Tumor volume and invasion to uterine body assessed by magnetic resonance imaging in the prediction of outcome for stage II cervical cancer / 부인종양

OBJECTIVE: The aim of this study was to evaluate the prognostic significance of primary tumor volume and uterine corpus invasion assessed by MRI in stage II uterine cervical cancer patients treated by concurrent chemotherapy and radiotherapy. METHODS: Fifty-two patients diagnosed with stage II cervical carcinoma were entered into the study. The tumor volume was calculated by the equation (Volume=widthXlengthXheightXpi/6) as an ellipsoid approximation. Univariate and multivariate analyses were performed to identify the prognostic factors for overall survival (OS), disease-free survival (DFS), pelvic control (PC), and distant metastasis-free survival (DMFS). RESUITS: The 5-year OS, DFS, PC, and DMFS rates were 65.8%, 59.3%, 72.6%, and 79.9%, respectively. The average volume of primary cervical tumor on MRI was 29.5 ml (5-109) and volume was not correlated with stage (p=0.180). Corpus invasion was exhibited in 50.0% and 93.8% of patients with small tumor volume ( or =30 ml), respectively; and strongly correlated with tumor volume (p<0.001). By univariate analyses, larger clinical tumor diameter (p=0.031), positive pelvic lymph node (p=0.033), uterine corpus invasion (p=0.045), and larger tumor volume (p=0.003) showed a statistically significantly relation to worse survival. In multivariate analyses, dividing patients according to whether the tumor volume was more or less than 30 ml predicted OS (p=0.048) and uterine corpus invasion also predicted DFS (p=0.042). CONCLUSION: Tumor volume and uterine corpus invasion determined by pre-treatment MRI examinations were significant prognostic factors for patients with invasive cervical carcinoma treated with concurrent chemotherapy and radiotherapy.

Evaluation of p53 and Bax Expression as Prognostic Markers in Invasive Cervical Carcinoma Stage IIB Patients Treated with Radiation Therapy / 대한방사선종양학회지

PURPOSE: The objective of our study was to evaluate the immunohistochemical expression of p53 and bax proteins as prognostic markers in FIGO stage IIb invasive squamous cell carcinoma of the uterine cervix. MATERIALS AND METHODS: Sixty-five cases of squamous cell carcinoma of the cervix (stage IIb) that were diagnosed from October 1996 to December 2003 were analyzed retrospectively for the bax and p53 expression. These expressions were determined immunohistochemically and they were correlated to the patients' overall survival and disease-free survival. RESULTS: The overall 5-year survival (OS) rate and the disease-free survival (DFS) rate were 65.1% and 62.9%, respectively. p53 and bax immunoreactivity was seen in 26.2% and 52.3% of cases, respectively, with variable levels of expression. On the univariate analysis, only p53 positivity correlated with poor survival in DFS (log-rank test p=0.027), but this significance was not maintained on multivariated analysis by Cox's regression. The nine cases with the immunophenotype p53+/bax- had the poorest survival. CONCLUSION: Neither p53 nor bax expression are independent predictors of the prognosis for stage IIb cervical squamous cancers. Evaluation of p53 and bax co-expression may affect the clinical outcome and further investigation is needed.

Comparison of the Result of Radiation Alone and Radiation with Daily Low Dose Cisplatin in Management of Locally Advanced Cervical Cancer / 대한방사선종양학회지

