SU-E-J-26: Automated Estimation Method of Patient Setup Errors Using Simulated Portal Images for Prostate Cancer Radiotherapy.

PURPOSE: We developed a novel automated estimation method for patient setup errors based on simulated and real portal images for prostate cancer radiotherapy. METHODS: The estimation of patient setup errors in this study was based on a template matching technique with a cross-correlation coefficient and Sobel filter between the real portal image and localized pelvic template of reference image, which were DRR (digitally reconstructed radiography) images and simulated portal images. The simulated portal image was derived by projecting a CT image according to an inverse exponential power law of x-ray attenuation for a water-equivalent path length of each voxel of the CT image on each ray from a source to each pixel on the EPID (electric portal imaging device). A localized pelvic template of each patient in AP (anterior-posterior) or lateral view was automatically extracted from the DRR or simulated portal images by cropping a rectangular region, which was determined by using the mean pelvic template and four anatomical feature points. We applied the proposed method to three prostate cancer cases, and evaluated it using the residual error between the patient setup error obtained by proposed method and the gold standard setup error determined by two radiation oncologists. RESULTS: The average residual errors of the patient setup error for the DRR and simulated portal images were 0.79 and 1.26 mm in the left-right (LR) direction, 3.17 and 2.05 mm in the superior-inferior (SI) direction, 1.69 and 5.82 mm in the anterior-posterior (AP) direction, 3.84 and 6.94 mm in Euclidean distance (ED), respectively. If we used the simulated portal image for LR and SI directions and the DRR image for AP direction, the Euclidean distance was 3.22 mm. CONCLUSIONS: The proposed method has a potential to correctly estimate patient setup errors for prostate cancer radiotherapy.

SU-E-I-91: Development of a Compact Radiographic Simulator Using Microsoft Kinect.

PURPOSE: Radiographic simulator system is useful for learning radiographic techniques and confirmation of positioning before x-ray irradiation. Conventional x-ray simulators have drawbacks in cost and size, and are only applicable to situations in which position of the object does not change. Therefore, we have developed a new radiographic simulator system using an infrared-ray based three-dimensional shape measurement device (Microsoft Kinect). METHODS: We made a computer program using OpenCV and OpenNI for processing of depth image data obtained from Kinect, and calculated the exact distance from Kinect to the object by calibration. Theobject was measured from various directions, and positional relationship between the x-ray tube and the object was obtained. X-ray projection images were calculated by projecting x-rays onto the mathematical three-dimensional CT data of a head phantom with almost the same size. The object was rotated from 0 degree (standard position) through 90 degrees in increments of 10 degrees, and the accuracy of the measured rotation angle values was evaluated. In order to improve the computational time, the projection image size was changed (512*512, 256*256, and 128*128). RESULTS: The x-ray simulation images corresponding to the radiographic images produced by using the x-ray tube were obtained. The three-dimensional position of the object was measured with good precision from 0 to 50 degrees, but above 50 degrees, measured position error increased with the increase of the rotation angle. The computational time and image size were 30, 12, and 7 seconds for 512*512, 256*256, and 128*128, respectively. CONCLUSIONS: We could measure the three-dimensional position of the object using properly calibrated Kinect sensor, and obtained projection images at relatively high-speed using the three-dimensional CTdata. It was suggested that this system can be used for obtaining simulated projection x-ray images before x-ray exposure by attaching this device onto an x-ray tube.

SU-E-J-117: Computer-Assisted Verification of Accumulated Dose Distribution during the Treatment Time Based on Estimation of Four-Dimensional Dose Distribution Using an Electronic Portal Imaging Device.

