Cochlea sparing effects of intensity modulated radiation therapy in head and neck cancers patients: a long-term follow-up study

Prevailing Practices in Ototoxicity Monitoring in Individuals With Head and Neck Cancer Undergoing Radiotherapy and Chemoradiotherapy: A Scoping Review

PURPOSE

The aim of the current scoping review is to identify the studies reporting ototoxicity monitoring in individuals with head and neck cancer (HNC) undergoing radiation therapy and/or chemoradiation therapy across the world. The specific objectives were to identify and report the test protocol used, identify the most common timeline of follow-up, and identify barriers and facilitators influencing the implementation of the monitoring program.

METHOD

A comprehensive search was conducted across six electronic databases, including PubMed, Embase, Web of Science, Scopus, Google Scholar, and ProQuest. The scoping review method adhered to relevant guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) and frameworks. The database search was carried out by two independent researchers, and studies were selected based on specific inclusion and exclusion criteria.

RESULTS

This scoping review identified 13 studies that fulfilled the inclusion criteria of this study. Only one study reported findings from the perspective of ototoxicity monitoring. Another study explicitly mentioned that ototoxicity monitoring was a standard of care in their hospital. Only one study reported using the relevant guidelines for monitoring ototoxicity. Specialized tests such as high-frequency audiometry, distortion product otoacoustic emissions, and vestibular tests were rarely used. Ototoxicity monitoring was influenced by awareness-related factors, technical factors, treatment-related factors, and organizational factors.

CONCLUSIONS

Research on ototoxicity monitoring programs is in its early stages, highlighting the need for standardized practices and multidisciplinary collaboration to enhance health care services for HNC patients. A standardized approach, improved awareness, and the incorporation of patient perspectives are crucial to enhancing ototoxicity monitoring in HNC patients.

Unmasking anxiety: a head-to-head comparison of open and closed masks in head and neck cancer radiotherapy

Background

Facemasks accurately immobilise patients with head and neck cancer (HNC) receiving radiotherapy (RT). However, such masks are associated with treatment related distress, a prognostic factor for poorer survival. Open masks offer increased comfort and patient satisfaction. We investigated whether open masks could immobilise patients without affecting treatment accuracy.

Materials and methods

Over an 18-month period, all HNC RT patients with anxiety were offered open masks. Once 30 patients had completed treatment, set-up data was compared to patients in closed masks. The mean displacement and one-dimensional standard deviations (SD) of the mean, systematic and random set-up errors were calculated for translational directions: anterior-posterior (x), superior-inferior (y), medial-lateral (z). The mean and SD of the mean was calculated for rotational displacements. Mann-Whitney U was used to determine any significant differences between set-up data.

Results

Sixty patients were included (30 open & 30 closed masks). There was no statistically significant difference found in the x (p = 0.701), y (p = 0.246) or z (p = 0.535) direction for the SD of the mean displacements between both masks. No statistically significant difference was found in the SD of means for rotational displacements. The calculated planning target volume (PTV) margin requirements were minimally less for the closed masks 3.5, 2.6, and 2.7 mm (x, y, z, respectively) versus 4.2, 3.2, and 3.7 mm, respectively, for open masks.

Conclusion

Our study demonstrates that open masks maintain accuracy at levels comparable to closed masks in patients with anxiety. The minor difference in the calculated PTV margin could be rectified with daily on-line imaging or surface guided imaging.

Prediction of auditory brain stem responses damage in patients with head-and-neck cancers receiving radiotherapy using the functional assays of normal tissue complication probability models

AIM

The purpose of this study was to set four NTCP models on clinical data and develop a model that calculates the possibility of hearing damage due to irradiation of healthy and at-risk brainstem tissue.

MATERIALS AND METHODS

ABR tests were performed on 50 head-and-neck cancer patients three years after radiotherapy for evaluation of lesions in a part of the auditory nerve or the auditory pathway in the brainstem.

