Hirobumi Oikawa

The circuit of Papez in mesial temporal sclerosis: MRI.

Abstract We looked at abnormalities in the circuit of Papez in patients with the mesial temporal sclerosis (MTS). We reviewed the MRI studies of 15 patients with probable MTS, seeking changes in the fornix, mamillary body, mamillothalamic tract, thalamus and cingulate and parahippocampal gyri. We correlated any abnormalities with each other and with clinical severity. Atrophy and/or signal change in one or more structures in the circuit of Papez were found in five patients. They involved the parahippocampal gyri in all five, the fornices in four, mamillary bodies in three, the thalamus in two and the cingulate gyrus in one. Changes in the fornix, mamillary body, thalamus or cingulate gyrus were always accompanied by hippocampal and parahippocampal atrophy. The patients with abnormalities of the circuit of Papez did not have more severe epilepsy than those without. Changes in the parahippocampal gyrus, including the entorhinal cortex and subiculum, in which forniceal fibres originate, may be crucial in causing abnormalities more distally in the circuit.

Disorganised unilateral cerebellar folia : a mild form of cerebellar cortical dysplasia?

Abstract We describe MRI findings in two patients with disorganised foliation of one cerebellar hemisphere, with folia running vertically rather than horizontally. The thickness of individual folia and corticomedullary interdigitations were normal. These patients have no cerebellar neurological deficit. This rare abnormality is probably a maldevelopment of the hemispheric part of the posterior lobe of the developing cerebellum, and no clinical significance can be elicited.

Three-dimensional summation of rectal doses in brachytherapy combined with external beam radiotherapy for prostate cancer

BACKGROUND AND PURPOSE To determine the dose constraints for rectal bleeding in brachytherapy (BRT) combined with external beam radiotherapy (EBRT). MATERIALS AND METHODS Post-BRT, pelvic computed tomography images were used for subsequent EBRT planning and BRT postplans in 37 patients. The physical doses for each plan were converted to biologically effective doses, and corresponding voxel doses were integrated to plot the summed dose-volume histogram (sum-DVH). Between 5 patients with (bled-pts) and 32 without (spared-pts) grade 2 or 3 rectal bleeding, the differences in the mean minimal dose (rDn) covering the rectal volume of 0.5-10.0 cc and the rectal volume (rVn) receiving the calculated dose of 20-150Gy were compared. RESULTS The differences in the summed-rDn were determined by BRT exposure, while those of the summed-rVn were determined in the low-dose range and superimposed in the high-dose range by EBRT exposure. Of the 13 patients with rV150 of >1.2 cc, 4 were bled-pts (30.8%). Of the 24 patients with rV150 of ≤ 1.2cc, 1 was a bled-pts (4.2%) (p=0.024; odds ratio, 10.2; CI (95%), 1.0-104.3). CONCLUSIONS The mono-scale DVH analysis is a promising method for exploring the threshold for rectal bleeding in combined radiotherapy.

The correlation between spontaneous and radiation-induced apoptosis in T3B bladder cancer (histological grade G3), and the precedence between the two kinds of apoptosis for predicting clinical prognosis

PURPOSE The correlation between the frequency of spontaneous and radiation-induced apoptosis, and the precedence between those for predicting prognosis were studied at clinical level. METHODS AND MATERIALS Twenty-one patients (mean age, 65.8 years; 16 men and 5 women) with bladder cancer (transitional cell carcinoma Grade 3, T3bN0M0, Stage IIIb) underwent intraoperative radiotherapy: single 30-Gy 12-MV electron beam irradiation to bladder, followed by total cystectomy 6 h after irradiation. The specimens of pretreatment and irradiated bladder cancer were assayed for apoptosis, using TUNEL staining with counter staining of hematoxylin. The apoptotic index (AI) was calculated by dividing the number of apoptotic cells by the total number of cells and multiplying by 100. The Pearsons linear fitting was used to test the correlation between spontaneous and radiation-induced apoptosis. The Kaplan-Meier product-limit estimation was used for overall survival (OS) and freedom from recurrence (FFR). The precedence between spontaneous and radiation-induced apoptosis for predicting the clinical prognosis was estimated using the proportional hazard regression. RESULTS The mean AI of spontaneous and radiation-induced apoptosis was 1.18 +/- 0.16 and 2.63 +/- 0.45, respectively, which was significantly different. There was strong correlation between spontaneous and radiation-induced apoptosis (r(2) = 0.864, adjusted r(2) = 0.857). Radiation-induced apoptosis was estimated by equation: y (radiation-induced apoptosis) = 2.67 x (spontaneous apoptosis) -0.52. However, the proportional hazard regression test indicated that only spontaneous apoptosis was significant for predicting OS and FFR (&z.sfnc;t&z.sfnc; > 0.2), but radiation-induced apoptosis was not. CONCLUSION Estimating AI in radiation-induced apoptosis from AI in spontaneous apoptosis is possible. However, spontaneous apoptosis is more accurate in predicting clinical prognosis.