PURPOSE: An analysis was to compare the results of radiation alone with those of radiation with daily low dose cisplatin as a radiation sensitizer in locally advanced cervical cancer. MATERIALS AND METHODS: A retrospective analysis of 59 patients diagnosed with locally advanced uterine cervix cancer between December 1996 and March 2001 was performed. Thirty one patients received radiation alone and 28 patients received daily low dose cisplatin, as a radiation sensitizer, and radiation therapy. The median follow-up period was 34 months, ranging from 2.5 to 73 months. The radiation therapy consisted of 4500 cGy external beam irradiation to the whole pelvis (midline block after 3060 cGy), a 900~1,000 cGy boost to the involved parametrium and high dose-rate intracavitary brachytherapy (a total dose of 3,000~3,500 cGy/500 cGy per fraction to point A, twice per week). In the chemoradiation group, 10 mg of daily intravenous cisplatin was given daily from the 1st day of radiation therapy to the 20th day of radiation therapy. According to the FIGO classification, the patients were subdivided into 51 (86.4%) and 8 (13.6%) stages IIB and stage IIIB, respectively. RESULTS: The overall 5 year survival rate was 65.65% and according to treatment modality were 56.75% and 73.42% in the radiation alone and chemoradiation groups, respectively (p=0.180). The 5 year disease-free survival rates were 49.39% and 63.34% in the radiation alone and chemoradiatoin groups, respectively (p=0.053). The 5 year locoregional control rates were 52.34% and 73.58% in the radiation alone and chemoradiation groups, respectively (p=0.013). The 5 year distant disease-free survival rates were 59.29% and 81.46% in the radiation alone and chemoradiation groups, respectively (p=0.477). Treatment related hematologic toxicity were prominent in the chemoradiation group. Leukopenia (> or =3 grade) occurred in 3.2% and 28.5% of the radiation alone and chemoradiation groups, respectively (p=0.02). There were no statistical differences in the incidences of vesical, rectal and small bowel complications between two groups. CONCLUSION: Radiation therapy with low dose cisplatin did not improve the rates of survival and response rates, but did improve the rate of disease free survival and locoregional control rates in locally advanced cervical cancer. The incidence of bone marrow suppression was higher in the chemoradiation group.

LiF TLD in TLD Holder for In Vivo Dosimetry / 대한방사선종양학회지

PURPOSE: LiF TLD has a problem to be used in vivo dosimetry because of the toxic property of LiF. The aim of this study is to develop new dosimeter with LiF TLD to be used in vivo dosimetry. MATERIALS AND METHODS: We designed and manufactured the teflon box(here after TLD holder) to put TLD in. The external size of TLD holder is 4x4x1 mm3. To estimate the effect of TLD holder on TLD response for radiation, the linearity of TLD response to nominal dose were measured for TLD in TLD holder. Measurement were performed in the 10 MV x-ray beam with LiF TLD using a solid water phantom at SSD of 100 cm. Percent Depth Dose (PDD) and Tissue-Maximum Ratio (TMR) with varying phantom thickness on TLD were measured to find the effect of TLD holder on the dose coefficient used for dose calculation in radiation therapy. RESULTS: The linearity of response of TLD in TLD holder to the nominal dose was improved than TLD only used as dosimeter. And in various measurement conditions, it makes a marginnal difference between TLD in TLD holder and TLD only in their responses. CONCLUSION: It was proven that the TLD in TLD holder as a new dosimetry could be used in vivo dosimetry.

A Survey for the Hospital Utilization of Cancer patients in Inchon / 대한암학회지

PURPOSE: The purpose of this study was to evaluate the hospital utilization of cancer patients in Inchon and to assess the feasibility of Inchon Cancer Registry (ICR). MATERIALS AND METHODS: We used two data sources from Korean Central Cancer Registry (KCCR) and Korean Medical Insurance (KMI) for analysis. RESULTS: KCCR data analysis showed that 50.8% of cancer patients visited hospitals in Seoul, 46% visited hospitals in Inchon, and 2.6% in other areas at first visit. The analysis of KMI data showed that 43% of cancer patients visited hospital in Seoul, 38.5% visited hospitals in Inchon, and 18.5% in other areas at first visit. From these results, we found many cancer patients visited hospitals located in Seoul. We estimated that 52.1% would be missed when we performed cancer registry project in Inchon area alone from the KCCR data analysis. On the other hand, 60% would be missed from the KMI data. However, if we used registration data at the nation-wide level and actively registered cancer patient data in Inchan, expected unregistration rates would be 5%. CONCLUSION: Even though registration rate to KCCR was relatively low (74%) in Inhon and many patients were treated in other area, we are convinced that almast all cancer patients would be registered because most cancer patients visited at least one of the cancer registry hospitals at the nation-wide level. Therefore, if ICR used KCCR and encouraged the hospitals in Inchon to actively participate in cancer registration, the population-based cancer registration in Inchon would be possible.

