Computer simulation study of the penetration of pulsed 30, 60 and 90 GHz radiation into the human ear.

There is increasing interest in applications which use the 30 to 90 GHz frequency range, including automotive radar, 5 G cellular networks and wireless local area links. This study investigated pulsed 30-90 GHz radiation penetration into the human ear canal and tympanic membrane using computational phantoms. Modelling involved 100 ps and 20 ps pulsed excitation at three angles: direct (orthogonal), 30° anterior, and 45° superior to the ear canal. The incident power flux density (PD) estimation was normalised to the International Commission on Non-Ionizing Radiation Protection (1998) standard for general population exposure of 10 Wm-2 and occupational exposure of 50 Wm-2. The PD, specific absorption rate (SAR) and temperature rise within the tympanic membrane was highly dependent on the incident angle of the radiation and frequency. Using a 30 GHz pulse directed orthogonally into the ear canal, the PD in the tympanic membrane was 0.2% of the original maximal signal intensity. The corresponding PD at 90 GHz was 13.8%. A temperature rise of 0.032° C (+20%, -50%) was noted within the tympanic membrane using the equivalent of an occupational standard exposure at 90 GHz. The central area of the tympanic membrane is exposed in a preferential way and local effects on small regions cannot be excluded. The authors strongly advocate further research into the effects of radiation above 60 GHz on the structures of the ear to assist the process of setting standards.

Outcomes of radiotherapy in advanced external auditory canal cancer.

External auditory canal cancer (EACC) is a rare malignant tumor. In the present study, we retrospectively evaluated the treatment results in patients with advanced EACC who were treated using external-beam radiotherapy (EBRT) combined with chemotherapy or radical surgery. Overall, 21 patients with Stage III (n = 8) or Stage IV (n = 13) EACC who underwent initial treatment at our hospital between 2003 and 2016 were enrolled in this study. The 2-year overall survival (OS) and locoregional control (LRC) rates of all patients were 62% and 71%, respectively. The 2-year OS and LRC rates in patients who had received EBRT and concurrent chemotherapy with docetaxel, cisplatin and 5-fluorouracil (TPF, n = 6) were 100%. These results were higher than the 2-year OS and LRC rates of 62% and 69%, respectively, in patients who had received radical surgery and EBRT (n = 13). The rates were 0% in those who had neither received TPF nor undergone surgery in addition to EBRT (n = 2). Grade 3 bone or soft tissue necrosis was observed in 2 patients who had undergone surgery and postoperative EBRT. Our data suggest that the combination therapy of EBRT and surgery and/or chemotherapy may be the most effective treatment options for advanced EACC, and EBRT with concurrent chemotherapy with TPF is potentially the most acceptable.

Malignant external otitis following radiotherapy for oral cancer: A case report.

RATIONALE: Although an ototoxicity is well-known as adverse event of the radiotherapy, it is not widely known that immunosuppressed patients who underwent radiotherapy in head and neck region have risk of malignant external otitis. PATIENT CONCERNS: A 68-year-old man with diabetes, who had been diagnosed as intraosseous squamous cell carcinoma of the right mandible, underwent surgical resection. He received a total of 60 Gy/30Fr postoperative radiation. Four months after the course of radiation, he suffered from right aural fullness, otalgia and otorrhea. DIAGNOSES: Clinical examination revealed granulation and existence of Pseudomonas aeruginosa in the external auditory canal. Computed tomography showed expansive inflammation and erosion in the temporal bone. The patient is elderly and diabetes. These findings led to the diagnosis of malignant external otitis. INTERVENTIONS: The ear irrigation and administration of quinolones were started. Afterwards, fistula was formed in the oral cavity, and connected to the right external auditory canal. Therefore, irrigations were performed not only from ear but also from the oral fistula. OUTCOMES: Eight weeks after starting treatment, the malignant external otitis was completely healed. LESSONS: Physicians should raise awareness of malignant external otitis in immunosuppressed patients with oral cancer after radiotherapy.

Safety assessment of trans-tympanic photobiomodulation.

