• Radiation Oncology Journal
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• v.11 no.1
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• pp.91-96
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• 1993

From September 1989 to June 1992,22 patients with nasopharyngeal carcinoma were treated in Asan Medical Center with an external beam of 60 Gy followed by a boost dose of 15 Gy HDR brachytherapy. There were 5 females and 17 males with median age of 44 years (range: 20-69 years). All patients were histologically confirmed and staged by physical examination, CT scan and/or MRI. By the AJCC TNM staging system, there were 2 patients with stge II (T2NO), 4 with stage III (T3NO, T1-3N1), and 16 with stage IV (T4 or N2-3). Four patients received chemotherapy with 5-FU and cisplatin prior to radiotherapy. All patients were followed up periodically by a telescopic examination and radiologic imaging study of CT scan or MRI with a median follow-up time of 13 months (range: 3-34 months). Twenty one patients showed a complete response ore month after completing therapy and one patient showed a complete response after three months. At the time of this analysis, seventeen patients remain alive without evidence of disease, but four patients developed distant metastasis and one patient died a month after treatment. The local control rate was $100{\%}$ in a median follow-up time of 13 months. The two year overall and disease free survival rates by the Kaplan-Meier method were $94{\%}$ and $67{\%}$, respectively. Serious radiation sequelae have not been observed yet. Although longer follow-up is needed, this retrospective analysis suggests that HDR brachytherap. given as a boost therapy for nasoharyngeal carcinoma may improve the local control. To reduce the incidence of distant metastasis, we need to develop a more effective systemic chemotherapy.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.357-366
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• 1998

Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week. 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4.1 Gy each to Point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as. 78-86$\%$ for Stage 1, 68-85$\%$ for stage 11, and 38-56$\%$ for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In addition, standardization of HDR application (clinical, computer algorithms, and dosimetric aspects) is necessary.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.197-201
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• 1990

The primary treatment modality of malignant tumors of the nasopharynx is radiation therapy owing to its inaccessibility to surgical intervention. Over the last two decades there were many changes in techniques of delivery, which include the use of higher doses of radiotherapy, the use of wide radiation field, including the elective radiation of the whole neck, the combined use of brachy- and teletherapy, and the use of split-course therapy. In spite of these advances local and regional recurrences remain the major cause of death. As a boost therapy after external irradiation, high-dose-rate intracavitary irradiation using remote control afterloading system(RALS) was used in two patients. Our results were satisfactory, however, this procedure should only be performed by those who have developed enough expertise in the use of intracavitary techniques for the treatment of nasopharyngeal cancer and have a supportive team including a physicist, dosimetrist, nurse, and trained technologist.

• Radiation Oncology Journal
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• v.8 no.2
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• pp.231-239
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• 1990

From May 1979 through December 1981 a total of 524 patients with carcinoma of the uterine cervix were treated by radiation therapy with curative intent. Among the 524 patients, 350 were treated with a high-dose-rate (HDR), remote-controlled, afterloading intracavitary irradiation (ICR) system using a cobalt source (Ralstron), and 168 patients received a low-dose-rate (LDR) ICR using a radium source. External beam irradiation with a total dose of 40-50 Gy to the whole pelvis followed by intracavitary irradiation with a total dose of 30-39 Gy in 10-13 fractions to point A was the treatment protocol. ICR was given three times a week with a dose of 3 Gy per fraction. Five-year actuarial survival rates in the HDR-ICR group were $77.6{\%}$ in stage IB (N=20), $68.2{\%}$ in stage II (N=182), and $50.9{\%}$ in stage III (N=148). In LDR-ICR group, 5-year survival rates were $87.5{\%}$ in stage IB (N=22), $66.3{\%}$ in stage II (N=91), and $55.4{\%}$ in stage III (N=52). Survival rates showed a statistically significant difference by stage, but there was no significant difference between the two ICR groups. Late bowel complications after radiotherapy were noted in $3.7{\%}$ of the HDR-ICR group and $8.4{\%}$ of the LDR-ICR group. There was no severe complication requiring surgical management. The incidence of bladder complications was $1.4{\%}$ in the HDR-ICR group and $2.4{\%}$ in the LDR-ICR group. The application of HDR-ICR was technically simple and easily performed on an outpatient basis without anesthesia, and the patients tolerated it very well. Radiation exposure to personnel was virtually nil in contrast to that of LDR-ICR. Within a given period of time, more patients can be treated with HDR-ICR because of the short treatment time. Therefore, the HDR-ICR system is highly recommended for a cancer center, particularly one with a large number of patients to be treated. In order to achieve an improved outcome, however, the optimum dose-fractionation schedule of HDR-ICR and optimum combination of intracavitary irradiation with external beam irradiation should be determined through an extensive protocol.