PURPOSE: The accumulated dose distributions during the course of radiation treatment are substantially important for verifying whether treatment dose distributions are produced according to planned dose distributions. The purpose of this study was to develop a computer-assisted verification method of accumulated dose distribution during the irradiation of a tumor based on estimation of four-dimensional (4D) dose distribution using an electronic portal imaging device (EPID). METHODS: The 4D 'treatment' computed tomography (CT) images during the irradiation were estimated based on affine transformations including respiratory motions, which were derived by registration between a planning portal dose image and treatment portal dose dynamic image. Planning portal dose images were calculated from planning CT images and an algorithm for calculation of dose spatial distribution. Treatment portal dose images were estimated from EPID dynamic images obtained during a treatment time. The planning portal dose images were registered to the treatment portal dose images to obtain the affine transformation, which could include respiratory motion in a patient body. The CT images at a treatment time were determined by deforming the planning CT images using the affine transformation matrix. 4D dose distributions during a treatment delivery were obtained by applying a dose calculation algorithm to the 4D treatment CT images. Finally, accumulated dose distributions during the course of radiation treatment were verified with planned dose distributions. RESULTS: We applied the proposed method to EPID dynamic images of 2 lung cancer patients, and evaluated the difference in accumulated dose distribution between the plan and treatment using a gamma evaluation (3mm/3%). The average pass rate for 2 cases was 78.2%. CONCLUSIONS: The proposed method can be used for adaptively modifying the plan based on the dose discrepancy between the plan and treatment. This work was partially supported by Grant-in-Aid for Scientific Research (C) (22611011) and Okawa Foundation for Information and Telecommunications.

Muscle endurance and power spectrum of the triceps brachii in wheelchair marathon racers with paraplegia.

OBJECTIVE: To investigate differences in triceps brachii endurance and electrical activity between elite marathon and recreational wheelchair athletes with paraplegia. DESIGN AND METHODS: Nine male elite wheelchair athletes between 20 and 46 years of age (average 29.0 +/- 8.2 years) with complete (ASIA-A) T4-L1 paraplegia were compared to a group of six male height- and weight-matched recreational wheelchair athletes with similar ages and injuries. Right triceps brachii maximum voluntary contraction (MVC), as well as the duration of the ability to maintain a 50% MVC were determined for all subjects. Median frequency (MF) and mean power frequency (MPF) were evaluated with fast Fourier transform spectrum analysis. MF and MPF rates of change were calculated and compared with the Student's t-test. SETTING: : Department of Rehabilitation Medicine, University of Occupational and Environmental Health, Japan. RESULTS: Right triceps brachii MVCs of the marathoners (42.4 +/- 8.8 N m (range 33-55 N m)) and recreational athletes (41.6 +/- 9.3 N m (range 32-56 N m)) did not differ significantly (P = 0.63). Endurance, however, did. All of the athletes, but none of the control subjects, were able to maintain a 50% MVC contraction of the right triceps brachii for 2 min (the average contraction duration in the latter group was 75.5+/-16.2 s). MF and MPF of the triceps brachii decreased linearly in both groups, but the slopes in the marathoners (-8.9 +/- 4.6 (-3.8 to -16.4) and -9.7 +/- 4.6 (-4.0 to -17.2)%/min, respectively) were statistically less steep than those in the recreational athletes (-22.3 +/- 8.2 (-9.6 to -31.4) and -21.2 +/- 6.4 (-11.4 to -28.6)%/min, respectively). CONCLUSION: Elite marathoners and active wheelchair users have similar triceps brachii strength. The marathoner's triceps brachii, however, display a significantly improved endurance and a slower decline of MF and MPF with time than do those of their recreational athlete control group.

Subjective evaluations and objective measurements of the ischial-ramal containment prosthesis.

We examined 12 transfemoral amputees, 6 using the IRC socket and 6 the QL socket, to confirm whether the ischial-ramal containment (IRC) socket is truly superior to the quadrilateral (QL) socket. In subjective evaluation, the IRC group was significantly better in the total score and in items of comfort, that is, to sit on a chair and lumbar lordosis at heel off (Mann-Whitney test, P < 0.05), better but not significant in the items of comfortable to wear, comfortable to go up and down stairs, and truncal sway during stance phase. By computed tomography, the femur of the IRC group was kept in a position significantly more medial than that of the QL group (Mann-Whitney test, P < 0.05); but no significant difference in gluteal medial muscle atrophy ratios between the two groups was found (Mann-Whitney test, P > 0.05). By X-ray, the stump of the IRC group was maintained significantly more adducted during one foot standing on the prosthesis (Mann-Whitney test, P < 0.05), but the lateral force ratio during mid-stance of the IRC group was smaller, but not significantly, than that of the QL group. Physiological cost index (PCI), an indirect simple method for evaluating oxygen consumption of gait, had no significant difference between the two groups (Mann-Whitney test, P > 0.05), and a multiple regression analysis revealed that the stump length ratio and lateral force ratio during mid-stance were significant explanatory variables for predicting PCI (adjusted R square: 0.87, F-value: 11.85, P < 0.05). The results of this study have revealed that the advantage of the IRC socket is a tender feeling of the stump, but that the metabolic efficiency is not superior to the QL socket at the most comfortable speed.