We evaluated functional and morphological changes after trans-tympanic laser application using several different powers of photobiomodulation (PBM). The left (L) ears of 17 rats were irradiated for 30 min daily over 14 days using a power density of 909.1 (group A, 5040 J), 1136.4 (group B, 6300 J), and 1363.6 (group C, 7560 J) mW/cm(2). The right (N) ears served as controls. The safety of PBM was determined by endoscopic findings, auditory brainstem response (ABR) thresholds, and histological images of hair cells using confocal microscopy, and light microscopic images of the external auditory canal (EAC) and tympanic membrane (TM). Endoscopic findings revealed severe inflammation in the TM of C group; no other group showed damage in the TM. No significant difference in ABR threshold was found in the PBM-treated groups (excluding the group with TM damage). Confocal microscopy showed no histological difference between the AL and AN, or BL and BN groups. However, light microscopy showed more prominent edema, inflammation, and vascular congestion in the TM of BL ears. This study found a dose-response relationship between laser power parameters and TM changes. These results will be useful for defining future allowance criteria for trans-tympanic laser therapies.

Radiation-Induced Necrosis of the Temporal Bone: Diagnosis and Management.

OBJECTIVE: To document our experience with osteoradionecrosis (ORN) of the temporal bone. STUDY DESIGN: Retrospective case review. SETTING: Tertiary care medical center. PATIENTS: Patients who developed exposed necrotic bone of the external auditory canal after radiation therapy to the head and neck. INTERVENTIONS: Temporal bone ORN was managed conservatively in all patients with a combination of systemic antibiotics, antibiotic ear drops, and in-office debridement. Three patients required surgery, two of which were for a cholesteatoma. MAIN OUTCOME MEASURE: The need for surgical intervention in the management of ORN. RESULTS: Twenty-three patients with ORN of the temporal bone comprise the study group. The average age of patients at the time of diagnosis was 58 years (range, 34-75 yr). The parotid gland was the most common primary tumor site (n = 10). The mean lag time from completion of radiotherapy to diagnosis of ORN was 11 years (range, 2-48 yr). The most common presenting symptom was hearing loss (n = 18), followed by tinnitus (n = 13) and otorrhea (n = 13). All 23 patients were managed conservatively with antibiotic therapy and in-office debridement of necrotic bone. None of the patients required temporal bone resection and/or free-flap reconstruction. CONCLUSION: ORN of the temporal bone is a rare adverse event that can occur after radiotherapy for a variety of neoplasms of the head, neck, and central nervous system. Conservative management, which includes directed antibiotic therapy and regular in-office debridement of necrotic bone, can adequately control the disease process and symptomatology, thus avoiding more invasive surgical interventions.

CT and MRI findings of radiation-induced external auditory canal carcinoma in patients with nasopharyngeal carcinoma after radiotherapy.

OBJECTIVE: To summarize the radiological and clinical features of radiation-induced external auditory canal carcinomas (RIEACCs) in patients with nasopharyngeal carcinomas (NPCs) after radiation therapy. METHODS: CT, MRI and clinical features in 16 patients with histologically proven RIEACCs were retrospectively reviewed. There were 2 females and 14 males, with a median age of 52.5 years at the time of diagnosis of RIEACC. Imaging parameters including lesion extent, size, margin, shape, bone destruction, adjacent structure invasion, density/signal intensity, and pattern and degree of enhancement were assessed. Clinical features including clinical staging, histological type, treatment and radiation dose (RD) of primary NPC as well as the histological type, staging of radiation-induced tumour and the latent period between NPC and RIT were recorded. RESULTS: All patients had a single RIEACC. The lesions had a size of 3.5 ± 1.4 cm and were localized (n = 7) or extensive (n = 9). Most of the lesions were partially or ill defined with an irregular shape and had an intermediate density/signal pattern and moderate homogeneous enhancement. The latent period of RIEACCs ranged from 10 to 20 years in nine patients with a RD of 68-70 Gy; from 2 to 10 years in five patients with a RD of 68-74 Gy; and more than 20 years in two patients with a RD of 70 or 72 Gy. CONCLUSION: An external auditory canal (EAC) mass with homogeneous, intermediate CT density or signal intensity in patients with NPC after radiotherapy is highly suggestive of RIEACC, which should be included in the routine surveillance for patients with NPC after radiotherapy. ADVANCES IN KNOWLEDGE: RIEACCs could occur as short as 2 years after radiotherapy in patients with NPC and have distinct features from otitis media and sarcomas. This EAC malignancy should be included in routine surveillance for patients with NPC after radiotherapy.