Photon Energy Dependence of the Sensitivity of LiF TLDs Loaded with Thin Material / 대한방사선종양학회지

PURPOSE: An investigation has been carried out on the factors which affect the response reading of thermoluminescent dosimeters (TLD-100) loaded with thin material in high energy photon. The aim of the study was to assess the energy response of TLD-100 to the therapeutic ranges of photon beam. MATERIALS AND METHODS: In this technique, TLD-100 (abbreviated as TLD) chips and three different thin material (Tin, Gold, and Tissue equivalent plastic plate) which mounted on the TLD chip were used in the clinical photon beam. The thickness of each metal plates was 0.1 mm and TE plastic plate was 1 mm thick. These compared with the photon energy dependence of the sensitivities of TLD (normal chip), TLD loaded with Tin or Gold plate, for the photon energy range 6 MV to 15 MV, which was of interest in radiotherapy. RESULTS: The enhancement of surface dose in the TLD with metal plate was clearly detected. The TLD chips with a Gold plate was found to larger response by a factor of 1.83 in 10 MV photon beam with respect to normal chip. The sensitivity of TLD loaded with Tin was less than that for normal TLD and TLD loaded with Gold. The relative sensitivity of TLD loaded with metal has little energy dependence. CONCLUSION: The good stability and linearity with respect to monitor units of TLD loaded with metal were demonstrated by relative measurements in high energy photon (6~15 MV) beams. The TLD laminated with metals embedded system in solid water phantom is a suitable detector for relative dose measurements in a small beam size and surface dose.

Low Dose Cisplatin as a Radiation Sensitizer in Management of Locally Advanced Squamous Cell Carcinoma of the Uterine Cervix: Evaluation of Acute Toxicity and Early Response / 대한방사선종양학회지

PURPOSE: To evaluate possible acute toxicity and early response of concurrent radiation therapy and low dose daily cisplatin as a radiosensitizer in patients with locally advanced uterine cervical carcinomas. MATERIALS AND METHODS: From December 1996 to January 1999, 38 previously untreated patients with locally advanced squamous cell carcinoma of the uterine cervix (from stage IIB to stage IIIB) were treated at Inha University Hospital. All patients underwent standard pretreatment staging procedures after the initial evaluation by gynecologists and radiation oncologists. Sixteen patients with huge cervical mass (>4 cm) were submitted to the group treated with concurrent radiation therapy and low dose daily cisplatin while the remainder was treated with radiation therapy alone. Radiation therapy consisted of 4500 cGy external beam irradiation to whole pelvis (midline block after 3060 cGy), 900~1000 cGy boost to involved parametrium, and high dose-rate intracavitary brachytherapy (a total dose of 3000~3500 cGy/500 cGy per fraction to point A, twice per week). In the group treated with low dose cisplatin concurrently, 10 mg of daily intravenous cisplatin was given from the 1st day of radiation therapy to the 20th day of radiation therapy. Acute toxicity was measured according to expanded common toxicity criteria of the NCI (C) Clinical Trials. Early response data were analyzed at minimum 4 weeks' follow-up after completion of the treatment protocol. RESULTS: Hematolgic toxicity was more prominent in patients treated with radiation therapy and cisplatin. Six of 16 patients (37.5%) treated with radiation therapy and cisplatin and one of 22 patients (4.5%) treated with radiation therapy alone experienced grade 3 leukopenia. In Fisher's exact test, there was statistically significant difference between two groups regarding leukopenia (P=0.030). There was no apparent difference in the frequency of gastrointestinal and genitourinary toxicity between two groups (P=0.066). Three of 16 patients (18.7%) treated with radiation therapy and cisplatin and two of 22 patients (9.1%) treated with radiation therapy alone experienced more than 5 kg weight loss during the treatment. There was no statistically significant difference on weight loss between two groups (P=0.63). Two patients on each group were not evaluable for the early response because of incomplete treatment. The complete response rate at four weeks' follow-up was 80% (16/20) for the radiation therapy alone group and 78% (11/14) for the radiation therapy and cisplatin group. There was no statistically significant difference in early response between two treatment groups (P=0.126). CONCLUSION: This study led to the conclusion that the hematologic toxicity from the treatment with concurrent radiation therapy and low dose daily cisplatin seems to be more prominent than that from the treatment of radiation therapy alone. There was no grade 4 hematologic toxicity or mortality in both groups. The hematologic toxicity in both treatment groups seems to be well managable medically. Since the risk factors were not balanced between two treatment groups, the direct comparison of early response of both groups was not possible. However, preliminary results regarding early response for patients with bulky cervical tumor mass treated with radiation therapy and low dose daily cisplatin was encouraging. Longer follow-up is necessary to evaluate the survival data. A phase III study is needed to evaluate the efficacy of concurrent daily low dose cisplatin with radiation therapy in bulky cervical cancer.