Isokinetic strength of elbow extensor muscles correlates with race time in wheelchair half marathon racers.

It has been reported that grasping power and isometric muscle strength of elbow extensors in fine wheelchair racers were greater than the poor racers in the wheelchair full marathon. The purpose of the present study was to investigate the relationship between muscle strength of elbow extensors and flexors and the race time in wheelchair half marathon race. Four wheelchair half marathon racers who completed the half marathon division of the 16th Oita International Wheelchair Marathon (OIWM) in 1996 participated in the present study. The day before the race, all subjects reported to the training room and the isokinetic muscle strength of elbow extensor and flexor muscle groups was measured at angular speeds of 60 degrees, 120 degrees and 240 degrees/sec using the isokinetic dynamometer. There was a significant correlation between race time and isokinetic muscle strength of the elbow extensors at 60 degrees, 120 degrees and 240 degrees/sec, but not flexor muscles. Our findings suggest that increased muscle strength of elbow extensors may improve the race time in wheelchair half marathon race.

Static exercise-induced increase in blood pressure in individuals with cervical spinal cord injury.

OBJECTIVE: To compare the pressor response to static exercise in subjects with cervical spinal cord injury (SCI) at the C6 to C8 level with that in able-bodied control subjects. In these SCI subjects, the descending supraspinal sympathetic neurons and afferent pathways from the contracting muscles to peripheral vessels via the medullary cardiovascular center are damaged. DESIGN: Mean arterial blood pressure, heart rate, and plasma concentrations of norepinephrine, epinephrine, renin activity, vasopressin, aldosterone, and human atrial natriuretic peptide were measured during a 2-minute period of sustained contraction of elbow flexor group muscle in 7 SCI subjects and 7 age-matched able-bodied control subjects. RESULTS: Static exercise resulted in a significant increase in mean blood pressure (p<.05) in both SCI subjects (pre-exercise. 74.7+/-2.2 mm Hg; static exercise, 81.9+/-4.1 mm Hg) and control subjects (pre-exercise, 101.0+/-4.2 mm Hg; static exercise, 117.0+/-4.9 mm Hg). In SCI subjects, there was no change in heart rate during exercise, whereas in control subjects heart rate increased during exercise (p<.05) (pre-exercise, 8.7+/-3.8 beats/min: static exercise, 76.0+/-3.1 beats/min). There were no significant changes in the hormone levels in the SCI subjects throughout the experiment. CONCLUSION: The significant increase in mean blood pressure observed in the present study indicates the presence of peripheral control from muscle receptors and evoked pressor response during static exercise in SCI subjects.

Exogenous recombinant human IL-12 augments MHC class I antigen expression on human cancer cells in vitro.

We investigated whether expressions of MHC class I and class II antigens relevant to tumor antigen presentation were changed on human tumor cells cultured with or without recombinant human IL-12(rhIL-12). We showed that the expression of MHC class I antigen on UTC-8, 28-1Cl and SBC-3 cells was augmented when these cancer cells were cultured with rhIL-12. The expression of class II antigen was slightly raised on UTC-8 and 28-1Cl cells by rhIL-12, but not enhanced on SBC-3 cells. These results suggest that rhIL-12 may provide possible enhancement of immunologic tumor recognition, and cytotoxic activity of lymphocytes against tumors through the enhanced expression of MHC class I antigen.

Spectral electromyographic fatigue analysis of back muscles in healthy adult women compared with men.

