Effects of radiation on the temporal bone in patients with head and neck cancer

Radiotherapy-induced Pathology of the Ear

Acute radiotherapy (RT)-induced external ear soft tissue changes start with erythema and dry desquamation and may progress to moist desquamation and epidermal ulceration. Chronic RT-induced changes include epithelial atrophy and subcutaneous fibrosis. Although RT-induced radiation dermatitis has been well studied, interventions for soft tissue disease involving the external auditory canal (EAC) warrant investigation. Medical management includes topical steroid treatment for EAC radiation dermatitis and topical antibiotic therapy for suppurative otitis externa. Hyperbaric oxygen and pentoxifylline-vitamin E therapy have shown promise for other applications, but their clinical effect on soft tissue EAC disease is currently undefined.

Reconstruction of Moderately and Severely Atrophic Scalp-A Multicentric Experience in Surgical Treatment of Patients Irradiated for Tinea Capitis in Childhood and Surgical Algorithm

Background and Objectives: Before the introduction of griseofluvin, the use of X-ray radiation was the treatment of choice for tinea capitis. More than half a century later various types of tumors have been found to be associated with childhood irradiation due to tinea capitis, most commonly cancers of the head and neck, as well as brain tumors. The often unusually aggressive and recurrent nature of these tumors necessitates the need for repeated surgeries, while the atrophic skin with an impaired vascular supply due to radiation often poses an additional challenge for defect reconstruction. We present our experience in the surgical treatment of such patients. Materials and Methods: This is a retrospective cohort study. In this study, 37 patients treated for acquired defects of the scalp with a history of irradiation therapy due to tinea capitis in childhood were included in this study, 24 male and 13 female patients. The mean age at the first appointment was 60.6 ± 7.8, with the youngest included patient being 46 and the oldest being 75 years old. Patients' characteristics, surgical treatment, and complications were analyzed and a reconstructive algorithm was developed. Results: Local flaps were used for reconstruction in 34 patients, direct sutures were used in 10 patients and 20 patients received split-thickness skin grafts for coverage of both primary and secondary defects for reconstruction of flap donor sites. One regional flap and one dermal substitute covered by an autologous skin graft were also used for reconstruction. Complications occurred in 43.2% of patients and were significantly associated with the presence of comorbidities (p = 0.001), aseptic bone necrosis (p = 0.001), as well as skin atrophy in frontal, occipital, and parietal region (p = 0.001, p = 0.042 and p = 0.001, respectively). A significant correlation between major complications and moderate skin atrophy was found only in the parietal region (p = 0.026). Conclusions: Unfortunately, many protocols developed for scalp reconstruction are not applicable in the setting of severe or diffuse scalp skin atrophy associated with high tumor recurrence rate and radiation-induced vascular impairment, such as in tinea capitis patients in Serbia. An algorithm has been developed based on the authors' experience in managing these patients.

Recognition and Management of the Long-term Effects of Cranial Radiation

OPINION STATEMENT

Cranial radiation is ubiquitous in the treatment of primary malignant and benign brain tumors as well as brain metastases. Improvement in radiotherapy targeting and delivery has led to prolongation of survival outcomes. As long-term survivorship improves, we also focus on prevention of permanent side effects of radiation and mitigating the impact when they do occur. Such chronic treatment-related morbidity is a major concern with significant negative impact on patient's and caregiver's respective quality of life. The actual mechanisms responsible for radiation-induced brain injury remain incompletely understood. Multiple interventions have been introduced to potentially prevent, minimize, or reverse the cognitive deterioration. Hippocampal-sparing intensity modulated radiotherapy and memantine represent effective interventions to avoid damage to regions of adult neurogenesis. Radiation necrosis frequently develops in the high radiation dose region encompassing the tumor and surrounding normal tissue. The radiographic findings in addition to the clinical course of the patients' symptoms are taken into consideration to differentiate between tissue necrosis and tumor recurrence. Radiation-induced neuroendocrine dysfunction becomes more pronounced when the hypothalamo-pituitary (HP) axis is included in the radiation treatment field. Baseline and post-treatment evaluation of hormonal profile is warranted. Radiation-induced injury of the cataract and optic system can develop when these structures receive an amount of radiation that exceeds their tolerance. Special attention should always be paid to avoid irradiation of these sensitive structures, if possible, or minimize their dose to the lowest limit.

