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D H Lim

Publications and source records attributed to D H Lim.

14 recordsLinked to original sources
PubMed2004

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view.

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

Adenocarcinoma↗
PubMed2003

Successive double high-dose chemotherapy with peripheral blood stem cell rescue collected during a single leukapheresis round in patients with high-risk pediatric solid tumors: a pilot study in a single center.

In total, 18 of 26 double high-dose chemotherapies (HDCT) in pediatric solid tumors were rescued with peripheral blood stem cells collected during a single leukapheresis round (single-harvest group, SHG). In the remaining eight HDCT, additional leukapheresis were necessary after the first HDCT (HDCT1) to rescue the second HDCT (HDCT2) (double-harvest group, DHG). Stem cell collection after HDCT1 was inefficient and delayed in patients who had received prior chemotherapy before HDCT1. The interval between HDCT1 and HDCT2 was shorter in SHG than in DHG (median 62.5 days vs 178.5 days, P-value=0.002). Hematologic recovery in HDCT2 was delayed compared to HDCT1. However, there was no difference in hematologic recovery between SHG and DHG. A high rate of treatment-related mortality (TRM) was recorded during HDCT2, but there was no evidence that the shorter interval caused a higher rate of TRM (P-value=0.454). The probability of disease-free survival at 2 years after HDCT2 in the SHG and DHG were 66.7 and 25.0%, respectively (P-value=0.031). Therefore, to administer the second HDCT earlier in double HDCT, and thus to improve the survival of patients with high-risk solid tumors, the single-harvest approach is recommended rather than the double-harvest approach.

Adolescent↗
PubMed2003

Postoperative chemoradiotherapy for gastric cancer.

BACKGROUND: We report the results of postoperative chemoradiotherapy after curative resection in gastric cancer patients. PATIENTS AND METHODS: Patients with gastric cancer staged IB to IV(M0) were treated with chemoradiotherapy after curative resection with extensive (D2) lymph node dissection. Nodal metastases were observed in 261 (90%) patients. The chemotherapy consisted of fluorouracil 400 mg/m(2) plus leucovorin 20 mg/m(2) for 5 days, followed by 4500 cGy of radiotherapy for 5 weeks with fluorouracil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two 5-day cycles of chemotherapy were given 4 weeks after the completion of radiotherapy. RESULTS: Of 290 patients accrued, 229 (79%) patients completed chemoradiotherapy as planned. With a median follow-up of 49 months, 114 (34%) patients have relapsed: 33 (29%) locoregional relapses, 76 (67%) peritoneal relapses and 41 (36%) distant metastases. The 5-year overall and relapse-free survivals were 60% and 57%, respectively. Tolerance was acceptable, the main toxicity being neutropenia. CONCLUSIONS: This postoperative chemoradiotherapy after curative resection of gastric cancer was feasible, with acceptable toxicities. Whether this adjuvant therapy in gastric cancer patients that have undergone a D2 lymph node dissection impacts on survival or reduces the incidence of relapses remains to be studied.

Adenocarcinoma↗
PubMed2001

Preoperative concurrent chemoradiotherapy for stage IIIA non-small cell lung cancer.

Thirty-one patients with stage IIIA non-small cell lung cancer (NSCLC) were treated with preoperative concurrent chemoradiotherapy (CCRT) followed by surgery. The treatment protocol could not be completed in eight patients. The acute hematologic toxicities of grade III or IV occurred in 48.4%, (15/31) after the first chemotherapy cycle, and in 39.1% (9/23) after the second cycle. The most common non-hematologic toxicity was radiation esophagitis. Surgery was attempted in 23 patients and successful in 22 patients (resection rate = 71.0%. Pathologic complete response and down-staging were achieved in 13.6% (3/22) and 68.2% (15/22). The median survival period, 2-year overall survival, local control and disease-free survival rates of all 31 patients and of 22 patients who underwent surgery were 19 months, 37.2%, 49.1%, 35.5%, and 19 months, 43.2%, 51.8%, 25.6%, respectively. On the basis of our observations, preoperative CCRT followed by surgery for stage IIIA NSCLC has resulted in outcomes comparable with those in previous reports.

Adult↗
PubMed2000

Fractionated stereotactic radiation therapy for extracranial head and neck tumors.