Evaluation of Usefulness of Portal Image Using Electronic Portal Imaging Device (EPID) in the Patients Who Received Pelvic Radiation Therapy / 대한방사선종양학회지

PURPOSE: To evaluate the usefulness of electronic portal imaging device through objective compare of the images acquired using an EPID and a conventional port film. MATERIAL AND METHODS: From Apr. to Oct. 1997, a total of 150 sets of images from 20 patients who received radiation therapy in the pelvis area were evaluated in the Inha University Hospital and Severance Hospital. A dual image recording technique was devised to obtain both electronic portal images and port film images simultaneously with one treatment course. We did not perform double exposure. Five to ten images were acquired from each patient. All images were acquired from posteroanterior (PA) view except images from two patients. A dose rate of 100-300 MU/min and a 10- MV X-ray beam were used and 2-10 MUs were required to produce a verification image during treatment. Kodak diagnostic film with metal/film imaging cassette which was located on the top of the EPID detector was used for the port film. The source to detector distance was 140 cm. Eight anatomical landmarks (pelvic brim, sacrum, acetabulum, iliopectineal line, symphysis, ischium, obturator foramen, sacroiliac joint) were assessed. Four radiation oncologist joined to evaluate each image. The individual landmarks in the port film or in the EPID were rated - very clear (1), clear (2), visible (3), not clear (4), not visible (5). RESULTS: Using an video camera based EPID system, there was no difference of image quality between no enhanced EPID images and port film images. However, when we provided some change with window level for the portal image, the visibility of the sacrum and obturator foramen was improved in the portal images than in the port film images. All anatomical landmarks were more visible in the portal images than in the port film when we applied the CLAHE mode enhancement. The images acquired using an matrix ion chamber type EPID were also improved image quality after window level adjustment. CONCLUSION: The quality of image acquired using an electronic portal imaging device was comparable to that of the port film. When we used the enhance mode or window level adjustment, the image quality of the EPID was superior to that of the port film. EPID may replace the port film.

