• Title/Summary/Keyword: Tumors

Search Result 4,797, Processing Time 0.041 seconds

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

Activity of Matrix Metalloproteinase-2 and its Significance after Resection of Stage I Non-small Cell Lung Cancer (제1기 비소세포폐암 환자의 수술적 절제 후 Matrix Metalloprotainase-2 활성도에 따른 재발 및 예후)

  • Kim Sang Hui;Hong Young-Sook;Lee Jinseon;Son Dae-Soon;Lim Yu-Sung;Song In-Seung;Lee Hye-Sook;Kim Do Hun;Kim Jingook;Choi Yong Soo
    • Journal of Chest Surgery
    • /
    • v.38 no.1 s.246
    • /
    • pp.38-43
    • /
    • 2005
  • Matrix metalloproteinase-2 (MMP-2) is a class of proteolytic enzymes that digest collagen type IV and other components of the basement membrane. It plays a key role in the local invasion and the formation of distant metastases by various malignant tumors. The aim of this study was to evaluate the activity of MMP-2 and its significance as a prognostic marker in resected stage I non-small cell lung cancer (NSCLC). Material and Method: In this study we obtained fresh-frozen samples of tumor and non-tumor tissues from 34 patients with stage I NSCLC who underwent resection without preoperative radiotherapy or chemotherapy. After the extraction of total protein from tissue samples, MMP-2 activities were assessed by gelatin-substrate-zymography. The activities were divided into the higher or lower groups. Result: The MMP-2 activities were higher in tumor tissues than in non-tumor tissues. The MMP-2 activity of non-tumor tissues in recurrent group was higher than in non-recurrent group (p<0.01). Also the patients with higher MMP-2 activity of non-tumor tissues showed poor 5 year survival (p<0.01). Conclusion: This result indicates that the higher level of MMP-2 activity in the non-tumor tissue is associated with the recurrence and survival after the resection of stage I NSCLC. Therefore, MMP-2 activity in the non-tumor tissue could be used as a potential prognostic marker for the resected stage I-NSCLC.

Immunohistochemical and Immunogold Electron Microscopic Studies on Effects of Cis-platin on the Ciliogenesis of Rat Oviducts (Cis-Platin이 흰쥐 난관의 섬모형성에 미치는 영향에 대한 면역조직학적 및 면역도금법에 의한 전자현미경적 연구)

  • Kim, Jin-Kook;Kim, Won-Kyu;Paik, Doo-Jin;Chung, Ho-Sam
    • Applied Microscopy
    • /
    • v.30 no.1
    • /
    • pp.45-59
    • /
    • 2000
  • Cis-platin is a widely used anticancer drug against certain solid tumors such as malignant ovarian tumor, malignant carcinoma of head and neck, bladder cancer and cervical cancer of uterus, and its major mechanism of action is inhibition of DNA synthesis of the tumor cell. To investigate the inhibitory effects of cis-platin on the ciliogensis of the ciliated cells in the mucosa of oviduct, the author pursued the alterations of $\alpha-tubulin$, which is the main constituent of the microtubles in cilia, after cis-platin treatment. To eliminate the possible variations due to ovarian cycle, female Spargue-Dawley rats ($150\sim200gm$ in B.W.) were pretreated with estradiol benzoate (20 mg/kg, once a day, for 4 consecutive days). Animals were administrated with cis-platin (6 mg/kg, i.p.) and sacrificed at 1day, 3days, 5days and 7days after treatment, respectively. Immunohistochemistry for $\alpha-tubulin$ using mouse anti-rat $\alpha-tubulin$ monoclonal antibody as primary antibody was done. Immunogold electronmicroscopy for intracellular distributions of $\alpha-tubulin$ was also performed with same primary antibody and Goat anti- mouse IgM which is preconjugated with gold particles of 15 nm as secondary antibody. The results obtained were as follows; 1. Strong immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1, 3 and 5 days after estradiol pretreatment. 2. Weak immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1 and 3 days after cis-platin treatment but it was recovered to strong immunoreactivity in 5 days 3. In immunogold electronmicroscopy, density of gold particles for $\alpha-tubulin$ reactions was decreased in apical cytoplasm, but few changes were observed in basal body or cilia at 1 and 3 days after cis-platin treatment. From these above results, it is indicated that synthesis of $\alpha-tubulin$ in ciliated cells of rat oviduct is inhibited by cis-platin treatment.