BACKGROUND: This study is to report the clinical experiences of fractionated stereotactic radiation therapy (FSRT) for extracranial head and neck tumors. METHODS AND MATERIALS: Between the period of July 1995 and November 1998, 48 patients with extracranial head and neck tumors were given FSRT as a boost and sole modality. Individualized treatment planning was performed using XKnife-3 system with relocatable Gill-Thomas-Cosman frame. In 24 patients, FSRT was applied as a boost technique following the 2-dimensional conventional external radiation therapy (ERT); in 24 patients FSRT was the sole radiotherapy modality. The primary diseases in the boost group consisted of nasopharynx cancer (19), lacrimal gland adenoid cystic carcinoma (3), orbital lymphoma (1), and skull-base recurrence of maxillary sinus adenoid cystic carcinoma (1). The primary diseases in the sole modality group consisted of recurrent nasopharynx cancer (12), orbital pseudotumor (4), skull-base recurrence of maxillary sinus, submandibular gland, and hypopharynx cancers (3), orbital rhabdomyosarcoma (2), orbital lymphoma (1), orbital metastasis of neuroblastoma (1), and nasal cavity melanoma (1). The fractionation schedule was to give 5 treatments per one week and the fractional doses were 2.0-3 Gy depending on the treatment aim and the FSRT volume. The FSRT doses varied depending on the nature of the primary diseases. RESULTS: The local tumor response in nasopharynx cancer patients was excellent compared to retrospective data without occurrence of unexpectedly severe complication. FSRT to other regions was well tolerated by the patients and resulted in good to excellent local tumor responses with no unacceptable side effects as expected by the authors. CONCLUSION: Based on the current observations, FSRT is a very effective and safe modality in the treatment of extracranial head and neck tumors.

Carcinoma, Adenoid Cystic↗
PubMed2000

A glass compensator filter to improve breast image quality in radiation therapy simulation.

PURPOSE: To improve the image quality of simulation films in tangential radiotherapy for breast cancer, we have designed a new compensator filter for the variation of breast contour using high-density-glass material. METHODS AND MATERIALS: The measurements and analyses of the body contour were done using CT scans, taken in the treatment position, of 20 breast cancer patients. The maximum tissue deficit that needed to be compensated for was 8 cm, and the authors fabricated the compensator system using high-density-glass material to maintain transparency. The glass compensator can be attached to the accessory mount of the simulator head and its position can be easily adjusted according to breast shape and position. The image qualities of simulation films taken with and without the glass compensator in tangential breast radiotherapy field were compared and the film densitometry was performed using the humanoid phantom. RESULTS: Using this compensator system, the overall image quality improved, resulting in enhanced contrast and resolution of the breast simulation image. The delineator wires for the beam margins were also well depicted, and the surgical clips within the breast tissue can be easily demonstrated. The film densitometry resulted in much less saturation over the breast tissue when using the glass compensator. CONCLUSION: Using the glass compensator system, the geographical miss may be reduced with the virtue of the improved image quality.

Breast Neoplasms↗
PubMed1999

Design and development of new collimator cones for fractionated stereotactic radiation therapy in Samsung Medical Center.

PURPOSE: In stereotactic radiotherapy using X-Knife system, the commercially supplied collimator cone system had a few mechanical limitations. The authors have developed new collimator cones to overcome these limitations and named them "SMC type" collimator cones. METHODS: We made use of cadmium-free cerrobend alloy within the stainless steel cylinder housing. We made nine cones of relatively larger sizes (3.0 cm to 7.0 cm in diameter) and of shorter length with bigger clearance from the isocenter than the commercial cones. The cone housing and the collimator cones were designed to insert into the wedge mount of the gantry head to enable double-exposure linac-gram taking. RESULTS: The mechanical accuracy of pointing to the isocenter was tested by ball test and cone rotation test, and the dosimetric measurements were performed, all of which were with satisfactory results. A new innovative quality assurance procedure using linac-grams on the patients at the actual treatment setup was attempted after taking 10 sets of AP and lateral linac-grams and the overall mechanical isocenter accuracy was excellent (average error = 0.4 +/- 0.2 mm). CONCLUSIONS: We have developed the SMC type collimator cone system mainly for fractionated stereotactic radiation therapy use with our innovative ideas. The new cones' mechanical accuracy and physical properties were satisfactory for clinical use, and the verification of the isocenter accuracy on the actual treatment setup has become possible.