Dosimetry for Total Skin Electron Beam Therapy in Skin Cancer / 대한치료방사선과학회지

Increasing frequency of skin cancer, mycosis fungoides, Kaposi's sarcoma etc, it need to treatment dose planning for total skin electron beam (TSEB) therapy. Appropriate treatment planning for TSEB therapy is needed to give homogeneous dose distribution throughout the entire skin surface. The energy of 6 MeV electron from the 18 MeV medical linear accelerator was adapted for superficial total skin electron beam therapy. The energy of the electron beam was reduced to 4.2 MeV by a 0.5cm x90cm x180cm acryl screen placed in a feet front of the patient. Six dual field beam was adapted for total skin irradiation to encompass the entire body surface from head to toe simultaneously. The patients were treated behind the acryl screen plate acted as a beam scatterer and contained a parallel-plate shallow ion chamber for dosimetry and beam monitoring. During treatment, the patient was placed in six different positions due to be homogeneous dose distribution for whole skin around the body. One treatment session delivered 400 cGy to the entire skin surface and patients were treated twice a week for eight consecutive weeks, which is equivalent to TDF value 57. Instrumentation and techniques developed in determining the depth dose, dose distribution and bremsstrahlung dose are discussed.

Brainstem Tumors : Results of 20 Patients Treated with Radiation Therapy / 대한치료방사선과학회지

A total of 20 patients(male : female=10:10, adult : children=8:12) with brainstem tumors had been received radiation therapy in the Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine between 1980 and 1990. Thirteen of 20 patients were treated with conventional radiation therapy (before 1989, 180~200 cGy per fraction, 5 days a week, total dose 4680~5400 cGy), and seven patients were treated with hypefractionated radiation therapy(in 1990, 100 cGy per fraction, twice daily 10 fractions a week, total dose 7200 cGy). Median follow up periods for conventional radiation therapy group and hyperfractionated radiation therapy group were 39 months and 10 months, respectively. Four of 20 Patients had histopathologic diagnosis prior to treatment ; 3 cases were low grade astrocytoma and 1 case was high grade astrocytoma. Overall 2-year actuarial survival rate was 30%. The prognosis of patients with a longer duration of symptom and sign was better(60% vs 12%), and the adult(52%) was better than children(14%). There was no significant difference between the focal(29%) and diffuse(20%) type. The initial clinical response was better in the hyperfractionated radiation therapy group. Because of the relatively small number of Patients and short follow up Period in hyPerFractionated radiation therapy group, there was no comparison between two group.

Histological studies of surgically resected hepatocellular carcinoma following combined radiotherapy and hyperthermia

Four cases of hepatocellular carcinoma (HCC) were surgically resected following combined radiotherapy (RT) and hyperthermia (HT). Complete necrosis of the tumor without viable tumor cell was found in one case and extensive tumor necrosis was observed in the other three cases; the percentage of necrosis in the specimens were 40%, 70%, and 80%, respectively. Histologic assessment showed mainly coagulative necrosis in the tumor with focal liquefactive necrosis. Cystic dilatation of sinusoids was observed in both tumor and nontumorous normal liver tissue. Other changes in normal liver tissue were unremarkable except for infiltration of inflammatory cells, fatty change, and proliferation of the bile ducts which can usually be seen beyond the area where any space occupying lesions are present. It is concluded that combined radiotherapy and hyperthermia can significantly induce coagulative necrosis of hepatocellular carcinoma with nonsignificant minimal histologic changes in adjacent nontumorous liver tissue.

The Role of Radiotherapy in the Treatment of Extrahepatic Bile Duct Carcinoma / 대한치료방사선과학회지