  • PDF

Photoimmunology -Past, Present and Future-

  • Daynes, Raymond A.;Chung, Hun-Taeg;Roberts, Lee K.
    • The Journal of the Korean Society for Microbiology
    • /
    • v.21 no.3
    • /
    • pp.311-329
    • /
    • 1986
  • The experimental exposure of animals to sources of ultraviolet radiation (UVR) which emit their energy primarily in the UVB region (280-320nm) is known to result in a number of well-described changes in the recipient's immune competence. Two such changes include a depressed capacity to effectively respond immunologically to transplants of syngeneic UVR tumors and a markedly reduced responsiveness to known inducers of delayedtype (DTH) and contact hypersensitivity (CH) reactions. The results of experiments that were designed to elucidate the mechanisms responsible for UVR-induced immunomodulation have implicated: 1) an altered pattern of lymphocyte recirculation, 2) suppressor T cells(Ts), 3) deviations in systemic antigen presenting cell (APC) potential. 4) changes in the production of interleukin-1-like molecules, and 5) the functional inactivation of epidermal Langerhans cells in this process. The exposure of skin to UVR, therefore, causes a number of both local and systemic alterations to the normal host immune system. In spite of this seeming complexity and diversity of responses, our recent studies have established that each of the UVR-mediated changes is probably of equal importance to creating the UVR-induced immunocompromised state. Normal animals were exposed to low dose UVR radiation on their dorsal surfaces under conditions where a $3.0\;cm^2$ area of skin was physically protected from the light energy. Contact sensitization of these animals with DNFB, to either the irradiated or protected back skin, resulted in markedly reduced CH responses. This was observed in spite of a normal responsiveness following the skin sensitization to ventral surfaces of the UVR-exposed animals. Systemic treatment of the low dose UVR recipients with the drug indomethacin (1-3 micrograms/day) during the UVR exposures resulted in a complete reversal of the depressions observed following DNFB sensitization to "protected" dorsal skin while the altered responsiveness found in the group exposed to the skin reactive chemical through directly UVR-exposed sites was maintained. These studies implicate the importance of EC as effective APC in the skin and also suggest that some of the systemic influences caused by UVR exposure involve the production of prostaglandins. This concept was further supported by finding that indomethacin treatment was also capable of totally reversing the systemic depressions in CH responsiveness caused by high dose UVR exposure (30K joules/$m^2$) of mice. Attempts to analyze the cellular mechanisms responsible established that the spleens of all animals which demonstrated altered CH responses, regardless of whether sensitization was through a normal or an irradiated skin site, contained suppressor cells. Interestingly, we also found normal levels of T effector cells in the peripheral lymph nodes of the UVR-exposed mice that were contact sensitized through normal skin. No effector cells were found when skin sensitization took place through irradiated skin sites. In spite of such an apparent paradox, insight into the probable mechanisms responsible for these observations was provided by establishing that UVR exposure of skin results in a striking and dose-dependent blockade of the efferent lymphatic vessels in all peripheral lymph nodes. Therefore, the afferent phases of immune responses can apparently take place normally in UVR exposed animals when antigen is applied to normal skin. The final effector responses, however, appear to be inhibited in the UVR-exposed animals by an apparent block of effector cell mobility. This contrasts with findings in the normal animals. Following contact sensitization, normal animals were also found to simultaneously contain both antigen specific suppressor T cells and lymph node effector cells. However, these normal animals were fully capable of mobilizing their effector cells into the systemic circulation, thereby allowing a localization of these cells to peripheral sites of antigen challenge. Our results suggest that UVR is probably not a significant inducer of suppressor T-cell activity to topically applied antigens. Rather, UVR exposure appears to modify the normal relationship which exists between effector and regulatory immune responses in vivo. It does so by either causing a direct reduction in the skin's APC function, a situation which results in an absence of effector cell generation to antigens applied to UVR-exposed skin sites, inhibiting the capacity of effector cells to gain access to skin sites of antigen challenge or by sequestering the lymphocytes with effector cell potential into the draining peripheral lymph nodes. Each of these situations result in a similar effect on the UVR-exposed host, that being a reduced capacity to elicit a CH response. We hypothesize that altered DTH responses, altered alloresponses, and altered graft-versus-host responses, all of which have been observed in UVR exposed animals, may result from similar mechanisms.