Effect of low-level laser treatment on cochlea hair-cell recovery after ototoxic hearing loss.

The primary cause of hearing loss includes damage to cochlear hair cells. Low-level laser therapy (LLLT) has become a popular treatment for damaged nervous systems. Based on the idea that cochlea hair cells and neural cells are from same developmental origin, the effect of LLLT on hearing loss in animal models is evaluated. Hearing loss animal models were established, and the animals were irradiated by 830-nm diode laser once a day for 10 days. Power density of the laser treatment was 900 mW/cm(2), and the fluence was 162 to 194 J. The tympanic membrane was evaluated after LLLT. Thresholds of auditory brainstem responses were evaluated before treatment, after gentamicin, and after 10 days of LLLT. Quantitative scanning electron microscopic (SEM) observations were done by counting remaining hair cells. Tympanic membranes were intact at the end of the experiment. No adverse tissue reaction was found. On SEM images, LLLT significantly increased the number of hair cells in middle and basal turns. Hearing was significantly improved by laser irradiation. After LLLT treatment, both the hearing threshold and hair-cell count significantly improved.

Radiation effects on the auditory and vestibular systems.

Definitive or postoperative radiation therapy (RT) is commonly used for the management of intracranial and extracranial head and neck tumors. Because of the variability of tumor location and dimensions, sparing of nontarget normal tissue and organs may not be possible. Treatment modalities that deliver the highest doses of radiation to the auditory system include stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for the treatment of vestibular schwannomas (VS), and fractionated radiotherapy (FRT) or intensity-modulated radiation therapy (IMRT) for the treatment of head and neck malignancies. Radiation therapy for VS is unique because of its involvement of the inner ear and preexisting auditory and vestibular dysfunction. Auditory and vestibular dysfunction following RT for VS may be limited by limiting the total dose of cranial nerve VIII irradiation and by fractionation.

Treatment and outcome of advanced external auditory canal and middle ear squamous cell carcinoma.

This is a retrospective study to evaluate the outcomes and complications of combined treatment, surgery with or without adjunctive intraoperative radiotherapy, of locally advanced temporal bone squamous cell carcinoma. A series of 17 patients with locally advanced squamous cell carcinoma of the temporal bone were treated between September 2002 and February 2007. Eleven patients had primary tumors, and 6 patients had recurrences. According to the University of Pittsburgh staging system, 5 patients were stage II (T2 N0), 6 patients were stage III (5, T3 N0 and 1, T1 N1), and 6 patients were stage IV (5, T3 N2b and 1, T4 N0). All patients underwent lateral temporal bone resection and pedicle flap reconstruction. Eight patients received intraoperative and postoperative radiotherapies, 4 patients underwent postoperative radiation alone, whereas 5 patients did not receive any adjunctive treatment. Median follow-up was 29.5 months. No major complications were observed. No patients were found to have residual gross tumor. Disease-free survival was 73.3%, and overall survival was 75.6%. Radical external auditory canal and/or middle ear canal resection is of utmost importance to obtain a good surgical outcome. Postoperative radiotherapy is necessary to obtain good local control; no major adverse effects were observed in the intraoperative radiotherapy patients. The incidence of major complication is minimal after pedicle flap reconstruction.

Osteoradionecrosis of external auditory canal in nasopharyngeal carcinoma.

