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author:("ohi, masami")
1.  Computer-aided beam arrangement based on similar cases in radiation treatment-planning databases for stereotactic lung radiation therapy 
Journal of Radiation Research  2012;54(3):569-577.
The purpose of this study was to develop a computer-aided method for determination of beam arrangements based on similar cases in a radiotherapy treatment-planning database for stereotactic lung radiation therapy. Similar-case-based beam arrangements were automatically determined based on the following two steps. First, the five most similar cases were searched, based on geometrical features related to the location, size and shape of the planning target volume, lung and spinal cord. Second, five beam arrangements of an objective case were automatically determined by registering five similar cases with the objective case, with respect to lung regions, by means of a linear registration technique. For evaluation of the beam arrangements five treatment plans were manually created by applying the beam arrangements determined in the second step to the objective case. The most usable beam arrangement was selected by sorting the five treatment plans based on eight plan evaluation indices, including the D95, mean lung dose and spinal cord maximum dose. We applied the proposed method to 10 test cases, by using an RTP database of 81 cases with lung cancer, and compared the eight plan evaluation indices between the original treatment plan and the corresponding most usable similar-case-based treatment plan. As a result, the proposed method may provide usable beam arrangements, which have no statistically significant differences from the original beam arrangements (P > 0.05) in terms of the eight plan evaluation indices. Therefore, the proposed method could be employed as an educational tool for less experienced treatment planners.
PMCID: PMC3650748  PMID: 23249674
radiotherapy treatment planning; similar planning cases; computer-assisted method; beam arrangements; stereotactic lung radiotherapy
2.  Transnasal Marsupialization Using Endoscopic Sinus Surgery for Treatment of Keratocystic Odontogenic Tumor in Maxillary Sinus 
Case Reports in Otolaryngology  2012;2012:281402.
Objective. We report the first utilisation of transnasal marsupialization to treat a keratocystic odontogenic tumor in the maxillary sinus of a 37-year-old man. Case Report. A 37-year-old man presented with a nasal discharge and right odontalgia. Computed tomography revealed an expanding cystic lesion with a calcificated wall containing an impacted tooth in the right maxillary sinus. The diagnosis was keratocystic odontogenic tumor. Transnasal marsupialization was performed using endoscopic sinus surgery to enlarge the maxillary ostium and remove a portion of the cystic wall. Pathological findings included lining squamous epithelium and inflammation. The remaining tumor shrank, becoming free of infection after surgery, without proliferation. Conclusion. Transnasal marsupialization using endoscopic sinus surgery is effective in treating keratocystic odontogenic tumors. It offers minimal surgical invasion and reductive change, making it advantageous for complete removal with fewer complications in the bones and surrounding tissue in the case of secondary surgery.
PMCID: PMC3465887  PMID: 23056975
3.  Computerized estimation of patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy 
Journal of Radiation Research  2012;53(6):961-972.
We have developed a computerized method for estimating patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy. The patient setup errors were estimated based on a template-matching technique that compared the portal image and a localized pelvic template image with a clinical target volume produced from a digitally reconstructed radiography (DRR) image of each patient. We evaluated the proposed method by calculating the residual error between the patient setup error obtained by the proposed method and the gold standard setup error determined by consensus between two radiation oncologists. Eleven training cases with prostate cancer were used for development of the proposed method, and then we applied the method to 10 test cases as a validation test. As a result, the residual errors in the anterior–posterior, superior–inferior and left–right directions were smaller than 2 mm for the validation test. The mean residual error was 2.65 ± 1.21 mm in the Euclidean distance for training cases, and 3.10 ± 1.49 mm for the validation test. There was no statistically significant difference in the residual error between the test for training cases and the validation test (P = 0.438). The proposed method appears to be robust for detecting patient setup error in the treatment of prostate cancer radiotherapy.
PMCID: PMC3483845  PMID: 22843375
Computerized method; patient setup error; prostate cancer; portal image; digitally reconstructed radiography; template matching technique
4.  Sensorineural Hearing Loss due to Air Bag Deployment 
Case Reports in Otolaryngology  2012;2012:203714.
Deployment of the air bag in a passenger vehicle accident rarely causes otologic injuries. However, sensorineural hearing loss induced by air bag deployment is extremely rare, with only a few cases reported in the English literature. A 38-year-old man involved in a traffic accident while driving his car at 40 km/hour presented with right sensorineural hearing loss and tinnitus, without associated vertigo. Pure-tone audiometry demonstrated elevated thresholds of 30 dB and 25 dB at 4 kHz and 8 kHz, respectively, on the right side. Air bag deployment in car accidents is associated with the risk of development of sensorineural hearing loss.
PMCID: PMC3420767  PMID: 22953102
5.  Dysphagia due to Diffuse Idiopathic Skeletal Hyperostosis 
Case Reports in Otolaryngology  2012;2012:123825.
Diffuse idiopathic skeletal hyperostosis (DISH) is usually asymptomatic. However, rarely, it causes dysphagia, hoarseness, dyspnea, snoring, stridor, and laryngeal edema. Herein, we present a patient with DISH causing dysphagia. A 70-year-old man presented with a 4-month history of sore throat, dysphagia, and foreign body sensation. Flexible laryngoscopy revealed a leftward-protruding posterior wall in the hypopharynx. Computed tomography and magnetic resonance imaging revealed a bony mass pushing, anteriorly, on the posterior hypopharyngeal wall. Ossification included an osseous bridge involving 5 contiguous vertebral bodies. Dysphagia due to DISH was diagnosed. His symptoms were relieved by conservative therapy using anti-inflammatory drugs. However, if conservative therapy fails and symptoms are severe, surgical treatments must be considered.
PMCID: PMC3420730  PMID: 22953098
6.  Thoracic Saccular Aortic Aneurysm Presenting with Recurrent Laryngeal Nerve Palsy prior to Aneurysm Rupture: A Prodrome of Thoracic Aneurysm Rupture? 
Case Reports in Otolaryngology  2012;2012:367873.
Left recurrent laryngeal nerve palsy rarely results from cardiac disease. We present 2 cases of left recurrent laryngeal nerve palsy caused by thoracic saccular aortic aneurysms. One patient suffered an aortic aneurysm rupture one month after the advent of hoarseness, necessitating emergency surgery with aortic arch replacement. The other patient underwent elective aortic arch replacement surgery. Both saccular aortic aneurysms protruded downward in the aortopulmonary window to compress the recurrent laryngeal nerves. This is only the 5th case report of the rare occurrence of acute recurrent laryngeal nerve palsy subsequent to saccular aneurysm rupture in the English literature. Recurrent laryngeal nerve palsy does not always indicate imminent aneurysm rupture, but should trigger awareness of a potential rupture in the near future. Left recurrent laryngeal nerve palsy might be a prodrome of aneurysm rupture.
PMCID: PMC3420719  PMID: 22953111

Results 1-6 (6)