Helical tomotherapy is an image-guided, intensity-modulated radiation therapy delivery system, a hybrid between a linear accelerator and a helical CT scanner. With its unique design features, tomotherapy has improved dose conformity and homogeneity of the target volumes, and conformal avoidance of the adjacent normal tissues. The daily pretreatment megavoltage computed tomography (MVCT) is a powerful tool used in image guided treatment delivery and patient setup verification. If anatomic changes occur during the course of treatment, MVCT images are utilized in correcting target volumes and constructing appropriate adaptive plans. Helical tomotherapy can be applied to more complicated cases, where conventional techniques find their limits: complex tumors with critical organ sparing, simultaneous irradiation of multiple targets, large volume and large superficial tumor irradiation, and recurrent tumor re-irradiation are a few examples. Tomothearpy may change the current paradigm in radiation oncology in the near future. Further studies regarding clinical implementation and treatment outcome of helical tomotherapy will be needed.
Chimera ; Humans ; Particle Accelerators ; Radiation Oncology ; Radiotherapy, Intensity-Modulated ; Tomography, Spiral Computed ; Treatment Outcome

Helical tomotherapy is an image-guided, intensity-modulated radiation therapy delivery system, a hybrid between a linear accelerator and a helical CT scanner. With its unique design features, tomotherapy has improved dose conformity and homogeneity of the target volumes, and conformal avoidance of the adjacent normal tissues. The daily pretreatment megavoltage computed tomography (MVCT) is a powerful tool used in image guided treatment delivery and patient setup verification. If anatomic changes occur during the course of treatment, MVCT images are utilized in correcting target volumes and constructing appropriate adaptive plans. Helical tomotherapy can be applied to more complicated cases, where conventional techniques find their limits: complex tumors with critical organ sparing, simultaneous irradiation of multiple targets, large volume and large superficial tumor irradiation, and recurrent tumor re-irradiation are a few examples. Tomothearpy may change the current paradigm in radiation oncology in the near future. Further studies regarding clinical implementation and treatment outcome of helical tomotherapy will be needed.
Chimera ; Humans ; Particle Accelerators ; Radiation Oncology ; Radiotherapy, Intensity-Modulated ; Tomography, Spiral Computed ; Treatment Outcome

BACKGROUND: Malignant skin cancers in Korea have been increasing as in other countries, but the previous epidemiological studies have been only attempted by a single hospital unit in a limited period of time. OBJECTIVE: This study aimed to investigate and compare the frequencies, age, sex distribution, and anatomical location of the frequent skin cancers collected from several hospitals over a 10 year period between 1984-5 and 1994-5. METHODS: 258 cases of skin cancer from 4 different places in Seoul were collected for the study. Histopathological records from pathology departments and medical records were reviewed to obtain information about the frequencies. RESULTS: Overall there were 141 cases of squamous cell carcinoma (SCC)1 basal cell carcinoma (BCC), and malignant melanoma (MM) in the mid-eighties and 117 in the mid-nineties. SCC was the most common skin cancer in both periods but the frequencies and the SCC/BCC ratio dropped at the later period. The ratio of males to females was getting smaller at 1.4:1 in the mid-eighties and 1.1:1 in the mid-nineties. BCC was concentrated on the face and SCC was rather evenly distributed over the body surface. The predilection site of malignant melanoma (MM) was quite different between the two periods. The lower extremities was the main site in the mid-nineties and the head and neck in the mid-eighties. CONCLUSION: Although there was no statistical significance, the BCC/SCC ratio was increased and the male/female ratio decreased at the later period.
Carcinoma, Basal Cell* ; Carcinoma, Squamous Cell* ; Epidemiologic Studies ; Epithelial Cells* ; Female ; Head ; Hospital Units ; Humans ; Korea* ; Lower Extremity ; Male ; Medical Records ; Melanoma* ; Neck ; Pathology ; Seoul ; Sex Distribution ; Skin Neoplasms

