Biomedical subjects

Kang Kyoo Lee

Publications and source records attributed to Kang Kyoo Lee.

4 recordsLinked to original sources

PubMed2006

Preliminary results of a phase I/II study of simultaneous modulated accelerated radiotherapy for nondisseminated nasopharyngeal carcinoma.

PURPOSE: To present preliminary results of intensity-modulated radiotherapy (IMRT) with the simultaneous modulated accelerated radiotherapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Twenty patients who underwent IMRT for nondisseminated NPC at the Asan Medical Center between September 2001 and December 2003 were prospectively evaluated. Intensity-modulated radiotherapy was delivered with the "step and shoot" SMART technique at prescribed doses of 72 Gy (2.4 Gy/day) to the gross tumor volume, 60 Gy (2 Gy/day) to the clinical target volume and metastatic nodal station, and 46 Gy (2 Gy/day) to the clinically negative neck region. Eighteen patients also received cisplatin once per week. RESULTS: The median follow-up period was 27 months. Nineteen patients completed the treatment without interruption; the remaining patient interrupted treatment for 2 weeks owing to severe pharyngitis and malnutrition. Five patients (25%) had Radiation Therapy Oncology Group Grade 3 mucositis, whereas 9 (45%) had Grade 3 pharyngitis. Seven patients (35%) lost more than 10% of their pretreatment weight, whereas 11 (55%) required intravenous fluids and/or tube feeding. There was no Grade 3 or 4 xerostomia. All patients showed complete response. Two patients had distant metastases and locoregional recurrence, respectively. CONCLUSION: Intensity-modulated radiotherapy with the SMART boost technique allows parotid sparing, as shown clinically and by dosimetry, and might also be more effective biologically. A larger population of patients and a longer follow-up period are needed to evaluate ultimate tumor control and late toxicity.

Adult↗

PubMed2006

Expression of Ku80 correlates with sensitivities to radiation in cancer cell lines of the head and neck.

The Ku protein is essential for the repair of a majority of DNA double-strand breaks in mammalian cells. The purpose of this study was to investigate the relationship between the expression of Ku70/80 and sensitivity to radiation in cancer cell lines of the head and neck. The sensitivity to radiation in various head and neck cancer cell lines (AMC-HN-1 to -9) was analyzed by colony forming assay. Of the nine cell lines examined, the most radiosensitive cell line (AMC-HN-3) and the most radioresistant cell line (AMC-HN-9) were selected for this experiments. The expression of Ku70/80 was examined after irradiation using real time PCR, Western blotting and immunofluorescence in two different cell lines. Cell cycle distribution after irradiation were analysed. A differential radioresponse was demonstrated by expression of Ku70/80 in AMC-HN-3 and AMC-HN-9 cells. While the expression of Ku70 was slightly increased in the radioresistant AMC-HN-9 cell line, the expression of Ku80 was remarkably increased, suggesting a correlation between Ku80 expression and radiation resistance. Overexpression of Ku80 plays an important role in the repair of DNA damage induced by radiation. Ku80 expression may provide an effective predictive assay of radiosensitivity in head and neck cancers.

Antigens, Nuclear↗

PubMed2003

Primary NK/T cell lymphoma of the testis. A case report and review of the literature.

We report a case of aggressive 'nasal type' natural killer (NK)/T cell lymphoma initially presenting as a testicular tumor in a Korean man, which quickly took a fatal course by widespread dissemination. Histologically, the testicular mass showed a diffuse dense infiltrate of medium-sized and atypical large lymphoid cells with angiocentric and angiodestructive infiltration and areas of coagulative necrosis on hematoxylin-eosin stained sections. Immunophenotyping by immunohistochemistry yielded surface markers consistent with NK/T cell lymphoma. The Epstein-Barr virus genome was detected by in situ hybridization. During involved-field irradiation and chemotherapy following radical orchiectomy, the tumor disseminated shortly to the skin and soft tissue of his anterior chest wall and central nervous system (CNS). Identical lymphoid infiltrates were present in the patient's skin. CNS involvement was interpreted as having a leptomeningeal seeding. To the best of our knowledge, this is the 9th reported case of confirmed NK/T cell lymphoma arising from the testis. Relevant literature is reviewed, and the clinicopathologic features, natural history, and treatment options for primary testicular NK/T cell lymphoma are discussed.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Intensity modulation technique using the complementary boost-fields for ethmoid sinus cancer.

PURPOSE: To explore a static intensity-modulated radiation therapy (IMRT) technique of a more homogeneous isodose distribution to an irregular-shaped tumour of the ethmoid sinus, with concomitantly sparing the adjacent critical normal organs including the orbit. METHODS AND MATERIALS: We conducted a static IMRT technique adding 2 or smaller complementary boost-fields to the underdosed volume in the PTV, which resulted from complete blocking of the orbits in all coplanar or non-coplanar main ports of the standard 3-D CRT. The standard 3-D CRT plans (Plan A) and IMRT plans adding complementary boost fields (Plan B) were established for 10 patients with ethmoid sinus cancer. Two sets of different plans for each patient were compared using isodose distribution, dose statistics, and dose volume histogram (DVH) of the planning target volume (PTV) and also using dose statistics and DVH of the adjacent critical structures. RESULTS: The IMRT plans adding 2 or more complementary boost-fields (Plan B) for each patient demonstrated better coverage and improved dose homogeneity of the PTV compared to the standard 3-D CRT plan (Plan A). Moreover, the radiation doses to adjacent normal tissue organs, such as the orbits, optic nerves, brain stem and optic chiasm were similarly spared in both plans. CONCLUSION: With concomitantly sparing the surrounding visual pathway structures, our IMRT technique using the complementary boost-fields was quantitatively better than current standard 3-D CRT technique with respect to the dose homogeneity within the PTV. Therefore, we believe that our technique, though still not ideal, is thorough enough to be used routinely in treatment of ethmoid sinus tumour.

Adult↗