• Radiation Oncology Journal
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• v.19 no.2
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• pp.118-126
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• 2001

Purpose : In this study, it was investigated whether dose response relation existed or not in local radiotherapy for primary hepatocellular carcinoma. Materials and Methods : From January 1992 to March 2000, 158 patients were included in present study. Exclusion criteria included the presence of extrahepatic metastasis, liver cirrhosis of Child's class C, tumors occupying more than two thirds of the entire liver, and performance status on the ECOG scale of more than 3. Radiotherapy was given to the field including tumor with generous margin using 6, 10-MV X-ray. Mean tumor dose was $48.2{\pm}7.9\;Gy$ in daily 1.8 Gy fractions. Tumor response was based on diagnostic radiologic examinations such as CT scan, MR imaging, hepatic artery angiography at $4\~8$ weeks following completion of treatment. Statistical analysis was done to investigate the existence of dose response relationship of local radiotherapy when it was applied to the treatment of primary hepatocellular carcinoma. Results : An objective response was observed in 106 of 158 patients, giving a response rate of $67.1\%$. Statistical analysis revealed that total dose was the most significant factor in relation to tumor response when local radiotherapy was applied to the treatment of primary hepatocellular carcinoma. Only $29.2\%$ showed objective response in patients treated with dose less than 40 Gy, while $68.6\%\;and\;77.1\%$ showed major response in patients with $40\~50\;Gy$ and more than 50 Gy, respectively. Child-Pugh classification was significant factor in the development of ascites, overt radiation induced liver disease and gastroenteritis. Radiation dose was an important factor for development of radiation induced gastroduodenal ulcer. Conclusion : Present study showed the existence of dose response relationship in local radiotherapy for primary hepatocellular carcinoma. Only radiotherapy dose was a significant factor to predict the objective response. Further study is required to predict the maximal tolerance dose in consideration of liver function and non-irradiated liver volume.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.192-198
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• 2003

Purpose: Current results of autologous stem cell transplantation (SCT) suggest that this procedure may prolong disease free survival In patients with acute myeloid leukemia (AML). Autologous SCT is increasingly used as treatment for AML in first remission. The aim of this study was to evaluate the outcome of autologous SCT for patients with AML in first remission treated by autologous SCT using cytarabine, melphalan and total body irradiation (TBI) as the conditioning regimen. Materials and Methods: Between January 1995 and December 1999, 29 patients with AML in first remission underwent autologous SCT. The median age of patients was 33 years (range, 16 to 47). The conditioning regimen consisted of cytarabine ($3.0\;gm/m^2$ for 3 days), melphalan ($100\;gm/m^2$ for 1 day) and TBI (total 1000 cGy in five fractions over 3 days). Results: The median follow up was 40 months with a range of 3 to 58 months. The 4-year cumulative probability of disease free survival was 69.0%, and median survival was 41.5 months. The 4-year relapse rate was 27.6%. The factor Influencing disease free survival and relapse rate was the French-American-British (FAB) classification ($M_3$ group vs. other groups; p=0.048, p=0.043). One patient died from treatment-related toxicity. Conclusion:: Although the small number of patients does not allow us to draw any firm conclusion, our results were encouraging and suggest that the association of cytarabine, melphalan and TBI as a conditioning regimen for autologous SCT for AML on first remission appears to be safe and effective.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.306-314
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• 2003

