• Radiation Oncology Journal
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• v.20 no.4
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• pp.343-352
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• 2002

Purpose : Radiotherapy is the main treatment modality for uterine cervix cancer. Since the rectum is in the radiation target volume, rectal bleeding is a common late side effect. This study evaluates the risk factors of radiation induced rectal bleeding and discusses its optimal management. Materials and Methods : total of 213 patients who completed external beam radiation therapy (EBRT) and intracavitary radiation (ICR) between September 1994 and December 1999 were included in this study. No patient had undergone concurrent chemo-radiotherapy. Ninety patients received radiotherapy according to a modified hyperfractionated schedule. A midline block was placed at a pelvic dose of between 30.6 Gy to 39.6 Gy. The total parametrial dose from the EBRT was 51 to 59 Gy depending on the extent of their disease. The Point A dose from the HDR brachytherapy was 28 Gy to 30 Gy $(4\;Gy\times7,\;or\;5\;Gy\times6)$. The rectal point dose was calculated either by the ICRU 38 guideline, or by anterior rectal wall point seen on radiographs, with barium contrast. Rectal bleeding was scored by the LENT/SOMA criteria. For the management of rectal bleeding, we opted for observation, sucralfate enema or coagulation based on the frequency or amount of bleeding. The median follow-up period was 39 months $(12\~86\;months)$. Results : The incidence of rectal bleeding was $12.7\%$ (27/213); graded as 1 in 9 patients, grade 2 in 16 and grade 3 in 2. The overall moderate and severe rectal complication rate was $8.5\%$. Most complications $(92.6\%)$ developed within 2 years following completion of radiotherapy (median 16 months). No patient progressed to rectal fistula or obstruction during the follow-up period. In the univariate analysis, three factors correlated with a high incidence of bleeding an icruCRBED greater than 100 Gy $(19.7\%\;vs.\;4.2\%)$, an EBRT dose to the parametrium over 55 Gy $(22.1\%\;vs.\;5.1\%)$ and higher stages of III and IV $(31.8\%\;vs.\;10.5\%)$. In the multivariate analysis, the icruCRBED was the only significant factor (p>0.0432). The total parametrial dose from the EBRT had borderline significance (p=0.0546). Grade 1 bleeding was controlled without further management (3 patients), or with sucralfate enema 1 to 2 months after treatment. For grade 2 bleeding, sucralfate enema for 1 to 2 months reduced the frequency or amount of bleeding but for residual bleeding, additional coagulation was peformed, where immediate cessation of bleeding was achieved (symptom duration of 3 to 10 months). Grade 3 bleeding lasted for 1 year even with multiple transfusions and coagulations. Conclusion : Moderate and several rectal bleeding occurred in $8.5\%$ of patients, which is comparable with other reports. The most significant risk factor for rectal bleeding was the accumulated dose to the rectum (icruCRBED), which corrected with consideration to biological equivalence. Prompt management of rectal bleeding, with a combination of sucralfate enema and coagulation, reduced the duration of the symptom, and minimized the anxiety/discomfort of patients.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.136-141
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• 2001

Purpose : To evaluate the significance of serum SCC for the monitoring of treatment response and the early detection of distant metastasis during radiotherapy (RT). Materials and Methods : In 13 patients with histologically proven primary squamous cell carcinoma of uterine cervix, serum SCC values were checked in pre-RT point, weekly during RT, and in post-RT point. Results : In 4 of 13 cases, metastasis appeared at the end of external RT, so that intracavitary radiation couldn't be peformed.01 these 4 cases,3 with elevated pre-RT SCC level, who resulted in lung metastasis on chest PA at the end of external RT showed decreased post-RT SCC value despite of metastasis. Of all 10 cases with elevated pre-RT SCC value (including 3 with metastasis at the end of external RT), SCC value was higher than pre-RT value in 7 at 9 Gy and the difference was statistically significant. At 18 Gy, SCC was higher in 4 and lower in 6 than pre-RT value. After 18 Gy, SCC value decreased continuously to the end of RT in all 10 cases. Conclusion : During RT, SCC value increased initially at 9 Gy. To 18 Gy, SCC value decreased to the nearly same with pre-RT value. After 18 Gy, to the end of RT, SCC value decreased continuously and normalized in completely responded cases. In cases with appearance of lung metastasis, SCC value also decreased with the disappearance of main mass of uterine cervix despite metastasis.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.199-206
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• 2003

