• Title/Summary/Keyword: 종격동 방사선조사

Search Result 31, Processing Time 0.025 seconds

Stereotactic Radiosurgery for Intracranial Tumors; Early Experience with Linear Accelerator (두개강내 종양에 대한 방사선 뇌수술의 역할)

  • Suh Chang Ok;Chung Sang Sup;Chu Sung Sil;Kim Young Soo;Yoon Do Heum;Kim Sun Ho;Loh John Juhn Kyu;Kim Gwi Eon
    • Radiation Oncology Journal
    • /
    • v.10 no.1
    • /
    • pp.7-14
    • /
    • 1992
  • Between August 1988 and December 1991, 24 patients with intracranial tumors were treated with stereotactic radiosurgery(RS) using a 10 MV linear accelerator at Severance Hospital, Yonsei University College of Medicine. There were 5 meningiomas, 3 craniopharyngiomas, 9 glial tumors, 2 solitary metastases, 2 acoustic neurinomas, 2 pineal tumors, and 1 non-Hodgkin's lymphoma. Ten patients were treated as primary treatment after diagnosis with stereotactic biopsy or neuroimaging study. Nine patients underwent RS for post-op. residual tumors and three patients as a salvage treatment for recurrence after external irradiation. Two patients received RS as a boost followed by fractionated conventional radiotherapy. Among sixteen patients who were followed more than 6 months with neuroimage, seven patients (2 meningiomas, 4 benign glial tumors, one non-Hodgkin's lymphoma) showed complete response on neuroimage after RS and nine patients showed decreased tumor size. There was no acute treatment related side reaction. Late complications include three patients with symptomatic peritumoral brain edema and one craniopharyngioma with optic chiasmal injury. Through this early experience, we conclude that stereotactically directed single high doses of irradiation to the small intracranial tumors is effective for tumor control. However, in order to define the role of radiosurgery in the management of intracraniai tumors, we should get the long-term results available to demonstrate the benefits versus potential complications of this therapeutic modality.

  • PDF

Radiation Therapy Alone for Early Stage Non-small Cell Carcinoma of the Lung (초기 비소세포폐암의 방사선 단독치료)

  • Chun, Ha-Chung;Lee, Myung-Za
    • Radiation Oncology Journal
    • /
    • v.20 no.4
    • /
    • pp.323-327
    • /
    • 2002
  • Purpose : To evaluate the outcome of early stage non-small cell lung cancer patients who were treated with radiation therapy alone and define the optimal radiotherapeutic regimen for these patients. Materials and Methods : A retrospective review was peformed on patients with sage I or II non-small cell carcinoma of the lung that were treated at our institution between June, 1987 and May, 2000. A total of 21 patients treated definitively with radiation therapy alone were included in this study. The age of the patients ranged from 53 to 81 years with a median of 66 years. All the patients were male. The medical reasons for inoperability were lack of pulmonary reserve, cardiovascular disease, poor performance status, old age, and patient refusal in the decreasing order. Pathological evidence was not adequate to characterize the non-small cell subtype in two patients. Of the remaining 19 patients, 16 had squamous cell carcinoma and 3 had adenocarcinoma. Treatment was given with conventional fractionation, once a day, five times a week. The doses to the primary site ranged from 56 Gy to 59 Gy. No patients were lost to follow-up. Results : The overall survival rates for the entire group at 2, 3 and 5 years were 41, 30 and $21\%$, respectively. The cause specific survivals at 2, 3 and 5 years were 55, 36 and $25\%$, respectively. An intercurrent disease was the cause of death in two patients. The cumulative local failure rate at 5 years was $43\%$. Nine of the 21 patients had treatment failures after the curative radiotherapy was attempted. Local recurrences as the first site of failure were documented in 7 patients. Therefore, local failure alone represented $78\%$ of the total failures. Those patients whose tumor sizes were less than 4 cm had a significantly better 5 year disease free survival than those with tumors greater than 4 cm $(0\%\;vs\;36\%)$. Those patients with a Karnofsky performance status less than 70 did not differ significantly with respect to actuarial survival when compared to those with a status greater than 70 $(25\%\;vs\;26\%,\;p>0.05)$. Conclusion : Radiation therapy 리one is an effective and safe treatment for early stage non-small ceil lung cancer patients who are medically inoperable or refuse surgery. Also we believe that a higher radiation dose to the primary site could improve the local control rate, and ultimately the overall survival rate.

