The Pseudo-Pelger huët Cell as a Retrospective Dosimeter: Analysis of a Radium Dial Painter Cohort.

Recently, the pseudo-Pelger Huët anomaly in peripheral blood neutrophils has been described as a new radiation-induced, stable biomarker. In this study, pseudo-Pelger Huët anomaly was examined in peripheral blood slides from a cohort of 166 former radium dial painters and ancillary personnel in the radium dial industry, 35 of whom had a marrow dose of zero above background. Members of the radium dial painter cohort ingested Ra and Ra at an early age (average age 20.6 ± 5.4 y; range 13-40 y) during the years 1914-1955. Exposure duration ranged from 1-1,820 wk with marrow dose 1.5-6,750 mGy. Pseudo-Pelger Huët anomaly expressed as a percentage of total neutrophils in this cohort rises in a sigmoidal fashion over five decades of red marrow dose. Six subjects in this cohort eventually developed malignancies: five osteosarcomas and one mastoid cell neoplasm. The pseudo-Pelger Huët anomaly percentage in these cases of neoplasm increases with marrow dose and is best fit with a sigmoid function, suggestive of a threshold effect. No sarcomas are seen for a marrow dose under 2 Gy. These results indicate that pseudo-Pelger Huët anomaly in peripheral blood is a reasonable surrogate for the estimation of alpha dose to bone marrow in historic radiation cases. Hypotheses are discussed to explain late (months to years), early (hours to days), and intermediate (weeks to months) effects of ionizing radiation, respectively, on the expression of genes encoding inner nuclear membrane proteins and their receptors, on the structure and function of nuclear membrane proteins and lipids, and on cytokinesis through chromatin bridge formation.

Role of mastoid pneumatization in temporal bone fractures.

BACKGROUND AND PURPOSE: The mastoid portion of the temporal bone has multiple functional roles in the organism, including regulation of pressure in the middle ear and protection of the inner ear. We investigated whether mastoid pneumatization plays a role in the protection of vital structures in the temporal bone during direct lateral trauma. MATERIAL AND METHODS: The study was performed on 20 human temporal bones isolated from cadavers. In the study group formed by 10 temporal bone samples, mastoid cells were removed and the resulting neocavities were filled. The mastoids were maintained intact in the control group. All samples were impacted at the same speed and kinetic energy. The resultant temporal bone fractures were evaluated by CT. RESULTS: Temporal squama fractures were 2.88 times more frequent, and mastoid fractures were 2.76 times more frequent in the study group. Facial nerve canal fractures were 6 times more frequent in the study group and involved all the segments of the facial nerve. Carotid canal fractures and jugular foramen fractures were 2.33 and 2.5 times, respectively, more frequent in the study group. CONCLUSIONS: The mastoid portion of the temporal bone plays a role in the absorption and dispersion of kinetic energy during direct lateral trauma to the temporal bone, reducing the incidence of fracture in the setting of direct trauma.

Radiation-induced middle ear and mastoid opacification in skull base tumors treated with radiotherapy.

PURPOSE: To assess the incidence of middle ear (ME) pathology in patients treated with radiotherapy (RT) for skull base tumors. METHODS AND MATERIALS: A retrospective analysis of 61 patients treated with RT between 2003 and 2008 for skull base tumors was conducted. Clinical outcomes and demographics were reviewed. Dose-volume histogram analysis was performed on the eustachian canal (EC), ME, mastoid air cells, vestibular apparatus, cochlea, internal auditory canal, lateral and posterior nasopharynx, and temporal lobes to relate doses to symptoms and radiographic change. Otomastoid opacification was rated 0 (none), 1 (mild), 2 (moderate), and 3 (severe) by a neuroradiologist blinded to clinical outcomes and doses. RESULTS: The median prescribed dose was 50.4 Gy (range, 14-74 Gy). The ME mean dose was 14 Gy and 34 Gy for Grade 0-1 and 2-3 opacification, respectively (p<0.0001). The mean mastoid dose was 10 Gy and 26 Gy for Grade 0-1 and 2-3, respectively (p<0.0001). The mean EC dose was 17 Gy and 32 Gy for Grade 0-1 and 2-3, respectively (p=0.0001). Otomastoid opacification resolved in 17 of 40 patients (42.5%), at a mean of 17 months after RT (range, 2-45 months). Otomastoid opacification persisted in 23 of 40 patients (57.5%), with a mean follow-up of 23 months (range, 2-55 months). Multivariate analysis showed that mastoid dose>30 Gy (odds ratio=28.0, p<0.001) and posterior nasopharynx dose of >30 Gy (odds ratio=4.9, p=0.009) were associated with Grade 2-3 effusions, whereas other factors including dose to EC and ME were not significant. CONCLUSIONS: A mean RT dose>30 Gy to the mastoid air cells or posterior nasopharynx is associated with increased risk of moderate to severe otomastoid opacification, which persisted in more than half of patients at 2-year follow-up.

Parosteal osteosarcoma of the mastoid bone following radiotherapy for nasopharyngeal carcinoma.