Purpose: This study was undertaken to evaluate the efficacy of postoperative radiotherapy, and to investigate the prognostic factors for FIGO stages IB-IIB cervical cancer patients who were treated with simple hysterectomy, or who had high-risk factors following radical hysterectomy and pelvic lymph node dissection. Materials and Methods: Between March 1986 and December 1998, 58 patients, with FIGO stages IB-IIB cervical cancer were included in this study. The indications for postoperative radiation therapy were based on the pathological findings, including lymph node metastasis, positive surgical margin, parametrial extension, lymphovascular invasion, invasion of more than half the cervical stroma, uterine extension and the incidental finding of cervix cancer fellowing simple hysterectomy. All patients received external pelvic radiotherapy, and 5 patients, received an additional intracavitary radiation therapy. The radiation dose from the external beam to the whole pelvis was $40\~50$ Gy. Vagina cuff Irradiation was peformed, after completion of the external beam irradiation, at a low-dose rate of Cs-137, with the total dose of $4488\~4932$ chy (median: 4500 chy) at 5 mm depth from the vagina surface. The median follow-up period was 44 months ($15\~108$ months). Results: The 5-yr actuarial local control rate, distant free survival and disease-free survival rate were $98\%,\;95\%\;and\;94\%$, respectively. A univariate analysis of the clinical and pathological parameters revealed that the clinical stage (p=0.0145), status of vaginal resection margin (p=0.0002) and parametrial extension (p=0.0001) affected the disease-free survival. From a multivariate analysis, only a parametrial extension independently influenced the disease-free survival. Five patients ($9\%$) experienced Grade 2 late treatment-related complications, such as radiation proctitis (1 patient), cystitis (3 patients) and lymphedema of the leg (1 patient). No patient had grade 3 or 4 complications. Conclusion: Our results indicate that postoperative radiation therapy can achieve good local control and survival rates for patients with stages IB-IIB cervical cancer, treated with a simple hysterectomy, as well as for those treated with a radical hysterectomy, and with unfavorable pathological findings. The prognostic factor for disease-free survival was invasion of the parametrium. The prognosic factor identified in this study for treatment failure can be used as a selection criterion for the combined treatment of radiation and che motherapy.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.396-404
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• 2002

Purpose : Many papers support a correlation between rectal complications and rectal doses in uterine cervical cancer patients treated with radical radiotherapy. In vivo dosimetry in the rectum following the ICRU report 38 contributes to the quality assurance in HDR brachytherapy, especially in minimizing side effects. This study compares the rectal doses calculated in the radiation treatment planning system to that measured with a silicon diode the in vivo dosimetry system. Methods : Nine patients, with a uterine cervical carcinoma, treated with Iridium-192 high dose rate brachytherapy between June 2001 and Feb. 2002, were retrospectively analysed. Six to eight-fractions of high dose rate (HDR)-intracavitary radiotherapy (ICR) were delivered two times per week, with a total dose of $28\~32\;Gy$ to point A. In 44 applications, to the 9 patients, the measured rectal doses were analyzed and compared with the calculated rectal doses using the radiation treatment planning system. Using graphic approximation methods, in conjunction with localization radiographs, the expected dose values at the detector points of an intrarectal semiconductor dosimeter, were calculated. Results : There were significant differences between the calculated rectal doses, based on the simulation radiographs, and the calculated rectal doses, based on the radiographs in each fraction of the HDR ICR. Also, there were significant differences between the calculated and measured rectal doses based on the in-vivo diode dosimetry system. The rectal reference point on the anteroposterior line drawn through the lower end of the uterine sources, according to ICRU 38 report, received the maximum rectal doses in only 2 out of the nine patients $(22.2\%)$. Conclusion : In HDR ICR planning for conical cancer, optimization of the dose to the rectum by the computer-assisted planning system, using radiographs in simulation, is improper. This study showed that in vivo rectal dosimetry, using a diode detector during the HDR ICR, could have a useful role in quality control for HDR brachytherapy in cervical carcinomas. The importance of individual dosimeters for each HDR ICR is clear. In some departments that do not have the in vivo dosimetry system, the radiation oncologist has to find, from lateral fluoroscopic findings, the location of the rectal marker before each fractionated HDR brachytherapy, which is a necessary and important step of HDR brachytherapy for cervical cancer.