Radiation Therapy of Testicular Seminoms (고환 정상피종의 방사선 치료 성적)

  • Wu, Hong-Gyun;Oh, Do-Hoon;Ha, Sung-Whan
    • Radiation Oncology Journal
    • /
    • v.12 no.3
    • /
    • pp.361-368
    • /
    • 1994
  • Purpose : Testicular seminomas are radiosensitive and adjuvant radiation therapy after orchiectomy results in long term survival in early stage diseases, Ten year results of radiation therapy after orchiectomy and results of definitive treatment of recurrent seminoma are Presented. Materials and Methods : Between August 1980 and February 1990. 32 Patients with testicular seminomas were treated at the Department of Therapeutic Radiology, Seoul Natoinal University Hospital. Twenty-seven Patients received radiation therapy after orchiectomy and 5 patients for treatment of recurrent tumors. Two of postoperatively treated patients and 2 of recurrent patients were excluded from the study because of incomplete treatment. Of the patients treated postoperatively, 18 were stage I, 5 were stage IIA, one was stage IIB, and one was stage IIC. There were 4 ipsilateral and 2 contralateral cryptorchids. Preoperatively, ${\beta}$-HCG levels were elevated in 5 patients. Median dose to pelvic and paraaortic lymph node area was 2900 cGy (1550-4550 cGy). One patient with stage I, 4 with stage IIA, and 1 with stage IIB received prophylactic mediastinal irradiation. Two patients were treated with chemotherapy before radiation therapy. Median follow-up period was 104(3-144) months. Result: Local control rates were 100% at 5 years after orchiectomy. Five year survival rates were 94.4% in Stage I and 100% in Stage II patients, One patient with stage I disease died 3 months after surgery due to mediastinal metastasis. AII the 3 patients treated for recurrent disease are alive without disease. Conclusion : Postorchiectomy radiation to the pelvis and para-aortic area remains the treatment of choice for Patient with early stage testicular seminoma. Radiation therapy is also an excellent treatment modality for recurrent seminoma.

  • PDF

The Role of Intraluminal Brachytherapy in Management of Esophageal Cancer (식도암 치료에 있어 관내근접치료의 역할)

  • Lee Chang Geol;Suh Chang Ok;Kim Gwi Eon;Chu Sung Sil;Chung Eun Ji;Kim Woo Cheol
    • Radiation Oncology Journal
    • /
    • v.13 no.4
    • /
    • pp.331-338
    • /
    • 1995
  • Purpose : To evaluate our clinical experience with the combination of teletherapy and intraluminal brachytherapy in patients with unresectable or inoperable esophageal cancers. Materials and Methods : From Nov 1989 to Mar 1993, twenty patients with esophageal cancer were treated with radical radiotherapy and intraluminal brachytherapy at Yonsei Cancer Center. All patients had squamous histolgy and stage distribution was as follows: stage II, 4($20{\%}$)patients; III, 15 ($75{\%}$)patients; IV, 1($5{\%}$)patients. A dose of S-12Gy/1-3weeks with intraluminal brachytherapy (3-5Gy/fraction) to 5mm from the outside of the esophageal tube using high dose rate Iridium-192 remotely afterloading brachytherapy machine was given 2 weeks after a total dose of 59-64Gy with external radiotherapy. Induction chemotherapy using cisplatin and 5-FU was performed in 13 patients with median 3 cycles(1-6 cycles), Response rate, local control rate, survival and complications were analysed retrospectively. Results : Two-year overall survival rate and median survival were $15.8{\%}$ and 13.5 months. Response rates were as follows complete remission(CR) 5($25{\%}$): partial remission a(PRa) 7($35{\%}$): partial remission b(PRb) 7($35{\%}$), no response(NR) 1($5{\%}$). Patterns of failure were as follows; local failure 13($65{\%}$), local and distant failure 3($15{\%}$), distant failure 0($0{\%}$). Ultimate local control rate was $20{\%}$. Treatment related complications included esophageal ulcer in two patients and esophageal stricture in one. Conclusion : Though poor local conrol rate, median survival was improved as compared with previous results of radiation therapy alone(8months) and chemoradiation combined treatment(11 months) in Yonsei Cancer Center High-dose-rate intraluminal brachytherapy following external irradiation is an effective treatment modality with acceptable toxicity in esophageal cancer.

