Alloys ; Animals ; Coronary Vessels ; Dogs ; Female ; Iridium ; Male ; Platinum ; Stents

Brachytherapy has been proved to be an effective method for the purpose of increasing radiation dose to the tumor and reducing the dose to the surrounding normal tissue. In head and neck cancer, the rationale of brachytherapy is as follows; Firstly, early small lesion is radiocurative and the major cause of failure is local recurrene. Seondly, it can diminish evidently the dose to the normal tissue especially masseteric muscle and salivary gland. Thirdly, the anatomy of head and neck is suitable to various technique of brachytherapy. On background of accumulated experience of LDR iridium brachytherapy of head and neck cancer for the last 15 years, the author reviewed the history of radioisotope therapy, the characteristics of radionuclides,and some important things in the method, clinical technique and treatment planning. The author analyzed the clinical result of 185 cases of head and neck cancer treated in the Korea Cancer Center Hospital. Finally the fu ture prospect of brachytherapy of head and neck cancer is discussed.
Brachytherapy* ; Head and Neck Neoplasms* ; Head* ; Iridium ; Korea ; Neck ; Radiotherapy ; Salivary Glands

OBJECTIVETo investigate the effect on the dose distribution of source position displacement with the target region margin in catheter-based 192Ir line source endovascular brachytherapy.

METHODDose rate distribution along longitudinal axes was estimated by the formula recommended by AAPM No.60 and No. 43.

RESULTSIn the two cases of source displacement (1.1 and 5 mm) doses of target region margin was decreased dramatically (at most 53.9% and 565.8% respectively) were compared to that of no source displacement, and the affected range was 6 mm and 9 mm respectively.

CONCLUSIONSource displacement will lead to the decrease of dose in target region margin.

Animals ; Brachytherapy ; methods ; Coronary Restenosis ; radiotherapy ; Coronary Vessels ; radiation effects ; Iridium Radioisotopes ; therapeutic use ; Radiotherapy Dosage

To investigate the effect of adipose-derived stem cells (ADSCs) on radiation-induced skin injury in SD rats.
 Methods: Radioactive particles 192Ir were used to irradiate the left medial thigh skin of SD rats, and the irradiation dose was at 90 Gy. Then, the rats were randomly allocated into a control group and a treatment group (each n=9). After the irradiation, the control group was injected with 60 μL PBS and the treatment group was injected with 60 μL ADSCs in irradiated skin. The progress of skin damage and healing was observed and photographed every day. Twenty-eighth days after the irradiation, the irradiated skin tissue was taken from the left thigh, and then fixed with formaldehyde fixative solution. At the same time, the skin tissue of the corresponding part of the normal group (n=9) that was not irradiated was also taken. After sampling, embedding and slicing, immunohistochemical staining was used to compare the levels of α-smooth muscle actin (α-SMA), and HE staining was used to compare pathological features of the skin.
 Results: Radioactive particle 192Ir caused the development of III or IV radioactive skin damage. The score of the treatment group was significantly lower than that of the control group. The wounds of the treatment group were basically healed at 28 days, while the ulcer of the control group was unhealed. So, the healing time was shorter in the treatment group. The expression of α-SMA in the skin of the two groups was increased after the radiotherapy. By analyzing the pathological microstructure image, we found that the thickness of epidermis in the control group was greater than that in the treatment group, while the vascular density in the treatment group was greater than that in the control group (all P<0.05).
 Conclusion: Radioactive particles 192Ir can cause skin damage, while the adipose-derived stem cells might alleviate radiation-induced skin injury and promote ulcer healing by promoting angiogenesis.
Adipocytes ; Animals ; Iridium Radioisotopes ; Rats ; Rats, Sprague-Dawley ; Skin ; Stem Cells

The Romberg's syndrome is characterized by unilateral facial hemiatrophy. Romberg's syndrome becomes manifest in 10 or 20 decades, and involves skin, subcutaneous tissue, muscle, cartilage and bone of one side of the face that will eventually lead to facial asymmetry. In one eye with Romberg's syndrome. Horner's syndrome, enophthalmos. mydriasis, heterochromia iridium, ptosis, superficial corneal erosion, blepharophimosis, oculomotor palsies, and nystagmus were found. A 20 year old man (Korean) was found to have Romberg's syndrome.
Blepharophimosis ; Cartilage ; Enophthalmos ; Facial Asymmetry ; Facial Hemiatrophy ; Horner Syndrome ; Humans ; Iridium ; Mydriasis ; Paralysis ; Skin ; Subcutaneous Tissue ; Young Adult