Twenty-seven patients with unresectable extrahepatic bile duct carcinoma (n=21) or with microscopic evidence of tumor rest after aggressive surgery for extrahepatic bile duct carcinoma(n=6) between 1985 and 1990 were given radiotherapy consisting intentionally external radiotherapy and /or intraluminal therapy using Gamma-Med 12i (192-lr) high dose rate (HDR) remote control afterloading system following bile drainage procedures and Gianturco stent insertion. The objectives of this study has been to assess the feasibility and effects on survival of a combination of external radiotherapy and brachytherapy with which we hope to achieve optimal loco-regional control for patients with unresectable extrahepatic bile duct tumors. Sixteen patients were men and deleven were women, and the mean age was 58 years (34-70). 10MV X-ray was used for radiation therapy, with the total dose ranging from 45 Gy to 55 Gy, and intraluminal brachytherapy performed after external radiotherapy, with the dose of total 15 Gy. The minimum follow up was 12 months. Failure were predominantly local-regional, without distant failure. Median survival was 10 months; 2-year actuarial survival rates was 21%. Median survival for common hepatic duct(CHD) cancer was 9 months; for common bile duct (CBD) cancer, was 16 months. And median survival for incomplete surgery/external radiotherapy group and external/intraluminal radiotherapy group was 10 months; for external radiotherapy alone group, was 6 months. Use of chemotherapy and/or hyperthermia were not affected in survival. Therefore, our result is that the survival rates in the group of external/intralumial radiotherapy were comparable with ones in the group of incomplete resection/external radiotherapy, andso we believe that the aggressive local and regional radiotherapy can improve the quality of life and the survival length

Postoperative radiotherapy for stage IB carcinoma of the uterine cervix

Sixty patients, treated with postoperative radiation therapy following radical hysterectomy and pelvic lymphadenectomy for stage lb carcinoma of the uterine cervix between Jan. 1980 and Dec. 1984 at Department of Radiation Oncology, Yonsei University College of Medicine, were retrospectively analysed. The minimum follow-up period was 5 years. The indications for postoperative radiotherapy were positive pelvic lymph node (34 pts), a large tumor size more than 3 cm in longest diameter (18 pts), positive surgical margin (10 pts), deep stromal invasion (10 pts), and lymphatic permeation (9 pts). The overall 5-year survival rate was 81.8%. The univariate analysis of prognostic factors disclosed tumor size (less than 3cm, greater than or equal to 3cm) and the status of the surgical margin (positive, negative) as significant factors (tumor size; 88.1% vs 6.3%, surgical margin; 85.5% vs 60%, p less than 0.05). Age (less than or equal to 40, greater than 40 yrs) was marginally significant (90.2% vs 73.1%, p less than 0.1). Multivariate analysis clarified two independent prognostic factors; tumor size (p = 0.010) and surgical margin (p = 0.004). Analysis of the tumor factors with the radiation dose disclosed a better survival rate for patients with a positive surgical margin who were given over 50 Gy than for those who were given below 50 Gy in patients (4/4, 100% vs 2/6, 33.4%; p = 0.06). Significant complications requiring surgical correction were not observed. In conclusion, it is believed that the status of the surgical margin and tumor size both have important prognostic significance, and that a radiation dose over 50 Gy is advisable for patients with a positive surgical margin.

The Heterogeneity of T2NO glottic Carcinoma Treated by Irradiation / 대한치료방사선과학회지

During a ten-year period from 1978 through 1987, 44 patients with T2NOMO glottic cancer were treated with radical radiation therapy at the Yonsei University Medical Center. Forty-two patients had a minimum follow-up of 3 years, and 81% had at least five years of follow-up. Patients were staged according to the AJCC system. Forty-two patients have been analyzed in detail with respect to two variables: the status of vocal cord mobility and the degree of local extension of the disease. Five-year local cord mobility (n=18), 69.1% versus patients with impaired vocal cord mobility (n=24), 43.4%(p<0.05); patients with subglottic extension (n=15). The most favorable prognostic group included the patients with normal mobility without subglottic extension (n=14), 83.1%. On the basis of this analysis, we confirmed the presence of heterogeneity in T2NOMO glottic cancer. This study indicates that further randomized controlled trials are warranted to evaluate individualized treatment according to its heterogeneity.