  • PDF

The Significance of $p27^{KIP1}$, MIB-1, bcl-2 and p53 Expression in the Differential Diagnosis of Follicular Adenoma and Carcinoma of the Thyroid Gland (갑상선 여포상 선종과 암종의 감별진단에서 $p27^{KIP1}$, MIB-1, bcl-2, p53 발현의 유용성에 대한 연구)

  • Kang Mi-Seon;Yoon Hye-Kyoung;Kim Sang-Hyo;Yoon Ki-Young;Lee Choong-Han;Choi Kyung-Hyun;Hur Bang;Roh Mi-Sook;Hong Sook-Hee
    • Korean Journal of Head & Neck Oncology
    • /
    • v.17 no.2
    • /
    • pp.139-147
    • /
    • 2001
  • Objectives: The most important differential point of follicular carcinoma from adenoma is capsular invasion or angioinvasion of follicular cells. Serial sections for examination of levels of tumor margins are necessary to watch the invasion. However, the interpretation of capsular invasion or angioinvasion is sometimes not feasible on the routine staining of tumor tissue. The aim of this study is to evaluate the clinical significance of expressions of $p27^{KIP1}$, MIB-1, bcl-2 and p53 in differential diagnosis of follicular adenoma and carcinoma. Materials and Methods: 16 cases of follicular carcinoma and 26 cases of follicular adenoma were entered on study of immunohistochemical stains for $p27^{KIP1}$, MIB-1, bcl-2 and p53. In carcinoma cases, correlation between the above markers, patient's age, tumor size, infiltration pattern and metastasis was studied. Results: $p27^{KIP1}$ labelling index (LI) of follicular carcinoma and adenoma was $4.89{\pm}6.92$ and $14.52{\pm}9.17$, respectively, but there was no significant difference between adenoma and carcinoma (p=0.2560). MIB-1 LI of carcinoma and adenoma was $4.11{\pm}3.89$ and $0.80{\pm}0.75$, respectively, and MIB-1 LI was significantly higher in carcinoma (p=0.0000). bcl-2 expression was seen in 2(12.5%) of 16 carcinoma cases and 130(50.0%) of 26 adenoma cases, and bcl-2 expression rate was higher in adenoma than in carcinoma(p=0.014). In one adenoma and one carcinoma case, p53 expression was noted. In follicular adenoma with atypia compared to adenoma without atypia, lower $p27^{KIP1}$ LI, higher MIB-1 LI and lower bcl-2 expression rate were seen. In follicular carcinoma, MIB-1 LI was significantly higher in invasive carcinoma(p=0.045) and was relatively increased in tumors larger than 3.0cm, showing angioinvasion and distant metastasis. But $p27^{KIP1}$ LI was higher in cases over 40 years old(p=0.008) and with conspicuous capsular invasion. There were no positive correlations between expressions of MIB-1, bcl-2 and p53. Conclusion: MIB-1 labelling index and bcl-2 expression could be helpful for differential diagnosis of follicular adenoma and carcinoma, but p53 showed very low expression rate and no significance in differential diagnosis. $p27^{KIP1}$ labelling index reveals decreasing tendency in carcinoma compared with adenoma, MIB-1 LI was considered as a poor prognostic marker in follicular carcinoma, but $p27^{KIP1}$ LI was higher in carcinoma cases over 40 years old with showing conspicuous capsular invasion. Further study for the significance of $p27^{KIP1}$ labelling index in follicular neoplasms is necessary to evaluate diagnostic value of follicular carcinoma.