Tetramethylpyrazine Attenuates Radiation-Induced Ototoxicity in a Rat Model

INTRODUCTION

Tetramethylpyrazine (TMP) is a chemical compound, which has been shown to possess numerous biological features such as anticoagulation, inhibition of platelet aggregation, anti-inflammation, capillary dilatation, improvement in microcirculation, and protection against reactive oxygen radicals. The aim of the present study was to investigate the protective effect of TMP against radiation-induced ototoxicity.

MATERIALS AND METHODS

40 rats were divided into four groups. The first group was irradiated for 5 days. The second group received a single dose of 140 mg/kg/day intraperitoneal TMP given to the rats 30 min before radiotherapy (RT) for 5 days. The third group received a single dose of 140 mg/kg/day i.p. TMP for 5 days, whereas the fourth group was administered saline. All rats underwent distortion product otoacoustic emission (DPOAE) and auditory brainstem response measurements before and after the application. The temporal bulla of animals was removed for immunohistopathological examination.

RESULTS

Signal-noise ratio values were significantly decreased in the RT group for the frequencies of 2-32 kHz after RT (p < 0.05), whereas the difference was not significant in terms of pre- and posttreatment values for the other groups. Also in the RT group, the ABR thresholds were significantly increased after treatment. In H&E staining, the mean scores for outer hair cells (OHCs), stria vascularis (SV), and spiral ganglion (SG) injuries were significantly higher in RT and RT + TMP groups than in the other groups. The mean OHCs and SV injury scores were also significantly higher in the RT group than in the RT + TMP group (p < 0.05). The number of cochleas that showed cytoplasmic caspase-3 immunoreactivity in the OHC, SV, and SG was significantly higher in RT and RT + TMP groups than in the other groups.

CONCLUSION

The findings of the present study suggest that TMP may have a therapeutic potential for preventing sensorineural hearing loss (SNHL) related to RT.

The dose-dependent impact of γ-radiation reinforced with backscatter from titanium on primary human osteoblasts

In head and neck cancer patients receiving dental implants prior to radiotherapy, backscatter from titanium increases the radiation dose close to the surface, and may affect the osseointegration. The dose-dependent effects of ionizing radiation on human osteoblasts (hOBs) were investigated. The hOBs were seeded on machined titanium, moderately rough fluoride-modified titanium, and tissue culture polystyrene, and cultured in growth- or osteoblastic differentiation medium (DM). The hOBs were exposed to ionizing γ-irradiation in single doses of 2, 6 or 10 Gy. Twenty-one days post-irradiation, cell nuclei and collagen production were quantified. Cytotoxicity and indicators of differentiation were measured and compared to unirradiated controls. Radiation with backscatter from titanium significantly reduced the number of hOBs but increased the alkaline phosphatase activity in both types of medium when adjusted to the relative cell number on day 21. Irradiated hOBs on the TiF-surface produced similar amounts of collagen as unirradiated controls when cultured in DM. The majority of osteogenic biomarkers significantly increased on day 21 when the hOBs had been exposed to 10 Gy, while the opposite or no effect was observed after lower doses. High doses reinforced with backscatter from titanium resulted in smaller but seemingly more differentiated subpopulations of osteoblasts.

Eustachian Tube Functions in Concurrent Chemoradiotherapy for Head and Neck Cancer Patients

Ototoxicity is a dose-limiting adverse event for concurrent chemoradiotherapy (CCRT) with high-dose cisplatin for locally advanced head and neck squamous cell carcinoma (HNSCC). Both irradiation to the Eustachian tube (ET) and weight loss are risk factors for patulous ET. The aim of this prospective, observational study was to elucidate the incidences of patulous ET conditions before and after CCRT in HNSCC patients by means of ET function tests. This prospective, observational study was conducted in 27 HNSCC patients who received CCRT with high-dose cisplatin, and ET function tests (sonotubometry and tubo-tympano-aerodynamic graphy) were performed before and 3 months after CCRT. Factors potentially affecting the incidence of patulous ET conditions after CCRT were evaluated. Of the 54 ears from 27 patients investigated, patulous ET conditions were observed in 12 ears (22.2%) from 9 patients (33.3%) before CCRT and 15 ears (27.8%) from 11 patients (40.7%) at 3 months after CCRT. Only patulous ET conditions before CCRT in each ear were significantly associated with patulous ET conditions after CCRT (p = 0.010). This is the first report to describe the incidences of patulous ET conditions before and after CCRT in HNSCC patients. HNSCC patients are potentially at higher risk of patulous ET.