Purpose : In our Previous study, we have shown the main cel1 death pattern Induced by irradiation or protein tyrosine kinase (PTK) inhibitors in K562 human myeiogenous leukemic cell line. Death of the cells treated with irradiation alone was characterized by mitotic catastrophe and typical radiation-induced apoptosis was accelerated by herblmycin A (HMA). Both types of cell death were inhibited by genistein. In this study, we investigated the effects of HMA and genistein on cell cycle regulation and its correlation with the alterations of radiation-induced cell death. Materials and Methods: K562 cells In exponential growth phase were used for this study. The cells were Irradiated with 10 Gy using 6 MeV Linac (200-300 cGy/min). Immediately after irradiation, cells were treated with 250 nM of HMA or 25 $\mu$N of genistein. The distributions of cell cycle, the expressions of cell cycle-related protein, the activities of cyclin-dependent kinase, and the yield of senescence and differentiation were analyzed. Results: X-irradiated cells were arrested In the G2 phase of the cell cycle but unlike the p53-positive cells, they were not able to sustain the cell cycle arrest. An accumulation of cells in G2 phase of first ceil-cycle post-treatment and an increase of cyclin Bl were correlated with spontaneous, premature, chromosome condensation and mitotic catastrophe. HMA induced rapid G2 checkpoint abrogation and concomitant p53-independent Gl accumulation. HMA-induced cell cycle modifications correlated with the increase of CDK2 kinase activity, the decrease of the expressions of cyclins I and A and of CDK2 kinase activity, and the enhancement of radiation-induced apoptosis. Genistein maintained cells that were arrested in the G2-phase, decreased the expressions of cyclin Bl and cdc25c and cdc25C kinase activity, increased the expression of pl6, and sustained senescence and megakaryocytic differentiation. Conclusion: The effects of HMA and genistein on the radiation-induced cell death of KS62 cells were closely related to the cell cycle regulatory activities. In this study, we present a unique and reproducible model in which for investigating the mechanisms of various, radiation-induced, cancer cell death patterns. Further evaluation by using this model will provide a potent target for a new strategy of radiotherapy.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.34-39
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• 2001

Purpose : It is not common to evaluate the response of the fractionated stereotactic radiotherapy (SRT) to primary hepatoma as compared with conventional radiotherapy. The purpose of the study was to take the preliminary result on the clinical trial of primary hepatoma by SRT. Materials and Methods : From July 1999 to March 2000, thirty three patients were hospitalized in the St. Mary's Hospital, and treated with SRT for extracranial tumors. Among them, 13 patients were diagnosed to primary hepatoma and then applied by frameless SRT using 6 MV linac accelerator. There were 12 male and 1 female patients. They had the age of $ 44\~66$ year old (median : 59) and the tumor size of $10\~825\;cc$ (median : 185 cc). SRT was given to them $3\~5$ fractions a week (5 Gy/fraction, $90\%$ isodose line) for $2\~3$ weeks. Median dose of SRT was 50 Gy and the range was $30\~50\;Gy$. Results : Follow-up period ranged from 3 months to 13 months with median of 8 months. After treating SRT to thirteen patients with primary hepatoma, the response of the tumor was examined by abdominal CT : they are classified by 1 complete regression $(7.7\%)$, 7 partial regression $(53.8\%)$, 4 minimal regression $(30.8\%)$, 1 stable disease $(7.7\%)$. The positive responses more than partial remission were 8 patients $(61.5\%)$ after the treatment. The level of serum alpha-fetoprotein (AFP) after the treatment as compared with pretreatment had been $92.3\%$ decreased. There was no severe complication except dyspepsia $84.6\%$, mild nausea $69.2\%$, transient decreased of hepatic function $15.4\%$ and fever $7.7\%$. Conclusion : SRT to the patients with primary hepatoma was potentially suggested to become the safe and more effective tool than the conventional radiotherapy even though there were relatively short duration of follow-up and small numbers to be tested.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.40-44
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• 2001

