• Title/Summary/Keyword: Materials and methods

Search Result 21,676, Processing Time 0.053 seconds

Cosmetic Results of Conservative Treatment for Early Breast Cancer (조기유방암에서 유방보존수술 및 방사선치료후의 미용적 결과)

  • Kim Bo Kyoung;Shin Seong Soo;Kim Seong Deok;Ha Sung Whan;Noh Dong-Young
    • Radiation Oncology Journal
    • /
    • v.19 no.1
    • /
    • pp.21-26
    • /
    • 2001
  • Purpose : This study was peformed to evaluate the cosmetic outcome of conservative treatment for early breast cancer and to analyze the factors influencing cosmetic outcome. Materials and Methods : From February 1992 through January 1997, 120 patients with early breast cancer were treated with conservative surgery and postoperative radiotherapy. The types of conservative surgery were quadrantectomy and axillary node dissection for 108 patients $(90\%)$ and lumpectomy or excisional biopsy for 10 patients $(8.3\%)$. Forty six patients $(38\%)$ received adjuvant chemotherapy (CMF or CAF). Cosmetic result evaluation was carried out between 16 and 74 months (median, 33 months) after surgery. The cosmetic results were classified into four categories, i.e., excellent, good, fair, and poor. The appearances of the patients' breasts were also analyzed for symmetry using the differences in distances from the sternal notch to right and left nipples. A logistic regression analysis was performed to identify independent variables influencing the cosmetic outcome. Results : Cosmetic score was excellent or good in $76\%$ (91/120), fair in $19\%$ (23/120) and poor in $5\%$ (6/120) of the patients. Univariate analysis showed that tumor size (T1 versus T2) (p=0.04), axillary node status (N0 versus N1) (p=0.0002), extent of surgery (quadrantectomy versus lumpectomy or excisional biopsy) (p=0.02), axillary node irradiation (p=0.0005) and chemotherapy (p=0.0001) affected cosmetic score. Multivariate analysis revealed that extent of surgery (p=0.04) and chemotherapy (p=0.0002) were significant factors. For breast symmetry, univariate analysis confirmed exactly the same factors as above. Multivariate analysis revealed that tumor size (p=0.003) and lymph node status (p=0.007) affected breast symmetry. Conclusion : Conservative surgery and postoperative radiotherapy resulted in excellent or good cosmetic outcome in a large portion of the patients. Better cosmetic results were achieved generally in the group of patients with smaller tumor size, without axillary node metastasis and treated with less extensive surgery without chemotherapy.

  • PDF

Failure Pattern of Pineal and Ectopic Pineal Germ Cell Tumor after Gamma Knife Radiosurgery (송과선 및 이소성 송과선 생식세포종의 감마 나이프 수술 후 재발 양상)

