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Chang Ok Suh

Publications and source records attributed to Chang Ok Suh.

At least 19 recordsLinked to original sources
PubMed2004

Angiocentric T-cell and NK/T-cell lymphomas: radiotherapeutic viewpoints.

PURPOSE: To investigate the patterns of local failure and the risk factors predictive of local failure and to establish the dose-response relationships influencing the probability of local control in patients with Stage I and II angiocentric T-cell or natural killer (NK)/T-cell lymphoma who were treated with radiotherapy (RT) alone. METHODS AND MATERIALS: We retrospectively reviewed the data from 102 patients with Ann Arbor Stage I and II angiocentric T-cell or NK/T-cell lymphoma who underwent RT alone to a median dose of 45 Gy (range, 20-70 Gy) between 1976 and 1998. The patterns of local failure, risk factors predictive of local failure, dose-response relationships, and survival data were analyzed. Because of the protean feature of local recurrences, the sites of local failure were allocated to one of three categories: true recurrence (TR), marginal recurrence (MR), and elsewhere recurrence (ER). RESULTS: Despite a higher complete remission rate (72%) after RT, 60 patients experienced treatment failure, including local failure in 48 (47%), regional failure in 3 (3%), and systemic failure in 28 (27%). The patterns of local failure were TR in 42, MR in 3, and ER in 5 patients. The median time to recurrence for TR/MR was shorter than that for ER (1 month for TR/MR vs. 12 months for ER). Patients with TR/MR had a more unfavorable prognosis than those experiencing ER (2-year survival rate after salvage treatment: 6% for TR/MR vs. 80% for ER; p <0.01). The dose-response curve was sigmoid in shape within the range of 20-54 Gy, which followed the plateau at doses in excess of about 54 Gy. A positive correlation was observed in the dose-response curve for the probability of local control (p = 0.017, logistic regression analysis). The overall 5-year actuarial survival and local recurrence-free survival rate for all patients was 42% and 53%, respectively. Achievement of complete remission was the most statistically significant risk factor predictive of TR/MR and the most important prognostic factor. CONCLUSION: Our data confirm that local failure remains the major obstacle for patients who receive RT alone and that achievement of complete remission is a particularly important determinant of treatment success. Although dose escalation up to >54 Gy cannot entirely reduce the incidence of TR/MR, we believe it is important to identify an appropriate subset of patients for whom an additional boost dose may be beneficial. Given the high rate of local failure, an investigational approach should be conducted to supplement RT using radiosensitizers or more effective chemotherapeutic agents in future trials.

Adolescent↗
PubMed2004

Synchronous coexpression of epidermal growth factor receptor and cyclooxygenase-2 in carcinomas of the uterine cervix: a potential predictor of poor survival.

PURPOSE: To evaluate the potential of the new prognostic information gained by analyzing the coexpression of epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) in cervical cancer patients. EXPERIMENTAL DESIGN: Sixty-eight patients with International Federation of Gynecology and Obstetrics stage IIB squamous cell carcinoma of the uterine cervix, who underwent concurrent chemoradiotherapy between 1993 and 1996, were divided into the following four groups according to their immunoreactivities for EGFR and COX-2 in paraffin-embedded sections: (a). the EGFR-negative/COX-2-negative group (n = 11); (b). the EGFR-negative/COX-2-positive group (n = 8); (c). the EGFR-positive/COX-2-negative group (n = 27); and (d). the EGFR-positive/COX-2-positive group (n = 22). The clinical features, patterns of treatment failure, and survival data in the four groups were compared. RESULTS: Positive immunoreactivity for EGFR and COX-2 was observed in 49 of 68 (72%) and 19 of 68 (28%), respectively. However, no strong correlation was found between the levels of EGFR and COX-2 immunopositivity (R(2) = 0.05, P = 0.07). Patients in the EGFR-positive/COX-2-positive group had a higher likelihood of locoregional recurrence than those in the other three groups (P = 0.02). Of the patients in the four groups, patients positive for both oncoproteins were found to have the worst prognosis with an overall 5-year disease-free survival rate of 55% compared with 91% for the EGFR-negative/COX-2-negative patients, 88% for the EGFR-negative/COX-2-positive patients, and 69% for the EGFR-positive/COX-2-negative patients (P = 0.05, log-rank test). In addition, the synchronous coexpression of the EGFR and COX-2 oncoproteins was found to be an independent prognostic factor by univariate and multivariate analyses (relative risk = 4.0, P = 0.03). CONCLUSIONS: Given these observations, we conclude that the coexpression of EGFR and COX-2 immunoreactivity may be used as a potent molecular risk factor for predicting the poor survival of patients with the International Federation of Gynecology and Obstetrics stage IIB squamous cell carcinoma of the uterine cervix.