Purpose : To evaluate effect and tolerance of external beam radiotherapy for carcinoma of the prostate and define the optimal radiotherapeutic regimen. Materials and methods : We retrospectively analyzed the records of 60 patients with prostate cancer who were treated with external beam radiotherapy with curative intent in our institution between September, 1987 and March, 2000. Histologic diagnosis was established by transurethral resection or ultrasonography guided biopsy. The major presenting symptoms were a nodule at routine prostatic examination and frequency and urgency of urination, along with dysuria. The median age was 63 years with range of 51 to 87 years. There were 6 patients in Stage A, 20 in Stage 8, 26 in Stage C, and 8 in Stage Dl. All patients were treated with megavoltage equipment producing 10 MV photons. The 4 field pelvic brick technique was used to a dose of 45 Gy or 50.4 Gy at 1.8 Gy per day in 5 to 6 weeks, after which a small boost field was delivered 2.0 Gy per day to a total dose of 66 to 70 Gy. The follow-up period ranged from 1 to 8 years. Results : Actuarial 5-year and 7-year survival rates for Stage A, B, C, and D1 were $100\%\;and\;84\%$, $83\%\;and\;72\%$, $67\%\;and\;54\%$, and $v$, respectively. The corresponding 5-year and 7-year relapse free survival rates were $84\%\;and\;84\%$, $77\%\;and\;67\%$, $48\%\;and\;40\%$, and $33\%\;and\;25\%$, respectively. Relapse free 5-year survival rates for Stage B were $80\%,\;80\%,\;and\;50\%$ for well, moderately, and poorly differentiated tumors, respectively. These were $64\%,\;44\%,\;and\;33\%$ for Stage C, respectively. The local control rates at 5 years were $84\%,\;85\%,\;78\%,\;and\;60\%$ for Stage A, B, C, and D1, respectively. Mild to moderate complications were observed in $22\%$ of patients. Severe complications requiring surgical procedures were documented in only $3\%$ of patients. Conclusion : This study confirms that external beam irradiation is an effective and safe treatment for prostatic cancer, providing long-term local control and good survival with acceptable complications.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.81-90
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• 1994

Purpose : The aim of this study is to analyze the clinical results of thermo-irradiation treatment for surgically unresectable advanced hepatoma with or without hepatic arterial chemo-embolization (HACE), chemotherapy (CT) and interferon (IFN) therapy. Materials and Methods : Between February 1990 and December 1992, 45 Patients with surgically unresectable advanced hepatomas were treated by thermo-irradiation with or without hepatic arterial chemo-embolization and other treatment modalities. Among them, We analyzed retrospectively 25 patients who received more than three times of hyperthermias. Mean age was 50 years (range : 18-71 years) and male to female ratio was 20 : 5. In the study, treatment was administered as follows : 3 patients received radiation therapy(RT) and hyperthermia (HT). 3 received RT+HT+CT. 3 received RT+HT+HACE. 1 received RT+HT+CT+HACE. 2 received RT+HT+CT+IFN. 10 received RT+HT+HACE+IFN. 3 received RT+HT+CT+HACE+IFN. Radiation therapy was done by a 6 MV linear accelerator Patients were treated with daily fractions of 180 cGy to doses of 11Gy-50Gy (median 30Gy). Local hyperthermia was done by HEH-500C(Omron Co. Japan), 30-45 min/session, 2 sessions/wk and the number of HT sessions ranged from 3 to 17 (median 7 times). 15 patients of 25 were followed by abdominal CT scan or abdominal ultra-sonogram. The following factors were analyzed :Age, histologic grade, sex. number of hyperthermia, total RT dose, hepatic arterial chemo-embolization. Results : Of 25 patients. there were observed tumor regression (partial response and minimal response) in 6 (24$ \% $), no response in 8 (32$ \% $), progression in 1 (4$ \% $) and not evaluable ones in 10 (40$ \% $) radiographically. The over all 1-year survival was 25$ \% $, with a mean survival of 33 weeks. The treatment modes of partial and minimal responsive patients (PR+MR)were as follows : Two were treated with RT+HT+HACE, 2 were done with RT+HT+HACE+IFN Remaining 2 were treated with RT+HT+CT+HACE+IFN. The significant factor affecting the survival rate were RT dose (more than 25 Gy), HACE, number of HT (above 6 times), responsiveness after treatment (PR + MR). Age, sex, histologic differentiation, chemotherapy, interferon therapy were not statistically significant factors affecting the survival rate. Conclusion : Although follow-up duration was short, the thermo-irr3diBtion with/without hepatic arterial chemo-embolization was well tolerated and there were no serious complicatons. In future, it is considered the longer follow up and prospective, well controlled trials should be followed to evaluate the efficacies of survival advantage.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.168-175
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• 2014