  • PDF

Review on Usefulness of EPID (Electronic Portal Imaging Device) (EPID (Electronic Portal Imaging Device)의 유용성에 관한 고찰)

  • Lee, Choong Won;Park, Do Keun;Choi, A Hyun;Ahn, Jong Ho;Song, Ki Weon
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.25 no.1
    • /
    • pp.57-67
    • /
    • 2013
  • Purpose: Replacing the film which used to be used for checking the set-up of the patient and dosimetry during radiation therapy, more and more EPID equipped devices are in use at present. Accordingly, this article tried to evaluated the accuracy of the position check-up and the usefulness of dosimetry during the use of an electronic portal imaging device. Materials and Methods: On 50 materials acquired with the search of Korea Society Radiotherapeutic Technology, The Korean Society for Radiation Oncology, and Pubmed using "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", and "In vivo dosimetry" as indexes, the usefulness of EPID was analyzed by classifying them as history of EPID and dosimetry, set-up verification and characteristics of EPID. Results: EPID is developed from the first generation of Liquid-filled ionization chamber, through the second generation of Camera-based fluoroscopy, and to the third generation of Amorphous-silicon EPID imaging modes can be divided into EPID mode, Cine mode and Integrated mode. When evaluating absolute dose accuracy of films and EPID, it was found that EPID showed within 1% and EDR2 film showed within 3% errors. It was confirmed that EPID is better in error measurement accuracy than film. When gamma analyzing the dose distribution of the base exposure plane which was calculated from therapy planning system, and planes calculated by EDR2 film and EPID, both film and EPID showed less than 2% of pixels which exceeded 1 at gamma values (r%>1) with in the thresholds such as 3%/3 mm and 2%/2 mm respectively. For the time needed for full course QA in IMRT to compare loads, EDR2 film recorded approximately 110 minutes, and EPID recorded approximately 55 minutes. Conclusion: EPID could easily replace conventional complicated and troublesome film and ionization chamber which used to be used for dosimetry and set-up verification, and it was proved to be very efficient and accurate dosimetry device in quality assurance of IMRT (intensity modulated radiation therapy). As cine mode imaging using EPID allows locating tumors in real-time without additional dose in lung and liver which are mobile according to movements of diaphragm and in rectal cancer patients who have unstable position, it may help to implement the most optimal radiotherapy for patients.

  • PDF

Clinical Experience of Nephron Sparing Surgery for Renal Tumor with a Normal Opposite Kidney (대측 신장이 정상인 신종양 환자에서 신보존수술의 임상 경험)

  • Lee, Jun-Young;Kim, Jung-Hyun;Lee, Kang-Min;Moon, Ki-Hak;Jung, Hee-Chang;Park, Tong-Choon
    • Journal of Yeungnam Medical Science
    • /
    • v.16 no.1
    • /
    • pp.94-100
    • /
    • 1999
  • The aim of this retrospective study was to determine whether a nephron sparing surgery might be feasible in patients with a small solid renal tumor. Materials and methods: Between 1988 and 1999, 21 patients with a radiologically detectable small solid renal tumor underwent enucleoresection, wedge resection and polar segmental nephrectomy. The mean age of the 11 men and 10 women in this study was 43 years (range 14 to 68). According to the preoperative radiological diagnosis, 15 among the 21 patients were considered to have renal cell carcinoma, 4 were considered to have angiomyolipoma, and in the remaining 2 patients, radiological differentiation of renal tumors was difficult. Among 15 patients considered to have renal cell carcinoma, 14 were found to have renal cell carcinoma and the remaining one patient was diagnosed as having oncocytoma on pathologic examination. Radiological determination of angiomyolipoma in four patients was confirmed to be correct on pathological examination. The 2 patients whose radiological diagnose was difficult were found to have cavernous hemangioma and angiomyolipoma. One patient with renal cell carcinoma developed arteriocaliceal fistula, the only immediate complication in this series and underwent nephrectomy on postoperative 10th day. The mean follow up duration for the 14 patients with renal cell carcinoma was 18.6 months (range:1-103). There was no other tumor involvement in the resection margins following the nephron sparing surgery. These results suggest that nephron sparing surgery provides an effective treatment for patients with a single, small, unilateral, localized renal tumor. Longer follow-up is suggested for more definite verification of the role of nephron sparing surgery.