Adult↗
PubMed2004

Low grade gastric mucosa associated lymphoid tissue lymphoma: treatment strategies based on 10 year follow-up.

AIM: To deduce strategic guidelines of gastric mucosa associated lymphoid tissue lymphoma (MALTOMA) by evaluating the long-term outcome of patients in respect to various treatment modalities. METHODS: A total of 55 patients with MALTOMA from May 1992 to August 2002 were retrospectively reviewed. RESULTS: Complete remission was obtained in 24 (82.8%) of 29 patients treated with anti Helicobacter pylori (H pylori) regimen only. The duration to reach complete remission was 12 months (85 percentile, 2-33 months). Five patients showed complete remission with radiation therapy (26-86 months). Two of them were H pylori treatment failure cases. CONCLUSION: H pylori eradication is an effective primary treatment option for low grade MALTOMA and radiation therapy could be considered in patients with no evidence of H pylori infection or who do not respond to H pylori eradication therapy 12 months after successful eradication.

Adult↗
PubMed2004

Clinical relevance of three subtypes of primary sinonasal lymphoma characterized by immunophenotypic analysis.

BACKGROUND: The purpose of this study was to investigate the clinical relevance of subtypes categorized by immunophenotypic analysis in primary sinonasal lymphomas. METHODS: Eighty patients with localized non-Hodgkin's lymphoma involving the nasal cavity and/or paranasal sinuses were divided into three subtypes on the basis of their immunohistochemical findings: (A) B-cell lymphoma (n = 19), (B) T-cell lymphoma (n = 27), and (C) natural killer (NK)/T-cell lymphoma (n = 34). The clinicopathologic profiles, immunophenotypic data, patterns of treatment failure, and survival data among the three patient groups were retrospectively compared. RESULTS: The nasal cavity was the predominant site of involvement in T-cell and NK/T-cell lymphoma, whereas sinus involvement without nasal disease was common in B-cell lymphoma. Systemic B symptoms were frequently observed in NK/T-cell lymphoma. Almost all patients with NK/T-cell lymphoma showed a strong association with the Epstein-Barr virus by in situ hybridization studies. Sixty-five patients (81%) patients achieved complete remission after initial treatment, but 36 (55%) of these subsequently experienced treatment failure. Although there were no significant differences in locoregional failure rates among the patients of the three groups, distant failure was far more common in B-cell or NK/T-cell lymphoma than in T-cell lymphoma (p =.005). Most B-cell lymphoma cases showed a predilection for sites of systemic failure in the nodal and extranodal sites below the diaphragm, such as the paraaortic lymph nodes or the gastrointestinal (GI) tract, whereas patients with NK/T-cell lymphoma showed an increased risk of systemic dissemination to the skin, testes, or GI tract, including the development of hemophagocytic syndrome. The 5-year actuarial and disease-free survival rates for all patients were 57% and 51%, respectively. Of the three subtypes of primary sinonasal lymphomas, T-cell lymphoma seemed to carry the most favorable prognosis and NK/T-cell lymphoma the worst. (The 5-year actuarial survival rate was 57% for B-cell lymphoma, 80% for T-cell lymphoma, 37% for NK/T-cell lymphoma; p =.02, log-rank.) By univariate and multivariate analyses, immunophenotype was identified as the most important prognostic factor. CONCLUSIONS: Our data indicate that the three subtypes of primary sinonasal lymphomas classified by immunohistochemical studies exhibit different clinical profiles, different patterns of failure, and different treatment outcomes. Given these observations, it is concluded that the recognition of these distinct subsets, diagnosed on the basis of immunophenotypic study, is very important and clinically relevant in predicting their potential behavior and prognosis.