RESULTS

It indicated a significant difference in the latency of the waves assessed by the ABR test between the two groups. The paired sample t-test indicated the latency time of waves I, III, V, I-III, and I-V (P < 0.001) in the right ear, and in the left ear latency time of waves III, V, I-III, I-V, and III-V (P < 0.001) were significantly higher in the case group's ear than those in the control group. The confidence interval of the fitted parameters was 95% for NTCP models. ABR test's binary outcome with differential dose-volume histograms (dDVHs) was calculated and imported as input to the NTCP modeling. The values of the parameters n = 2.3-2.9 and the value s = 1 were obtained, which indicated that the brainstem organ is seriality.

CONCLUSION

The best model ranked for the prediction of brainstem hearing damage was the logit model, which had the lowest Akaike value. The nervousness of the auditory organ of the brainstem (VIII nerve) can be declared as one of the reasons for being independent of the received dose.

Factors Affecting Permanent Sensorineural Hearing Loss and Bone Conduction in Patients After Receiving Radiotherapy to the Head and Neck Region

Objective

This study aimed to investigate the factors affecting permanent sensorineural hearing loss (SNHL) and causing changes in bone conduction (BC) thresholds over time in patients after receiving radiotherapy (RT) or chemoradiotherapy (CRT) to the head and neck region.

Methods

A total of 63 patients with irradiated HNC that were admitted to the Radiation Oncology Department between 2011 and 2018 were included in the study. All patients were assessed with pure tone audiometry at eight different time points (first before RT and last five years after completion of RT). A chi-square test was used to analyze the variables that affected permanent SNHL occurrence. Repeated measure analysis of variance was conducted to investigate the factors affecting change in the BC threshold at pure-tone average (0.5-2 kHz) and the air conduction (AC) threshold at 4 and 6 kHz frequencies over time.

Results

Median follow-up was 52 months (range, 12-110 months). SNHL was found in 18 (14%) of the 126 ears. According to the receiver operating characteristic analysis, the cut-off values of cochlear D_mean and D_max radiation doses were 40 Gy [p=0.017, area under the curve (AUC): 0.676] and 45 Gy (p=0.008, AUC: 0.695). D_mean (≤40 Gy vs. >40 Gy) and D_max (≤45 Gy vs. >45 Gy) cochlear doses and age (≤40 vs. >40 years) were determined as factors affecting SNHL in the chi-square test. Repeated measures showed that BC thresholds between 0.5-2 kHz and AC thresholds at 4 and 6 kHz increased over time. Age (≤40 vs. >40 years), treatment of head and neck cancer (RT vs. CRT), cisplatin use, and D_mean (≤40 Gy vs. >40 Gy) and D_max cochlear dose (≤45 Gy vs. >45 Gy) were important factors affecting the course of BC threshold over time.

Conclusion

D_mean and D_max cochlear doses and age were found to be associated with permanent SNHL. Conduction thresholds worsened over time at all frequencies, and this trend was affected by cochlear doses, age, CRT, and cisplatin use.

Comparison of radiation and chemoradiation-induced sensorineural hearing loss in head and neck cancer patients

Aim

The purpose of this study was to assess and compare the incidence and severity of sensorineural hearing loss (SNHL) in head-and-neck patients undergoing radiotherapy (RT) and concurrent cisplatin-based chemoradiotherapy (CRT).

Materials and Methods

Pure tone audiometry (PTA) was performed at 0.25-12 kHz on 35 RT and 25 CRT patients after 12-month followed up. The hearing loss was evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) criteria.

Results

SNHL increased to 84% in patients who had received CRT, compared with 26% increasing in patients who had treated with RT. There was an increased risk of SNHL at all frequencies for ears received a cochlear mean dose >50 Gy in RT group, compared to those receiving cochlear mean dose >30 Gy in CRT group. SNHL was more severe at higher frequencies in both patient groups.

Conclusion

Characteristic of radiation-induced SNHL is different from CRT-induced SNHL, especially in threshold radiation dose and PTA frequency.