OBJECTIVE AND DESIGN: To investigate the difference in back muscle endurance between normal adult women and men using surface electromyographic (EMG) power spectral analyses. METHODS: Forty-five healthy subjects (22 men and 23 women) were studied during an unsupported trunk holding test for 120 seconds. Recording surface electrodes were placed over each erector spinae muscle at L1 level. OUTCOME MEASURES: Median frequency (MF), mean power frequency (MPF), and zero crossing rate (ZCR) were evaluated using the ME3000P Fast Fourier Transform spectrum analysis program. The rate of change was determined for each parameter during the test, and correlation was examined by Pearson's correlation. RESULTS: The negative slopes of all indices of back muscle fatigue were significantly steeper in men than in women. CONCLUSION: Our results indicated that the trunk holding test combined with EMG power spectral analysis of lumbosacral muscles is useful for the evaluation of fatigue performance of these muscles. Our results also showed a higher muscle endurance in healthy adult women than in men.

Disuse muscle atrophy of lower limbs in hemiplegic patients.

OBJECTIVE: To clarify the histopathologic findings from lower limb muscles in hemiplegic patients and determine whether the findings are related to the severity of paralysis or daily physical activity. DESIGN: Nonrandomized control trial. SETTING: Referral center. PATIENTS: Eight patients were selected from 21 hemiplegic persons who underwent a muscle biopsy, and the controls were four men who had no abnormal findings in their histopathology. MAIN OUTCOME MEASURES: Morphometric evaluations of bilateral vastus lateralis muscles on the involved (I-VL) and non-involved (N-VL) sides in eight hemiplegic subjects, five flexor hallucis longus muscles on the involved side (I-FHL), and vastus lateralis muscles of four controls (C-VL) were performed. Muscle fiber diameters were measured with an image analyzer, and atrophy factors, hypertrophy factors, and fiber type proportions were calculated based on the data. RESULTS: The morphometric measurements revealed that the hemiplegic patients had type 2 fiber atrophy, type 2B fiber atrophy, and type 2 fiber atrophy with type 1 fiber hypertrophy in the I-VL, N-VL, and I-FHL, respectively, and that the controls had no muscle fiber atrophy or hypertrophy. The muscle fiber atrophy in the hemiplegic patients was not related to the period after the onset, the severity of paralysis, or activities of daily living score but was related to daily physical activity. CONCLUSIONS: Although the hemiplegic patients had undergone rehabilitative treatments, which did not include muscle strengthening exercises, in a hospital without a board-certified doctor of rehabilitation medicine, a considerable amount of muscle atrophy was found characteristic of changes seen in disuse.

Neuroradiological applications of a new system of stereoscopic biplane digital subtraction angiography.

A stereoscopic biplane digital subtraction angiography (DSA) system was developed, capable of obtaining frontal and lateral projections simultaneously during a single injection of contrast medium. This new system combines the advantages of both biplane and stereoscopic single-plane DSA, and permits high-quality neuroangiography.

Serum insulin-like growth factor-I (IGF-I) in normal Japanese adults.

To evaluate surgical and medical treatment of GH-producing pituitary tumors and GH supplement to GH-deficient patients, we determined the reference values for serum IGF-I in Japanese adults. The serum IGF-I concentration in 454 apparently healthy subjects (246 men aged 21-70 years and 208 women aged 21-72 years) was measured with a commercial RIA kit after acid-ethanol extraction. The concentration of serum IGF-I decreased with age in both sexes. The IGF-I in females was significantly higher than that in males in the group aged 21-30 years and lower in the group aged 61-72 years. We conclude that an age- or sex-related standard is necessary for comparing IGF-I values in patients.

Impairment of lymphocyte locomotion in the tumor microenvironment and the effect of systemic immunotherapy with liposome-encapsulated muramyl-tripeptide-phosphatidylethanolamine.