Adolescent↗
PubMed2004

Lack of correlation between P-glycoprotein and chemotherapy resistance in nasal NK/T-cell lymphomas.

Thirty patients with nasal natural killer (NK)/T-cell lymphoma, who underwent systemic chemotherapy with or without involved-field radiotherapy between 1993 and 1998, were retrospectively reviewed to determine the clinical significance of P-glycoprotein immunohistochemically identified in tumor specimens. Eighty percent of previously untreated patients expressed P-glycoprotein. According to P-glycoprotein immunoreactivity, all patients with nasal NK/T-cell lymphoma were divided into 2 groups; (a) P-glycoprotein-negative group (N = 6) and (b) P-glycoprotein-positive group (N = 24). There was no significant difference in clinical profiles between both groups. Regardless of the P-glycoprotein expressions, Epstein-Barr virus genomes were almost identically detected in patients of the 2 groups. Contrary to our expectations, however, P-glycoprotein expressions were not found to be a strong predictor of chemotherapy resistance. Although 2 (33%) of 6 P-glycoprotein-negative patients and 10 (42%) of the 24 P-glycoprotein-positive patients showed a favorable response to systemic chemotherapy, 4 (67%) of 6 P-glycoprotein-negative patients did not achieve complete response (CR) to chemotherapy, which led to an early death, whereas 4 (17%) of the 24 P-glycoprotein-positive patients achieved CR to chemotherapy despite positive P-glycoprotein immunoreactivity. Overall, there were no significant differences in either CR rate or the response rate of patients in the two groups. Overall 5-year actuarial survival and disease-free survival for all patients were 44% and 47%, respectively, but no differences in survival rates were observed between 2 groups. (5-year actuarial survival rate: 33% for the P-glycoprotein-negative, 50% for the P-glycoprotein-positive) (P = 0.7093, log-rank). On univariate and multivariate analyses, P-glycoprotein expressions by immunohistochemical study were not found to be an important prognostic factor. Given these observations, we conclude that the molecular mechanisms of resistance to chemotherapy in nasal NK/T-cell lymphoma patients are not entirely dependent on P-glycoprotein, and that other complex mechanisms of drug action and resistance may be likely to be involved.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

Eleven-year experience of low grade lymphoma in Korea (based on REAL classification).

Low grade lymphomas are malignancies of predominantly small lymphocytes that typically have long median survival periods due to low proliferative rates. It is considered an indolent disease, but patients with low grade lymphoma can almost never be cured with conventional treatment. New low- grade lymphoma entities have been classified by the International Lymphoma Study Group (ILSG) and are also categorized into the Revised European American Lymphoma (REAL) classification. The REAL classification utilizes a multiparameter definition of clinico-pathologic and biologic entities. According to this classification, we investigated the incidence, various clinical characteristics, treatment outcome and prognostic factors of low grade lymphoma. Many clinical characteristics of low grade lymphoma in Korea differed from those of Western countries, especially in the incidence, therapeutic outcome and prognostic factors. In Korea, although the general incidence of low grade lymphoma is relatively low, the relative number of mucosa-associated lymphoid tissue lymphoma (MALToma) is very high, and the overall survival rate is better than that reported of Western countries. Thus, further investigation on treatment outcome and prognosis of low grade lymphoma entities, other than mucosa- associated lymphoid tissue lymphoma, are warranted.

