The effectiveness of an immobilization device in conformal radiotherapy for lung tumor: reduction of respiratory tumor movement and evaluation of the daily setup accuracy.

PURPOSE: To evaluate the daily setup accuracy and the reduction of respiratory tumor movement using a body frame in conformal therapy for solitary lung tumor. METHODS AND MATERIALS: Eighteen patients with a solitary lung tumor underwent conformal therapy using a body frame. The body shell of the frame was shaped to the patient's body contour. The respiratory tumor movement was estimated using fluoroscopy, and if it was greater than 5 mm, pressure was applied to the patient's abdomen with the goal of minimizing tumor movement. CT images were then obtained, and a treatment planning was made. A total dose of 40 or 48 Gy was delivered in 4 fractions. Portal films were obtained at each treatment, and the field displacements between them and the simulation films were measured for daily setup errors. The patients were repositioned if the setup error was greater than 3 mm. Correlations were analyzed between patient characteristics and the tumor movement, or the tumor movement reduction and the daily setup errors. RESULTS: Respiratory tumor movement ranged from 0 to 20 mm (mean 7.7 mm). The abdominal press reduced the tumor movement significantly from a range of 8 to 20 mm to a range of 2 to 11 mm (p = 0.0002). Daily setup errors were within 5 mm in 90%, 100%, and 93% of all verifications in left-right, anterior-posterior, and cranio-caudal directions, respectively. Patient repositioning was performed in 25% of all treatments. No significant correlation was detected between patient characteristics and tumor movement, tumor movement reduction, and the daily setup errors. CONCLUSIONS: The abdominal press was successful in reducing the respiratory tumor movement. Daily setup accuracy using the body frame was acceptable. Verification should be performed at each treatment in hypofractionated conformal therapy.

The use of a permanent magnetic resonance imaging system for radiotherapy treatment planning of bone metastases.

PURPOSE: To evaluate the usefulness of magnetic resonance (MR) imaging-based radiotherapy treatment planning (RTTP) for bone metastases in clinical applications. METHODS AND MATERIALS: MR imaging-based RTTP was carried out for 28 patients with bone metastases using a permanent magnetic MR unit. Twenty-three patients received MR imaging-assisted X-ray simulation, and five underwent MR simulation. In MR imaging-assisted X-ray simulation, the radiation fields defined by an X-ray simulator were modified based on MR information scanned in the exact treatment position using MR skin markers. In MR simulation, both isocenter position and field size were determined on MR images and projected onto the patient's skin. RESULTS: All lesions unclear on other imaging modalities could be clearly identified on MR imaging. Of the 23 patients receiving MR imaging-assisted X-ray simulation, modification of the original radiation field was necessary in 14 patients (extended in 9, reduced in 4, and completely changed in 1). In MR simulation, appropriate radiation fields could be easily and quickly determined using MR imaging. CONCLUSION: Methods for MR imaging-based RTTP were developed and clinically implemented for patients with bone metastases, and they were shown to be useful for improving the accuracy of the tumor location. They would provide better therapeutic/palliative benefit to particular patients with bone metastases and could also be applied to other lesions in the future.

Transverse instability of solitary waves in the generalized kadomtsev-petviashvili equation

The linear stability of planar solitary waves with respect to long-wavelength transverse perturbations is studied in the framework of the generalized Kadomtsev-Petviashvili equation. It is newly discovered that for some nonlinearities in this family, the solitary waves could be transversely unstable even in a medium with negative dispersion. In the case of positive dispersion, they are found to be always unstable.

Reproducibility of geometric distortion in magnetic resonance imaging based on phantom studies.