This study was designed to assess whether the conventional tangential technique, using a multileaf collimator (MLC), allows a reduced dose to the organs at risk (OAR) in breast radiation therapy. A total of forty right and left 20 for each breast cancer patients that underwent radiation therapy after breast conserving surgery were included in this study. For each patient, the planning target volume (PTV) and OAR (heart, left anterior descending artery (LAD), liver and lung) were defined and dose distribution were produced for conventional tangential beams using 6 MV photons. The treatment plans were made using the following two techniques for all patients. For the first plan (P1), MLC was designed to shield as much of OAR as possible without compromising the coverage of PTV. In the second plan (P2), the treatment plan was created without using MLC. Dose-volume histograms for OARs were calculated for all plans. For left breast cancer, the percentage of maximum dose ($D_{max%}$) and mean dose ($D_{mean%}$) of OARs (heart and LAD) were calculated, and for right breast cancer, the percentage of the mean dose ($D_{mean%}$) of the liver was calculated. The $D_{mean%}$ of the lung was calculated in all patients. The mean values of $D_{max%}$ of the heart ($86.9{\pm}19.5%$ range, 35.1-100.6%) in P1 were significantly lower than in P2 ($98.3{\pm}3.4%$ range, 91.7-105.2%) (p=0.001). The mean values of $D_{max%}$ of LAD ($78.4{\pm}22.5%$ range, 26.5-99.7%) in P1 was significantly lower than in P2 ($93.3{\pm}8.1%$ range, 67.9-102.1%) (p<0.001). In P1, the mean values of $D_{mean%}$ of the liver ($4.8{\pm}2.0%$) were significantly lower than in P2 ($6.2{\pm}2.5%$) (p<0.001). The mean values of $D_{mean%}$ of the lung were significantly lower in P1 ($9.3{\pm}2.3%$) than in P2 ($9.7{\pm}2.4%$) (p<0.001). P1, by using MLC, allows a significantly reduced dose to OAR compared with P2. We can suggest that it is reasonable to routinely use MLC in the conventional tangential technique for breast radiation therapy considering the primary tumor location.

• Progress in Medical Physics
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• v.12 no.2
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• pp.161-169
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• 2001

For the head and neck radiotherapy, the technique of half beam using independent collimator is very useful to avoid overlapping of fields particularly when the lateral neck fields are placed adjacent to anterior supraclavicular field. Also abutting photon field with electron field is frequently used for the irradiation of posterior neck when tolerable dose on spinal cord has been reached. Using 6 MV X-ray and 9 MeV electron beams of Clinac1800(Varian, USA) linear accelerator, we performed film dosimetry by the X-OMAT V film of Kodak in solid water phantom and the dose distribution at beam center of 2 half beams further examined according to depths(0 cm, 1.5 cm, 3 cm, 5 cm) for single anterior half beam and anterior/posterior half beam. The dose distribution to the junction line between photon and electron fields was also measured. For the single anterior half beam, the absorption doses at 0.3 cm, 0.5 cm and 1 cm distances from beam center were 88%, 93% and 95% of open beam, respectively. In the anterior/posterior half beams, the absorption doses at 0.3 cm, 0.5 cm and 1 cm distances from beam center were 92%, 93% and 95% of open beam, respectively At the junction line between photon and electron fields, hot spot was developed on the side of the photon field and a cold spot was developed on that of the electron field. The hot spot in the photon side was developed at depth 1.5 cm with 7 mm width. The maximum dose of hot spot was increased to 6% of reference doses in the photon field. The cold spot in the electron side was developed at all measured depths(0.5 cm-3 cm) with 1-12.5 mm widths. The decreased dose in the cold spot was 4.5-30% of reference dose in the electron field. With above results, we concluded that when using electron beam or independent jaw for head and neck radiotherapy, the hot and cold dose area should be considered as critical point.

