• Radiation Oncology Journal
• /
• v.18 no.1
• /
• pp.32-39
• /
• 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
• /
• v.13 no.4
• /
• pp.349-357
• /
• 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.

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

• Radiation Oncology Journal
• /
• v.7 no.2
• /
• pp.171-183
• /
• 1989

A general effect for cell proliferation has been incorporated into Roesch's survival equation (Accumulation Model). From this an isoeffect formula for the low dose-rate regimen is obtained. The prediction for total doses equivalent to 60Gy delivered at the constant dose-rate over 7 days agrees well with the dose-time data of Paterson and of Green, when the parameter ratio A/B (${\approx}{\alpha{\mu}}/2{\beta}\;where\;{\mu}$ is the repair rate) is chosen to be 0.7Gy/h. When a constant proliferation rate and known facts of division delay are assumed, an isoeffect relation between low dose-rate treatment and acute dose-rate treatment can be derived. This formula in the regimens where proliferation is negligible predicts exactly the data of Ellis that 8 fractions of 5 Gy/day for 7 days are equivalent to continuously applied 60Gy over 7days, provided the A/B ratio is 0.7 Gy/h and the $\alpha/\beta$ ratio is 4Gy. Overall agreement between the clinical data and the predictions made by the formula at the above parameter values suggests that the biologcal end points used as the tolerance level in the studies by Paterson, Green, and Ellis all agree and they are not entirely the early effects as generally assumed. The absence of dose-rate effects observed in the mouse KHT sarcoma can better be explained in terms of a large value for the A/B ratio. Similarly, the same total dose used independently of the dose-rate to treat head and neck tumors by Pierquin can be justified.

• 대한방사선방어학회:학술대회논문집
• /
• 2011.11a
• /
• pp.90-91
• /
• 2011

• Radiation Oncology Journal
• /
• v.17 no.3
• /
• pp.179-187
• /
• 1999

Brachytherapy has been proved to be an effective method for the purpose of increasing radiation dose to the tumor and reducing the dose to the surrounding normal tissue. In head and neck cancer, the rationale of brachytherapy is as follows; Firstly, early small lesion is radiocurative and the major cause of failure is local recurrence. Seondly, it can diminish evidently the dose to the normal tissue especially masseteric muscle and salivary gland. Thirdly, the anatomy of head and neck is suitable to various technique of brachytherapy. On background of accumulated experience of LDR iridium brachytherapy of head and neck cancer for the last 15 years, the author reviewed the history of radioisotope therapy, the characteristics of radionuclides, and some important things in the method, clinical technique and treatment planning. The author analyzed the clinical result of 185 cases of head and neck cancer treated in the Korea Cancer Center Hospital. Finally the future prospect of brachytherapy of head and neck cancer is discussed.

• 한국생태학회:학술대회논문집
• /
• 1999.05a
• /
• pp.134.2-134.2
• /
• 1999

• Progress in Medical Physics
• /
• v.15 no.2
• /
• pp.63-69
• /
• 2004

HDR brachytherapy administers a large dose of radiation in a short time compare with LDR, and its optimization for treatment is related to several complex factors, such as physical, radiation and optimization algorithms, so there is a need for these to be verified for accurate dose delivery. In our approach, a previous study concerning the phantom for dose verification has been modified, and a new pelvic phantom fabricated for the purpose of localization, including a structure enabling the use of a CT or MRI system. In addition, a comparison study was performed to verify an orthogonal method that is commonly used for brachytherapy localization by comparing target coordinates from a CT system. Since the developed phantom was designed to simulate the clinical setups of cervix cancer, it included an air-filled bladder and a rectum structure shaped sphere and cylinder An N-shaped localizer was used to obtain precision coordinates from both CT and films. Moreover, the IDL 5.5 software program for Windows was used to perform coordinates analysis based on an orthogonal algorithm. The film results showed differences within 1.0 mm of the selected target points compare with the CT coordinates. For these results, a Plato planning system (Nucletron, Netherlands) could be independently verified using this phantom and software. Furthermore, the new phantom and software will be efficient and powerful qualify assurance (QA) tools in the field of brachytherapy QA.

• Journal of radiological science and technology
• /
• v.32 no.2
• /
• pp.129-140
• /
• 2009

As CT has been increasingly used as an accurate screening tool for lung disease, radiation dose becomes an important issue for both radiographers and patients. Many researches have been done for a low-dose CT as a screening tool for early detection of asymptomatic lung diseases. From those studies, it has been reported that chest dose rate from the low-dose CT is considerably lower than from standard CT. The patient dose is determined by scanning parameters such as kVp, mAs, pitch, scan time and the radiation risk of lung in screening examination may not be negligible. Herein, we suggest that Low-dose CT is useful as a screening tool in routine clinical practice on the basis of published articles, but further study is necessary because Low-dose CT has poor sensitivity and specificity for screening early stage of lung cancer according to the results of the studies. This article is to provide a brief overview of the screening examinations by Low-dose CT.

• Journal of Radiation Protection and Research
• /
• v.37 no.3
• /
• pp.159-166
• /
• 2012

The present study was performed to investigate the toxicity of low-dose-rate irradiation in BALB/c mice. Twenty mice of each sex were randomly assigned to four groups of five mice each and were exposed to 0 (sham), 0.02, 0.2, or 2 Gy, equivalents to low-dose-rate irradiation to 3.49 $mGy{\cdot}h^{-1}$. Urine, blood, and blood biochemistry were analyzed, and organ weight was measured. The low-dose-rate irradiation did not induce any toxicologically significant changes in mortality, clinical signs, body weight, food and water consumption, urinalysis, and serum biochemistry. However, the weights of reproductive organs including the testis, ovary, and uterus decreased in a dose-dependent manner. Irradiation at 2 Gy significantly decreased the testis, ovary, and uterus weights, but did not change the weights of other organs. There were no adverse effects on hematology in any irradiated group and only the number of neutrophils increased dose dependently. The low-dose-rate irradiation exposure did not cause adverse effects in mice at dose levels of 2 Gy or less, but the reproductive systems of male and female mice showed toxic effects.