BACKGROUND AND PURPOSE: Image distortion is one of the major drawbacks of magnetic resonance (MR) imaging for use in radiotherapy treatment planning (RTTP). In this study, the reproducibility of MR imaging distortion was evaluated by repeated phantom measurements. MATERIALS AND METHODS: A grid-pattern acrylic phantom was scanned with a 0.2-Tesla permanent magnetic unit. We repeated a series of scans three times to evaluate the reproducibility of the distortion. In each series, co-ordinates at 432 intersections of the grid were measured for both T1- and T2-weighted spin-echo (SE) pulse sequences. Positional displacements and their variations at the intersections were calculated. RESULTS: Averages of the displacements were distributed between 1.58 and 1.74 mm, and maximum values (MAX) between 12.6 and 15.0 mm. Within 120 mm of the image center, the average values ranged from 0.73 to 0.80 mm, and from 3.4 to 5.0 mm for MAX. The absolute values of the positional variations among three series were distributed between 0.41 and 0.88 mm for average values, and between 1.4 and 4.5 mm for MAX. CONCLUSIONS: The positional variations were mostly within 3 pixels, and most of the positional displacements within the radius of 120 mm of the image center were 2 mm or less. Therefore, it will be possible to use this MR system in RTTP under limited situations, although careful applications are required for RTTP of the body. The development of a computer program to correct image distortion is expected.

Biochemical markers of bone turnover during hormone replacement therapy.

OBJECTIVE: To assess the clinical usefulness of bone turnover markers, including serum osteocalcin (OC), urinary pyridinoline (Pyr) and deoxypyridinoline (D-Pyr), in monitoring and predicting bone response to hormone replacement therapy (HRT). METHOD: The relationships between baseline levels or changes in markers and change in lumbar bone mineral density were examined in 21 surgically-induced postmenopausal women. RESULTS: Levels of OC, Pyr and D-Pyr in the estrogen effective group (responders) significantly decreased during HRT and baseline levels of Pyr and D-Pyr in responders were significantly higher than those in premenopausal women. CONCLUSION: Bone turnover markers were useful in monitoring the bone effect of HRT and baseline levels of markers reflect subsequent bone response to HRT.

Radiotherapy combined with transcatheter arterial infusion chemotherapy for locally advanced cervical cancer.

Twenty-four patients with locally advanced cervical cancer were treated with radiation therapy (RT) and transcatheter arterial infusion (TAI) chemotherapy, while 22 patients were treated with RT alone. RT consisted of a combination of external irradiation and high-dose-rate intracavitary brachytherapy. TAI therapy consisted of two sessions using cisplatin and pirarubicin, performed concurrently during the periods of external irradiation. The local-regional control rates at 1 year for the patients treated with RT plus TAI and for those treated with RT alone were 87.5% and 58.3%, respectively (p < 0.05). The 3-year cause-specific survival (CSS) rates for RT plus TAI, and RT alone were 67.1% and 55.9%, respectively (p = n.s.). The 3-year CSS rate for the 14 patients treated with RT and TAI who had well- or moderately differentiated squamous cell carcinoma without pelvic lymph node swelling was 100%, while that for the 19 patients with the same background treated with RT alone was 49% (p < 0.01). Radiation therapy combined with TAI appears to be an effective and safe treatment modality for patients with locally advanced cervical cancer.

[Bone mineral content in premenopausal women treated with gonadotropin-releasing hormone analogue].

To assess bone metabolism during treatment with gonadotropin-releasing hormone analogue (GnRHa), serum osteocalcin (BGP), alkaline phosphatase (ALP), parathyroid hormone (PTH), calcitonin (CT), calcium (Ca) and phosphorus (P) were determined before and after 6 months of GnRHa treatment in 15 premenopausal women with clinically diagnosed endometriosis. The bone mineral content (BMC) of the lumbar spine (L3) was measured by single energy quantitative computed tomography in 9 women, and in 6 of these 9 women microdensitometry was performed simultaneously during the treatment. BMC decreased significantly to 92.5 +/- 6.8% (mean +/- SD) of the pretreatment value after 6 months of treatment. On the other hand, microdensitometry revealed no significant change during treatment. Serum BGP and ALP were significantly higher after 6 months of treatment than before treatment, indicating an increase in bone formation. These data indicate that the GnRHa treatment induces an increase in bone turnover and a significant bone loss.