Large Cell Carcinoma of the Lung: An analysis of clinical features and survival / 대한치료방사선과학회지

This is a retrospective review of 33 patients with large cell lung carcinoma treated at Yonsei University Cancer Center between Jan. 1985 and Dec. 1989. Of the thirty-three patients, twenty eight were men and five women. Median age was 59 years. Large cell undifferentiated carcinoma was the most common pathologic type, 78.8%. Twenty one of thirty three patients had far advanced diseases, stage IIIB-IV at the time of initial diagnosis. Pleural effusion was initially presented in 12 patients, and SVC syndrome appeared in 5 patients. As to location of the primary tumor, 19(57.6%) appeared in the right lung and 14 (42.4%) in the left. Patients with a centrally located primary tumor mass were nearly the same as those peripherally located (17 vs. 16). Fifteen of thirty three patients developed metastasis involving not only bone, brain, the opposite lung, adrenal gland but also soft tissue, skin, pancreas and appendix. Treatment was individualized with 19 treated radically and 14 palliatively. After treatment, only two patients showed a complete response. Long term survival was observed in 4 patients: 1 (24 mo.), 2 (41 mo.) and 1 (54 mo.). The overall 2 year survival rate was 14.3% while the median survival time was 6.0 months. Through the analysis of the various factors affecting survival, we observed that pleural effusion-absent group and complete response group had a statistical significant better survival rate (p<0.01).

Treatment of Carcino ma of the Uterine Cervix with High-Dose-Rate Intracavitary Irradiation using Ralstron / 대한치료방사선과학회지

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, 356 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 (LER) 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 or 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 HER-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 tachieve an improved outcome, however, the optimum dose-fractionation schedule of HDR-ICRand optimum combination of intracavitary irradiation with external beam irradiation should be determined through an extensive protocol study with different treatment regimens.

Treatment of Pineal Region Tumors and CNS Germ Cell Tumors ; Evolution of Treatment Policy and Results

A retrospective analysis has been made of 40 patients with pineal region tumors and CNS germ cell tumors who were treated at Yonsei University Hospital, Department of Radiation Oncology between 1971 and 1985. A tissue diagnosis was obtained before radiotherapy in 19 patients and 21 patients were irradiated without histological diagnosis. Among 19 biopsy-proven cases, 14 were germinomas, 2 were teratomas, and the others were two pineocytomas and one pineoblastoma. In the earlier period, every attempt was made to obtain a tissue pathology by either stereotaxic biopsy or open craniotomy before irradiation. However, in recent years, with the advent of CT scan, a trial radiotherapy with a modest dose of 20 Gy in 2 weeks was attempted in cases of highly suspected germinomas by CT scan findings. Further management after trial radiation depended on the radiation response shown on the follow-up CT scan and tumor marker study. Radiation fields varied from a small local field to whole brain or entire neuroaxis irradiation. Most patients received 40-50 Gy to the primary tumor site and 20-30 Gy to the neuroaxis. Twenty-nine of the total 40 patients are alive without of disease 22-144 months after treatment and the overall 5-year recurrence-free survival rate was 74.4%, Univariate analysis of prognostic factors at presentation showed that tumor type was highly correlated with outcome. Two of fourteen biopsy-proven germinomas and none of nine presumed germinomas by trial radiation recurred. On the other hand, five of six patients who showed poor response to trial radiation died of uncontrolled disease and only one patient with elevated AFP in serum and CSF was salvaged by chemotherapy. On the basis of the results of this study, application of trial radiation therapy without tissue biopsy is well justified as a treatment modality in a suspected germinoma by CT scan finding. Aggressive combined modality approaches with surgery, radiotherapy and chemotherapy need to be investigated to improve results in radioresistant tumors.