• Radiation Oncology Journal
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• v.24 no.1
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• pp.37-43
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• 2006

Purpose: We wanted to determine the clinical characteristics and prognosis according to the VEGF expression in stage II cervical carcinoma patients treated with definitive radiotherapy. Materials and Methods: We enrolled 31 patients who were diagnosed with cervical cancer from 1995 to 2003 at Samsung Medical Center and their paraffin block tissue samples were available for study. The median age of the patients was 65 years. The mean tumor size was 4.1 cm $(range:\;1.2{\sim}8.2cm)$. Seven patients (22.6%) were suspected of having pelvic lymph node metastasis. An external beam irradiation dose of 45-56.4 Gy was administered to the whole pelvis with a 15 MV linear accelerator, and an additional 24 Gy was given to point A by HDR intracavitary brachytherapy. VEGF staining was defined as positive when more than 10% of the tumor cells were stained. The median follow-up duration was 58 months. Results: A positive VEGF expression was observed in 21 patients (67.7%), There was no significant correlation between the VEGF expression and pelvic lymph node metastasis, tumor size and the response of radiotherapy. During follow-up, 7 patients had recurrence. The complete response rate was not significant between the VEGF(-) and VEGF(+) tumors. However, the VEGF(+) tumors showed a significantly higher recurrence rate in comparison with the VEGF(-) tumors (p=0.040), The three year disease-free survival rates were 100% and 66.7%, respectively, for patients with VEGF(-) or VEGF(+) tumor (p=0.047), Conclusion: The VEGF expression was a significant factor for recurrence and disease-free survival. However, the significance of the VEGF expression is still controversial because of the various definitions of VEGF expression and the mismatches of the clinical data in the previous studies.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5259-5264
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• 2014