[Bone mass and biochemical parameters in metabolic bone diseases].

We studied the relationship between the bone mass and biochemical parameters in 175 normal premenopausal, 72 normal postmenopausal and osteoporotic postmenopausal women, between 20 and 88 years old, and in 40 patients with hyperthyroidism, and 23 patients with primary hyperparathyroidism, between 13 and 64 years old. The bone mineral density (BMD) of the spine (L2-L4) and proximal femur (femoral neck) was measured by dual-energy X-ray absorptiometry using a QDR-1000, Hologic. The bone mineral content (BMC) of the radius was measured by single photon absorptiometry (SPA) using a model 2780, Norland. Serum PTH, BGP and calcitonin (CT) were determined by radioimmunoassay. The BMD of the spine (L2-L4), and the proximal femur in postmenopausal women were negatively correlated with age. The mean BMD in patients with postmenopausal osteoporosis was significantly lower than that in normal postmenopausal women. In postmenopausal women, age was positively correlated with BGP, PTH, CT and negatively correlated with P. In patients with osteoporosis, the BMD of the spine was negatively correlated with serum BGP. The BMC of radius in patients with hyperthyroidism decreased significantly compared with that in the controls, and was negatively correlated with F-T3. The BMC of the radius in patients with primary hyperparathyroidism was significantly lower than that in the controls, and was negatively correlated with serum BGP and serum calcium. The measurements of biochemical parameters such as serum BGP, ALP and PTH may be useful in the assessment of metabolic bone diseases.

[Acute nephrotoxicity by CDDP (on tubular damage)].

Cisplatin (CDDP) is known to cause a nephrotoxic side effect. By using urinary trehalase which is localized renal tubular brush border, we examined an acute cisplatin nephrotoxicity. 1) With less than 300 mg of CDDP, urinary trehalase activity in the 1st day was significantly increased than preadministration. And urinary beta 2-MG was significantly increased in the 2nd day. But urinary NAG was not significantly increased. 2) With 300 mg or more of CDDP, urinary trehalase, beta 2-MG and NAG were more increased than preadministration. Urinary trehalase and beta 2-MG were inclined to increment. But urinary NAG was not inclined to decrement. Above all, renal tubular damage is reversible with less than 300 mg of CDDP, but is irreversible with 300 mg or more of CDDP.

Detection of some retinoid radicals using high-performance liquid chromatography with electron spin resonance spectroscopy or electrochemical detection.

Radical species were detected in the incubation mixtures of some retinoids (retinoic acid, retinal, retinol and retinyl acetate) by using the spin-trapping technique. The spin-adducts were resolved by high-performance liquid chromatography on a reversed-phase column with isocratic elution and detected by electron spin resonance spectroscopy and electrochemical detection. The spin-adducts were eluted in the order retinoic acid, retinol, retinyl acetate, in a similar manner to the retinoids themselves. These results suggest that the spin-adducts are products of nitrosobenzene with retinoid radicals in which the retinoid radicals retain their original chemical structures.

Detection of radical species in mixtures of some retinoids with hematin by using the ESR spin-trapping technique.

Radical species were detected in mixtures of some retinoids with hematin by using the ESR spin-trapping technique. The rates of radical formation were approximately proportional to the oxygen consumption during the incubation of the retinoids with hematin. HPLC analyses of the incubation mixtures of the retinoids with hematin showed that 5,6-epoxides of the retinoids were formed. The amounts of the epoxides formed were proportional to both oxygen consumption and the amounts of radicals formed. These results suggest that the 5,6-epoxidations proceed via radical intermediates.

Inhibition by chlorogenic acid of haematin-catalysed retinoic acid 5,6-epoxidation.