The ability of the lymphocytes to move through the interstitium is obligatory to the immune response. We previously showed that tumor-infiltrating lymphocytes (TIL) from human melanoma and renal cell carcinoma demonstrate a dramatic decrease in their spontaneous locomotion through three-dimensional collagen gel when compared with peripheral blood lymphocytes (PBL) and lymph node lymphocytes. To determine if this decrease is caused by contact with tumor cells, or mediated through certain diffusible factors, we examined the effects of autologous tumor cells on the locomotion of PBL in a model system where tumor cells were separated from lymphocytes by a 3-mm layer of gelled collagen. After 21-22 h incubation in chamber slides, locomotion distances were assessed in the presence and absence of tumor and normal cells. In the presence of tumor cells, PBL from 14 of 18 patients displayed substantial (466.5 +/- 2.7 microns compared to control 568.9 +/- 10.9 microns, P < 0.001) loss of motility. Inhibition was more prominent in melanoma patients than in renal cell carcinoma patients. Thus the impaired locomotion previously observed in TIL was at least partially due to the presence of tumor. The locomotion of TIL was restored in four of five melanoma patients treated with liposome-encapsulated muramyl-tripeptide-phosphatidylethanolamine (L-MTP-PE). Furthermore, in six of seven examined L-MTP-PE-treated patients, an increase in intrinsic PBL locomotion during the first month of the therapy was observed. These results suggest that the environment of the tumor is not conducive to locomotion of advancing lymphocytes and the therapeutic intervention may ameliorate the loss of lymphocytic infiltration.

Increase in the capability of interleukin 2 gene-transduced renal cell carcinoma cells to induce cytotoxic lymphocytes.

The immunogenicity of human cancer cells transfected with interleukin 2 (IL-2) gene, a potent vaccine candidate, has not yet been fully investigated. Human renal cell carcinoma (RCC) cells transduced with human IL-2 gene (RCC-IL-2) were investigated in vitro for the capability to induce lymphokine-activated killer (LAK) or cytotoxic T lymphocyte (CTL) activity in peripheral blood mononuclear cells (PBMC) or tumor-infiltrating lymphocyte (TIL). The RCC-IL-2 cells stimulated PBMC to demonstrate LAK activity, and also stimulated autologous TILs to proliferate and exhibit cytotoxicity relatively restricted to autologous tumor cells. In contrast, both parental RCC and RCC transduced with neomycin gene alone failed to induce these activities. These results indicate that RCC-IL-2 cells are more potent than the other RCC cells with regard to inducing cytotoxic lymphocytes against autologous tumor cells.

Increase in the ability of human cancer cells to induce cytotoxic T lymphocytes by ultraviolet irradiation.

The roles of ultraviolet-B (UV) radiation in the immunogenicity of human cancer cells have not been fully studied. We have investigated the effects of UV radiation on metastatic melanoma and renal cell carcinoma cells with regard to MHC antigen expression and the ability to induce cytotoxic T lymphocyte (CTL) activity in peripheral blood mononuclear cells (PBMC) or tumor-infiltrating lymphocytes (TIL) against untreated autologous tumor cells. UV radiation respectively decreased or increased MHC class I expression of freshly isolated tumor cells or cultured tumor cells, and also decreased MHC class I expression of starved cultured tumor cells. It increased the ability of both freshly isolated and cultured tumor cells to induce CTL activity from PBMC against untreated autologous tumor cells. UV-irradiated subclones that were more susceptible to CTL lysis were more potent for CTL induction from TIL than either an untreated parental clone or a UV-irradiated subclone that was resistant to CTL lysis. In summary, UV radiation increased the ability of tumor cells to induce CTL activity without a corresponding effect on MHC antigen expression.

Cytochemical and immunocytochemical demonstration of acetylcholinesterase of the prenatal rat lower limb.

Acetylcholinesterase (AChE) activities in the prenatal rat lower limb were investigated by both cytochemistry and immunocytochemistry. Results indicate that the epidermal cells show immunoreactions of AChE at a limited stage at prenatal day 15, and mesenchymal cells which are occasionally in contact with the basal lamina or with the adjacent myotubes begin to show AChE activities at prenatal day 17. Such AChE-positive mesenchymal cells, involved in the formation of the muscular tissues, have almost disappeared in the subepidermis by prenatal day 19. This suggests that AChE independent of the neuromuscular system may be involved in the mesenchymal cell differentiation especially in the inductive process during myogenesis.