  • PDF

National Survey of Sarcoidosis in Korea (유육종증 전국실태조사)

  • 대한결핵 및 호흡기학회 학술위원회
    • Tuberculosis and Respiratory Diseases
    • /
    • v.39 no.6
    • /
    • pp.453-473
    • /
    • 1992
  • Background: National survey was performed to estimate the incidence of sarcoidosis in Korea. The clinical data of confirmed cases were analysed for the practice of primary care physicians and pulmonary specialists. Methods: The period of study was from January 1991 to December 1992. Data were retrospectively collected by correspondence with physicians in departments of internal medicine, dermatology, ophthalmology and neurology of the hospitals having more than 100 beds using returning postcards. In confirmed and suspicious cases of sardoidosis, case record chart for clinical and laboratory findings were obtained in detail. Results: 1) Postcards were sent to 523 departments in 213 hospitals. Internal medicine composed 41%, dermatology 20%, ophthalmology 20% and neurology 19%. 2) Postcards were returned from 241 departments (replying rates was 48%). 3) There were 113 confirmed cases from 50 departments and 10 cases. The cases were composed from internal medicine (81%), dermatology (13%), ophthalmology (3%) and neurology (3%). 78 confirmed cases were analysed, which were composed from department of internal medicine (92%), dermatology (5%), and neurology (3%). 4) The time span for analysed cases was 1980 to 1992. one case was analysed in 1980 and the number gradually increased to 18 cases in 1991. 5) The majority of patients (84.4%) were in the age group of 20 to 49 years. 6) The ratio of male to female was 1 : 1.5. 7) The most common chief complains were respiratory symptoms, dermatologic symptoms, generalized discomforts, visual changes, arthralgia, abdominal pains, and swallowing difficulties in order. 16% of the patients were asymptomatic. 8) Mean duration between symptom onset and diagnosis was 2 months. 9) The most common symptoms were respiratory, general, dermatologic, ophthalmologic, neurologic and cardiac origin in order. 10) Hemoglobin, hematocrits and platelet were in normal range. 58% of the patients had lymphopenia measuring less than 30% of white cell count. The ratio of CD4 to CD8 lymphocytes was $1.73{\pm}1.16$ with range of 0.43 to 4.62. ESR was elevated in 43% of the cases. 11) Blood chemistry was normal in most cases. Serum angiotensin converting enzyme (S-ACE) was $66.8{\pm}58.6\;U/L$ with the range of 8.79 to 265 U /L. Proteinuria of more than 150 mg was found in 42. 9% of the patients. 12) Serum IgG was elevated in 43.5%, IgA in 45.5%, IgM in 59.1% and IgE in 46.7%. The levels of complement C3 and C4 were in the normal range. Anti-nuclear antibody was detected in 11% of the cases. Kweim test was performed in 3 cases, and in all cases the result was positive. 13) FVC was decreased in 17.3%, FEV1 in 11.5%, FEV1/FVC in 10%, TLC in 15.2%, and DLco in 64.7%. 14) PaO2 was decreased below 90 mmHg in 48.6% and PaCO2 was increased above 45 mmHg in 5.7%. 15) The percentage of macrophages in BAL fluid was $51.4{\pm}19.2%$, lymphocytes $44.4{\pm}21.1%$, and the ratio of CD4 to CD8 lymphocytes was $3.41{\pm}2.07$. 16) There was no difference in laboratory findings between male and female. 17) Hilar enlargement on chest PA was present in 87.9% (bilaterally in 78.8% and unilaterally in 9.1%). 18) According to Siltzbach's classification, stage 0 was 5%, stage 158.3%, stage 228.3%, and stage 38.3%. 19) Hilart enlargement on chest CT was present in 92.6% (bilaterally 76.4% and unilaterally in 16.2%). 20) HRCT was done in 16 cases. The most common findings were nodules, interlobular thickening, focal patchy infiltrations in order. Two cases was normal finding. 21) Other radiologic examinations showed bone change in one case and splenomegaly in two cases. 22) Gallium scan was done in 12 cases. Radioactivity was increased in hilar and mediastinal lymph nodes in 8 cases and in parenchyme in 2 cases. 23) The pathologic diagnosis was commonly performed by transbrochial lung biopsy (TBLB, 47.3%), skin and mediastinal lymph nodes biopsy (34.5%), peripheral lymph nodes biopsy (23.6%), open lung biopsy (18.2%) and bronchial biopsy in order. 24) The most common findings in pathology were non·caseating granuloma (100%), multi-nucleated giant cell (47.3%), hyalinized acellular scar (34.5%), reticulin fibrin network (20%), inclusion body (10.9%), necrosis (9.1%), and lymphangitic distribution of granuloma (1.8%) in order. Conclusion: Clinical, laboratory, radiologic and pathologic findings were summarized. This collected data will assist in finding a test for detection and staging of sarcoidosis in Korea in near future.