Copper-containing titanium alloys promote angiogenesis in irradiated bone through releasing copper ions and regulating immune microenvironment

Poor vascularization was demonstrated as a factor inhibiting bone regeneration in patients receiving radiotherapy. Various copper-containing materials have been reported to increase angiogenesis, therefore might improve bone formation. In this study, a Ti6Al4V-1.5Cu alloy was prepared using selective laser melting (SLM) technology. The immunomodulatory and pro-angiogenic effects of the Ti6Al4V-1.5Cu alloys were examined. In vitro, Ti6Al4V-1.5Cu stimulated vascular formation by restraining inflammatory factors and provoking angiogenic factors in non-irradiated and irradiated macrophages. In vivo, the angiogenic effects of the Ti6Al4V-1.5Cu alloy were confirmed using an irradiated rat femur defect model. Moreover, we found that the biological effects of the Ti6Al4V-1.5Cu alloy were partially due to the release of copper ions and associated with PI3K-Akt signaling pathway. In conclusion, this study indicated the potential of the Ti6Al4V-1.5Cu alloy to promote angiogenesis by releasing copper ions and inhibiting inflammation in normal and irradiated tissues.

Special Considerations for Tympanoplasty Type I in the Oncological Pediatric Population: A Case-Control Study

Introduction

Although cutting-edges antineoplastic therapies increase survival in children with malignancies, the optimal surgical strategy to address associated comorbidities such as chronic tympanic membrane perforation is still poorly documented. The aim of this study is to evaluate the outcomes of type I tympanoplasty in pediatric cancer survivors who received chemo and/or radiotherapy to the skull and to identify potential associated risk factors.

Methods

This case-control study included medical records review of oncologic patients (age <21) treated at the same Academic medical oncologic center between March 2015 and July 2021 and referred for conductive hearing loss and chronic tympanic membrane perforation. Patients and middle ear status-related variables were analyzed, and outcomes were compared with matched peers without any history of malignancies.

Results

A total of seven pediatric cancer survivors and seven paired children without any history of malignancies were included in this report. The mean age at tympanoplasty type I surgery was 10.2 years (range = 4.3–19.9; median = 7.9 years) for the pediatric cancer survivors' group and 10.1 years (range = 5.5–19.2; median = 7.9 years) in the control group. Three pediatric cancer patients had received chemotherapy alone, one patient had radiotherapy to the skull base, and three patients had received chemoradiotherapy. On average, surgery was performed 3.9 years after chemo and/or radiotherapy termination, except for 1 patient for whom the tympanoplasty was performed during chemotherapy treatment. A retroauricular approach was used for one of the pediatric cancer patients, a transcanal approach was performed in one other and five patients benefited from an otoendoscopic approach. Tragal perichondrium with cartilage was used in most of the pediatric cancer survivor cases (four out seven cases) while xenograft (Biodesign) and Temporalis fascia without cartilage graft were used in five out of the seven control cases. Rate of tympanic membrane perforation recurrence was similar between groups (28.6%). Mean functional gain for air conduction Pure Tone Average (AC PTA) was 2.6 and 7.7 dB HL for the oncologic and control group, respectively. Mean postoperative air-bone gap (ABG) was 10.7 dB HL [median = 8.7; inter-quartile range (IQR) = 13.8] for the oncologic cohort and 10.1 dB HL (median = 10.7; IQR = 9.6) for the control group.

Discussion

Chemo- and chemoradiotherapy to the skull are associated with damages to the inner and middle ear structures with secondary eustachian tube dysfunction and chronic middle ear effusion. Although healing abilities and immunological defenses are compromised as part of the expected effects of antineoplastic therapies, type I tympanoplasty can be safe and effective in this population. While different approaches may be considered, otoendoscopy showed excellent results with less morbidity in this vulnerable population.