  • PDF

The Relationship between Intracellular Protein Kinase C Concentration and Invasiveness in U-87 Malignant Glioma Cells (교모세포종 세포주 U-87에서 세포내 PKC 농도와 종양침습성과의 상관 관계)

  • Ji, Cheol;Cho, Kyung-Keun;Lee, Kyung Jin;Park, Sung Chan;Cho, Jung Ki;Kang, Joon Ki;Choi, Chang Rak
    • Journal of Korean Neurosurgical Society
    • /
    • v.30 no.3
    • /
    • pp.263-271
    • /
    • 2001
  • Objective : Glioblastomas, the most common type of primary brain tumors, are highly invasive and cause massive tissue destruction at both the tumor invading edges and in areas that are not in direct contact with glioma cells. As a result, patients with high-grade gliomas are faced with a poor prognosis. Such grim statistics emphasize the need to better understand the mechanisms that underlie glioma invasion, as these may lead to the identification of novel targets in the therapy of high grade gliomas. Protein kinase C(PKC) is a family of serine/threonine kinases and an important signal transduction enzyme that conveys signals generated by ligand-receptor interaction at the cell surface to the nucleus. PKC appears to be critical in regulating many aspects of glioma biology. The purpose of this study was to assess accurately the role of PKC in the invasion regulation of human gliomas based on hypothesis that protein kinase C(PKC) is functional in the process of glial tumor cell invasion. Method : To test this hypothesis, U-87 malignant glioma cell line intracellular PKC levels were up and down regulated and their invasiveness was tested. Intracellular PKC level was characterized using PKC activity assays. Invasion assays including barrier migration and spheroid confrontation were used to study the relationship between PKC concentration and invasiveness. Result : The cell line which were treated by PKC inhibitor tamoxifen and hypericin exhibited decreased PKC activity and decreased invasive abilities dose dependently both in matrigel invasion assay and tumor spheroid fetal rat brain aggregates(FRBA) confrontation assay. However, the cell line that was treated by PKC activator 12-O-tetradecanylphorbol-13acetate(TPA) did not exhibit increases in either PKC activity or invasive ability. Conclusion : These studies suggest that PKC may be a useful molecular target for the chemotherapy of glioblastoma and other malignancies and that a therapeutic approach based on the ability of PKC inhibitors may be helpful in preventing invasion.

  • PDF

Comparison of Proliferative Activity in Each Histological Subtypes of Benign and Atypical Intracranial Meningiomas by PCNA and Ki-67 Immunolabeling (양성 뇌수막종의 조직학적 아형 및 이형성 뇌수막종에서 PCNA와 Ki-67 표지지수의 비교)