• Progress in Medical Physics
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• v.6 no.1
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• pp.13-18
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• 1995

Dose distribution of HDR-RALS source represents an inverse square law as the distance. Difference of measurement value and calculation value according of brachytherapy. Therefore, in HDR-RALS dose calibration and calculation have an important effect in treatment of uterine cervical cancer and absorbed dose of interesting points. In intracavitary therapy, particula attention is paid for precise determination of the doses to be applied. In this report, we have discussed that the calibration of a HDR-RALS, differences between calculation dose use of isodose chart and measurement in rectum. Dose rate calibration of radiation sources are obtained from air kerma and Г factor with calibraed ion chamber for cobalt source. and used semiconductor detector for compared with measurement in phantom. Eighteen patients were treated with a HDR-RALS for intrcavitarty irradiation (ICR) using a cobalt-cesium source. Repoductivity of dose measurements were 0.3 -1.1％ in phantom. The means of dose distribution was -6- ＋21％ between calculation of isodose chart and measurement of recyum, and was same mean value upper 6.3％ in measurement value than calculation does.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.32-39
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• 2000

Purpose :The incidence of adenocarcinoma of the uterine cervix is low. Traditionally, Low Dose Rate (LDR) brachytherapy has been used as a standard modality in the treatment for patients with carcinoma of the uterine cervix. The purpose of this report is to evaluate the effects of the High dose rate (HDR) brachytherapy in the patients with adenocarcinoma of the uterine cervix compared with the LDR. : From January 1971 to December 1992, 106 patients of adenocarcinoma of uterine cervix were treated with radiation therapy in the Department of Radiation Oncology, Yonsei University with curative intent. LDR brachytherapy was carried out on 35 patients and 71 patients were treated with HDR brachytherapy. In LDR Group, 8 patients were in stage I, 18 in stage II and 9 in stage III. External radiation therapy was delivered with 10 MV X-ray, daily 2 Gy fractionation, total dose 40$\~$46Gy (median 48 Gy). And LDR Radium intracavitary irradiation was peformed with Henschke applicator, 22$\~$59 Gy to point A (median 43 Gy). In HDR Group, there were 16 patients in stage 1, 38 in stage II and 17 in stage III. The total dose of external radiation was 40$\~$61 Gy(median 45 Gy), daily 1.8$\~$2.0 Gy. HDR Co-60 intracavitary irradiation was peformed with RALS (Remote Afterloading System), 30 $\~$ 57 Gy(median 39 Gy) to point A, 3 times a week, 3 Gy per fraction. Conclusion : The 5-year overall survival rate in LDR Group was 72.9$\%$, 61.9$\%$, 45.0$\%$ in stage I, II, III, respectively and corresponding figures for HDR were 87.1$\%$, 58.3$\%$, 41.2$\%$, respectively (p>0.05). There was no statistical difference in terms of the 5-year overall survival rate between HDR Group and LDR Group in adenocarcinoma of the uterine cervix. There was 11$\%$ of late complication rates in LDR Group and 27$\%$ in HDR Group. There were no prognostic factors compared HDR with LDR group. The incidence of the late complication rate in HDR Group stage II, III was higher than that in LDR Group(16.7$\%$ vs. 31.6$\%$ in stage II, 11.1$\%$ vs. 35.3$\%$ In stage III, p>0.05). Although the incidence of radiation induced late complication rate was higher in HDR Group stage II and III patients than that in the LDR Group, statistical significance was not detected and within acceptable level. Conclusion : There was no difference in terms of 5-year survival rate and failure pattern in the patients with adenocarcinoma of the uterine cervix treated with HDR and LDR brachytherapy. Even late complication rates were higher in the HDR group It was an acceptable range. This retrospective study suggests that HDR brachytherapy seems to replace the LDR brachytherapy in the adenocarcinoma of the uterine cervix. However, further studies will be required to refine the dose rate effects.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.355-361
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• 1993