PURPOSE: Canine left single lung allotransplantation has become a frequently used model, but has some limitation. The purpose of this study is to verify and compare canine sequential bilateral allotrasplant model with canine left single lung transplant model. We prepared LPDG (low potassium dextran glucose)solution for lung preservation study. In this study we examined the efficacy of LPDG solution in 24-hour lung preservation by using a sequential bilateral canine lung allotransplant model. METHODS: Seven bilateral lung transplant procedures were performed using adult mongrel dogs. Comparative group was 9 cases of left single lung. The donor lungs were flushed with LPDG solution and maintained hyperinflated with 100% oxygen at 10oC for a planned ischemic time of 24 hours. After sequential bilateral lung transplantation, dogs were maintained on ventilators for 3 hours: arterial resistance were determined and compared with donor values which were used as controls. After 2 hours of reperfusion, the chest X-ray, computed tomogram and lung perfusion scan were checked. Pathological examinations for ultrastructural findings of alveolar structure and endothelial structure of pulmonary artery were performed. RESULTS: Five of seven experiments successfully finished the whole assessments after bilateral reperfusion for 3 hours. Arterial oxygen tension in the recipients was markedly decreased in immediate reperfusion period but gradually recovered after reperfusion for 3 hours. The pulmonary arterial pressure and pul-monary vascular resistance showed significant elevation (P<0.05 vs. control values) but also recovered after reperfusion for three hours (P<0.05 vs. immediate period value). The ultrastructural findings of alveolar structure and endothelial structure of pulmonary artery showed reversible mild injury in 24 hours of lung perservation and reperfusion on both groups. CONCLUSION: The present study suggests that LPDG solution provide excellent preservation in a canine sequential bilateral lung transplant model in which the dog is completely dependent on the function of the transplanted lung and under physiologic condition. Sequential bilateral lung transplant model was more appropriate and accurate experimental model compared to single lung transplant model.
Adult ; Animals ; Arterial Pressure ; Dextrans ; Dogs ; Humans ; Lung Transplantation ; Lung* ; Models, Theoretical ; Oxygen ; Perfusion ; Potassium ; Pulmonary Artery ; Reperfusion ; Thorax ; Tissue Donors ; Vascular Resistance ; Ventilators, Mechanical

PURPOSE: Canine left single lung allotransplantation has become a frequently used model, but has some limitation. The purpose of this study is to verify and compare canine sequential bilateral allotrasplant model with canine left single lung transplant model. We prepared LPDG (low potassium dextran glucose)solution for lung preservation study. In this study we examined the efficacy of LPDG solution in 24-hour lung preservation by using a sequential bilateral canine lung allotransplant model. METHODS: Seven bilateral lung transplant procedures were performed using adult mongrel dogs. Comparative group was 9 cases of left single lung. The donor lungs were flushed with LPDG solution and maintained hyperinflated with 100% oxygen at 10oC for a planned ischemic time of 24 hours. After sequential bilateral lung transplantation, dogs were maintained on ventilators for 3 hours: arterial resistance were determined and compared with donor values which were used as controls. After 2 hours of reperfusion, the chest X-ray, computed tomogram and lung perfusion scan were checked. Pathological examinations for ultrastructural findings of alveolar structure and endothelial structure of pulmonary artery were performed. RESULTS: Five of seven experiments successfully finished the whole assessments after bilateral reperfusion for 3 hours. Arterial oxygen tension in the recipients was markedly decreased in immediate reperfusion period but gradually recovered after reperfusion for 3 hours. The pulmonary arterial pressure and pul-monary vascular resistance showed significant elevation (P<0.05 vs. control values) but also recovered after reperfusion for three hours (P<0.05 vs. immediate period value). The ultrastructural findings of alveolar structure and endothelial structure of pulmonary artery showed reversible mild injury in 24 hours of lung perservation and reperfusion on both groups. CONCLUSION: The present study suggests that LPDG solution provide excellent preservation in a canine sequential bilateral lung transplant model in which the dog is completely dependent on the function of the transplanted lung and under physiologic condition. Sequential bilateral lung transplant model was more appropriate and accurate experimental model compared to single lung transplant model.
Adult ; Animals ; Arterial Pressure ; Dextrans ; Dogs ; Humans ; Lung Transplantation ; Lung* ; Models, Theoretical ; Oxygen ; Perfusion ; Potassium ; Pulmonary Artery ; Reperfusion ; Thorax ; Tissue Donors ; Vascular Resistance ; Ventilators, Mechanical

