Hearing loss associated with repeated MRI acquisition procedure-related acoustic noise exposure: an occupational cohort study

Raaijmakers C, Philippens ME. Individual elective lymph node irradiation for the reduction of complications in head and neck cancer patients (iNode): A phase-I feasibility trial protocol

Introduction

The long-term complication rate in head-and-neck squamous cell carcinoma (HNSCC) patients caused by radiotherapy (RT) can be decreased by restricting elective neck irradiation (ENI) from large adjacent lymph node levels to only individual elective lymph nodes. The primary objective of this study is to treat the first HNSCC patients with individual elective lymph node irradiation by means of a Magnetic Resonance-linac (MR-linac) in order to assess the feasibility.

Methods and analysis

In this phase I feasibility study, 20 patients will be included with histologically proven cT2-4N0-1M0 HNSCC originating from the oropharynx, hypopharynx or larynx, planned for treatment with primary radiotherapy and bilateral elective neck irradiation (ENI). Patients will be treated with 35 fractions in six weeks, according to the DAHANCA schedule. Individual lymph nodes inside the conventional lymph node levels will be categorized in low-risk, intermediate-risk and high-risk based on cytology, histology and imaging parameters. Low-risk and intermediate-risk lymph nodes will irradiated in 20 and 23 fractions respectively, with a fraction dose of 2 Gy (=40/46 Gy EQD2). The high-risk lymph nodes and the primary tumor will be irradiated in 35 fractions of 2 Gy (=70 Gy equivalent dose in 2 Gy fractions (EQD2)). To limit treatment burden, 20 fractions will be applied on the MR-linac. The last 15 fractions (sequential boost at the primary tumor, intermediate-risk and high-risk lymph nodes) will be applied on a conventional linear accelerator. The main study endpoint is the percentage of fractions that are successfully completed on the MR-linac.

Ethics and dissemination

With individual elective lymph node irradiation we expect less toxicity and a better quality of life for HNSCC patients. However, as the treatment time on the MR-linac will be longer (30-45 vs 15 min per fraction) we need to examine if patients can endure this new treatment concept.

Health effects related to exposure of static magnetic fields and acoustic noise-comparison between MR and CT radiographers

OBJECTIVES

We explored the prevalence of health complaints subjectively associated with static magnetic field (SMF) and acoustic noise exposure among MR radiographers in Sweden, using CT radiographers as a control group. Additionally, we explored radiographers' use of strategies to mitigate adverse health effects.

METHODS

A cross-sectional survey was sent to all hospitals with MR units in Sweden. MR and/or CT personnel reported prevalence and attribution of symptoms (vertigo/dizziness, nausea, metallic taste, illusion of movement, ringing sensations/tinnitus, headache, unusual drowsiness/tiredness, forgetfulness, difficulties concentrating, and difficulties sleeping) within the last year. We used logistic regression to test associations between sex, age, stress, SMF strength, working hours, and symptom prevalence. Data regarding hearing function, work-environmental noise, and strategies to mitigate adverse symptoms were also analysed.

RESULTS

In total, 529 out of 546 respondents from 86 hospitals were eligible for participation. A ≥ 20 working hours/week/modality cut-off rendered 342 participants grouped into CT (n = 75), MR (n = 121), or mixed personnel (n = 146). No significant differences in symptom prevalence were seen between groups. Working at ≥ 3T increased SMF-associated symptoms as compared with working at ≤ 1.5T (OR: 2.03, CI₉₅: 1.05-3.93). Stress was a significant confounder. Work-related noise was rated as more troublesome by CT than MR personnel (p < 0.01). MR personnel tended to use more strategies to mitigate adverse symptoms.

CONCLUSION

No significant differences in symptom prevalence were seen between MR and CT radiographers. However, working at 3T increased the risk of SMF symptoms, and stress increased adverse health effects. Noise nuisance was considered more problematic by CT than MR personnel.