Sensorineural Hearing Loss in Nasopharyngeal Carcinoma Survivors in the Modern Treatment Era - The Early and Late Effects of Radiation and Cisplatin

AIMS

Hearing loss is a common debilitating complication in nasopharyngeal carcinoma (NPC) survivors. The aim of the present study was to investigate the impact of inner ear/cochlear radiation dose and cisplatin use on early and late sensorineural hearing loss (SNHL) in NPC patients treated with radiotherapy alone, concurrent chemoradiation (cCRT) and induction chemotherapy followed by cCRT (iCRT) in the intensity-modulated radiotherapy era.

MATERIALS AND METHODS

The study included 81 NPC patients treated with intensity-modulated radiotherapy between 2014 and 2016. Pure tone audiometry was carried out at baseline and follow-up. The effects of cochlear/inner ear radiation and cisplatin doses on early (<12 months) and late (≥24 months) SNHL were analysed using multivariable regression after adjusting for important predictors.

RESULTS

In total, 156 ears were examined. In early SNHL (n = 136), cisplatin use predicted the incidence of early high-frequency SHNL (HF-SNHL) (odds ratio 6.4, 95% confidence interval 1.7-23.9, P = 0.005). Ninety ears were analysed for late SNHL (median follow-up 38 months). Inner ear/cochlear radiation and cisplatin doses and better pre-treatment hearing were independent predictors of threshold change at 4 kHz. Every 10 Gy increase in inner ear/cochlear Dmean resulted in 5-dB and 6-dB threshold changes, respectively (cochlear Dmean: B = 0.005, 95% confidence interval 0.0004-0.009, P = 0.031; inner ear Dmean: B = 0.006, 95% confidence interval 0.001-0.010, P = 0.014). Cisplatin use was associated with late HF-SNHL (odds ratio 3.74, 95% confidence interval 1.1-12.3, P = 0.031). In the cCRT and iCRT subgroups, no cisplatin dose-dependent ototoxicity was observed. Severe (≥30 dB) late HF-SNHL occurred in 14% and 25% of the patients when the cochlear dose constraints were 40 Gy and 44 Gy, respectively. The radiotherapy-alone group did not develop severe late HF-SNHL.

CONCLUSION

Cochlear/inner ear radiation dose and cisplatin use showed differential and independent ototoxicity in early and late SNHL. As cochlear/inner ear dose-dependent ototoxicity was demonstrated, the cochlear dose constraint should be as low as reasonably achievable, especially when cisplatin is also administered.

Insight into the current practice of ototoxicity monitoring during cisplatin therapy

Background

The aim of this study is to evaluate the current state of ototoxicity monitoring for patients receiving cisplatin chemotherapy in an academic medical center with particular attention to how closely monitoring adheres to national ototoxicity guidelines.

Methods

Case series including retrospective medical records review of patients (age > 18) treated with cisplatin at University of California Davis Medical Center between January 2014 and August 2017. Patient and ototoxicity related variables were analyzed. Patients that underwent a transfer of care during treatment and with less than 3 months of follow-up were excluded.

Results

Three hundred seventy-nine patients met study criteria, of which 104 (27.4%) had a prior history of hearing loss. Prior to treatment, 196 (51.7%) patients were counseled regarding the ototoxic nature of cisplatin and 92 (24.3%) patients had a pretreatment audiogram. During treatment, 91 (24%) patients had documented otologic complaints. Only 17 patients (4.5%) patients had an audiogram ordered during their cisplatin treatment period. 130 (34.3%) patients had otologic complaints following cisplatin treatment. Audiograms were ordered for 20 (7.8%), 13 (5.1%), and 16 (6.2%) patients at 1-month, 3-month, and 6-month follow-ups, respectively. No patients in the study cohort received baseline, treatment, and post-treatment audiograms as recommended by national ototoxicity monitoring protocols. Patients with Head and Neck Cancer (HNC) represented the largest subgroup that received cisplatin (n = 122, 32.2%) and demonstrated higher rates of ototoxicity counseling (n = 103, 84.4%) and pretreatment audiograms (n = 70, 57.4%) compared to the non HNC group (n = 36, 36.2%, P < 0.0001 and n = 22, 8.5%, P < 0.0001).