Factors influencing survival outcome for radiotherapy for biliary tract cancer: A multicenter retrospective study

PURPOSE To seek for the possible factors influencing overall survival (OS) with radiotherapy (RT) for biliary tract cancer. MATERIALS AND METHODS Data were collected retrospectively from RT database of 31 institutions in Japan. All patients underwent at least external beam RT. The factors influencing OS were investigated. RESULTS Data of 498 patients were analyzed. Median OS of the 212 patients who underwent surgery was significantly better than that of the 286 patients without surgery (31 vs. 15 months, p<0.001). The OS for the R0 or R1 resection group was significantly longer than that for the R2 or non-surgery group, as well as for n0 compared to n1 (all p<0.001). Chemoradiotherapy (CRT), both sequential and concurrent, resulted in a better OS than RT alone for the n1 group (31 vs. 13 months, p<0.001), and marginally better for the R0/R1 group (p=0.065; p=0.054 for concurrent CRT). However, no such benefit was observed for the R2/non-surgical patients. Multivariate analysis identified performance status, clinical stage, and surgery as significant factors. CONCLUSION Surgery, especially R0/R1 resection, seemed as the gold standard for treatment of biliary tract cancer including RT, even in the highly heterogeneous population obtained from the multicenter retrospective study. The possibility was shown that CRT yielded better survival benefit especially for n1 patients. We recommend that future prospective trials include an arm of adjuvant CRT at least for n1 and possibly R0/R1 patients.

Zero-dark-counting high-speed X-ray photon detection using a cerium-doped yttrium aluminum perovskite crystal and a small photomultiplier tube and its application to gadolinium imaging

X-ray photons are detected using a cerium-doped yttrium aluminum perovskite [YAP(Ce)] single-crystal scintillator with a decay time of 30 ns and a small-sized photomultiplier tube (SPMT). The negative output pulse from the SPMT is amplified by a high-speed inverse amplifier, and the event pulses are sent to a multichannel analyzer to measure X-ray spectra. The energy resolution of the spectrometer was 15% at 59.5 keV. We carried out photon-counting computed tomography using gadolinium media with a maximum rate of 650 kilo counts per second and confirmed the energy-dispersive effect with changes in the description voltage of event pulses using a high-speed comparator.

Impact of Intraluminal Brachytherapy on Survival Outcome for Radiation Therapy for Unresectable Biliary Tract Cancer: A Propensity-Score Matched-Pair Analysis

PURPOSE To determine whether adding intraluminal brachytherapy (ILBT) to definitive radiation therapy (RT) for unresectable biliary tract cancer has a positive impact on survival outcome. METHODS AND MATERIALS The original cohort comprised 209 patients, including 153 who underwent external beam RT (EBRT) alone and 56 who received both ILBT and EBRT. By matching propensity scores, 56 pairs (112 patients) consisting of 1 patient with and 1 patient without ILBT were selected. They were well balanced in terms of sex, age, performance status, clinical stage, jaundice, and addition of chemotherapy. The impact of ILBT on overall survival (OS), disease-specific survival (DSS), and local control (LC) was investigated. RESULTS The 2-year OS rates were 31% for the ILBT+ group and 40% for theILBT- group (P=.862). The 2-year DSS rates were 42% for the ILBT+ group and 41% for the ILBT- group (P=.288). The 2-year LC rates were 65% for the ILBT+ group and 35% for the ILBT- group (P=.094). Three of the 4 sensitivity analyses showed a significantly better LC for the ILBT+ group (P=.010, .025, .049), and another showed a marginally better LC (P=.068), and none of the sensitivity analyses showed any statistically significant differences in OS or DSS. CONCLUSIONS In the treatment for unresectable biliary tract cancer, the addition of ILBT to RT has no impact on OS or DSS but is associated with better LC. Therefore, the role of ILBT should be addressed by other measures than survival benefit, for example, by less toxicity, prolonged biliary tract patency decreasing the need for further palliative interventions, or patient quality of life.

