Hidenari Akiba

Prognostic factors of nasopharynx tumors investigated by MR imaging and the value of MR imaging in the newly published TNM staging

PURPOSE To examine the usefulness of MR imaging for predicting local control of nasopharyngeal carcinoma (NPC) and the value of MR imaging in the newly published fifth edition of the TNM classification. METHODS AND MATERIALS We studied 29 patients with NPC with MR imaging and CT before and after treatment. Staging was done according to the fourth and newly published fifth editions of the International Union Against Cancer (UICC) staging system. The radiotherapy protocol was designed to deliver 66 to 68 Gy to the primary tumor and clinically involved nodes. RESULTS MR proved better than CT at identifying obliteration of the pharyngobasilar fascia, invasion of the sinus of Morgagni, through which the cartilaginous portion of the eustachian tube and the levator veli palatini muscle pass, invasion of the skull base, and metastases to lymph nodes in the carotid and retropharyngeal spaces. All seven patients without invasion of the pharyngobasilar fascia had local control. The local control rates of patients with invasion of the skull base were not good (60 to 73%). There was no apparent relationship between tumor volume determined by T1-weighted MR images and local control when the tumor volume was more than 20 cc. The newly published N staging system appears to successfully identify the high-risk group for distant metastasis as N3. In our series, four of five patients with N3 disease developed distant metastases. CONCLUSION Deep infiltration of the tumor is a more important prognostic factor in NPC than tumor volume. Since the newly published T staging system requires a search for tumor invasion into soft tissue such as parapharyngeal space and bony structures, MR imaging may be indispensable for the newly published NPC staging system.

Radiotherapy for Kimura's disease: the optimum dosage.

PURPOSE To evaluate retrospectively the optimum dosage of irradiation for Kimuras disease. METHODS AND MATERIALS Twenty patients with Kimuras disease were treated with radiotherapy. The sex ratio was 19 males to 1 female. The mean ages at onset, initial treatment, and radiotherapy were 26.2, 29.5, and 32.2 years, respectively. Radiotherapy was mainly applied for residual or recurrent tumors. The eosinophil count increased by more than 10% in 18 of the 20 patients. In most instances, irradiation was given through a single field with dosages ranging from 20 to 44 Gy. RESULTS At the completion of radiotherapy, a marked response in tumor size was noted in all cases. The minimum follow-up was 48 months. Local control was obtained in 23 of 31 lesions (74.1%). At dosages of < or =25 Gy, 26-30 Gy, and > 30 Gy, local control was obtained in 2 of 8 (25.0%), 9 of 10 (90.0%), and 12 of 13 sites (92.3%), respectively. CONCLUSIONS Radiotherapy is an effective treatment for Kimuras disease. This strongly suggests that no surgical procedure other than a biopsy should be carried out. The radiation field should be limited to the lesion and swelling of the adjacent lymph nodes as much as possible, with a optimum dosage of 26-30 Gy regardless of tumor size.

Vascular Compressive Abducens Nerve Palsy Disclosed by Magnetic Resonance Imaging

PURPOSE To assess magnetic resonance imaging as a diagnostic tool of neurovascular compression in a patient with abducens nerve palsy. METHODS We performed magnetic resonance imaging of the brainstem of a 46-year-old patient with left abducens nerve palsy using spoiled gradient recalled acquisition in the steady state (SPGR), which allows high-resolution T1-weighted imaging and detection of the arteries across the plane of slices as a high-signal-intensity area. RESULTS Computed tomography of the brain was unremarkable except for leftward shifting of the basilar artery. As disclosed by magnetic resonance imaging with the SPGR, the right vertebral artery was shifted to the left and joined with the left vertebral artery, and the left abducens nerve was compressed by the vertebral artery. No other abnormal signals were seen in the brainstem. CONCLUSIONS These findings suggest that the abducens nerve palsy in this patient was caused by vascular compression at the root exit zone. Magnetic resonance imaging with the SPGR is useful for the diagnosis of vascular compressive neuropathy.

Vascular compression of the oculomotor nerve disclosed by thin-slice magnetic resonance imaging

PURPOSE To describe the thin-slice magnetic resonance imaging features of vascular compressive oculomotor nerve paresis. METHODS We performed thin-slice (2 mm thick) magnetic resonance imaging of the brainstem in a 74-year-old woman with right partial oculomotor nerve paresis using spoiled gradient recalled acquisition in the steady state. RESULTS Thin-slice magnetic resonance images disclosed that the right oculomotor nerve was compressed and dislocated superiorly and laterally by the tortuous basilar artery. No other abnormalities were observed. CONCLUSION This is the first case report of vascular compressive oculomotor nerve paresis disclosed by thin-slice magnetic resonance imaging.

Radiotherapy of Vertebral Hemangiomas

Between 1975 and 1996, 14 patients (11 females, 3 males) with vertebral hemangioma received treatment with radiotherapy. Thirteen patients had a history of back pain or lumbago and 2 patients had neurological symptoms such as sensory impairment or paraplegia. The standard dose administered was 36 Gy in 18 fractions (five treatments per week). In the 13 patients with pain, this was completely or partially relieved. The condition of a man with hypesthesia of the legs deteriorated and a woman with paraplegia who was treated with decompressive laminectomy followed by radiotherapy recovered completely after irradiation. CT scan before irradiation showed thickened trabeculae as small punctate areas of sclerosis in all patients. At MR imaging before irradiation, T2-weighted MR images showed areas of high intensity in all patients and MR images demonstrated lesion enhancement. However, none of the patients who were treated successfully with radiation demonstrated any changes of the affected vertebra in the conventional radiographic films. CT scan or MR imaging, even 5 years after irradiation. Radiological imaging is indispensable for the diagnosis of vertebral hemangiomas but does not appear to be useful for evaluating the effects of radiotherapy.