  • Choi, Seung Jin;Chang, Eun Deok;Kwon, Seung Oh;Kye, Dae Kon;Park, Choon Keun;Lee, Sang Won;Kang, Joon Ki
    • Journal of Korean Neurosurgical Society
    • /
    • v.29 no.9
    • /
    • pp.1215-1221
    • /
    • 2000
  • Objective : The clinical prognosis and biological behavior of atypical and especially malignant meningiomas are well known to be worse than benign meningioma, but the degree of biological aggressiveness in each classical subtypes of benign meningioma is controversy. This study was performed to see whether there is a difference in the proliferative activity between each different histological subtypes of benign meningioma as well as atypical meningioma. Methods : Paraffin-embedded surgical specimens of 27 meningiomas, including two recurrent tumors, were studied to evaluate proliferative activity by immunohistochemical method with monoclonal antibodies to proliferating cell nuclear antigen(PCNA) and MIB-1. The specimens consisted of 8 cases of meningothelial, 9 cases of transitional, 5 cases of fibroblastic subtypes and 5 cases of atypical meningiomas. Results : Mean PCNA labeling indices of meningothelial, transitional and fibroblastic meningiomas were $4.82{\pm}5.10%$, $9.01{\pm}4.25%$ and $5.66{\pm}5.32%$, but that of atypical meningiomas was $27.62{\pm}19.67%$, noting a higher value compared to all three subtypes of benign meningiomas. Mean Ki-67 labeling indices of the above 3 subtypes were $0.43{\pm}0.85%$, $0.44{\pm}1.08%$ and $0.24{\pm}0.18%$, and that of atypical meningiomas was also revealed to be of higher value ($0.84{\pm}0.59%$). PCNA and Ki-67 labeling indices were not statistically different between histological subtypes of benign meningioma(p>0.05), but the differences of both immunolabeling between benign and atypical meningiomas were statistically significant(p<0.05). Conclusion : Immunolabeling of PCNA and Ki-67 in intracranial meningiomas reveals no prognostic difference between meningothelial, transitional and fibroblastic subtypes in classical benign meningiomas by measuring expression of PCNA and Ki-67, but it seems to be helpful in differentiating benign and atypical meningioma, later showing more proliferative activity and biological aggressiveness.

  • PDF

A Study of volumetric modulated arc therapy for stereotactic body radiation therapy in case of multi-target liver cancer using flattening filter free beam (다중표적 간암의 정위적체부방사선치료에서 무편평화여과기선질 용적변조회전치료의 유용성 평가)

  • Yeom, Misuk;Yoon, Inha;Hong, Donggi;Back, Geummun
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.27 no.1
    • /
    • pp.31-43
    • /
    • 2015
  • Purpose : Stereotactic body radiation therapy (SBRT) has proved its efficacy in several patient populations with primary and metastatic limited tumors. Because SBRT prescription is high dose level than Conventional radiation therapy. SBRT plan is necessary for effective Organ at risk (OAR) protection and sufficient Planning target volume (PTV) dose coverage. In particular, multi-target cases may result excessive doses to OAR and hot spot due to dose overlap. This study evaluate usefulness of Volumetric modulated arc therapy (VMAT) in dosimetric and technical considerations using Flattening filter free (FFF) beam. Materials and Methods : The treatment plans for five patients, being treated on TrueBeam STx(Varian$^{TM}$, USA) with VMAT using 10MV FFF beam and Standard conformal radiotherapy (CRT) using 15MV Flattening filter (FF) beam. PTV, liver, duodenum, bowel, spinal cord, esophagus, stomach dose were evaluated using the dose volume histogram(DVH). Conformity index(CI), homogeneity index(HI), Paddick's index(PCI) for the PTV was assessed. Total Monitor unit (MU) and beam on time was assessed. Results : Average value of CI, HI and PCI for PTV was $1.381{\pm}0.028$, $1.096{\pm}0.016$, $0.944{\pm}0.473$ in VMAT and $1.381{\pm}0.042$, $1.136{\pm}0.042$, $1.534{\pm}0.465$ in CRT respectively. OAR dose in CRT plans evaluated 1.8 times higher than VMAT. Total MU in VMAT evaluated 1.3 times increase than CRT. Average beam on time was 6.8 minute in VMAT and 21.3 minute in CRT. Conclusion : VMAT for SBRT in multi-target liver cancer using FFF beam is effective treatment techniqe in dosimetric and technical considerations. VMAT decrease intra-fraction error due to treatment time shortening using high dose rate of FFF beam.

  • PDF