  • PDF

Surgical Treatment of Stage IIIA Non Small Cell Lung Cancer(NSCLC) (제 IIIA기 비소세포 폐암의 수술 성적)

  • 정경영;홍기표;김창수;김길동;김주항;신동환
    • Journal of Chest Surgery
    • /
    • v.32 no.2
    • /
    • pp.144-150
    • /
    • 1999
  • Background: Surgery has been considered the most effective and standard treatment modality in non-small cell lung cancer(NSCLC). However in stage IIIA lung cancer, the role of surgery is still controversial. To evaluate the role of surgery for stage IIIA NSCLC, we investigated the survival after surgery and the prognostic factors. Material and Method: We evaluated 158 consecutive cases of stage IIIA NSCLC patients operated on between 1990 and 1996. There were 130 male patients and 28 female patients, and the mean age was 58.5 years. All patients except one underwent lung resection beyond lobectomy and extended mediastinal dissection. Postoperative adjuvant therapy were undertaken in 145(94.8%) patients. All patients(153) were followed and the mean follow-up period was 21.4months. Result: Twenty nine cases of the postoperative complications developed in 25 patients (15.8%). There were 5 operative mortality cases(3.2%) and the main cause of death was acute respiratory distress syndrome (ARDS). Local or distant recurrences developed in 84 patients(54.9%). The 5-year survival of 153 patients was 29.6% and the median survival time was 18.0 months. The 5-year survival of non N2 disease group(36.8%) was better than that of N2 disease group(26.6%)(p=0.35) and the 5-year survival of squamous cell carcinoma (38.1%) was better than that of adenocarcinoma(25.7%)(p=0.39) however there were no significant differences. Regarding the postoperative adjuvant therapy, in combined therapy group(84 patients), radiotherapy group(37 patients) and chemotherapy group(24 patients), the 5-year survival were 31.3%, 32.4%, and 14.6% respectively. There was no difference of survival between radiotherapy and combined therapy group(p=0.31), however the survival of the combined therapy group was better than the chemotherapy group(p=0.005). The survival of the complete resection group(31.9%) was better than the incomplete resection group(16.6%) however there was no significant difference(p=0.19). Conclusion: These observations indicate that the good 5-year survival(29.6%) in patients with stage IIIA NSCLC result from the agressive surgical treatment including extensive mediastinal nodes dissection.

  • PDF

Primary Adenoid Cystic Carcinoma Arising in the Bronchus (기관지에 발생한 선양 낭포성 암종)

  • Kim, Young-Keun;Chung, Kyung-Young;Shin, Dong-Hwan;Kim, Hae-Jin;Kim, Chang-Nyun;Kang, Shin-Myung;Ko, Won-Ki;Kim, Young-Sam;Lee, Jun-Gu;Park, Jae-Min;Kim, Se-Kyu;Chang, Joon
    • Tuberculosis and Respiratory Diseases
    • /
    • v.50 no.5
    • /
    • pp.591-598
    • /
    • 2001
  • Background : Primary adenoid cystic carcinoma arising in the bronchus is an uncommon disease that is histologically and ultrastructurally identical to the salivary gland tumor of the same name and regarded as a slow growing low-grade malignancy. We examined its clinical characteristics. Method : We collected 13 Korean cases of primary adenoid cystic carcinoma arising in the bronchus including 5 cases of our own and 8 cases from the literature. Result : The patients ages ranged from 20 to 74. Men numbered 9 and women 4. The presenting symptoms were cough, dyspnea, and hemoptysis. The fiberoptic bronchoscopic findings were primarily hypervascular polypoid mass with a smooth surface that obstructed airway totally or near totally. There were three inoperable cases including two cases with distant metastasis to bone or cervical lymph node and one case with mediastinal invasion. The remaining 10 patients underwent surgical resection. Among them, two patients received postoperative radiotherapy. The median survival was 21 months in the 8 surgical and evaluable cases. One patient lived 13 years without recurrence. The prognosis was relatively favorable in operable cases. Conclusion : It was not common for primary adenoid cystic carcinoma arising in the bronchus to have distant metastasis or invasion to the mediastinum on presentation. The prognosis was relatively favorable in operable cases. It would be important to perform flexible bronchoscopy for early diagnosis and to do surgical treatment if possible.