• Radiation Oncology Journal
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• v.14 no.3
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• pp.201-209
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• 1996

Purpose : To assess the efficacy of high dose rate - intracavitary radio-therapy (HDR-ICR) in the radiotherapy of FIGO stage IB squamous cell carcinoma of uterine cervix and to determine the optimum dose combination scheme of external radiotherapy and ICR to achieve acceptable local control without severe complication. Materials and Methods : One hundred and sixty two patients with FIGO stage Ib squamous cell carcinoma of uterine cervix who received definitive radiotherapy between May 1979 and December 1990 were retrospectively analyzed. All the patients received external radiotherapy combined with HDR-ICR. External dose of 40-46 Gy in 4.5-5 weeks was given to whole pelvis(median 45 Gy) and ICR dose of 30-39 Gy in 10-13 times was given to the point A. Midline shielding was done after 20-45 Gy of external radiotherapy(median 40 Gy) Summation of external dose Plus ICR dose to the point A range were 64.20-95.00 Gy. and mean was 83.94 Gy. We analyzed the local control rate, survival rate, and late complication rate. Rusults : Initial complete response rate was $99.4\%$ for all patients. Overall 5-year survival rate was $91.1\%$ and 5-year disease free survival rate was $90.9\%$. Local failure rate was $4.9\%$ and distant failure rate was $4.3\%$. Tumor size was the only significant prognostic factor. When tumor size greater than 3cm, 5-rear survival rate was $92.6\%$ and less than 3cm, that was $79.6\%$. Late complication rate was $23.5\%$ with $18.5\%$ of rectal complication and $4.9\%$ of bladder complication. Mean rectal dose summation of external midline dose plus ICR rectal point dose was lower in the patients without rectal complication(74.88 Gr) than those with rectal complication (78.87 Gy). Complication rate was increased with low rate of improvement of survival rate when summation of external midline dose plus point A or point R dose by ICR was greater than 70-75 Gy. Conclusion : The definitive radiation therapy using high dose rate ICR in FIGO stage IB uterine cervical cancer is effective treatment modality with good local control and survival rate without severe complication.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.277-282
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• 2000

Purpose : Though It has been known that the to tolerance of the liver to external beam irradiation depends on the irradiated volume and dose, few data exist which Quantify this dependence. However, recently, with the development of three dimensional (3-D) treatment planning, have the tools to Quantify the relationships between dose, volume, and normal tissue complications become available. The objective of this study is to investigate the relationships between normal tissue complication probabili쇼 (WCP) and the risk of radiation hepatitis for patients who received variant dose partial liver irradiation. Materials and Methods : From March 1992 to December 1994, 10 patients with hepatoma and 10 patients with bile duct cancer were included in this study. Eighteen patients had normal hepatic function, but 2 patients (prothrombin time 73$\%$, 68$\%$) had mild liver cirrhosis before irradiation. Radiation therapy was delivered with 10MV linear accelerator, 180$\~$200 cGy fraction per day. The total dose ranged from 3,960 cGy to 6,000 cGy (median dose 5,040 cGy). The normal tissue complication probability was calculated by using Lyman's model. Radiation hepatitis was defined as the development of anicteric elevation of alkaline phosphatase of at least two fold and non-malignant ascites in the absence of documented progressive. Results: The calculated NTCP ranged from 0.001 to 0.840 (median 0.05). Three of the 20 patients developed radiation hepatitis. The NTCP of the patients with radiation hepatitis were 0.390, 0.528, 0.844(median : 0.58$\pm$0.23), but that of the patients without radiation hepatitis ranged fro 0.001 to 0.308 (median .0.09$\pm$0.09). When the NTCP was calculated by using the volume factor of 0.32, a radiation hepatitis was observed only in patients with the NTCP value more than 0.39. By contrast, clinical results of evolving radiation hepatitis were not well correlated with NTCP value calculated when the volume factor of 0.69 was applied. On the basis of these observations, the volume factor of 0.32 was more correlated to predict a radiation hepatitis. Conclusion : The risk of radiation hepatitis was increased above the cut-off value. Therefore the NTCP seems to be used for predicting the radiation hepatitis.