Adolescent↗
PubMed2003

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↗
PubMed2003

Clinical results of 3-dimensional conformal radiotherapy combined with transarterial chemoembolization for hepatocellular carcinoma in the cirrhotic patients.

PURPOSE: Recent reports have shown that a portion of the liver can tolerate higher radiation doses, which can be further accomplished by the application of 3-dimensional conformal radiotherapy (3-DCRT). The purpose of this study was to investigate the efficacy and toxicity of 3-DCRT combined with transcatheter arterial chemoembolization (TACE) for HCC in the cirrhotic patients. METHODS AND MATERIALS: From 1994 to 2000, 50 HCC patients with liver cirrhosis (LC) were included in this study. The degree of LC was Child A in 38 and Child B in 12. The UICC stages were II in 12, III in 16, and IVa in 22. The mean tumor size was 8.3+/-3.5 cm. Patients were treated with TACE and then followed by 3-DCRT within 7-14 days. 3-DCRT planning was used to define both the target and normal liver volumes. The total dose of radiation (mean 50.1+/-8.3 Gy) was determined by the fractional volume of normal liver receiving 50% of the isocenter dose. RESULTS: A partial response (PR) was observed in 33 patients (66%). A subsequent surgical resection was successful in three patients, showing complete necrosis in one and near total necrosis in two. Most common acute toxicity was alteration in liver function test (13 patients) and none of the patients showed an acute toxicity more than grade 3. Subacute and chronic toxicity involved radiation induced liver disease (RILD) (six patients) and gastrointestinal toxicity (seven patients; ulcer in five and hemorrhagic mucositis in two). The actuarial survival rate at 3 years was 43% from the commencement of radiotherapy. CONCLUSIONS: Radiotherapy using 3-DCRT combined with TACE can achieve a substantial tumor response and survival rate for HCC in the cirrhotic patients.

Journal Article↗
PubMed2003

CD30 (Ki-1)-positive large-cell cutaneous T-cell lymphoma with secondary xanthomatous changes after radiation therapy.

A 72-year-old woman with a large mass on her forehead was found to have primary cutaneous CD30-positive large T-cell lymphoma and was treated with radiation therapy. Five weeks after the completion of radiation therapy, a large, yellow plaque developed on the forehead. Histopathologic examination showed numerous xanthoma-like cells with clear and foamy cytoplasm that infiltrated the upper and mid dermis with no residual lymphoma. To our knowledge, this is the first report of xanthomatous change after radiation therapy for primary cutaneous CD30-positive large cell lymphoma. We believe that the xanthomatous change after radiation therapy probably was caused by lysis of radiosensitive lymphoma cells and histiocytic scavenging of lipid-membrane debris.

Aged↗
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↗
PubMed2003

Radiation treatment for aggressive fibromatosis: findings from observed patterns of local failure.

PURPOSE: We retrospectively evaluated the outcome of patients treated with radiotherapy, with or without surgery, for aggressive fibromatosis. The patterns of local failure were analyzed to determine the optimum radiation dose and volume for irradiation. PATIENTS AND METHODS: Twenty-four patients with histologically confirmed aggressive fibromatosis were treated with radiation therapy at the Yonsei Cancer Center between 1990 and 1998. The radiation dose per patient ranged from 39.6 to 59.4 Gy (mean: 49.4 Gy). The entire operative bed, with a generous margin, was included in the radiotherapy volume. Patients were considered as locally controlled if there was no evidence of the disease during their follow-up period, and if the tumors were stable for more than 2 years. The minimum duration of the follow-up period was 26 months, with a median of 69 months. RESULTS: The actuarial 10-year recurrence-free and overall survival were 88.5 and 100%, respectively. Patients who had a recurrence were salvaged by combined surgery and re-irradiation. Recurrences developed only in patients who had a recurrent disease after surgery and were treated with an inadequate radiation volume. In 9 patients with a gross measurable disease, there were no in-field failures; these had been treated with a median of 50.4 Gy (range: 40-60 Gy) of radiation. Eight patients with a microscopic residual disease were also locally controlled with 41.4-59.4 Gy (median: 45 Gy) of radiation. No patient has developed either secondary malignancy or any serious radiation complications. CONCLUSION: Radiotherapy for aggressive fibromatosis can be an effective treatment option for maintaining a disease-free status. As fibromatosis, with either a microscopic, or a gross residual disease, can be controlled with a moderate dose of radiation, adjuvant postoperative radiotherapy following surgical excision is recommended with the least sufficient margin to preserve good function and cosmesis. The geographic relationship may require a more precise definition; in addition, regardless of the existence of neighborhood normal tissue barriers, a wide coverage of the radiation volume may be needed.