KEY POINTS

• No significant differences in symptom prevalence were seen between MR and CT radiographers. • Working at ≥ 3 T doubled the odds of experiencing SMF symptoms (vertigo/dizziness, nausea, metallic taste, and/or illusion of movement) as compared to working exclusively at ≤ 1.5 T. • Work-related acoustic noise was less well mitigated and was rated as more troublesome by CT personnel than by MR personnel.

Noise pollution in hospitals - A study of public perception

Introduction:

Hospitals are categorized under silent zone, but noise pollution in this setup is inevitable. The noise in hospitals may have adverse effects on the patients, caregivers and professionals working in hospitals.

Aim:

The aim of the study was to determine awareness of public regarding noise pollution in hospitals, its health effects and mitigation measures.

Method:

The present study was an internet-based questionnaire survey. The questionnaire consisted of a common Section-I for all participants and an additional Section-II for participants of the study who were Audiologists. Descriptive statistical analysis was done on the acquired data.

Results:

174 completed questionnaires were received and analysed, out of which 108 were general public and 66 were Audiologists. The data analysis revealed that the public is aware of the presence of noise in hospitals, some of its overt health effects and measures that can be taken to control the noise pollution in hospitals. Only 22.7% Audiologists who participated in the study were aware of the more technical aspects like permissible noise level in hospitals and their response was similar to that of the general public.

Conclusion:

Though the public is aware of some of the basic facts related to noise in hospitals, there is a need to create public awareness and to train Audiologists regarding hearing conservation program in hospital setups.

Grades of hearing loss affect the presence of acoustically evoked short latency negative responses in children with large vestibular aqueduct syndrome

OBJECTIVES

We aimed to investigate the relationship between grades of hearing loss and the presence of acoustically evoked short latency negative response (ASNR) in children with large vestibular aqueduct syndrome (LVAS), so as to enhance the reference value of ASNR for the diagnosis of LVAS in children.

METHODS

Two hundred sixteen ears from 108 patients (aged 4-90 months) diagnosed with bilateral LVAS, with slight to profound hearing loss, were enrolled in the present study from January 2012 to December 2018. All of the cases were diagnosed with LVAS according to high-resolution computed tomography (HRCT) or magnetic resonance imaging (MRI) scans of the inner ears. The auditory brain stem response (ABR) tests were performed on these subjects with click stimulus (ck-ABR), and the ASNRs were detected based on the method recommended by previous studies. The degree of hearing loss for each ear was classified by the estimated pure-tone average (PTA) thresholds, which were calculated according to the ck-ABR thresholds.

RESULTS

ASNRs were present in 40.7% (88/216) ears during ck-ABR tests. Both thresholds of ABR (Z = 2.977, p = 0.003) and estimated PTA (Z = 2.977, p = 0.003) were significantly higher in the ASNR absent group than in the ASNR present group. The frequency of not profound hearing impairment (≤80 dB HL) was much higher in the ASNR present group (44/88; 50%) than in the ASNR absent group (40/128; 31.3%) (χ² = 7.714, p = 0.005). The results of the logistic regression model, adjusted by cases' age and gender, showed that compared with those ears with profound hearing impairment (>80 dB HL), the not profound impaired ears were associated with a 2.48-fold increased odds of recording ASNR presence in the ck-ABR test [odds ratio (OR) = 2.48, 95% confidence interval (CI): 1.38-4.46, p = 0.003].

CONCLUSIONS

Grades of hearing loss affect the presence of ASNR in children with LVAS, and manifesting as cases with not profound hearing impairment showed increased odds of recording ASNR in the ck-ABR test. Furthermore, more studies should be performed imperatively to determine the diagnosis value of ASNR in children with LVAS.