Radiation-induced tumors subsequent to nasopharyngeal carcinoma are very rare. To date, no post-irradiation parosteal osteosarcoma of the craniofacial bone has been reported in the English literature. In October 2000, a 57-year-old Chinese woman presented 5 years after radiotherapy for nasopharyngeal carcinoma with a 6-month history of a gradually enlarging left postauricular mass. CT scans revealed a densely calcified mass with radiating bony spicules, applied to left mastoid tip. The lesion was excised en-bloc through a postauricular incision. The histologic diagnosis was a parosteal osteosarcoma. Because of inadequate safe margins and the patient refusal of another surgery, 6600 cGy of radiation was subsequently administered to the temporal bone. Post-operative follow-up in 3 years was negative for any evidence of tumor recurrence and post-irradiation complications.

Extra-oral craniofacial endosseous implants and radiotherapy.

This paper discusses the use of extra-oral endosseous craniofacial implant (EOECI) therapy in irradiated bone. The survival rate of EOECIs in irradiated bone is reviewed and the controversy over the optimal time prior to place implants is described. The advantages and disadvantages of pre- and post-implant radiotherapy are addressed. The EOECI rehabilitation and osteoradionecrosis and the evidence of the potential role of hyperbaric oxygen are reviewed. Strategies for improving the clinical outcome of EOECIs are suggested.

Radiation dose to otologic structures during head and neck cancer radiation therapy.

BACKGROUND: Otologic structures are often contained within head and neck cancer radiation treatment ports. The dosimetry to otologic structures has not been routinely analyzed and radiation treatment planning does not currently attempt to specifically avoid the inner ear structures when dosimetry is calculated. Recent studies demonstrate that up to 30% of patients experience sensorineural hearing loss on multimodality therapy with cisplatin and radiation. METHODS: In the current case series, radiation dosimetry to otologic structures was calculated from computed tomogram treatment plans on patients. Fifteen nasopharyngeal, oral cavity, oropharyngeal, and hypopharyngeal cancer patients were analyzed. RESULTS: Between 8% and 102% of the total dose is delivered to the petrous bone/cochlea, with 4 of 15 patients getting more than 50% of the dose to at least one cochlea The mastoid air cells received between 3% and 75% of the total dose, with higher doses being delivered to patients with bulky high neck metastases or nasopharyngeal tumors. The eustachian tubes received between 20% and 102% of the total dose, with 10 of 15 patients receiving more than 50% of the dose to this anatomic site. CONCLUSION: We conclude that the cochlea and eustachian tubes receive significant radiation during treatment, particularly in nasopharyngeal cancer patients. Careful design of radiation treatment ports may allow for the reduction of radiation to hearing structures.

MR evaluation of radiation otomastoiditis.

PURPOSE: The purpose of this study was to evaluate the incidence of radiation otomastoiditis, on using T2-weighted magnetic resonance (MR) imaging, in relation to radiation fields, doses, intervals, and clinical symptoms after radiotherapy that included the temporal bone in the fields. METHODS AND MATERIALS: We performed follow-up MR examinations at various intervals after radiotherapy including the temporal bones for 270 ears of 114 patients with various diseases of the head and neck and intracranial regions. The middle ear and mastoid air cells on T2-weighted images were scored as follows; showing no high signal intensity, a local high signal intensity area, or a high signal intensity area occupying the entire middle ear and all mastoid air cells. The radiation fields as depicted on the lateral simulator films classed as anterior to the clival line, posterior to the clival line, or both. RESULTS: The incidence of radiation otomastoiditis depicted on T2-weighted MR images increased in the patients who had received irradiation doses of 50 Gy or more. In the patients with doses of less than 50 Gy, the incidence was 18% within 6 months following radiotherapy, 13% at between 6 and 12 months, and 8% after 12 months, whereas it was more than 50% at any period after radiotherapy in the patients with 50 Gy or more. The incidence of radiation otomastoiditis was quite high in the patients whose radiation fields included region both anterior and posterior to the clival line. CONCLUSION: The incidence of radiation otomastoiditis as demonstrated on T2-weighted MR images is increased at irradiation doses of 50 Gy or more. To reduce the incidence of severe radiation otomastoiditis, the irradiation fields of the temporal bone when the dose is 50 Gy or more should be limited to as small as possible. The clival line is considered to be a good landmark in reducing the irradiation field when doses of 60-70 Gy are delivered in curative radiotherapy.

Plasmacytoma of the middle ear and mastoid.

Extramedullary plasmacytomas are rare plasma cell tumors of the soft tissue that predominantly occur in the head and neck. They are most commonly seen in the upper respiratory passages and oral cavity. There have been only a few reports in the world literature of plasmacytomas occurring within the temporal bone. This report presents a case of plasmacytoma of the middle ear and mastoid that presented as a middle ear mass. Work-ups for systemic dissemination and multiple myeloma were negative, classifying this as a localized extramedullary plasmacytoma. This is the first report in the English literature of this malignant tumor occurring as an isolated lesion within the middle ear and mastoid. The patient was treated with surgical debulking and radiotherapy with complete resolution of the tumor. Although extremely rare, plasmacytoma should to be included in the differential for soft tissue tumors of the middle ear and mastoid.

Radiotherapy in the treatment of middle ear and mastoid carcinoma.

The treatment of temporal bone carcinoma is a widely discussed topic with marked variation in published results. Most conclude that a combination of radical surgery and radiotherapy is the optimum treatment. The present study reviews the results of radiotherapy used as the main primary treatment for this condition. Five-year survival in 56 patients was 32% for radical and palliative therapy, with an excellent response in 'early' cases. It is concluded that improvement in survival could be attained by defining those groups which would benefit from a combination of treatment methods.