Chlorogenic acid (3-O-caffeoylquinic acid) inhibited haematin- and haemoglobin-catalysed retinoic acid 5,6-epoxidation. Some other phenol compounds (caffeic acid and 4-hydroxy-3-methoxybenzoic acid) also showed inhibitory effects on the haematin- and haemoglobin-catalysed epoxidation, but salicylic acid did not. Of the above compounds, caffeic acid and chlorogenic acid were potent inhibitors compared with the other two, suggesting that the o-hydroquinone moiety of chlorogenic acid and caffeic acid is essential to the inhibition of the epoxidation. Although caffeic acid inhibited retinoic acid 5,6-epoxidation requiring the consumption of O2, formation of retinoic acid radicals was not inhibited on the addition of caffeic acid to the incubation mixture. The above results suggest that caffeic acid does not inhibit the formation of retinoic acid radicals but does inhibit the step of conversion of retinoic acid radical into the 5,6-epoxide.

Detection of radical species in haematin-catalysed retinoic acid 5,6-epoxidation by using h.p.l.c.-e.p.r. spectrometry.

E.p.r. signals were detected in an all-trans-retinoic acid/haematin incubation mixture by using an e.p.r. spin-trapping technique. The spin adducts are presumably attributable to some intermediates in haematin-catalysed retinoic acid 5,6-epoxidation, since addition of nitrosobenzene to the reaction mixture dose-dependently inhibited the epoxidation. Analysing the reaction mixture by h.p.l.c.-e.p.r. spectrometry resulted in the detection of three peaks (III-1, III-2, IV) ascribable to the radical species. Two (peaks III-1 and -2) of the three peaks, which appeared 10 min after the reaction had started, seem to be attributable to the radical species directly participating in the epoxidation. The radicals trapped by nitrosobenzene do not appear to be derived from active oxygen, since none of these peaks were detected in a similar h.p.l.c. analysis of O2- and OH.-generating systems. They are presumably derived from retinoic acid. This view is also supported by the following results: none of these peaks were detected in the h.p.l.c. elution profile of the reaction mixture when retinoic acid was absent; peaks III-1 and 2 were detected even under anaerobic conditions, and their peak heights were unchanged under aerobic conditions.

Retinoic acid 5,6-epoxidation by hemoproteins.

Retinoic acid 5,6-epoxidase activity was found in several hemoproteins such as human oxy- and methemoglobin (HbO2 and MetHb), equine skeletal muscle oxy- and metmyoglobin (MbO2 and MetMb), bovine liver catalase, and horseradish peroxidase. Hematin also catalyzed retinoic acid 5,6-epoxidation. The results suggest that the heme moiety participates in the epoxidation. However, neither horse heart cytochrome c, nor free ferrous ion nor free ferric ion exhibited the epoxidase activity. Some hemoproteins (HbO2, MetHb, MbO2, MetMb, catalase, peroxidase, and hematin) exhibited characteristic individual pH dependences of the activity, suggesting that the epoxidase activities of the hemoproteins are influenced by the apoenzymes to some degree. This view is also supported by the finding that preincubation of an HbO2 preparation at various temperatures (37-70 degrees C) reduced its epoxidase activity with increasing temperature, whereas the activity of hematin was unaffected. Active oxygen scavengers such as mannitol, catalase, and superoxide dismutase exhibited no effect on the epoxidase activities of HbO2, MetHb, MbO2, and MetMb. A ligand of heme, CN- (100 mM), inhibited the epoxidase activities but N3- (100 mM) did not. The epoxidase activities were completely inhibited by NADPH, NADH, and/or 2-mercaptoethanol but not by NADP+ and/or NAD+. An intermediate in the epoxidation may be reduced by NADPH, NADH and/or 2-mercaptoethanol. Radical species can be considered as plausible candidates for the intermediate.

Effects of interferon preparations on rabbit corneal xenograft.

High doses of rabbit interferon (2 X 10(6) and 2 X 10(5) units/ml, a drop of about 0.1 ml administered topically into the eye twice daily) suppressed the rejection of rabbit corneal xenograft, whereas a low dose (2 X 10(3) units/ml) enhanced it, However, neither heat-inactivated rabbit interferon nor mouse L cell interferon showed any effects on rabbit corneal grafts.