BACKGROUND: Osteoradionecrosis (ORN) is one of the most serious complications of radiotherapy of nasopharyngeal carcinoma (NPC). ORN rarely occurs in the external auditory canal. METHODS: This is a retrospective review of 11 NPC patients who had ORN in the external auditory canal. Exposed necrotic bone over the external auditory canal was the diagnostic hallmark. Three patients wore hearing aids and 2 had had previous otological surgery. ORN was detected between 2 and 15 years after radiation therapy (mean 8 years). The radiation dose ranged from 6480 to 8460 rads in 8 patients. RESULTS: The symptoms of external auditory canal ORN were crust (100%), otorrhea (91%), otalgia (91%), hearing impairment (73%), foul odor (45%) and retroauricular discharging fistula (9%), all of which mimicked those of chronic otitis media. After treatment, the diagnoses of 2 patients were rectified to external auditory canal malignancy and external auditory canal cholesteatoma, and the other 9 (82%) patients' diagnoses remained as ORN. After combined treatment with local cleansing, hyperbaric oxygen therapy, sequestrectomy and ear drops, resolution of symptoms was achieved in all the patients. Three patients who underwent sequestrectomy were free of disease. CONCLUSIONS: External auditory canal ORN is rare in NPC patients. The clinical presentation mimics that of chronic otitis media and differentiation is difficult. The disease is prone to occur in patients who wear hearing aids or have had previous surgery. A high index of suspicion is mandatory for early diagnosis. The disease may lead to disastrous complications and should never be neglected by clinicians.

Primary radical radiotherapy for squamous cell carcinoma of the middle ear and external auditory cana--an historical series.

AIMS: To evaluate patients treated with radical radiotherapy alone for squamous cell carcinoma of the middle ear (MEC) and external auditory canal (EAC) in terms of freedom from local recurrence, cancer-specific survival and morbidity. MATERIALS AND METHODS: Between 1965 and 1988, 123 patients were treated, 70 with MEC and 53 with EAC. The median age was 64 years (range 21-86) and 78% presented as late stage. The median dose was 55 Gy (range 39-55) in 16 once daily fractions (range 13-21). RESULTS: At 5 and 10 years, respectively, freedom from local recurrence was 56 and 56%, disease-free survival was 45 and 43%, cancer-specific survival was 53 and 51%, and overall survival was 40 and 21%. Cancer-specific survival was significantly worse with late stage as opposed to early stage (P = 0.0026), as was local recurrence (P = 0.0088). No differences in survival and local control were seen according to site. Radionecrosis developed in 6% of patients. CONCLUSIONS: Combined treatment using radiotherapy and radical surgery is often favoured. This large series shows that radical radiotherapy achieves comparable results in terms of local control and cancer-specific survival. Our radiotherapy regimen is now 55 Gy in 20 daily fractions to reduce late morbidity. Radiotherapy alone remains a viable option, especially as morbidity can be minimised and target volume delineation optimised using computer planning in the future.

Effects of laserneedle stimulation in the external auditory meatus on brainstem and very early auditory evoked potentials in humans.

OBJECTIVES: For the first time, brainstem auditory evoked potentials (BAEP) and very early auditory evoked potentials (EAEP) were investigated in 23 volunteers (mean age: 26.5 +/- 3.6 years) under resting conditions and during continuous and frequency modulated (2 Hz) laser stimulation in the external auditory meatus. METHODS: Using a new ear adapter, the outer region of the auditory canal was stimulated with laser light (685 nm, 4 x 30-40 mW, duration: 10 minutes). RESULTS: The EAEPs were significantly changed during continuous (p=0.019), as well as frequency modulated (p=0.014) laser stimulation compared with control measurements. DISCUSSION: Physiologic alterations of inner ear mechanism such as extra-cerebral changes in conductance or stimulation-dependent depolarization processes in extra-cerebral regions of the auditory system could be possible explanations for the significant difference in measurement parameters.

[Carcinoma of the external auditory canal and middle ear: therapeutic strategy and follow up]. / Therapeutisches Management von Gehörgangs- und Mittelohrkarzinomen.