The Role of Postoperative Adjuvant Radiation Therapy in the Management of Adenocarcinoma of the Colon: A review of 21 Patients / 대한치료방사선과학회지

From March 1970 to December 1984, treatment results of 21 patients treated initially with curative surgery for adenoarcinoma of the colon and referred to the Department of Radiation Oncology, College of Medicine, Yonsei University, were analyzed retrospectively. Thirteen of 21 patients who were considered to be at high risk (i.e, stage B2 or above), received postoperative adjuvant radiation therapy. However, 2 of 13 patients did not complete their courses of radiotherapy as planned because of poor tolerance to radiotherapy or patient's refusal and were excluded from this study. Remaining 8 of 21 patients who did not receive postoperative radiotherapy, presented with recurrence at the time of referral and treated for palliation. In 11 patients who finished postoperativc radiotherapy, overall local failure rate was 9%(1/11) and the 5 year actuarial survival rate was 55%. Local failure rates by stage were 0(0/4), 14%(1/7) for stage B2+B3, C1+C2+C3 respectively and 0(0/2), 17%(1/6), 0(0/3) for stage C1, B2+C2, B3+C3 respectively.

Treatment Planning and Dosimetry of Small Radiation Fields for Stereotactic Radiosurgery / 대한치료방사선과학회지

The treatment planning and dosimetry of small fields for stereotactic radiosurgery with 10 MV x-ray isocentrically mounted linear accelerator is presented. Special consideration in this study was given to the variation of absorbed dose with field size, the central axis percent depth doses and the combined moving beam dose distributon. The collimator scatter correction factors of small fields (1x1~3x3 cm2) were measured with ion chamber at a target chamber distance of 300cm where the projected fields were larger than the polystyrene buildup caps and it was calibrated with the tissue equivalent solid state detectors of small size (TLD, PLD, ESR and semiconductors). The central axis percent depth doses for 1x1 and 3x3 cm2 fields could be derived with the same acuracy by interpolating between measured values for larger fields and calcu1ated zero area data, and it was also calibrated with semiconductor detectors. The agreement between experimental and calculated data was found to be under +/-2% within the fields. The three dimensional dose planning of stereotactic focusing irradiation on small size tumor regions was performed with dose planning computer system (Therac 2300) and was verified with film dosimetry. The more the number of strips and the wider the angle of arc rotation, the larger were the dose delivered on tumor and the less the dose to surrounding the normal tissues. The circular cone, we designed, improves the alignment, minimizes the penumbra of the beam and formats ball shape of treatment area without stellate patterns. These dosimetric techniques can provide adequate physics background for stereotactic radiosurgery with small radiation fields and 10 MV x-ray beam.

Phase II study of cyclophosphamide, doxorubicin, and vincristine (CAV) and etoposide plus cisplatin (EP) alternating chemotherapy combined with radiotherapy in small cell lung cancer

The development of drug resistance is the major limiting factor influencing the survival of patients with small cell lung cancer (SCLC). We have thus examined the activity of cyclophosphamide, doxorubicin and vincristine (CAV) alternating with etoposide and cisplatin (EP) in 35 patients with SCLC. The treatment courses were alternated every 3 or 4 weeks. After induction chemotherapy, patients with limited disease (LD) received thoracic radiotherapy (5000 cGy), prophylactic cranial irradiation (3000 cGy) and maintenance chemotherapy and patients with extensive disease (ED) received maintenance chemotherapy only. In this group of 35 patients, 13 had limited disease (LD) and 22 had extensive disease (ED). After completion of the therapy, 100% of the patients with LD achieved complete plus partial remission (CR + PR) and 68% of the patients with ED achieved CR + PR. The median survival time was 66 weeks (15.3 months) in patients with LD and 44 weeks (10.2 months) in patients with ED. The over all survival for patients with LD was superior to that for patients with ED (p less than 0.05). Also, median response duration for patients with LD (35 wks) was longer than that for patients with ED (17 weeks) (p less than 0.05). The primary site was the most vulnerable site to relapse (18 patients). Toxicity was mild to moderate and acceptable, and there were no treatment-related deaths. These results suggest that the alternation of CAV and EP is effective treatment strategy in the management of SCLC. A randomized controlled study will be required to discriminate the actual effect of this alternating regimen.