Radiotherapy and Concomitant Intra-Arterial Docetaxel Combined With Systemic 5-Fluorouracil and Cisplatin for Oropharyngeal Cancer: A Preliminary Report—Improvement of Locoregional Control of Oropharyngeal Cancer

PURPOSE To confirm the advantage of chemoradiotherapy using intra-arterial docetaxel with intravenous cisplatin and 5-fluorouracil. PATIENTS AND METHODS A total of 26 oropharyngeal cancer patients (1, 2, 2, and 21 patients had Stage I, II, III, and IVa-IVc, respectively) were treated with two sessions of this chemoradiotherapy regimen. External beam radiotherapy was delivered using large portals that included the primary site and the regional lymph nodes initially (range, 40-41.4 Gy) and the metastatic lymph nodes later (60 or 72 Gy). All tumor-supplying branches of the carotid arteries were cannulated, and 40 mg/m(2) docetaxel was individually infused on Day 1. The other systemic chemotherapy agents included 60 mg/m(2) cisplatin on Day 2 and 500 mg/m(2) 5-fluorouracil on Days 2-6. RESULTS The primary response of the tumor was complete in 21 (81%), partial in 4 (15%), and progressive in 1 patient. Grade 4 mucositis, leukopenia, and dermatitis was observed in 3, 2, and 1 patients, respectively. During a median follow-up of 10 months, the disease recurred at the primary site and at a distant organ in 2 (8%) and 3 (12%) patients, respectively. Three patients died because of cancer progression. Two patients (8%) with a partial response were compromised by lethal bleeding from the tumor bed or chemotherapeutic toxicity. The 3-year locoregional control rate and the 3-year overall survival rate was 73% and 77%, respectively. CONCLUSION This method resulted in an excellent primary tumor response rate (96%) and moderate acute toxicity. Additional follow-up is required to ascertain the usefulness of this modality.

Effects of ellipsoid prostate deformation on dose delivery during permanent interstitial brachytherapy

PURPOSE To elucidate the potential effects of prostate deformation on dose distribution during Iodine-125 ((125)I) seed implantation brachytherapy for prostate cancer. METHODS AND MATERIALS A retrospective analysis of 245 patients who underwent only transperineal brachytherapy for low-risk prostate adenocarcinoma was performed. The maximum diameters of the prostate were measured before treatment by transrectal ultrasound volumetry along right to left (RL), anterior to posterior (AP), and apex to base (Length) directions. The seeds were inserted by the modified peripheral loading method using real-time ultrasound-guided seed placement. The ellipsoid deformation rates in the axial plane (E(ax)) and in the sagittal plane (E(sag)) were defined as [RL-AP]/RL and [Length-AP]/Length, respectively. The correlation between them and the dose-volume histogram parameters at 30 days after the operation was evaluated. A simulation test was additionally performed to ascertain the change in dose distribution among virtual volumes built in a radiotherapy planning device that corresponds to prostates with increased Eax or Esag. RESULTS The mean Esag and Eax of patients were 0.313 (range, -0.28 to 0.844) and 0.261 (range, -0.02 to 0.54), respectively. Esag showed a positive correlation with dose (Gy) covering 90% of the prostate volume (pD(90)), prostate volume (%) covered by 100% of the prescribed dose (pV(100)), the rectal volume (cc) irradiated by 100% of the prescribed dose (rV(100)), and the rectal volume (cc) irradiated by 150% of the prescribed dose (rV(150)), whereas Eax showed a positive correlation with prostate volume (%) covered by 150% of the prescribed dose (pV(150)) and the urethral dose (Gy) delivered to 5% of its volume (uD(5)). The simulation test suggested that the prescribed dose resulted in the best coverage in patients with increased E(sag), and that patients with increased E(ax) exhibited poor urethral sparing from overdosage. CONCLUSION In the seed implantation method, ellipsoid deformation of the prostate causes higher rectal dose exposure or dose delivery to the urethra.

Measurement of X-ray spectra using a Lu2(SiO4)O-multipixel-photon detector with changes in the pixel number.

To measure X-ray spectra with high count rates, we developed a detector consisting of a Lu2(SiO4)O [LSO] crystal with a decay time of 40 ns and a multipixel photon counter (MPPC). The photocurrents flowing through the MPPC are converted into voltages and amplified by a high-speed current-voltage amplifier, and event pulses from the amplifier are sent to a multichannel analyzer to measure spectra. We used three MPPCs of 100, 400 and 1600 pixels/mm(2), and the MPPCs were driven under pre-Geiger mode at a temperature of 20 °C. At a tube voltage of 100 kV and a tube current of 5.0 μA, the maximum count rate was 12.8 kilo-counts per second. The event-pulse widths were 200 ns, and the energy resolution was 53% at 59.5 keV using a 100-pixel MPPC.