Biomedical subjects
Publications and source records attributed to K H Shin.
We reviewed 26 patients with brain stem tumors. None had a pre-treatment tissue diagnosis. Four of the 20 treated patients are alive from 22 months to 12 years later, representing no improvement from a preceding series in the same centre.
Seventy-nine children with histologically proven astrocytomas, 32 cerebral, 30 cerebellar, 9 thalamic, 6 optic nerve, and 2 in the 4th ventricular floor were reviewed retrospectively. Seventy-one per cent of the astrocytomas were well differentiated. Unlike adult astrocytomas, there was slight female predominance in our group. Cerebral astrocytomas were more frequent beyond nine years of age. The overall five-year survival rate of cerebral astrocytomas was 95% (19/20) for well-differentiated, and 19% (2/12) for poorly-differentiated tumors. In cerebellar astrocytomas the survival rates were 75% (18/24) and 33% (2/6) respectively.
Primary intracranila choriocarcinoma, either alone or with malignant teratoma, is a rare tumor. The 22 reported cases of primary intracranila mixed choriocarcinoma and malignant teratoma are reviewed, and a further case is added. This 4 1/2-year-old girl presented with multiple cranial nerve palsies, panhypopituitarism and markedly elevated blood and urine human chorionic gonadotrophin (HCG) titres. After subtotal removal of the suprasellar tumor, supervoltage radiation was given with a remarkably rapid and complete response. She died 14 months after diagnosis with no evidence of local recurrence nor of distant metastases.
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Malignant lymphoma of the thyroid gland is a rare entity; only 200 cases have been reported to date since 1960. Four patients with this disease presented at the Kingston clinic of the Ontario Cancer Treatment and Research Foundation. Those with localized malignant lymphoma, particularly the histiocytic types, responded favourably to resection of as much of the tumour as possible and subsequent local radiation with cobalt-60 telecurietherapy (3000 to 4000 rads in 3 to 4 weeks). The results of local radiation alone after a biopsy in patients with inoperable localized diseases are encouraging; it is possible, but not yet established, that some of these patients are cured. It has been suggested that the tumour is dependent on thyroid-stimulating hormone but conclusive evidence is not yet available.
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Twenty-one MRI studies with a fat-suppression three-dimensional spoiled gradient-recalled echo in a steady state (3D SPGR) pulse sequence after intravenous contrast injection were evaluated to assess the accuracy in depicting chondromalacia of the knee. On the basis of MR images, chondromalacia and its grade were determined in each of five articular cartilage regions (total, 105 regions) and then the results were compared to arthroscopic findings. The sensitivity, specificity, and accuracy of MRI were 70%, 99%, and 93%, respectively. MR images depicted 7 of 11 lesions of arthroscopic grade 1 or 2 chondromalacia, and seven of nine lesions of arthroscopic grade 3 or 4 chondromalacia. The cartilage abnormalities in all cases appeared as focal lesions with high signal intensity. Intravenous contrast-injection, fat-suppression 3D SPGR imaging showed high specificity in excluding cartilage abnormalities and may be considered as an alternative to intra-articular MR arthrography when chondromalacia is suspected.
PURPOSE: To evaluate the usefulness of a mixture of absolute ethanol and lipiodol in the management of venous malformations. METHODS: Percutaneous sclerotherapy was performed with a mixture of absolute ethanol and lipiodol (9:1) in 17 patients with venous malformations, once in 12 patients, twice in 5. The therapeutic efficacy was evaluated by pain reduction. Conventional radiographs (n = 15) and posttreatment magnetic resonance imaging (n = 5) were obtained for the follow-up evaluation. RESULTS: Sclerotherapy was successful in all but two patients. The therapeutic effect was excellent in two patients, good in seven, fair in five, and poor in one. Radiopacity of lipiodol was beneficial for monitoring the procedure rather than for follow-up evaluations. Areas with low signal-intensity strands were increased on T2-weighted images obtained after the sclerotherapy. CONCLUSION: Sclerotherapy with a mixture of ethanol and lipiodol is effective in treating venous malformations.
Multimodality image registration is useful in diagnostic imaging and treatment planning for radiation therapy. In this paper, we present a technique which registers the surfaces of two volumes acquired by different medical imaging modalities. We represent the image volumes in terms of their surface elements known as tiles. We identify the fuzzy variables, assign fuzzy membership functions to them and generate a fuzzy rule database. The fuzzy algorithm reduces the discrepancy between the two set of tiles until the surfaces are matched. In order to study the efficacy of our approach, we severely warp a simulated image and register it with its original. We register CT and MR volumes of humanoid phantom images. Finally, we present the results at the end of the article.