PURPOSE: This study was designed to demonstrate the potential therapeutic advantage of 3-dimensional (3-D) treatment planning over the conventional 2-dimensional (2-D) approach in patients with carcinoma of the nasopharynx. MATERIAL AND METHODS: The two techniques were compared both qualitatively and quantitatively for the boost portion of the treatment (19.8 Gy of a total 70.2 Gy treatment schedule) in patient with T4. The comparisons between 2-D and 3-D plans were made using dose statistics, dose-volume histogram, tumor control probabilities, and normal tissue complication probabilities. RESULTS: The 3-D treatment planning improved the dose homogeneity in the planning target volume. In addition, it caused the mean dose of the planning target volume to increase by 15.2% over 2-D planning. The mean dose to normal structures such as the temporal lobe, brain stem, parotid gland, and temporomandibular joint was reduced with the 3-D plan. The probability of tumor control was increased by 6% with 3-D treatment planning compared to the 2-D planning, while the probability of normal tissue complication was reduced. CONCLUSION: This study demonstrated the potential advantage of increasing the tumor control by using 3-D planning, but prospective studies are required to define the true clinical benefit.
Brain Stem ; Humans ; Nasopharynx* ; Parotid Gland ; Temporal Lobe ; Temporomandibular Joint

PURPOSE: To find the more effective treatment methods that improving thesurvival of patients with glioblastoma multiforme(GBM), we analyze the prognostic factors and the outcome of therapy in patients with GBM. METHODS AND MATERIALS: One hundred twenty-one patients with a diagnosis of GBM treated at Severance Hospital between 1973 and 1993 were analyzed for survival with respect to patients characteristics, that is, duration of symptom, age, and Karnofsky performance status, as well as treatment related variables such as extent of surgery and radiotherapy. RESULTS: The median survival time(MST) and 2-year overall survival rate (OSR) of the patients with GBM were 13 months and 20.8%, respectively. Duration of symptom, age, Karnofsky performance status(KPS), radiotherapy, and extent of surgical resection were associated with improved survival in a univariate analysis. Patients whose duration of symptom was longer than 3 months, had the 2-year OSR of 47.2%(p=0.0082), who were younger than age 50, 32.9%(p=0.0003). In patients with a KPS of 80 or higher, the 2 year OSR was 36.9%(p=0.0422). Patients undergoing radiotherapy had the 2-year OSR of 22.9%(p=0.030), and surgical resection of 23.3%(p<0.000). A cox regression model confirmed a significant correlation of duration of symptom, age, radiotherapy,and extent of surgical resection with survival, excluding KPS(p=0.8823). The 2-year OSR were 22.3% and 19.4%, combined with chemotherapy or without, respectively(p=0.06028). The duration of symptom of 3 months or shorter. 50 years of age or older, and undergoing stereotactic biopsy only were considered as risk factors. then patients without any risk factors had the MST of 29 months and 2-year OSR of 53.9% compared to 4 months and 0% for patients who had all 3 risk factors. Most of all treatment failure occurred in the primary tumor site(86.4%) CONCLUSION: The duration of symptom, age, radiotherapy, and extent of surgical resection were a prognostically significant independent variables. To get a better survival, it seems to be reasonable that the study design which improves the local control rates is warranted.
Biopsy ; Diagnosis ; Drug Therapy ; Glioblastoma* ; Humans ; Karnofsky Performance Status ; Radiotherapy ; Risk Factors ; Survival Rate ; Treatment Failure

PURPOSE: Early hypopharyngeal squamous cell carcinoma (HPSCC) is a rarely diagnosed disease, for which the optimal treatment has not been defined yet. We assessed patterns of failure and outcomes in early HPSCC treated with various therapeutic approaches to identify its optimal treatment. MATERIALS AND METHODS: Thirty-six patients with stage I (n = 10) and II (n = 26) treated between January 1992 and March 2014 were reviewed. Patients received definitive radiotherapy (RT) (R group, n = 10), surgery only (S group, n = 19), or postoperative RT (PORT group, n = 7). All patients in both the R and PORT groups received elective bilateral neck irradiation. In the S group, 7 patients had ipsilateral and 8 had bilateral dissection, while 4 patients had no elective dissection. RESULTS: At a median follow-up of 48 months, the 5-year locoregional control (LRC) rate was 65%. Six patients had local failure, 1 regional failure (RF), 3 combined locoregional failures, and 2 distant failures. There was no difference in 5-year LRC among the R, S, and PORT groups (p = 0.17). The presence with a pyriform sinus apex extension was a prognosticator related to LRC (p = 0.01) in the multivariate analysis. Patients with a bilaterally treated neck showed a trend toward a lower RF rate (p = 0.08). CONCLUSION: This study shows that patients with early stage HPSCC involving the pyriform sinus apex might need a tailored approach to improve LRC. Additionally, our study confirms elective neck treatment might have an efficacious role in regional control.
Carcinoma, Squamous Cell ; Cohort Studies ; Follow-Up Studies ; Humans ; Hypopharyngeal Neoplasms ; Multivariate Analysis ; Neck ; Pyriform Sinus ; Radiotherapy ; Treatment Failure