Conclusions

There is poor adherence to national ototoxicity monitoring guidelines at a large academic medical center. This is a missed opportunity for intervention and aural rehabilitation. Improved education and collaboration between otolaryngology, audiology, and medical oncology is needed to develop and promote an effective ototoxicity-monitoring program.

Graphical abstract

Radiation Necrosis of the Lateral Skull Base and Temporal Bone

Radiation therapy plays a critical role in the treatment of malignancies involving the head and neck. Although the therapeutic effects of ionizing radiation are achieved, normal tissues are also susceptible to injury and significant long-term sequelae. Osteoradionecrosis of the temporal bone (ORNTB) is among the many complications that can arise after therapy. ORNTB is a debilitating and potentially lethal condition that continues to challenge patients and treating physicians. Herein, we review the pathophysiology, presentation, work-up, and management of ORNTB.

Is the risk of idiopathic sudden sensorineural hearing loss higher in nasopharyngeal carcinoma than in hypopharyngeal cancer? A population-based study

BACKGROUND

The aim of this study was to compare the risk of developing sudden sensorineural hearing loss (SSHL) in patients with hypopharyngeal cancer with that in patients with nasopharyngeal carcinoma (NPC).

METHODS

A population-based, retrospective cohort study was performed using the Taiwan National Health Research Database databank. Patients selected for this study were diagnosed with hypopharyngeal cancer or NPC and treated with radiotherapy in the period from 2001 to 2004. Routine follow-up was conducted for 8 years (2004-2012), and the incidence of SSHL was calculated at the final follow-up.

RESULTS

There was no significant difference in the risk of developing SSHL between the hypopharyngeal cancer group and its control group (p = 1.000). In hypopharyngeal cancer and NPC groups, the rates of SSHL were 0.12% and 1.00%, respectively (p < 0.001). The cumulative hazard of SSHL during the follow-up period was significantly higher in the NPC group than in the control group (p < 0.001).

CONCLUSION

Radiotherapy in patients with hypopharyngeal cancer did not increase the risk of developing SSHL, but postirradiation NPC was significantly associated with an increased incidence of SSHL.

Cell therapy stimulates bone neoformation in calvaria defects in rats subjected to local irradiation

BACKGROUND

The purpose of the study was to analyze the effect of cell therapy on the repair process in calvaria defects in rats subjected to irradiation.

METHODS

Bone marrow mesenchymal cells were characterized for osteoblastic phenotype. Calvariae of male Wistar rats were irradiated (20 Gy) and, after 4 weeks, osteoblastic cells were placed in surgically created defects in irradiated (IRC) and control animals (CC), paired with untreated irradiated (IR) and control (C) animals. After 30 days, histological and microtomographic evaluation was performed to establish significant (P < 0.05) differences among the groups.

RESULTS

Higher alkaline phosphatase detection and activity, along with an increase in mineralized nodules, in the IRC, C and CC groups compared to the IR group, confirmed an osteoblastic phenotype. Histology showed impaired bone neoformation following irradiation, affecting bone marrow composition. Cell therapy in the IRC group improved bone neoformation compared to the IR group. Microtomography revealed increased bone volume, bone surface and trabecular number in IRC group compared to the IR group.

CONCLUSION

Cell therapy may improve bone neoformation in defects created after irradiation.

Mandibular Invasion by Oral Squamous Cell Carcinoma: Clinicopathologic Features of 74 Cases

OBJECTIVES

(1) For patients with oral squamous cell carcinoma (OSCC) and mandibular invasion, to determine whether prior radiation to the head and neck region (PXRTHN) affects the density of osteoblasts, osteoclasts, or fibroblasts along the tumor interface invading the mandible and whether this is significantly associated with overall survival. (2) To identify clinicopathologic features that are associated with overall survival.

STUDY DESIGN

Case series with chart review.

SETTING

University of Missouri hospital.

SUBJECTS AND METHODS

Retrospective review of 74 cases with pathologically confirmed mandible invasion by OSCC and surgical treatment between January 1, 2005, and December 31, 2015. A board-certified anatomic pathologist reviewed the slides from all mandibulectomy cases.