PURPOSE: Our goal was to describe the MR appearance of distal femoral cortical irregularity (DFCI). METHOD: With plain radiographs and MR images of 100 knees, the presence of DFCIs was determined, and the shapes of DFCIs were classified into three subgroups: concave, convex, and divergent cortical shapes. Radiographic and MR shapes of DFCIs were compared. RESULTS: DFCIs were shown in various shapes on both the radiographs and the MR images. Forty-four DFCIs were found both on radiograph and by MR image. An additional 14 DFCIs were identifiable only on MR images. However, the majority of DFCIs showed an association between radiographic and MR shapes. MRI revealed that all 58 DFCIs were located at the attachment site of the medial gastrocnemius muscle. DFCIs were enhanced in three of the four patients who underwent postcontrast MR study. CONCLUSION: A good understanding of radiographic and MR findings of the DFCI may be of great help in the differential diagnosis of distal femoral lesions.
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Osteosarcoma is one of the most common juvenile malignant tumors in Korea. Combined modality treatment (pre-operative chemotherapy + limb salvage surgery + adjuvant therapy) improved the patients' overall survival and quality of life. We evaluated the efficacy and feasibility of pre-operative chemotherapy with intra-arterial (IA) cisplatin plus continuous intravenous infusion (CI) of adriamycin. We assessed the rate of limb salvage, recurrence pattern and the survival impact based on the histologic response of pre-operative chemotherapy. Fourty-one patients with histologically-proven high grade osteosarcoma of the extremities were enrolled from January 1990 to June 1995. Pre-operative chemotherapy, cisplatin 120 mg/m2 IA and adriamycin 75 mg/m2/72 h CI was administered every 3 weeks for 3 cycles, followed by limb salvage surgery if possible or by amputation. According to the histologic tumor response, if the tumor necrosis was >90%, the same regimen was administered for 3 cycles as an adjuvant therapy. A salvage regimen (Ifosfamide 7.5 gm/m2/5 d IV + high dose MTX 10 gm/m2 IV+VP-16 360 mg/m2/3 d IV) was administered every 3 weeks for 6 cycles if the tumor necrosis was <90%. Of 41 patients, 37 patients were evaluable for efficacy and toxicities, because 4 patients refused chemotherapy after 1 or 2 cycles. Twenty-one patients were male and 16 were female with median age of 16 years (range 8-41). The tumor locations were: distal femur 20, proximal tibia 8, humerus 6, distal tibia 2 and 1 in proximal femur. All but one patient, who died of neutropenic sepsis, completed the planned pre-operative therapy. Of the 36 patients who received surgery, limb salvage surgery was possible in 30 patients (83.3%) and 27 patients (75%) showed a good response (grade III 10; 27.8%, grade IV 17; 47.2%). With a median follow-up of 23 months, 3-year disease-free survival rate was 54.7% and overall survival rate was 78.3%. Of the 15 patients who recurred, the major metastatic site was the lung. No operation-related mortality was observed. Most patients experienced grade III-IV nausea, vomiting and hematologic toxicities, which were reversible with supportive cares. Pre-operative chemotherapy with IA DDP+CI ADR followed by surgery showed 75% histologic tumor response rate, 83% limb salvage rate and 54.7% 3-year disease-free survival rate with tolerable side effects. To improve the survival rate, the possible role of good salvage chemotherapy with a non-cross resistance regimen in poor responders should be evaluated.
PURPOSE: To investigate the correlation between late rectal complications and rectal dose in uterine cervix cancer patients treated with high dose rate intracavitary radiotherapy (HDR ICR) and to analyze dose factors reducing complications. METHODS: A retrospective analysis was done of 74 patients treated with external beam RT and HDR ICR between 1995 and 1997. Radiotherapy (RT) consisted of a median 50.4 Gy external beam plus six fractions of HDR ICR given two times per week, concurrent with the last three weeks of external beam therapy, to a total dose of median 24 Gy to point A or the reference point. Rectal doses were calculated at rectal reference points using barium contrast criteria. In vivo measurement of rectal dose was performed with thermoluminescent dosimeters (TLD) immediately prior to the first fraction of HDR ICR. RESULTS: Eight patients developed rectal complications (11%). There was a significant difference between measured rectal doses for patients with rectal complications and those without (p < 0.05), and the doses were higher in complicated patients. A significant increase in the probability of development of complications was found for patients receiving measured rectal doses of ICR fractional dose 320 cGy or more, ICR total dose 2000 cGy or more, and ICR% to point A 80% or more. CONCLUSIONS: This study showed that in vivo dosimetry using TLD during HDR ICR could have a useful role as a predictor of late rectal complications. Dose limitation to the rectum could possibly be achieved by thorough vaginal packing or use of an applicator with proper shielding while maintaining a high dose to the tumor.