Background: CT based brachytherapy allows 3-dimensional (3D) assessment of organs at risk (OAR) doses with dose volume histograms (DVHs). The purpose of this study was to compare computed tomography (CT) based volumetric calculations and International Commission on Radiation Units and Measurements (ICRU) reference-point estimates of radiation doses to the bladder and rectum in patients with carcinoma of the cervix treated with high-dose-rate (HDR) intracavitary brachytherapy (ICBT). Materials and Methods: Between March 2011 and May 2012, 20 patients were treated with 55 fractions of brachytherapy using tandem and ovoids and underwent post-implant CT scans. The external beam radiotherapy (EBRT) dose was 48.6Gy in 27 fractions. HDR brachytherapy was delivered to a dose of 21 Gy in three fractions. The ICRU bladder and rectum point doses along with 4 additional rectal points were recorded. The maximum dose ($D_{Max}$) to rectum was the highest recorded dose at one of these five points. Using the HDRplus 2.6 brachyhtherapy treatment planning system, the bladder and rectum were retrospectively contoured on the 55 CT datasets. The DVHs for rectum and bladder were calculated and the minimum doses to the highest irradiated 2cc area of rectum and bladder were recorded ($D_{2cc}$) for all individual fractions. The mean $D_{2cc}$ of rectum was compared to the means of ICRU rectal point and rectal $D_{Max}$ using the Student's t-test. The mean $D_{2cc}$ of bladder was compared with the mean ICRU bladder point using the same statistical test. The total dose, combining EBRT and HDR brachytherapy, were biologically normalized to the conventional 2 Gy/fraction using the linear-quadratic model. (${\alpha}/{\beta}$ value of 10 Gy for target, 3 Gy for organs at risk). Results: The total prescribed dose was $77.5Gy{\alpha}/{\beta}10$. The mean dose to the rectum was $4.58{\pm}1.22Gy$ for $D_{2cc}$, $3.76{\pm}0.65Gy$ at $D_{ICRU}$ and $4.75{\pm}1.01Gy$ at $D_{Max}$. The mean rectal $D_{2cc}$ dose differed significantly from the mean dose calculated at the ICRU reference point (p<0.005); the mean difference was 0.82 Gy (0.48-1.19Gy). The mean EQD2 was $68.52{\pm}7.24Gy_{{\alpha}/{\beta}3}$ for $D_{2cc}$, $61.71{\pm}2.77Gy_{{\alpha}/{\beta}3}$ at $D_{ICRU}$ and $69.24{\pm}6.02Gy_{{\alpha}/{\beta}3}$ at $D_{Max}$. The mean ratio of $D_{2cc}$ rectum to $D_{ICRU}$ rectum was 1.25 and the mean ratio of $D_{2cc}$ rectum to $D_{Max}$ rectum was 0.98 for all individual fractions. The mean dose to the bladder was $6.00{\pm}1.90Gy$ for $D_{2cc}$ and $5.10{\pm}2.03Gy$ at $D_{ICRU}$. However, the mean $D_{2cc}$ dose did not differ significantly from the mean dose calculated at the ICRU reference point (p=0.307); the mean difference was 0.90 Gy (0.49-1.25Gy). The mean EQD2 was $81.85{\pm}13.03Gy_{{\alpha}/{\beta}3}$ for $D_{2cc}$ and $74.11{\pm}19.39Gy_{{\alpha}/{\beta}3}$ at $D_{ICRU}$. The mean ratio of $D_{2cc}$ bladder to $D_{ICRU}$ bladder was 1.24. In the majority of applications, the maximum dose point was not the ICRU point. On average, the rectum received 77% and bladder received 92% of the prescribed dose. Conclusions: OARs doses assessed by DVH criteria were higher than ICRU point doses. Our data suggest that the estimated dose to the ICRU bladder point may be a reasonable surrogate for the $D_{2cc}$ and rectal $D_{Max}$ for $D_{2cc}$. However, the dose to the ICRU rectal point does not appear to be a reasonable surrogate for the $D_{2cc}$.

• Journal of radiological science and technology
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• v.29 no.2
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• pp.83-92
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• 2006

Based on the data of cervical cancer patients who were treated by the radiotherapy with concurrent chemotherapy at the radiation oncology department of National Cancer Center from January 2002 to February 2003, we have studied the method recommended by ICRU 38 to maximize the prescription dose to the planing target volume (PTV) with minimizing the dose to surrounding normal organs. Clinical stage of the patients are 1 patient for stage IB, 3 patients for IIA, 19 patients for IIB, 3 patients for IIIA, 3 patients for IIIB and 1 patient for IV. All patients took the MRI before treatment and the maximum size of the gross tumor volume were under 4cm for 17 patients and from 4 cm to 6 cm for 12 patients and above 6 cm for 1 patient. The results show that while the irradiated volume can be reduced with optimized dose distribution using PTV treatment planning (p<0.0001) when the remained tumor size is small, the surrounding normal organs will receive unnecessarily large dose when the irradiated tumor volume is relatively large. This is because there is some limitation in controling the intensity of radiation in Fletcher Williamson Applicator. To overcome the limit of applicator and to achieve the optimal dose distribution, we have virtually applied 4 needles with Fletcher Williamson Applicator for 10 patients who have relatively large tumor and studied the change in dose distribution before and after application. The results show that this new virtual treatment plan reduces the volume covered by 100 % isodose (p=0.0608, p=0.0607) and reduces the dose of normal organs (p=0.0162, p=0.008). This evidence suggest that this method is superior than the currently used method such as PTV treatment and ICRU treatment.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.55-61
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• 1995