Adolescent↗
PubMed2002

Dose-response relationship in local radiotherapy for hepatocellular carcinoma.

PURPOSE: Dose escalation using three-dimensional conformal radiotherapy (3D-CRT) is based on the hypothesis that increasing the dose can enhance tumor control. This study aimed to determine whether a dose-response relationship exists in local radiotherapy for primary hepatocellular carcinoma (HCC). METHODS AND MATERIALS: One hundred fifty-eight patients were enrolled in the present study between January 1992 and March 2000. The exclusion criteria included the presence of an extrahepatic metastasis, liver cirrhosis of Child class C, tumors occupying more than two-thirds of the entire liver, and a performance status on the Eastern Cooperative Oncology Group scale of more than 3. Radiotherapy was given to the field, including the tumor, with generous margin using 6- or 10-MV X-rays. The mean radiation dose was 48.2 +/- 7.9 Gy in daily 1.8-Gy fractions. The tumor response was assessed based on diagnostic radiologic examinations, including a computed tomography scan, magnetic resonance imaging, and hepatic artery angiography 4-8 weeks after the completion of treatment. Liver toxicity and gastrointestinal complications were evaluated. RESULTS: An objective response was observed in 106 of 158 (67.1%) patients. Statistical analysis revealed that the total dose was the most significant factor associated with the tumor response. The response rates in patients treated with doses <40 Gy, 40-50 Gy, and >50 Gy were 29.2%, 68.6%, and 77.1%, respectively. Survivals at 1 and 2 years after radiotherapy were 41.8% and 19.9%, respectively, with a median survival time of 10 months. The rate of liver toxicity according to the doses <40 Gy, 40-50 Gy, and >50 Gy was 4.2%, 5.9%, and 8.4%, respectively, and the rate of gastrointestinal complications was 4.2%, 9.9%, and 13.2%, respectively. CONCLUSIONS: The present study showed the existence of a dose-response relationship in local radiotherapy for primary HCC. Only the radiation dose was a significant factor for predicting an objective response. The results of this study showed that 3D-CRT can theoretically be used for treating primary HCC.

Carcinoma, Hepatocellular↗
PubMed2002

Overexpression of cyclooxygenase-2 is associated with a poor prognosis in patients with squamous cell carcinoma of the uterine cervix treated with radiation and concurrent chemotherapy.