Adverse Cochlear Effects After Head and Neck Cancer Therapy

This study aims to report the incidence of adverse cochlear effects when treating patients of HNSCC with different radiation techniques and to compare the effect of different treatment modalities on the cochlea. This prospective observational study took place in a tertiary care centre, of 132 individual ears from 66 patients of HNSCC treated with conventional RT (group-1), IMRT (group-2), conventional RT with chemotherapy (group-3) and IMRT in combination with chemotherapy (group-4). Pure tone audiometry was performed during the follow-up period at 3 months and 1 year of completion of therapy. Correlation of audiometric change of both the ears at high frequencies (pure tone average 4 kHz, 6 kHz, 8 kHz), low frequencies (pure tone average 0.5-2 kHz) and BC (average 500-4 kHz) with series of factors were analyzed. There was a significant deterioration of hearing threshold 1 year after complete treatment, in all groups. There was an average drop in BC (0-1 year) by 19.63 ± 31.25% in group-2, 24.57 ± 21.96% in group-1 and a drop of 36.48 ± 43.97% and 70.78 ± 21.11% in group-3 and group-4 respectively. When we compared the audiometric change (PTAv at high and low frequency) from 0 to 1 year of group-1&2 the p value was significant (p = 0.050 at high frequency, p = 0.040 at low frequency). The audiological outcome of the different treatment modalities when compared, it was observed that the maximum hearing loss was in group-4 (IMRT with Chemotherapy) followed by group-3 (RTCT), group-1 (Conventional RT) and group-2 (IMRT).

Results of a multicentre randomised controlled trial of cochlear-sparing intensity-modulated radiotherapy versus conventional radiotherapy in patients with parotid cancer (COSTAR; CRUK/08/004)

Purpose

About 40–60% of patients treated with post-operative radiotherapy for parotid cancer experience ipsilateral sensorineural hearing loss. Intensity-modulated radiotherapy (IMRT) can reduce radiation dose to the cochlea. COSTAR, a phase III trial, investigated the role of cochlear-sparing IMRT (CS-IMRT) in reducing hearing loss.

Methods

Patients (pT1-4 N0-3 M0) were randomly assigned (1:1) to 3-dimensional conformal radiotherapy (3DCRT) or CS-IMRT by minimisation, balancing for centre and radiation dose of 60Gy or 65Gy in 30 daily fractions. The primary end-point was proportion of patients with sensorineural hearing loss in the ipsilateral cochlea of ≥10 dB bone conduction at 4000 Hz 12 months after radiotherapy compared using Fisher's exact test. Secondary end-points included hearing loss at 6 and 24 months, balance assessment, acute and late toxicity, patient-reported quality of life, time to recurrence and survival.

Results

From Aug 2008 to Feb 2013, 110 patients (54 3DCRT; 56 CS-IMRT) were enrolled from 22 UK centres. Median doses to the ipsilateral cochlea were 3DCRT: 56.2Gy and CS-IMRT: 35.7Gy (p < 0.0001). 67/110 (61%) patients were evaluable for the primary end-point; main reasons for non-evaluability were non-attendance at follow-up or incomplete audiology assessment. At 12 months, 14/36 (39%) 3DCRT and 11/31 (36%) CS-IMRT patients had ≥10 dB loss (p = 0.81). No statistically significant differences were observed in hearing loss at 6 or 24 months or in other secondary end-points including patient-reported hearing outcomes.

Conclusion

CS-IMRT reduced the radiation dose below the accepted tolerance of the cochlea, but this did not lead to a reduction in the proportion of patients with clinically relevant hearing loss.

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Ipsilateral hearing loss is experienced by 35–40% of patients having radiotherapy to their parotid.

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Reducing the radiation dose to the cochlea does not spare hearing loss.

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The radiosensitivity of the cochlea may be much greater than previously understood.