Since May 1991, authors have conducted a pilot study to determine the feasibility and evaluate the effect of concurrent radiation therapy and chemotherapy with 5-FU and Cis-platinum for locally advanced cervical cancer (stage IIB-IVA). Radiation therapy consisted of external irradiation to whole pelvis (4140 cGy/23 fx) in 4.5 weeks followed by high dose rate intracavitary radiation therapy (HDR ICRT) to deliver a dose of 30 to 35 Gy to A point in 6 to 7 fractions. After the intracavitary radiation therapy, parametrial boost was delivered for B point dose of 60 Gy in Stage IIB and 65 Gy in stage IIIB. 5-FU (1000 $mg/m^2/24hr$ for 96 hour iv infusion) and Cis-platinum (20 $mg/m^2/day$ IV bolus for 3 days) were given during the second week of external RT and the second course chemotherapy administered at the first HDR ICRT with the same method as the first chemotherapy. Sixteen patients (10 stage IIB,4 stage IIIB,2 stage IVA) were registered to this protocol. Among these 16 patients, two refused treatment after 2 fractions of external irradiation, and one could not continue intracavitary irradiation because of treatment related genitourinary toxicity. So 14 patients were evaluated for toxicity and 13 patients were evaluated for response analysis. Five of 14 patients developed grade 3 gastrointestinal toxicity but 4 of them recovered at the completion of treatment. One stage IIIB patient with inguinal lymph node metastasis who received higher dose of radiation in spite of initial poor performance status did not recover from gastrointestinal toxicity at the completion of treatment. And she died of distant metastasis at one month after the completion of treatment. Two of 14 evaluable patients showed weight loss, more than $10\%$ of initial weight. One patient developed grade 3 leukopenia. In this study, the average total treatment period of completely treated patients was 75 days and three of them took more than 80 days (84, 84, 89 days). Toxicities were generally acceptable and there were no treatment related death. At the last follow-up, complete response was achieved in $62\%(8/13)$ and especially of nine patients with stage IIB, eight patients showed complete response. This study suggests that concurrent radiation therapy and chemotherapy (5-FU and Cis-platinum) is tolerable and effective. Further follow-up is needed to determine whether this protocol will have a favorable impact on survival and to evaluate the late effect on normal tissues. In future, prospective randomized trials are needed to compare the standard radiation therapy alone with concurrent chemotherapy and radiation therapy for locally advanced cervical carcinoma.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.1
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• pp.73-77
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• 2004

Purpose of the radio-therapy is maximize the radiation dose to the tumor while minimizing the dose to the critical organ. Carcinoma of the uterine cervix treatment are external irradiation or an interstitial brachtheraphy make use of isotope. Brachytherapy is a method of radiotherapy in advantage to achieve better local control with minimum radiation toxicity in comparison with external irradiation because radiation dose is distributed according to the inverse square low of gamma-ray emitted from the implanted sources. Authors make use of the patients data which 192Ir gives medical treatment intrcavity. Intracavitary radiation of the uterine cervix cancer, critical organ take $20\%$ below than exposure dose of A point in the ICRU report. None the less of the advice, Radiation proctitis and radiation cystitis are frequent and problematic early complications in patients treated with radiation for the uterine cervix cancer. In brachytherapy of uterine cervical cancer using a high dose rate remote afterloading system, it is of prime importance to deliver a accurate dose in each fractionated treatment by minimizing the difference between the pre-treatment planned and post-treatment calculated doses. Use of packing to reduce late complications intracavitary radiation of the uterine cervix cancer. Bladder and rectum changes exposure dose rate by radiotherphy make use of packing.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.349-357
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• 1995