BACKGROUND: We performed a retrospective study in patients with previously untreated advanced(Stage III or IV) laryngeal and hypopharyngeal cancer to compare the results of induction chemotherapy followed by definitive radiation therapy (CT+RT) with those of conventional laryngectomy and postoperative radiation therapy (OP+RT). METHOD: Between 1985 and 1990, twenty four patients were treated with two or three courses of chemotherapy and radiation therapy(66~75 Gy). Twenty-five patients were received laryngectomy and radical neck dissection(except 3 patients) and postoperative radiation therapy (55~04 Gy). RESULT: After a median follow-up of 20 months, the actuarial 5-year overall survival rate was 24% (chemotherapy group) and 36% (op group).(P>0.1). The local control rate was the 65%,(13/20) and 68.2%(15/22).(P>0.1). The rate of laryngeal preservation was 65%(13/20) in chemotherapy group. CONCLUSION: Induction chemotherapy and definitive radiation therapy can be effective in preserving the larynx in a high percentage of patients with advanced laryngeal and hypopharyngeal cancer.
Drug Therapy ; Follow-Up Studies ; Humans ; Hypopharyngeal Neoplasms* ; Induction Chemotherapy* ; Laryngectomy ; Larynx ; Neck ; Radiotherapy ; Retrospective Studies ; Survival Rate

PURPOSE: This paper reports a dosimetric study of 88 patients treated with a combination of external radiotherapy and high dose rate ICR for FIGO stage IIB carcinoma of the cervix. The purpose is to investigate the correlation between the radiation doses to the rectum. external radiation dose to the whole pelvis. ICR reference volume. TDF, BED and the incidence of late rectal complications, retrospectively METHODS AND MATERIALS: From November 1989 through December 1992, 88 patients with stage IIB cervical carcinoma received radical radiotherapy at Department or Radiation Oncology in Yonsei University Hospital. Radiotherapy consisted of 44-54 Gy(median 49 Gy) external beam irradiation plus high dose rate intracavitary brachy therapy with 5 Gy per fraction twice a week to a total dose of 30 Gy on point A. The maximum dose to the rectum by contrast(r,R) and reference rectal dose by ICRU 38(dr, DR) were calculated. The ICR reference volume was calculated by Gamma Dot 3.11 HDR planning system, retrospectively. The time-dose factor(TDF) and the biologically effective dose (BED) were calculated. RESULTS: Twenty seven(30.7%) of the 88 patients developed late rectal complications : 12 patients(13.6%) for grade 1, 12 patients(13.6%) for grade 2 and 3 patients(3.4%) for grade 3. We found a significant correlation between the external whole pelvis irradiation dose and grade 2, 3 rectal complicaition. The mean dose to the whole pelvis for the group of patients with grade 2, 3 complication was higher, 4093.3+/-453.1 cGy, than that for the patients without complication 3873.8+/-415.6 (0.05p<0.1). The gradual increase in the frequency of grade 2, 3 rectal compication increased as a function of the dose of external beam therapyto the whole pelvis(midline shielding start dose) and total rectal dose. The mean total rectal dose by rectal barium(R) for the group of patients with grade 2, 3 rectal complication was higher, 7163.0+/-838.5 cGy, than that for the patients without rectal complication, 6772.7+/-884.0(p<0.05). There was no correlation of the rate of grade 2, 3 rectal complication with the ICR rectal doses(r,dr), ICR reference volume, TDF and BED. CONCLUSION: This investigation has revealed a significant correlation between the dose calculated at the rectal dose by ICRU 38(DR) or the most anterior rectal dose by contrast(R), dose to the whole pelvis and the incidence of grade 2,3 late rectal complications in patients with stage IIB cervical cancer undergoing external beam radiotherapy and HDR ICR. Thus there rectal reference points doses and whole pelvis dose appear to be useful prognostic indicators of late rectal complication in high dose rate ICR treatment in cervical carcinoma.
Brachytherapy* ; Cervix Uteri* ; Female ; Humans ; Incidence ; Pelvis ; Radiation Oncology ; Radiotherapy ; Rectum ; Retrospective Studies ; Uterine Cervical Neoplasms