  • PDF

Concurrent Chemoradiation in Patients with Cancer of the Esophagus (식도암에서의 동시화학방사선요법)

  • Lee Kang Kyoo;Park Kyung Ran;Lee Jong Young;Shin Hyun Soo;Lee Chong In;Chang Woo Ick;Shim Young Hak
    • Radiation Oncology Journal
    • /
    • v.16 no.1
    • /
    • pp.7-16
    • /
    • 1998
  • Purpose : To evaluate survival rate and prognostic factors affecting survival of patients with esophageal cancer treated with concurrent chemoradiation. Materials and Methods : Eligibility included biopsy proven invasive carcinoma of the cervical or thoracic esophagus, confined to esophagus and mediastinum with or without regional lymph node and supraclavicular lymph node, and ECOG Performance status $H_0-H_2$. Patients received radiation therapy with 5940cGy over 7 weeks and chemotherapy, consisted of 5-FU(1000 $mg/m^2/day$ in continuous infusion for 5 days, days 1 to 5 and days 29 to 33) and mitomycin C($8mg/m^2$ intravenous bolus at day 1). After concurrent chemoradiation, maintenance chemotherapy was followed with 5-FU(1000 $mg/m^2/day$ in continuous infusion for 5 days at 9th, 13th, and 17th weeks) and cisplatin($80mg/m^2$ intravenous bolus at the first day of each cycle). Results : From November 1989 to November 1995, 44 patients were entered in this study. After treatment, complete response rate and partial response rate were $59\%$ and $41\%$. Overall 1, 2, and 5-year survivals were $59\%$, $38\%$, and $9.6\%$(median 17 months), Prognostic factors affecting survival were response to treatment and T-stage. Among 26 complete responders, there were 6 local recurrences, 3 distant recurrences, 1 local and distant recurrence, and 2 unknown site recurrences Acute and chronic complication rates with grade 3 or more were $20\%$ and $13.0\%$ and there was no treatment-related mortality. Conclusion : Concurrent chemoradiation, compared with historical control groups that treated with radiation alone, improved median survival and did not significantly increase treatment-related complications. Complete responders had longer survival duration than partial responders. Predominant failure pattern was local failure. So, efforts to improve local control should be proposed.

  • PDF

Clinical Manifestations of 15 Cases of Pulmonary Sequestration (폐격리증 15예의 임상양상에 관한 고찰)