Angioplasty, Balloon, Coronary ; methods ; Coronary Restenosis ; prevention & control ; radiotherapy ; Drug-Eluting Stents ; adverse effects ; Humans ; Iridium ; Rhenium ; Xenon Isotopes

PURPOSE: To observe the efficiency of reirradiation with high dose rate intraluminal brachytherapy in symptomatic palliation of recurrent endobronchial tumors. MATERIALS and METHODS: Between January 1994 and June 1998, 21 patients diagnosed with recurrent endobronchial tumors following external beam radiotherapy were treated palliatively with high dose rate intraluminal irradiation at Hacettepe University Oncology Institute. A single fraction of 10Gy was prescribed to the specified area in 9 patients and 15Gy to 12. RESULTS: Endobronchial treatment improved the performance and reduced symptomatology in 17 (81%) patients. Ten dyspneic patients (10/14, 71%) recovered clinically with an accompanying radiological downstaging. The median symptomatic palliation was 45 days (range, 0-9 months), and the overall median survival was 5.5 months (range, 4-12 months). The palliative intrabronchial brachytherapy was well tolerated, with the exception of in one patient with a fatal hemorrhage, and another with medically salvaged bronchospasm and intrabronchial edema. CONCLUSION: Recurrent patients with a history of previous thoracic external beam irradiation can be effectively palliated with high dose rate endobronchial reirradiation if the symptoms are directly related to the endobronchial tumor.
Adult ; Aged ; *Brachytherapy ; Dose-Response Relationship, Radiation ; Female ; Humans ; Iridium/*therapeutic use ; Isotopes ; Lung Neoplasms/*radiotherapy ; Male ; Middle Aged ; Neoplasm Recurrence, Local/*radiotherapy ; *Palliative Care

OBJECTIVE: To assess actual rates of late vaginal stenosis and identify predisposing factors for complications among patients with previously untreated cervical cancer following high-dose-rate brachytherapy. METHODS: We performed longitudinal analyses of 57 patients using the modified Dische score at 6, 12, 18, 24, 36, and 60 months after treatment, which consisted of 15 interstitial brachytherapys and 42 conventional intracavitary brachytherapys, with a median follow-up time of 36 months (range, 6 to 144 months). RESULTS: More than half of the patients developed grade 1 (mild) vaginal stenosis within the first year of follow-up, and grade 2 (97.5%, moderate) to grade 3 (severe) stenosis gradually increased with time. Actual stenosis rates for grade 1, 2, and 3 were 97.5% (95% confidence interval [CI], 92.7 to 97.5), 60.7% (95% CI, 42.2 to 79.3), and 7.4% (95% CI, 0 to 18.4) at 3 years after treatment. Pallor reaction grade 2-3 at 6 months was only a statistically significant predisposing factor for grade 2-3 late vaginal stenosis 3 years or later with a hazard ratio of 3.48 (95% CI, 1.32 to 9.19; p=0.018) by a multivariate Cox proportional hazard model. Patients with grade 0-1 pallor reaction at 6 months showed a grade > or =2 vaginal stenosis rate of 53%, whereas the grade 2-3 pallor reaction group achieved a grade > or =2 vaginal stenosis rate at 3 years at 100% (p=0.001). CONCLUSION: High-dose-rate brachytherapy was associated with high incidence of late vaginal stenosis. Pallor reaction grade 2-3 at 6 months was predictive of late grade 2-3 vaginal stenosis at 3 years after treatment. These findings should prove helpful for patient counseling and preventive intervention.
Adult ; Aged ; Aged, 80 and over ; Brachytherapy/*adverse effects/methods ; Constriction, Pathologic/etiology/pathology ; Female ; Humans ; Iridium Radioisotopes/therapeutic use ; Middle Aged ; *Pallor ; Prognosis ; Prospective Studies ; Radiopharmaceuticals/therapeutic use ; Retrospective Studies ; Uterine Cervical Neoplasms/*radiotherapy ; Vaginal Diseases/*etiology/pathology

BACKGROUNDPost-stenting restenosis is a significant clinical problem, involving vascular smooth muscle cells (VSMCs) proliferation and apoptosis. It is reported that c-myc antisense oligodeoxynucleotides (ASODNs) local delivered by catheter can inhibit VSMCs proliferation. This study was designed to assess tissue distribution of c-myc ASODN local delivered using gelatin-coated platinum-iridium (Pt-Ir) stents, and its effect on apoptosis of VSMCs.