Cochlea sparing with a stratified scheme of dose limitation employed in intensity-modulated radiotherapy for nasopharyngeal carcinoma: A dosimetry study

Hearing loss is 1 of the major complications after radiotherapy in nasopharyngeal carcinoma (NPC) patients, how to minimize dose to cochlea in order to reduce the incidence of sensorineural hearing loss is a critical task. This study is to investigate a stratified scheme of cochlea sparing based on T stage in intensity-modulated radiotherapy. We designed a comparison between 2 plans of cochlea sparing plan (C-Plan) and regular noncochlea sparing plan (R-Plan) from 19 NPC patients with 2, 3, 8, and 6 cases of T1, T2, T3, and T4 stage, respectively. The outcomes showed that target coverage parameters and dose-volume histogram features were of no significant difference, with a significant difference in dose distribution between C-Plan and R-Plan in cochlea and eustachian, e.g., ipsilateral cochlea D_mean 4619.75 ± 1134.09 cGy in C-Plan and 5061.03 ± 1121.09 cGy in R-Plan (p = 0.000), contralateral cochlea D_mean 4386.73 ± 945.14 cGy in C-Plan and 4991.38 ± 961.21 cGy in R-Plan (p = 0.000). Meanwhile, there was no significant difference in dose distribution in spinal cord, brainstem, and other OARs. Our dosimetry study showed cochlea sparing in intensity-modulated radiotherapy for NPC reduced cochlea dose to different extent, so we suggested a stratified scheme of cochlea sparing based on T stage could be a useful and practical tool for both physicists and radiation doctors.

Unilateral cochlea sparing in locoregionally advanced head and neck cancer: a planning study

BACKGROUND

Cochlea sparing can reduce late ototoxicity in head and neck cancer patients treated with cisplatin-based radiochemotherapy. In this situation, a mean cochlear dose (MCD) constraint of 10 Gy has been suggested by others based on the dose-effect relationship of clinical data. We aimed to investigate whether this is feasible for primary and postoperative radiochemotherapy in locoregionally advanced tumors without compromising target coverage.

PATIENTS AND METHODS

Ten patients treated with definitive and ten patients treated with adjuvant intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy were investigated. The cochleae and a planning risk volume (PRV) with a 3 mm margin were newly delineated, whereas target volumes and other organs at risk were not changed. The initial plan was recalculated with a constraint of 10 Gy (MCD) on the low-risk side. The quality of the resulting plan was evaluated using the difference in the equivalent uniform dose (EUD).

RESULTS

A unilateral MCD of below 10 Gy could be achieved in every patient. The mean MCD was 6.8 Gy in the adjuvant cohort and 7.6 Gy in the definitive cohort, while the non-spared side showed a mean MCD of 18.7 and 30.3 Gy, respectively. The mean PRV doses were 7.8 and 8.4 Gy for the spared side and 18.5 and 29.8 Gy for the non-spared side, respectively. The mean EUD values of the initial and recalculated plans were identical. Target volume was not compromised.

CONCLUSION

Unilateral cochlea sparing with an MCD of less than 10 Gy is feasible without compromising the target volume or dose coverage in locoregionally advanced head and neck cancer patients treated with IMRT. A prospective evaluation of the clinical benefit of this approach as well as further investigation of the dose-response relationship for future treatment modification appears promising.

Chemoradiation-induced hearing loss remains a major concern for head and neck cancer patients

OBJECTIVE

Review of the literature regarding hearing loss in patients with head and neck cancer treated with chemoradiation.

DESIGN

Studies in the literature are reviewed that pertain to hearing loss sustained in head and neck cancer patients receiving cisplatin-based chemoradiation. Personal observations noted while treating these patients are also detailed.

STUDY SAMPLE

PubMed was searched for pertinent articles regarding hearing loss in head and neck cancer patients receiving cisplatin chemotherapy and/or radiation.

RESULTS

Studies on the incidence and severity of hearing loss in head and neck cancer patients are limited, but those studies suggest that the risk of hearing loss is greater with higher-dose regimens.

CONCLUSIONS

Newer cisplatin chemotherapy regimens using lower, weekly doses may be associated with a lower incidence and severity of hearing loss; however, large prospective studies are needed. Such information will be paramount to effective pre-treatment counselling of head and neck cancer patients.