[A case of ruptured aortic arch aneurysm into the lung].

Successful surgical treatment of aortic arch aneurysm ruptured into the left lung was reported. The patient was a 74-year-old man suffering from recurrent hemoptysis. Computed tomography and aortic angiography demonstrated a giant aortic arch aneurysm. Emergency operation was performed. Arch reconstruction by a Dacron graft was performed with hypothermic circulatory arrest. The post operative course was uneventful and there was no evidence of cerebral complication. In the emergency operation for ruptured aortic arch aneurysm, hypothermic circulatory is very useful method for cerebral protection.

Histochemical and immunological analyses of differentiating skeletal muscle fibers of the postnatal rat.

Fiber type differentiation as revealed by myosin ATPase activities and the immunological analysis of myosin light chains (MLC) by the Western blotting method were done on the postnatal rat soleus and extensor digitorum longus (EDL) muscles. In the soleus, type 1 (slow-twitch) muscle fibers gradually increase in percentage after postnatal day 10, and, in the EDL, the differentiation of type 2A and 2B (fast-twitch) muscle fibers is also pronounced between postnatal days 10 and 15. The present immunological analysis of MLC indicates that the antigenicity of Lc1S becomes more intense with a rapid decrease in antigenicity of Lc2F from postnatal day 7 in the soleus, while the antigenicity of Lc1F becomes noticeable during the same period in the EDL. These results suggest that the differentiation of slow-twitch fibers is mainly due to that of Lc1S in the soleus and the differentiation of fast-twitch fibers is mainly due to that of Lc1F in the EDL.

Cadmium toxicity in the thyroid gland of pregnant rats.

The toxic effects of cadmium on the thyroid gland of pregnant rats were studied with an electron microscope and an X-ray microanalyzer. Serum levels of thyroid hormones (T3 and T4) were also analyzed. Deterioration of the rough-surfaced endoplasmic reticulum occurred in the thyroid follicular epithelium on the fifth day of cadmium treatment. Large intracellular vacuoles, which arose from dilated cisternae of the rough-surfaced endoplasmic reticulum, were fused together, and marked swelling of the mitochondria was also noted. Thyroglobulin-secreting granules at the apical cytoplasm were decreased in number. By energy dispersive X-ray microanalysis, cadmium peaks were preferentially obtained from swollen mitochondria in the follicular epithelial cells. Serum levels of T3 and T4 were significantly decreased in cadmium-treated rats dams when compared to those of controls. In the present experiment, cycloheximide also caused degenerative changes in the rough-surfaced endoplasmic reticulum and the disappearance of thyroglobulin-secreting granules. Cycloheximide is a known inhibitor of protein synthesis on cytosolic ribosomes. These results indicated that accumulated cadmium in the mitochondria of thyroid follicular epithelial cells might disturb the oxidative phosphorylation of this organelle and the loss of energy supply possibly caused the inhibition of the synthesis and release of thyroid hormones.

Corneal edema induced by bis (tributyltin) oxide.

Corneal edema induced by bis (tributyltin) oxide (TBTO) was studied with an electron microscope and the accumulation sites of tin were determined with an X-ray microanalyzer. Male Wistar rats received an intramuscular injection of 0.5 ml/kg TBTO. After time intervals of 2, 4, 6, 8, 10, 12 h after injection, corneas were isolated and provided for electron microscopy. Corneas from untreated rats served as controls. Marked swelling of mitochondria in the corneal endothelial cells occurred at 4 h after TBTO injection. The corneal edema appeared in the endothelial layer and the stroma at 6 h after injection. By X-ray microanalysis, Sn peaks were obtained from swollen mitochondria in the endothelial cells. At 12 h after TBTO injection, edematous swelling of the corneal tissue became more advanced. These results indicated that parenterally administered TBTO accumulated in the mitochondria of corneal endothelial cells. The direct toxic effects of TBTO on the mitochondria might cause the interference with active pump function of endothelial cells and induced the corneal edema.