Double-subtraction maximum intensity projection MR angiography for detecting the artery of Adamkiewicz and differentiating it from the drainage vein

To evaluate the efficacy of double‐subtraction magnetic resonance angiography (MRA) (subtraction of the subtracted venous phase image from the subtracted arterial dominant phase image) for depicting the artery of Adamkiewicz and differentiating it from the drainage vein.

ACCELERATED RADIOTHERAPY FOR T1, 2 GLOTTIC CARCINOMA: ANALYSIS OF RESULTS WITH KI-67 INDEX

PURPOSE Hyperfractionated and accelerated radiotherapy without a split was performed to improve the local control probability of early glottic carcinomas. We analyzed the results of this regimen by using the Ki-67 index. METHODS AND MATERIALS Over a 12-year period, 85 T1N0M0 glottic cancers and 50 T2N0M0 glottic cancers were treated with conventional fractionation (CF) from 1984 to 1989 and with accelerated fractionation (AF) since 1990. The CF program consisted of five daily fractions of 2 Gy per week, for a total of 64 Gy. The AF program consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, for a total of 55 or 58 Gy. The specimens, taken before radiotherapy, were immunohistochemically stained with anti-Ki-67 antibody. RESULTS The 5-year local control probability for T1 tumors was 79.6 +/- 6.9% with CF treatment, whereas with AF it was 86.9 +/- 5.6%. For T2 tumors it was 62.7 +/- 12.2% with CF, whereas it was 74.7 +/- 7.8% with AF. The difference between CF and AF did not reach the point of statistical significance. However, when T1 tumors had a Ki-67 index lower than 50%, the local control rate achieved with AF was significantly better than that with CF (p = 0.018). When the tumors had a Ki-67 index that was 50% or more, there was no difference in the local control rate between CF and AF, whether they were T1 or T2. The peak mucosal reactions at the larynx and/or hypopharynx were much more severe and appeared at smaller doses and earlier in AF than in CF. The patients with AF showed no severe late complications. CONCLUSIONS AF could not obtain statistically significant improvement in local control probability of T1 or T2 glottic carcinomas.

Serial Dynamic Magnetic Resonance Imaging of Orbital Cavernous Hemangioma

PURPOSE To assess serial dynamic magnetic resonance imaging after rapid intravenous injection of contrast material as a tool for diagnosing orbital cavernous hemangioma. METHODS Two patients with orbital cavernous hemangioma were studied. Gadolinium-DTPA, 0.1 mmol/kg, was injected intravenously in 10 seconds. RESULTS On early imaging after the injection, one small point of enhancement was initially noted, and then the tumor was homogeneously enhanced. The initial enhancement point represented the connecting point of feeding vessels to the lesion. CONCLUSIONS Dynamic magnetic resonance imaging is useful for diagnosing cavernous hemangioma and for estimating the connecting point of feeding vessels.

Gadolinium-enhanced dynamic magnetic resonance imaging with endorectal coil for local staging of rectal cancer.

PurposeThe aim of this study was to evaluate the accuracy of dynamic gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) with endorectal coil for assessing tumor invasion based on simple classification criteria.Materials and methodsA total of 58 patients with operable primary rectal cancer underwent preoperative MRI. An enhancement pattern in Gd-enhanced dynamic MRI with regard to tumor penetration was clarified. Retrospectively, two observers independently scored T2-weighted MRI and T2-weighted MRI combined with Gd-enhanced dynamic MRI for tumor penetration using the following criteria: With Gd-enhanced dynamic MRI, T1 tumors showed an early enhanced line around the tumor as rim enhancement; T2 tumors appeared as black lines or double layers, as the muscularis propria kept its integrity; T3 tumors showed partial discontinuity of the muscularis propria as a dotted line and a perforated area as an interrupted line. A confidence level scoring system was used, and receiver operating characteristic curves were generated.ResultsThere were no significant differences at the T1 stage. There were significant differences for observer 1 (P = 0.001 for observer 1) at the T2 stage. There were significant differences for both observers (P = 0.001 for observer 1 and P = 0.005 for observer 2) at the T3 stage.ConclusionOur criteria for Gd-enhanced dynamic MRI were effective for T3 stage tumors.

Effects of blood flow control on clinical outcomes after ethanolamine oleate sclerotherapy for vascular malformations

PurposeThe purpose of this study was to assess the control of nidus blood flow and the association between such control and clinical outcomes after ethanolamine oleate (EO) sclerotherapy for vascular malformations.Materials and methodsMorphological grades on magnetic resonance (MR) images (grades 1–3), preprocedure nidus blood flow control, and clinical results in 22 cases of vascular malformation were reviewed.ResultsCases were subdivided by MR morphological grade as follows: grade 1, 3 patients; grade 2A, 6 patients; grade 3, 13 patients. Responses to EO sclerotherapy were as follows: excellent, 3 patients; good, 5 patients; poor, 14 patients. An excellent response was achieved in one grade 1 case, one grade 2A case, and one grade 3 case. Preprocedure nidus flow was controlled in 8 lesions (type A) and not controlled in 14 lesions (type B). Three (37.5%) type A lesions had an excellent response, five had a good response; and none had a poor response. All type B lesions had a poor response. Flow control predicted an excellent result (P < 0.05).ConclusionPreprocedure nidus blood flow control (versus lack of control) is associated with a significantly higher incidence of favorable clinical responses to EO sclerotherapy for vascular malformations.