BACKGROUND: The objective of this study was to determine whether cyclooxygenase-2 (COX-2) overexpression was an indicator of prognosis in patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IIB uterine cervical carcinoma who underwent radiation and concurrent chemotherapy. METHODS: Seventy-five patients with FIGO Stage IIB squamous cell carcinoma (SCC) of the uterine cervix who were treated with radiotherapy and concurrent chemotherapy between 1991 and 1996 were divided into two groups according to their COX-2 level in an immunohistochemical study: the COX-2 negative group (n = 54 patients) and the COX-2 positive group (n = 21 patients). The clinicopathologic features, patterns of treatment failure, and survival data for patients in the COX-2 positive group were compared with data from the patients in the COX-2 negative group. Univariate and multivariate analyses were performed to determine the prognostic factors that influenced patient survival. RESULTS: In the immunohistochemical study, COX-2 overexpression was observed in approximately 30% of patients with FIGO Stage IIB SCC of the uterine cervix. With delayed regression to the initial treatment, the treatment failure rate of patients in the COX-2 positive group was much higher compared with the treatment failure rate of patients in the COX-2 negative group. The higher incidence of central failure and lymph node failure for patients in the COX-2 positive group was statistically significant (48% for the COX-2 positive group vs. 13% for the COX-2 negative group). However, there was no difference in the incidence of hematogenous metastases between the two groups (5% for the COX-2 positive group vs. 7% for the COX-2 negative group). In addition, increased COX-2 expression in tumor cells also was correlated with a shorter interval to tumor recurrence (median interval to recurrence, 9 months in the COX-2 positive group vs. 26 months in the COX-2 negative group). Compared with patients in the COX-2 negative group, patients in the COX-2 positive group had lower overall actuarial and disease free survival rates (overall 5-year actuarial survival rates: 56% for the COX-2 positive group vs. 94% for the COX-2 negative group; P = 0.003). Univariate and multivariate analyses showed that COX-2 overexpression was an independent prognostic factor that surpassed other well-known clinicopathologic parameters. CONCLUSIONS: COX-2 overexpression can be used as a potent molecular risk factor in patients with FIGO Stage IIB SCC of the uterine cervix who are treated with radiotherapy and concurrent chemotherapy.

Adult↗
PubMed2002

Dose optimization of fractionated external radiation and high-dose-rate intracavitary brachytherapy for FIGO stage IB uterine cervical carcinoma.

PURPOSE: To determine the optimal dose combination scheme of external beam radiotherapy (EBRT) and high-dose-rate (HDR) intracavitary radiation (ICR) for maximizing tumor control while conferring an acceptable late complication rate in the treatment of Stage IB uterine cervical cancer. METHODS AND MATERIALS: We retrospectively analyzed 162 patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB squamous cell carcinoma of the uterine cervix who received definitive RT between May 1979 and December 1990. Before HDR-ICR, all patients received EBRT to a total dose of 40-46 Gy (median 45), administered during 4-5 weeks to the whole pelvis. HDR-ICR was given 3 times weeks to a total dose of 24-51 Gy (median 39) at point A, using a dose of 3 Gy/fraction. Central shielding from EBRT was begun after the delivery using 20-45 Gy (median 40) of the external dose. The total dose to point A, calculated by adding the EBRT biologically effective dose (BED) and the ICR BED to point A, was 74.1-118.1 Gy (mean 95.2). The rectal point dose was calculated at the anterior rectal wall at the level of the cervical os. The local control rate, survival rate, and late complication rate were analyzed according to the irradiation dose and BED. RESULTS: The initial complete response rate was 99.4%. The overall 5-year survival rate and 5-year disease-free survival rate was 91.1% and 90.9%, respectively. The local failure rate was 4.9%, and the distant failure rate was 4.3%. Late complications were mild and occurred in 23.5% of patients, with 18.5% presenting with rectal complications and 4.9% with bladder complications. The mean rectal BED (the sum of the external midline BED and the ICR rectal point BED) was lower in the patients without rectal complications than in those with rectal complications (125.6 Gy vs. 142.7 Gy, p = 0.3210). The late rectal complication rate increased when the sum of the external midline BED and the rectal BED by ICR was >or=131 Gy (p = 0.1962). However, 5-year survival rates did not increase with the external midline BED (p = 0.4093). The late rectal complication rate also increased, without a change in the survival rate, when the sum of the external midline BED and the ICR point A BED was >90 Gy. CONCLUSION: In treating Stage IB carcinoma of the uterine cervix with HDR-ICR, using fractions of 3 Gy, it is crucial to keep the point A BED at <or=90 Gy to minimize late rectal complications without compromising the survival rate. To achieve this goal, appropriate central shielding from EBRT is needed.

Adult↗
PubMed2002

Effective local control of malignant melanoma by intratumoural injection of a beta-emitting radionuclide.