  • Park, Kwang-Joo;Kim, Eun-Sook;Kim, Hyung-Jung;Chang, Joon;Ahn, Chul-Min;Kim, Sung-Kyu;Lee, Won-Young;Kim, Sang-Jin;Lee, Doo-Yun
    • Tuberculosis and Respiratory Diseases
    • /
    • v.44 no.2
    • /
    • pp.401-408
    • /
    • 1997
  • Background : Pulmonary sequestration is a rare congenital malformation, which is manifested by formation of nonfunctioning lung tissue lacking normal communication with the tracheobronchial tree. The preoperative diagnostic rate has been relatively low, and without consideration of pulmonary sequestration, unexpected bleeding from aberrant vessels may be a serious problem during the operation. The purpose of our study is to describe the clinical features of pulmonary sequestration based on a review of 15 cases treated by operation. Method : Fifteen patients with pulmonary sequestration who had undergone surgical treatment from 1991 through May 1996 at Yongdong Severance Hospital and Severance Hospital were reviewed retrospectively. Results : The mean age of the patients was 22.5 years (range 5~57), and male to female ratio was 9 : 6. Clinical presentations varied from recurrent respiratory infections such as fever, cough, and sputum or chest pain to no symptom. The chest simple X-rays showed multicystic shadow(10/15) and solid mass-like shadow(5/15). The chest CT scans, done in twelve cases, showed multicystic lesion with or without lung infiltration(8/12), solid mass-like lesion(4/12), The chest MRIs, done in three cases, revealed the aberrant arteries originating from descending aorta(2/3). Aortograms, done in four cases, showed the aberrant arteries originating from descending thoracic aorta(2/4), abdominal aorta(I/4), and intercostal artery(1/4). and the venous returns were via the pulmonary veins. Pulmonary sequestration was considered preoperatively in six patients of fifteen. Other preliminary diagnosis were lung tumor(3/15), lung abscess(21/15), bronchiectasis(2/15), and mediastinal tumor(2/15). In the operative findings, twelve cases were of intralobar type and three cases of extralobar type. The left lower lobe was most often affected(9/15) and one extralobar sequestration was in the pericardium. The aberrant arteries originated from descending thoracic aorta(6/15), abdominal aorta(1/15), internal thoracic arteries (2/15), intercostal artery(1/15), pericardiophrenic artery(1/15), but in four cases, the origins could not be defined. There was no mortality or complication postoperatively. Conclusion : In our study, preoperative diagnostic rate was relatively low, and clinical features were similar to previous reports. Preoperative vigorous diagnostic approach including aortography is strongly advocated not only for its diagnostic value, but also for accurate localization of the aberrant vessels, which is major concern to surgical procedure.

  • PDF

Inhomogeneity correction in on-line dosimetry using transmission dose (투과선량을 이용한 온라인 선량측정에서 불균질조직에 대한 선량 보정)

  • Wu, Hong-Gyun;Huh, Soon-Nyung;Lee, Hyoung-Koo;Ha, Sung-Whan
    • Journal of Radiation Protection and Research
    • /
    • v.23 no.3
    • /
    • pp.139-147
    • /
    • 1998
  • Purpose: Tissue inhomogeneity such as lung affects tumor dose as well as transmission dose in new concept of on-line dosimetry which estimates tumor dose from transmission dose using the new algorithm. This study was carried out to confirm accuracy of correction by tissue density in tumor dose estimation utilizing transmission dose. Methods: Cork phantom (CP, density $0.202\;gm/cm^3$) having similar density with lung parenchyme and polystyrene phantom (PP, density $1.040\;gm/cm^3$) having similar density with soft tissue were used. Dose measurement was carried out under condition simulating human chest. On simulating AP-PA irradiation, PPs with 3 cm thickness were placed above and below CP, which had thickness of 5, 10, and 20 cm. On simulating lateral irradiation, 6 cm thickness of PP was placed between two 10 cm thickness CPs additional 3 cm thick PP was placed to both lateral sides. 4, 6, and 10 MV x-ray were used. Field size was in the range of $3{\times}3$ cm through $20{\times}20$ cm, and phantom-chamber distance (PCD) was 10 to 50 cm. Above result was compared with another sets of data with equivalent thickness of PP which was corrected by density. Result: When transmission dose of PP was compared with equivalent thickness of CP which was corrected with density, the average error was 0.18 (${\pm}0.27$) % for 4 MV, 0.10 (${\pm}0.43$) % for 6 MV, and 0.33 (${\pm}0.30$) % for 10 MV with CP having thickness of 5 cm. When CP was 10 cm thick, the error was 0.23 (${\pm}0.73$) %, 0.05 (${\pm}0.57$) %, and 0.04 (${\pm}0.40$) %, while for 20 cm, error was 0.55 (${\pm}0.36$) %, 0.34 (${\pm}0.27$) %, and 0.34 (${\pm}0.18$) % for corresponding energy. With lateral irradiation model, difference was 1.15 (${\pm}1.86$) %, 0.90 (${\pm}1.43$) %, and 0.86 (${\pm}1.01$) % for corresponding energy. Relatively large difference was found in case of PCD having value of 10 cm. Omitting PCD with 10 cm, the difference was reduced to 0.47 (${\pm}$1.17) %, 0.42 (${\pm}$0.96) %, and 0.55 (${\pm}$0.77) % for corresponding energy. Conclusion When tissue inhomogeneity such as lung is in tract of x-ray beam, tumor dose could be calculated from transmission dose after correction utilizing tissue density.

  • PDF