METHODSGelatin-coated Pt-Ir stents that had absorbed caroboxyfluorescein-5-succimidyl ester (FAM) labeled c-myc ASODNs (550 microg per stent) were implanted into the right carotid arteries of 6 rabbits. Tissue samples were obtained at 45 minutes, 2 hours, and 6 hours. Tissue distribution of c-myc ASODNs was assessed by fluorescence microscopy. In addition, 32 rabbits were randomly divided into two groups. Rabbits in the control group (n = 16) were implanted with gelatin-coated Pt-Ir stents, and those in the treatment group (n = 16) were implanted with gelatin-coated stents that had absorbed c-myc ASODNs. 7, 14, 30, or 90 days (n = 4, respectively, for each group) after the stenting procedure, the stented segments were harvested, and histopathological examinations were performed to calculate neointimal area and mean neointimal thickness. The expression of c-myc was assessed using in situ hybridization (ISH) and immunohistochemical methods. Apoptotic VSMCs were detected using terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM).

RESULTSAccording to fluorescence microscopic results, FAM-labeled c-myc ASODNs were concentrated in the target vessel media at the 45 minutes time point, and then dispersed to the adventitia. Morphometric analysis showed that neointimal area and mean neointimal thickness increased continuously up to 90 days after stent implantation, but that total neointimal area and mean neointimal thickness were less in the treatment group than in the control group at all time points (P < 0.0001). At day 7 and day 14 after stenting, there were no detectable apoptotic cells in either group. However, apoptotic cells were present in the neointima 30 and 90 days after stenting, and the number of apoptotic cells was less at 30 days than at 90 days. Meanwhile, c-myc ASODNs appeared to induce apoptosis in more cells in the treatment group than that in the control group. Typical apoptotic VSMCs were observable under TEM. The expression of c-myc was positive in the control group and negative or weakly positive in the c-myc ASODN treatment group, according to both ISH and immunohistochemical examination.

CONCLUSIONGelatin-coated Pt-Ir stent mediated local delivery of c-myc ASODNs is feasible. The localization of c-myc ASODN is primarily in the target vessel walls. c-myc ASODNs can inhibit VSMCs proliferation and induce its apoptosis after local delivery in vivo.

Animals ; Apoptosis ; drug effects ; Carotid Arteries ; Female ; Gelatin ; Genes, myb ; genetics ; In Situ Hybridization ; Iridium ; Male ; Microscopy, Fluorescence ; Myocytes, Smooth Muscle ; pathology ; Oligodeoxyribonucleotides, Antisense ; administration & dosage ; metabolism ; pharmacology ; Platinum ; Rabbits ; Random Allocation ; Stents ; Tissue Distribution ; Tunica Intima ; metabolism ; Tunica Media ; metabolism

We aimed to compare the duration of survival among subjects receiving brachytherapy (BT) in combination with Nd:YAG laser therapy (LT), and those receiving LT or BT alone. The medical records of subjects who received endobronchial treatment for unresectable tracheobronchial malignancies between January 1997 and December 1999 in a single center were reviewed retrospectively. A total of 80 patients were evaluated. The overall symptomatic response rate after treatment was 86.5%. Median survival durations for the LT, BT, and combined therapy (CT) group were 111, 115, and 264 days, respectively. The survival duration was significantly longer in the CT group than in the BT group (p=0.0078), but the difference was not statistically significant between the CT and the LT group. The bronchoscopic finding of endobronchial polypoid lesion was associated with a longer survival time than extraluminal with compression type (p=0.0023) by univariate analysis. Other factors associated with the better prognosis included hemoglobin > or = 12.5 g/dL, serum albumin level > or =37 g/L, and BT dose > or = 15 Gy at 1 cm distance. Of these factors, specific bronchoscopic findings, serum albumin level, CT modality, and dose of BT retained statistical significance in multivariate analysis. In conclusion, combined LT and BT is associated with increased patient survival compared with BT alone. Combined therapy may improve survival time in selected patients with endobronchial malignancies.
Aged ; *Brachytherapy ; Carcinoma, Non-Small-Cell Lung/*mortality/*radiotherapy/surgery ; Combined Modality Therapy ; Female ; Humans ; Iridium Radioisotopes/therapeutic use ; Laser Therapy ; Lung Neoplasms/*mortality/*radiotherapy/surgery ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Survival Analysis