RESULTS

The mean density of osteoclasts was 2.0 per linear mm among the patients with PXRTHN and 7.1 among those without PXRTHN ( P < .001). Positive soft tissue frozen section margin was significantly associated with overall survival on univariate analysis ( P < .001; hazard ratio [HR], 0.34; 95% CI, 0.19-0.62) and multivariate analysis ( P = .026; HR, 0.41; 95% CI, 0.19-0.90). Maximum tumor dimension was significantly associated with overall survival on univariate analysis ( P = .021; HR, 1.19; 95% CI, 1.03-1.38) and multivariate analysis ( P = .002; HR, 1.49; 95% CI, 1.16-1.93). Osteoclast, osteoblast, and fibroblast density were not associated with overall survival.

CONCLUSIONS

(1) Osteoclast density along the tumor front is significantly lower among patients with PXRTHN. Stromal cell density was not associated with overall survival. (2) Positive soft tissue frozen section margin and maximum tumor dimension are significantly associated with overall survival among patients with mandibular invasion by OSCC.

Surgical management of temporal bone osteoradionecrosis: Single surgeon experience of 47 cases

PURPOSE

To report the outcomes of 47 patients with temporal bone osteoradionecrosis treated primarily with surgical resection in order to analyze whether flap type and hyperbaric oxygen use affect wound breakdown.

MATERIALS AND METHODS

Between January 1998 and January 2016, 47 patients were treated for temporal bone osteoradionecrosis with surgery. Some patients were also treated with hyperbaric oxygen. Resection of grossly necrotic temporal bone was followed by immediate reconstruction with local, regional, or free flaps. Minimum follow-up was 6months. If patients had breakdown of their initial reconstructions, secondary reconstruction was performed with either a regional or free flap. During the post-operative period, wound breakdown, flap complications, and patient survival were noted.

RESULTS

30 patients developed ORN from primary radiotherapy while 17 had post-operative radiation. It was found that wound breakdown was significantly associated with type of flap reconstruction (p=0.02) with local flap reconstruction portending a poorer prognosis. Hyperbaric oxygen was not associated with decreased wound breakdown (p=0.5).

CONCLUSIONS

Surgical treatment can be an effective treatment for temporal bone osteoradionecrosis, without hyperbaric oxygen providing any additional benefit. Reconstruction with regional or free flaps may be a more reliable method to resurface defects compared to local flaps.

Treatment of late sequelae after radiotherapy for head and neck cancer

Radiotherapy (RT) is used to treat approximately 80% of patients with cancer of the head and neck. Despite enormous advances in RT planning and delivery, a significant number of patients will experience radiation-associated toxicities, especially those treated with concurrent systemic agents. Many effective management options are available for acute RT-associated toxicities, but treatment options are much more limited and of variable benefit among patients who develop late sequelae after RT. The adverse impact of developing late tissue damage in irradiated patients may range from bothersome symptoms that negatively affect their quality of life to severe life-threatening complications. In the region of the head and neck, among the most problematic late effects are impaired function of the salivary glands and swallowing apparatus. Other tissues and structures in the region may be at risk, depending mainly on the location of the irradiated tumor relative to the mandible and hearing apparatus. Here, we review the available evidence on the use of different therapeutic strategies to alleviate common late sequelae of RT in head and neck cancer patients, with a focus on the critical assessment of the treatment options for xerostomia, dysphagia, mandibular osteoradionecrosis, trismus, and hearing loss.

Potential for low-value palliative care of patients with recurrent head and neck cancer

Curative treatment for patients with advanced head and neck cancer can be associated with many side-effects, and many patients suffer from persistent treatment-related side-effects. Patients with recurrent cancer bear the burden of these effects along with additional symptoms attributed to the recurrent tumour. To better understand the benefits and burden of palliative treatments for patients with recurrent head and neck cancer, we reviewed the evidence on commonly used palliative treatments and their effect on quality of life. When used for palliative care purposes, chemotherapy and radiotherapy have limited effectiveness in improving quality of life. Moreover, if these treatments are not congruent with a patient's end-of-life goals, they could constitute low-value care. We recommend that patients with advanced and recurrent cancer should be offered early, comprehensive palliative and supportive services to maximise benefit. The principles of beneficence and respect for patients in the context of shared decision making must prevail if the trust of this vulnerable patient population is to be honoured.