Intensity-modulated radiotherapy for head and neck surgeons

The development of intensity-modulated radiotherapy (IMRT) has played a major role in improving outcomes and decreasing morbidity in patients with head and neck cancer. This review addresses this vital modality with a focus on the important role of the head and neck surgeon. The technique as well as its benefits and points of caution are outlined, the definitions of tumor and treatment volumes are discussed, and the dose and fractionation are detailed. Following this are several sections dedicated to the role of the head and neck surgeon in the planning of both definitive and postoperative radiotherapy to the primary site and neck. There is a focus throughout on anatomic and surgical considerations; commonly encountered situations are illustrated. With a deeper understanding of this technique and their own pivotal contribution to target delineation, head and neck surgeons will be poised to expand their role and improve cancer care for their patients. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2368-E2373, 2016.

Sensorineural Hearing Loss after Combined Intensity Modulated Radiation Therapy and Cisplatin-Based Chemotherapy for Nasopharyngeal Carcinoma

PURPOSE

The incidence of sensorineural hearing loss (SNHL) after treatment with combination of intensity-modulated radiation therapy (IMRT) and cisplatin-based chemotherapy in nasopharyngeal carcinoma (NPC) patients was evaluated, and relationships of SNHL with host factors, treatment-related factors, and radiation dosimetric parameters were investigated.

METHODS

Fifty-one NPC patients treated with IMRT from 2004 to 2009 were analyzed. All patients received neoadjuvant, concurrent, or adjuvant use of cisplatin. Pure tone audiometry was performed during the follow-up period with a median time of 60months, ranging from 28 to 84months. Correlation of SNHL at low frequencies (pure tone average, 0.5-2kHz) with a series of factors was analyzed.

RESULTS

Among 102 ears, 12.7% had low-frequency SNHL and 42.2% had high-frequency (4kHz) SNHL. The incidence of low-frequency SNHL was greater in patients with age>40, with T-stage 4, or who received cumulative cisplatin dose (CCD)>200mg/m(2) (P=.034, .011, and .003, respectively) and in ears with secretory otitis media (SOM) (P=.002). Several dosimetric parameters were found to be correlated with SNHL. Univariate analysis showed that the minimum radiation dose to 0.1ml highest dose volume (D0.1ml) of the cochlea was the best radiation-related predictive parameter. Multivariate analysis indicated that CCD, SOM, and D0.1ml of cochlea (P=.035, .012, and .022, respectively) were the factors associated with SNHL.

CONCLUSION

For NPC patients treated with IMRT and chemotherapy, the incidence of treatment-related SNHL was associated with CCD, D0.1ml of cochlea, and SOM.

Intensity-modulated radiotherapy and volumetric-modulated arc therapy have distinct clinical advantages in non-small cell lung cancer treatment

This study was conducted to compare the efficacy of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) in delivering the planned dosage in the treatment of non-small cell lung cancer (NSCLC). Between September 2013 and March 2014, 125 NSCLC patients were randomly chosen and allocated to the IMRT group (n = 65) and VMAT group (n = 60). We compared multiple parameters such as target dose, organ dosimetry, monitor unit (MU) and time of therapy between IMRT and VMAT groups. The prescribed dose coverage of both planning techniques was 95 % of the planning target volumes (PTVs). PTV 95 % and homogeneous index in IMRT plan were greater than those in VMAT plan (both P < 0.05), while no significant difference in conformity index was observed (P > 0.05). The mean total lung V5 and V10 in VMAT group were markedly higher than those in IMRT group, but the V20, V30, and V40 in VMAT group were significantly lower (all P < 0.05), but no statistically significant difference was observed in V15 and V20 (P > 0.05). Furthermore, the planning spine and esophagus at risk volume showed no statistical significances in both groups (P > 0.05). MU of IMRT plan was about 4.2 % less than that of VMAT plan, which was statistically significant (P < 0.001). Both IMRT and VMAT had significant advantages in the treatment of NSCLC. The IMRT may be better for NSCLC patients with poor pulmonary function, and VMAT may be recommended for NSCLC patients with normal pulmonary function.