BACKGROUND: Carcinomas of the external auditory canal (EAC) and the middle ear are rare and considered to have a poor prognosis. The recommended therapeutic strategy consists of surgical excision and postoperative radiotherapy. However, there are different opinions about the extend of the primary operation. PATIENTS AND METHODS: A series of 21 patients with carcinoma of the EAC and middle ear were treated at the ENT-Department of the Hospital Fulda from 1985 to 2003. Their records and radiologic findings were reviewed retrospectively with particular reference to tumor type and size, its relation to surrounding tissues, surgical procedures and radiation techniques. The tumors were staged according to the modified Pittburgh staging system for temporal bone carcinomas. The average follow-up time was 6.2 years (range 0.2 - 18.75). RESULTS: 17 patients suffered from carcinoma of the EAC, 4 carcinomas were primarily located in the middle ear. There were 15 squamous cell carcinomas, 3 adenoidcystic carcinomas, 2 adenocarcinomas and one mucoepidermoid carcinoma. 12 patients came primarily to our institution and were staged as follows: pT1 (n = 2), pT3 (n = 2), pT4 (n = 8). 8 patients showed up with recurrent or residual tumors (all of T3 or T4 stage). One patient could not be classified. In 5 cases the tumor was inoperable. These patients underwent combined chemoradiation therapy. All other 16 patients were operated and most of them received adjuvant radiation therapy. In the group of patients who were primarily operated overall 5-year survival rate was 100 %. In contrast, patients who's recurrent or residual tumors were resected had a 5-year survival rate of only 33 %. Patients who received combined chemoradiation therapy showed a 2-year survival rate of 75 %. CONCLUSION: Carcinoma of the EAC and middle ear should be treated primarily by a lateral or subtotal temporal bone resection stage dependent combined with a parotidectomy as well as a neck dissection. Local resection of the EAC is not sufficient, not even in T1 tumors. As from stage T2, in cases of recurrent tumor removal and questionable free margins as well as in cases with lymph node metastases an adjuvant radiation therapy should be added. The most important survival factor is removal of the primary tumor with histologically clear margins.

External auditory canal stenosis after radiation therapy.

OBJECTIVES: To determine whether the risk of external auditory canal stenosis from external-beam radiation therapy is dose dependent. STUDY DESIGN: Retrospective chart review. METHODS: The presence of external auditory canal disease was recorded for patients who received low-dose (e.g., lymphoma [20-40 Gy]), medium-dose (e.g., chemodectoma [40-55 Gy]), or high-dose (e.g., parotid and nasopharyngeal neoplasms [55-75 Gy]) external-beam radiation therapy from 6 months to over 8 years following treatment. The incidence of external auditory canal disease was compared between groups. RESULTS: None of 13 low-dose, none of 19 medium-dose, and 8 of 91 (8.7%) high-dose external-beam radiation therapy subjects developed ipsilateral external auditory canal stenosis. No external auditory canal stenosis developed in patients treated with high-dose external-beam radiation therapy in the absence of parotid surgery. External auditory canal stenosis developed only in patients treated with parotidectomy and high-dose external-beam radiation therapy (P =.0059), and all of these cases of external auditory canal stenosis developed within 3 years of radiation therapy. CONCLUSIONS: High dose external-beam radiation therapy alone does not significantly predispose patients to external auditory canal stenosis. However, combined high-dose external-beam radiation therapy and surgery around the external auditory canal do significantly increase the risk of external auditory canal stenosis.

Late radiation effects on hearing, vestibular function, and taste in brain tumor patients.

PURPOSE: To investigate late radiation effects on hearing, vestibular function, and taste after conventional radiotherapy in brain tumor patients. METHODS AND MATERIALS: Hearing, vestibular function, and taste were assessed in 33 brain tumor patients irradiated unilaterally to the tumor-bearing hemisphere and the temporal bone. Median observation time after completion of radiotherapy was 13 years; the fraction dose was 1.8 Gy, and mean radiation dose was 53.1 Gy. RESULTS: Deep ulceration in the external ear canal and osteoradionecrosis on the irradiated side was seen in three patients. Reduced hearing was found for air and bone conduction of the irradiated side compared to the opposite side (0.25-2 kHz: 6.1 dB, 4 kHz: 10.3 dB, 6 kHz: 15.6 dB, and 8 kHz: 16.5 dB). For bone conduction, the corresponding figures were 0.25-2 kHz: 5.5 dB and 4 kHz: 8.2 dB. Three patients had a canal paresis of the irradiated side, and three patients had affection of the chorda tympani. CONCLUSION: Irradiation of the temporal bone with doses usually given in the treatment of patients with brain tumors may cause osteoradionecrosis, sensorineural hearing loss, dysfunction of the vestibular inner ear, and loss of taste. Head-and-neck examination should be included in the follow-up of long-term survivors.

