PubMed Health⌕ Search

Biomedical subjects

Sun Rock Moon

Publications and source records attributed to Sun Rock Moon.

2 recordsLinked to original sources

Combination of external beam irradiation and high-dose-rate intraluminal brachytherapy for inoperable carcinoma of the extrahepatic bile ducts.

PURPOSE: To assess the feasibility and therapeutic benefits of a combination of external beam radiotherapy (EBRT) and high-dose-rate intraluminal brachytherapy (ILBT) for treating patients with inoperable carcinoma of the extrahepatic bile ducts. METHODS AND MATERIALS: Of 31 patients who received RT at the Yonsei Cancer Center, Yonsei University College of Medicine in Seoul, Korea between 1986 and 1995, 17 patients underwent EBRT alone (Group 1) and 14 patients were treated with EBRT in combination with high-dose-rate ILBT (Group 2). After external drainage, EBRT was delivered with a total dose ranging from 36 to 55 Gy (median 50.4) in both groups. High-dose-rate ILBT for the patients in Group 2 was performed using a high-intensity (192)Ir source (Gamma-med remote afterloading system) within the expandable intrabiliary prosthesis (Gianturco stent), inserted transhepatically at the site of the obstruction. The radiation dose of the high-dose-rate ILBT was prescribed at 1.5 cm from the center of the source with a single daily dose of 5 Gy to a total of 15 Gy given in three fractions. The response rate, patterns of treatment failure, treatment morbidity, and survival data in the two groups were compared. RESULTS: Although locoregional recurrence was the most common pattern of failure in both groups, no statistically significant difference was found in the recurrence rates between those who did and did not receive ILBT (53% for Group 1 vs. 36% for Group 2; p > 0.05). However, a prolongation of the median time to tumor recurrence was observed in the Group 2 patients (5 months for Group 1 vs. 9 months for Group 2; p = 0.06). When the EBRT dose delivered was >50 Gy, most patients experienced various degrees of GI symptoms, but the frequency of radiation-induced complications in the two groups was similar. No enhancement in treatment morbidity was attributed to the addition of high-dose-rate ILBT to EBRT. With a median follow-up of 12 months, the overall actuarial 2-year survival rate for Group 2 patients was significantly better than that for Group 1 patients (0% for Group 1 vs. 21% for Group 2; p = 0.015). CONCLUSION: Given these observations, we believe that the combined use of EBRT and high-dose-rate ILBT is a beneficial, relatively safe, and effective method of improving the treatment outcome in selected patients with inoperable carcinoma of the extrahepatic bile ducts.

Adult↗

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↗