Alloys↗
PubMed1998

Effect of customized small bowel displacement system in pelvic irradiation.

PURPOSE: Authors designed a customized small bowel displacement system (SBDS) to displace the small bowel out of the pelvic radiation fields and to minimize treatment related bowel morbidity. METHODS AND MATERIALS: From August 1995 to May 1996, 55 consecutive patients who received pelvic radiation therapy with the SBDS were included in this study. The SBDS consists of a customized Styrofoam compression device that can displace the small bowel out of the radiation fields and an individualized immobilization abdominal board for easy daily setup of the patient in prone position. After opacifying the small bowel with barium, the patients were laid prone and posterior-anterior (PA) and lateral (LAT) simulation films were taken with and without the SBDS. The volume of the small bowel included in the radiation fields with and without the SBDS were compared. RESULTS: Using the SBDS, the mean small bowel volume was reduced by 59% on PA and 51% on LAT films (p = 0.0001). In six patients (6 of 55, 11%), it was possible that no small bowel was included within the treatment fields. The mean upward displacement of the most caudal small bowel was 4.8 cm using the SBDS. Patients treated with the SBDS manifested a significantly lower incidence of diarrhea requiring medication (8 of 55, 15%) vs. those without the SBDS (24 of 39, 62%) (p < 0.05). CONCLUSION: The SBDS is a novel method that can be used to displace the small bowel away from the treatment portal effectively and to reduce the radiation therapy morbidity. Compliance with setup is excellent.

Adult↗
PubMed1998

Effects of Ginkgo biloba extract on the cochlear damage induced by local gentamicin installation in guinea pigs.

Investigations evaluating the protective effect of Ginkgo biloba extract (EGb) on gentamicin (GM) ototoxicity were undertaken. Guinea pigs treated with 5 mg/kg gentamicin sulfate on the round window niche (RWN) showed acute changes on electrocochleogram and hair cell or microvilli damage on scanning electron microscopy (SEM). There was accumulation of GM in the whole cochlea, especially in the organ of Corti, stria vascularis, and type III fibrocyte on immunohistochemical study. However, the guinea pigs pretreated with local or systemic EGb revealed no significant changes by local GM installation. From these results, we concluded that EGb has a protective effect on the development of GM ototoxicity in the cochlea.

Animals↗
PubMed1997

Nonparametric tests for comparing umbrella pattern treatment effects with a control in a randomized block design.

This paper treats the problem of comparing umbrella pattern treatment effects with a control in a randomized block design. An extension of the Chen-Wolfe test (1993, Biometrics 49, 455-465) and its modification are proposed for both cases where the peak of the umbrella is known or unknown. Approximate critical values are given and the results of a Monte Carlo power study are presented.

Animals↗
PubMedDate not supplied

Analysis of correlation between rectal complications and rectal dose following high dose rate intracavitary radiotherapy in patients with uterine cervix cancer: in vivo dosimetric analysis.

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.

Adult↗
PubMedDate not supplied

Secondary angiosarcoma following irradiation--case report and review of the literature.

Angiosarcoma is a rare malignant tumor that accounts for 1% to 2% of all soft tissue sarcomas. This paper reports a case of radiation-associated angiosarcoma with a literature review of 66 cases. Twenty-nine years after transabdominal hysterectomy and adjuvant radiation therapy for uterine cervix cancer, cutaneous angiosarcoma developed in the abdominal wall of a 63-year-old woman. She underwent wide excision of the abdominal wall mass, radiation therapy, and chemotherapy, and has been alive and well without any evidence of metastasis for 23 months since the initial diagnosis of angiosarcoma. After an intensive literature review, we found 66 cases of radiation-associated angiosarcoma. The most common primary disease was breast cancer (44%), with gynecologic cancer (21%) next. Eighty-five percent of radiation-associated angiosarcomas developed in the cutaneous area. The median age at diagnosis was 65 years, and the median latency period from irradiation to diagnosis was 96 months. The median survival period of 48 patients whose survival lengths could be reviewed was 12 months.

Female↗