[Advanced squamous carcinoma of external ear canal]. / Carcinoma escamoso avanzado de conducto auditivo externo.

Squamous carcinoma of the external ear canal (CEEC) is an uncommon neoplasm which prognostic changes following the tumour spread. Because of its location in ECC as well as the anatomical fissures between osseous and cartilaginous parties it's possible the spread to areas of surgical accessibility complicated restricting the complete tumoral removal. We report one of those cases, when first visited had already meningeal infiltration and was accordingly treated with radiotherapy. Analysis of the case and review of the literature.

An unusual localisation of Kaposi's sarcoma: the external auditory canal.

The epidemic form of Kaposi's sarcoma is associated with human immunodeficiency virus infection. Cutaneous and mucosal manifestations are frequently reported in the ENT sphere, mostly involving the oral cavity. The external and middle ear are only rarely concerned with only one case of a mastoid lesion without extension to the external auditory canal (EAC) being reported to this day. The present article describes the first case of involvement of the EAC with extension to adjacent structures. This patient presented other Kaposi lesions and had been treated by systemic hormonal therapy. Thereafter local injection of a cytotoxic agent was given without effect. Finally, radiotherapy resulted in a 50% regression of the tumour mass. The epidemiologic factors and therapeutic modalities with their results are described.

Pseudoepitheliomatous hyperplasia versus squamous cell carcinoma of the external auditory canal.

Four case reports are presented to demonstrate the clinical and histopathologic similarity of pseudoepitheliomatous hyperplasia (PH) to squamous cell carcinoma (SCC) in the external auditory canal (EAC). In all four cases the original report of SCC on a biopsy specimen of an EAC lesion was corrected on review to PH. In one patient conservative management resulted in resolution of the EAC lesion. A second patient underwent radiation therapy and partial temporal bone resection with no SCC found in the surgical specimen. A third patient's ear canal had healed with conservative treatment and repeated biopsy revealed no malignancy. After a 6-year symptom-free interval, she developed invasive SCC with bone involvement that required surgery and radiation treatment. A fourth patient underwent a sleeve resection of the skin of the EAC that proved to be PH, and no evidence of SCC was found. A thoughtful clinical history, careful physical examination, response to conservative treatment, and close communication with the pathologist should be exercised in the evaluation of EAC lesions.

Osteoradionecrosis of the petrous bone and recurrent cerebrospinal fluid otorrhoea.

A case is reported of delayed necrosis of the petrous bone following a course of radiotherapy for a well-differentiated squamous cell carcinoma in a 60-year-old female who presented with recurrent intractable cerebrospinal fluid otorrhoea, meningitis and pneumocephalus. Multiple attempts at surgical repair of the necrosed dural deficit and tegmental fistula failed and eventually petrousectomy was necessary leading to a successful outcome.

[Malignant melanoma of the temporal bone]. / Malignes Melanom des Felsenbeins.

The present article describes a case of malignant melanoma with the rare localisation in the right temporal bone. The 79-year old female patient presented a polypous tumour with obturation of the outer ear canal and sanguineous otorrhoea (Fig. 1). The inner ear function was impaired showing a combined defective hearing and complete peripheral palsy of the facial nerve as well as an abducens nerve palsy (Fig. 1) with diplopia. CT and MR imaging showed a tumour destroying the temporal bone up to the apex of the pyramid and the clivus reaching the middle cranial fossa (Fig. 2-3). After palliative radiotherapy with 40 Gy the general condition and clinical symptoms improved. After a period of 8 months with no signs of further tumour progression the patient was admitted again in reduced general condition showing pulmonary and pleural metastases. The patient died 14 days later.