A Comprehensive Practice Guideline for Magnetic Resonance Imaging Compatibility in Implanted Neuromodulation Devices

OBJECTIVES

The evolution of neuromodulation devices in order to enter magnetic resonance imaging (MRI) scanners has been one of understanding limitations, engineering modifications, and the development of a consensus within the community in which the FDA could safely administer labeling for the devices. In the initial decades of neuromodulation, it has been contraindicated for MRI use with implanted devices. In this review, we take a comprehensive approach to address all the major products currently on the market in order to provide physicians with the ability to determine when an MRI can be performed for each type of device implant.

MATERIALS AND METHODS

We have prepared a narrative review of MRI guidelines for currently marketed implanted neuromodulation devices including spinal cord stimulators, intrathecal drug delivery systems, peripheral nerve stimulators, deep brain stimulators, vagal nerve stimulators, and sacral nerve stimulators. Data sources included relevant literature identified through searches of PubMed, MEDLINE/OVID, SCOPUS, and manual searches of the bibliographies of known primary and review articles, as well as manufacturer-provided information.

RESULTS

Guidelines and recommendations for each device and their respective guidelines for use in and around MR environments are presented.

CONCLUSIONS

This is the first comprehensive guideline with regards to various devices in the market and MRI compatibility from the American Society of Pain and Neuroscience.

MRI-related FDA adverse event reports: A 10-yr review

PURPOSE

To provide an overview of the types of adverse events reported to the US Food and Drug Administration (US FDA) for magnetic resonance (MR) systems over a 10-yr period.

METHODS

Two reviewers independently reviewed adverse events reported to FDA for MR systems from 1 January 2008 to 31 December 2017 and manually categorized events into eight event types. Thermal events were further subcategorized by probable cause. Objects that became projectiles were also categorized.

RESULTS

FDA received 1568 adverse event reports for MR systems between 1 January 2008 and 31 December 2017. This analysis included 1548 reports. Thermal events were the most commonly reported serious injury (59% of analyzed reports). Mechanical events - defined as slips, falls, crush injuries, broken bones, and cuts; musculoskeletal injuries from lifting or movement of the device - (11%), projectile events (9%), and acoustic events (6%) were also observed.

CONCLUSIONS

Adverse events related to MR systems consistent with the known hazards of the MR environment continue to be reported to FDA. Increased awareness of the types of adverse events occurring for MR imaging systems is important for prevention.

Development of hypertension after long-term exposure to static magnetic fields among workers from a magnetic resonance imaging device manufacturing facility

OBJECTIVE

To assess the association between long-term exposure to static magnetic fields (SMF) in a magnetic resonance imaging (MRI)-manufacturing environment and hypertension.

METHODS

In an occupational cohort of male workers (n = 538) of an MRI-manufacturing facility, the first and last available blood pressure measurements from the facility's medical surveillance scheme were associated with modeled cumulative exposure to SMF. Exposure modeling was based on linkage of individual job histories from the facility's personnel records with a facility specific historical job exposure matrix. Hypertension was defined as a systolic pressure of above 140 mm Hg and/or a diastolic blood pressure above 90 mm Hg. Logistic regression models were used to associate cumulative SMF exposure to hypertension while adjusting for age, body mass index and blood pressure at time of first blood pressure measurement. Stratified analysis by exposure duration was performed similarly.

RESULTS

High cumulative exposure to SMF (≥ 7.4 K Tesla minutes) was positively associated with development of hypertension (Odds Ratio [OR] 2.32, 95% confidence interval [CI] 1.27 - 4.25, P = 0.006). Stratified analysis showed a stronger association for those with high cumulative SMF exposure within a period up to 10 years (OR 3.96, 95% CI 1.62 - 9.69, P = 0.003), but no significant association was found for (high) cumulative exposure accumulated in a period of 10 or more years. Our findings suggest SMF exposure intensity to be more important than exposure duration for the risk of developing hypertension.

CONCLUSIONS

Our data revealed that exposure to high levels of MRI-related SMF during MRI-manufacturing might be associated with developing hypertension.