers of the head and neck and the complications that may arise as a result of tumor invasion, surgery and reconstruction, and radiation therapy.