Purpose : Despite a development of therapeutic machines and advance in modern radiation therapy techniques, locally advanced cervical carcinoma has shown high rate of local failure and poor survival rate, Combination of chemotherapy and radiotherapy demonstrated benefit in improving local control and possibly the overall survival. Our study was performed to evaluate effect of concurrent chemoradiation on locally advanced uterine cervical cancer. Methods and Materials : Twenty six patients with locally advanced stage(FIGO stage IIB with ${\geq}5cm$ in diameter, III, IVA) were treated with combination of radiation therapy and concurrent cisplatinum between May of 1988 and September of 1993 at our hospital. Radiation therapy consisted of external irradiaton and 1-2 sessions of intracavitary irradiation. Cisplatinum was administered in bolus injection of 25mg/$m^2$ at weekly intervals during the course of external radiation therapy. Results : Of the 26 Patients, twenty-five patients were evaluable for estimation of response. Median follow-up period was 25 months with ranges from 3 to 73 months. Stage IIB, III, and IVA were 16, 5, 4 patients, respectively, Twenty patients were squamous cell carcinoma. Response was noted in all 25 patients: complete response(CR) in 17/25($68\%$), Partial response(PR) in 8/25($32\%$). Of the 24 patients except one who died of sepsis at 3 months follow-up, seventeen patients($70.8\%$) maintained local control in the pelvis: 16/17($94.1\%$) in CR, 1/17($14.3\%$) in PR. Fourteen of the 17 patients with CR are alive disease free on the completion of follow-up. Median survival is 28 months for CR and 15 months for PR. Analysis of 5-year survival by stage shows 11/16($59.8\%$) in IIB, 3/5($60.0\%$) in III, and 1/4($25.0\%$) in IVA. Overall 5-year survival rate was $55.2\%$. Ten patients recurred: 4 at locoregional, 3 in distant metastasis and 3 with locoregional and distant site. Toxicity by addition of cisplatinum was not excessive. Conclusion : Although the result of this study was obtained from small number of patients, it is rather encouraging in view of markedly improved response rate compared with the results of historical group.

• Radiation Oncology Journal
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• v.2 no.2
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• pp.261-270
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• 1984

The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiation and medical records of 203 patients who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analized. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem applicator to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids were measured for low dose rate irradiation system and high dose rate remote control afterloading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results ; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as $4\~7cm$ width and high dose rate system showed as $5\~6cm$. 2. In horizontal angulation of tandem to body axis, the low dose rate system revealed mid position$64.6\%$, left deviation $19.2\%$and right deviation $16.2\%$. 3. In longitudinal angulation of tandem to body axis, the mid position was $11.8\%$ and anterior angulation $88.2\%$ in low dose rate system but in high dose rate system, anterior angulation was $98.5\%$. 4. Down ward displacement of ovoids below external os was only $3\%$ in low dose rate system and $66.7\%$ in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses an4 TDF were 50, 70 Gy and 141, 123, including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 93, 47 Gy and 230, 73 in high dose rate system but in low doss rate system, 123, 52 Gy and 262, 75 respectively. 8. Doses and TDF in bladder and rectum were 70, 68 Gy and 124, 120 in low dose rate system, but in high dose rate system, 58, 64 Gy 98, 110 respectively, and then grades of injuries in bladder and rectum were 25, $30\%$ and 18, $23\%$ respectively.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.429-435
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• 2021

In intracavitary radiotherapy, incorrect location of the source can cause excessive dose to normal tissue, so it is essential to evaluate the location accuracy of the source. In this study, basic research was performed on digital line dosimeter based on lead (II) oxide (PbO) to improve analog verification method. Therefore, a polycrystalline PbO unit cell dosimeter was manufactured and the measurement performance for Ir-192 sources was evaluated. As a result, the reproducibility satisfies the evaluation criteria of 1.5% with a relative standard deviation of 0.85%. Linearity showed excellent results with a linear coefficient of R² of 0.9998. In the case of distance dependence evaluation, the power function R² showed 0.9855 for PbO and 0.9974 for diode, and the overall average difference was 1.66% for PbO and 2.18% for diode. This study presents the basic detection performance of the polycrystalline PbO dosimeter for the Ir-192 source and can provide basic data in the field of radiation measurement.