Purpose : To analyze survival rate and late rectal and bladder complication for patients with stage I and II carcinoma of uterine cervix treated by radiation alone or combined with chemotherapy Materials and Methods : Between November 1984 and December 1993, 127 patients with stage I and II carcinoma of uterine cervix treated by radiation alone or combined therapy of radiation and chemotherapy. Retrospective analysis for survival rate was carried out on eligible 107 patients and review for complication was possible in 91 patients. The median follow-up was 47 months (range 3-118) and the median age of patiens was 56 years (range 31-76). 26 patients were stage IB by FIGO classification, 40 were stage IIA and 41 were stage IIB. 86 cases were treated by radiation alone and 21 were treated by radiation and chemotherapy. 101 patients were treated with intracavitary radiation therapy (ICRT), of these, 80 were received low dose rate (LDR) ICRT and 21 were received high dose rate (HDR) ICRT. Of the patients who received LDR ICRT, 63 were treated by 1 intracavitary insertion and 17 were underwent 2 insertions And we evaluated the external radiation dose and midline shield. Results : Actuarial survival rate at 5 years was $92{\%}$ for stage IB, $75{\%}$ for stage IIA, $53{\%}$ for stage IIB and $69{\%}$ in all patients Grade 1 rectal complications were developed in 20 cases ($22{\%}$), grade 2 were in 22 cases ($24{\%}$). 22 cases ($24{\%}$) of grade 1 urinary complications and 17 cases ($19{\%}$) of grade 2 urinary complications were observed But no patient had severe complications that needed surgical management or admission care. Maximum bladder dose for the group of patients with urinary complications was higher than that for the patients without urinary complications (7608 cGy v 6960cGy. p<0.01) Maximum rectal dose for the group of patients with rectal complications was higher than that for the patients without rectal complications (7041cGy v 6269cGy, p<0.01). While there was no significant difference for survival rate or bladder complication incidence as a function of dose to whole pelvis, Grade 2 rectal complication incidence was significantly lower for the patients receiving less than 4500cGy ($6.3{\%}$ v $25.5{\%}$, p<0.05). There was no significant differance between HDR ICRT group and LDR ICRT group for survival rate according to stage, on the other hand complication incidence was higher in the HDR group than LDR group, This was maybe due to different prescription doses between HDR group and LDR group. Midline shield neither improved survival rate nor decreased complication rate. The number of insertion in LDR ICRT group did not affect on survival and compication rate. Conclusion : In stage I and II carcinoma of uterine cervix there was no significant differance for 5 year survival rate by radiation therapy technique. Rectal complication incidence was as a function of dose to whole pelvis and there were positive correlations of maximum dose of rectum and bladder and each complication incidence. So we recommand whole pelvis dose less than 4500cGy and maximum dose of rectum and bladder as low as possible.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.61-66
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• 2012

Purpose: The purpose of this study is to compare plans prescribed to point A with these prescribed to point H recommended by ABS (American Brachytherapy Society) in high dose rate intracavitary brachytherapy for cervical carcinoma. Materials and Methods: This study selected 103 patients who received HDR (High Dose Rate) brachytherapy using tandem and ovoids from March 2010 to January 2012. Point A, bladder point, and rectal point conform with Manchester System. Point H conforms with ABS recommendation. Also Sigmoid colon point, and vagina point were established arbitrarily. We examined distance between point A and point H. The percent dose at point A was calculated when 100% dose was prescribed to point H. Additionally, the percent dose at each reference points when dose is prescribed to point H and point A were calculated. Results: The relative dose at point A was lower when point H was located inferior to point A. The relative doses at bladder, rectal, sigmoid colon, and vagina points were higher when point H was located superior to point A, and lower when point H was located inferior to point A. Conclusion: This study found out that as point H got located much superior to point A, the absorbed dose of surrounding normal organs became higher, and as point H got located much inferior to point A, the absorbed dose of surrounding normal organs became lower. This differences dose not seem to affect the treatment. However, we suggest this new point is worth being considered for the treatment of HDR if dose distribution and absorbed dose at normal organs have large differences between prescribed to point A and H.