Intratumoural injection of an unsealed beta-emitting radionuclide is a new technique for the local control of tumours that has the advantage of delivering a higher radiation dose to tumour while minimising radiation hazard to the surrounding normal tissues. In this study, therapeutic effect, morphological alterations and biological responses to the high-dose continuous irradiation delivered using this new technique were evaluated in an animal model with B16 melanoma. For evaluation of the therapeutic effect, 92 C57BL/6 mice with B16 melanoma were divided into four groups. In each group, intratumoural injections were performed when the tumour measured approximately 1 cm along its long axis. Group 1 (n=25) received 0.3 ml of normal saline, group 2 (n=15) 37 MBq of carrier-free holmium-166 in 0.3 ml saline, group 3 (n=27) 185 MBq of 166Ho in 0.3 ml saline and group 4 (n=25) 185 MBq of 166Ho in 0.5 ml saline. In addition, another 30 mice were used for morphological and biological analysis of the radiation effect. These 30 mice were injected with 185 MBq of 166Ho in 0.3 ml saline, and five were sacrificed at each of the following six time points: before injection and 1, 2, 3, 6 and 14 days post injection. Haematoxylin-eosin (H&E) staining, immunohistochemical analysis for p53, p21, PCNA and cyclin D1, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) staining, reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry were performed. For visual side-by-side comparison, melanoma cells were inoculated bilaterally into the back of ten additional mice, and 185 MBq of 166Ho in 0.3 ml of saline or an equal volume of normal saline was injected separately into the bilateral tumours. Nine days after inoculation of melanoma cells, mean tumour volume reached 492.5-631.9 mm3. Tumours of the control group (group 1) showed rapid growth, and the mean tumour volume reached approximately 30 times the original volume. None of the control group lived for more than 16 days following the injection of normal saline. On the other hand, mean tumour volume of the treated groups showed a gradual decrease, and 67%-74% of the treated animals were alive when all the control animals had died. The median survival of the control group was 9 days following injection, whereas it was 29 days in group 2, 33 days in group 3 and 33 days in group 4. The survival rate of group 3 was higher than that of groups 2 and 4, but statistical significance was not observed. H&E stain of the tumours demonstrated central necrosis and peripheral residual cells with progressive cytoplasmic and nuclear swelling without apoptotic features. Expression of proteins and mRNAs of p53 and bax increased until 3 days, as compared with 48 h for p21; thereafter, the expression gradually decreased. TUNEL-positive nuclei could be seen from 2 days until 2 weeks after treatment. Flow cytometry did not demonstrate an increase in apoptotic features as compared with the control animals. In conclusion, intratumoural injection of the unsealed beta-emitting radionuclide 166Ho appears to be a promising alternative radiotherapeutic modality for the local control of malignant melanoma. The main cell death mechanisms with this technique seem to be radiation-induced central necrosis and peripheral growth arrest or secondary necrosis of tumour cells, rather than apoptosis.

Animals↗
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↗
PubMed2002

Role of radiotherapy for primary orbital lymphoma.

To define the role of radiation therapy of primary orbital lymphoma, a retrospective analysis was undertaken for 18 patients with primary orbital lymphoma who were treated with curative radiotherapy between 1984 and 1995. The histology was found to be low grade lymphoma in 11 patients, intermediate grade in 7. All patients were of Ann Arbor stage IE, but bilateral involvement of the orbit was observed in 3 patients (16.6%). Anatomical subsites involved were the retrobulbar, eyelid, and conjunctiva in eight, five, and four patients, respectively. The median radiation dose was 30 Gy ranging from 20 Gy to 50 Gy. Twelve of 18 patients received a radiation dose of 30 Gy or less. To properly protect the lens during irradiation, the contact lens blocks were used for nine patients with conjunctival and eyelid tumor or the hanging eye bar blocks were applied for eight patients with retrobulbar tumor. Chemotherapy was given for seven patients with intermediate-grade malignant lymphoma. Two patients had been treated by surgery before referral.

Adolescent↗