Carbon ion radiotherapy for locally advanced squamous cell carcinoma of the external auditory canal and middle ear.

BACKGROUND: The prognosis of advanced squamous cell carcinoma (SCC) of the external auditory canal and middle ear remains poor. Carbon ion radiotherapy (C-ion RT) has shown promise for locally advanced head and neck cancer. Therefore, we evaluated the safety and efficacy of C-ion RT for locally advanced SCC of the external auditory canal and middle ear. METHODS: The cases of 13 patients with advanced (T3 and T4) SCC of the external auditory canal and middle ear who received C-ion RT as the primary treatment were reviewed. RESULTS: The median follow-up for all patients and the 7 surviving patients was 12 and 32 months, respectively. The 1-year and 3-year local control and overall survival (OS) rates were 72% and 54% and 70% and 40%, respectively. Severe temporal bone necrosis was observed in 2 patients. CONCLUSION: C-ion RT is effective and generally safe for locally advanced SCC of the external auditory canal and middle ear.

Feasibility of carbon ion radiotherapy for locally advanced sinonasal adenocarcinoma.

BACKGROUND AND PURPOSE: To evaluate the safety and efficacy of carbon ion radiotherapy (CIRT) for locally advanced sinonasal adenocarcinoma. MATERIAL AND METHODS: Twenty-two patients with sinonasal adenocarcinoma were treated with CIRT. CIRT was the primary treatment for 16 patients. Four patients received CIRT for local recurrence after surgery and two for residual tumour after surgery or chemotherapy. At the start of CIRT, 1 patient had T-classification (T) 2 disease, 2 had T3 disease, 5 had T4a disease, and 14 had T4b disease. Fourteen patients were treated with 57.6 Gy equivalent (GyE)/16 fractions, and 8, with 64.0 GyE/16 fractions. RESULTS: The median follow-up period was 43 months for all patients. The 3-year local control and loco-regional control rates for all patients were 76.9% (95% confidence interval [CI]=56.7-97.1%) and 61.3% (95% CI=38.5-84.1%), respectively. The 3-year overall survival and disease-specific survival rates were 59.1% (95% CI=38.6-79.6%) and 65.6% (95% CI=44.9-86.3%), respectively. Acute reactions of grade 3 of the skin and mucosa were observed in 2 and 4 patients, respectively. Late reactions included lateral visual loss (5 patients), mucosal ulceration (1 patient), and brain necrosis with clinical symptoms (1 patient). In the 5 patients who developed visual loss, the optic nerve was close to the tumour. CONCLUSIONS: CIRT was effective and generally safe for locally advanced sinonasal adenocarcinoma.

Effects of the dose-volume relationship on and risk factors for maxillary osteoradionecrosis after carbon ion radiotherapy.

BACKGROUND: Osteoradionecrosis (ORN) is a critical complication after carbon ion (C-ion) or photon radiotherapy (RT) for head and neck tumors. However, the risk factors for ORN after C-ion RT remain unclear. Therefore, the present study aimed to investigate the effects of the dose-volume relationship on and risk factors for ORN development after C-ion RT. We, however, focused on the maxillary bone because most tumors treated with C-ion RT were primarily located in the sinonasal cavity. METHODS: The patients enrolled in this study received more than 10% of the prescribed total dose of 57.6 Gy equivalent (GyE) in 16 fractions to their maxilla. All patients were followed up for more than 2 years after C-ion RT. Those with tumor invasion to the maxilla before C-ion RT or local recurrence after the treatment were excluded from the study to accurately evaluate the effects of irradiation on the bone. Sixty-three patients were finally selected. The severity of ORN was assessed according to the Common Terminology Criteria for Adverse Events version 4.0. The correlation between clinical and dosimetric parameters and ORN incidence was retrospectively analyzed. RESULTS: The median follow-up period was 79 months. Of the 63 enrolled patients, 26 developed ORN of grade ≥1. Multivariate analysis revealed that the maxilla volume receiving more than 50 GyE (V50) and the presence of teeth within the planning target volume were significant risk factors for ORN. Dose-volume histogram analysis revealed that V10 to V50 parameters were significantly higher in patients with ORN than in those without ORN. CONCLUSIONS: V50 and the presence of teeth within the planning target volume were independent risk factors for the development of ORN after C-ion RT using a 16-fraction protocol.

Aberrant internal carotid artery in the middle ear with a deficiency in the origin of the anterior cerebral artery: a case report.

An aberrant internal carotid artery (ICA) in the middle ear is rare and difficult to diagnose, and may lead to severe complications. We present here a case of aberrant ICA with a deficiency in the origin of the anterior cerebral artery. The only symptom was aural fullness, and a nonpulsatile and white tympanic mass in the anteroinferior area was noted. Computed tomography (CT) and magnetic resonance angiography (MRA) are useful tools that provide excellent visualization of the temporal bone for the diagnosis of aberrant ICA by the following features: intratympanic mass, enlarged inferior tympanic canaliculus, absence of the vertical segment of the ICA canal, and absence of bone covering the tympanic portion of the ICA. In addition, in this case, a deficiency in the origin of the anterior cerebral artery on the same side was identified by MRA, and cerebral arteriography and a carotid occlusion test were performed. Because of the deficiency in the origin of the anterior cerebral artery, the ICA compression revealed that there was almost no cross flow from the other ICA. Our experience illustrates that after confirmation of the diagnosis of aberrant ICA, localized treatment and/or surgical procedures should be considered carefully.