  • Cho, Heung-Lae;Sohn, Seung-Chang
    • Radiation Oncology Journal
    • /
    • v.18 no.2
    • /
    • pp.92-100
    • /
    • 2000
  • Purpose :This study was performed to determine the optimal treatment velum of Patients treating with radiation therapy for intracranial germ cell tumor. Materials and Methods : From 1993 to 1998, 19 patients with intracranial germ cell tumors treated by gamma knife radiosurgery were analyzed. The location of tumor was as follows; 9 cases on pineal region, 1 case on suprasellar region, and 9 cases of multiple lesion. 7 patients were pathologically verified; 5 cases of germ cell tumor and 2 cases of non germinomatous germ cell tumor. Tumor volume was ranged from 2.4 cm$^{3}$ to 74 cm$^{3}$. Irradiation dose was 10 Gy to 20 Gy with 50% isodose curve. Follow up period was 10 months to 54 months. Results : Recurrences were observed in 14 cases among 19 (74%) patients. Complete remission and partial remission were achieved in 2 (11%) and 10 (53%) respectively. No response was observed in 7 (36%). 2 cases were recurred within original tumor bed. 6 cases were recurred beyond but contiguous with tumor bed. Ventricular relapses separated from pretreatment tumor bed were 3. Spinal recurrences were 4. Among 8 recurred cases of which tumor volume is smaller than 20 cm$^{3}$, 2 were recurred within original tumor bed, 4 were recurred beyond but contiguous with tumor bed, and 1 spinal recurrence. Meanwhile, 6 cases of which tumor volume larger than 20 cm3, 1 case was recurred beyond but contiguous with tumorbed, 2 ventricular recurrences separated with original tumor bed, and 3 spinal recurrences. 5 cases which did not show any recurrence sign showed characteristics of single lesion, tumor volume smaller than 20 cm$^{3}$ and normal tumor marker. All of 4 cases of spinal recurrences happened in the case having ventricular invasion or lesion. Among 9 cases having multiple lesion, only 3 cases recurred within original tumor bed or around tumor bed, the other 6 cases recurred separated from pretreatment tumor bed. Conclusion : Gamma knife radiosurgery is not recommended for the treatment of intracranial germ cell tumor. It is because of small treatment volume and inadequate radiation dose that are characteristics of gamma knife radiosurgery. Tumor volume, ventricular invasion or ventricular lesion in multiple lesion are important factors to be considered for the wide field radiation therapy Tumor volume smaller than 20 cm$^{3}$, single lesion, no ventricular lesion or invasion, and normal tumor marker are ideal indications for small involved field radiation therapy. Prophylactic spinal irradiation seems to be necessary when there is ventricular lesion, ventricular invasion, and multiple lesions. When the tumor volume is larger than 20 cm$^{3}$, multiple lesions, abnormal tumor marker, and whole ventricular irradiation or partial brain irradiation would be possible and neoadjuvant chemotherapy would be most beneficial in these group.

  • PDF

Mumps- and Rubella-specific IgG Levels in Adolescents (청소년기의 연령증가에 따른 볼거리 및 풍진 항체가 변동)

  • Cheon, Hae Won;Shin, Young Kyoo;Lee, Kang Woo;Choung, Ji Tae;Tockgo, Young Chang
    • Pediatric Infection and Vaccine
    • /
    • v.5 no.1
    • /
    • pp.128-135
    • /
    • 1998
  • Purpose : This study was intended to measure seropositivities and the level of mumps- and rubella-specific IgG of MMR vaccinees from 12 to 17 years of age in Korea. Materials and Methods : From May 1996 to July 1996 we obtained sera from students of 1 middle and 2 high schools in Seoul, who were MMR vaccinees from 12 to 17 years of age and had no evidence of immunodeficiency. These 216 study population include 110 males and 106 females. Mumps- and rubella-specific IgG antibody levels were measured by ELISA. Cut-off values for seropositivity were 20 U(Gamma Unit) in mumps and over 0.17 in rubella. Results : 1) As age increased, seropositivities to mumps increased, being 68.4% in 12 year, 79.3% in 13 year, 72.2% in 14 year, 82.0% in 15 year, 87.5% in 16 year, 87.0% in 17 year, which however has no statistical significance. 2) As age increased, the level of mumps-specific IgG antibody(mean+standard deviation, GU) increased, being $52.0{\pm}49.2$ in 12 year, $65.9{\pm}51.4$ in 13 year, $71.1{\pm}66.0$ in 14 year, $67.8{\pm}53.6$ in 15 year, $82.8{\pm}67.8$ in 16 year, $92.0{\pm}68.9$ in 17 year, which however has no statistical significance. 3) As age increased, seropositivities of rubella-specific IgG increased significantly, being 26.3% in 12 year, 20.7% in 13 year, 50.0% in 14 year, 67.2% in 15 year, 66.7% in 16 year, 65.2% in 17 year(P<0.001). 4) As age increased, rubella-specific IgG increased significantly, being $0.13{\pm}0.145$ in 12 year, $0.087{\pm}0.101$ in 13 year, $0.194{\pm}0.168$ in 14 year, $0.260{\pm}0.187$ in 15 year, $0.305{\pm}0.213$ in 16 year, $0.325{\pm}0.221$ in 17 year(P<0.001). There was positive correlation between age and rubella-specific IgG titer(rubella-specific $IgG=0.0517{\times}age-0.5586$, r=0.3752, P<0.001). Conclusion : In adolescent, seropositivities and the level of mumps-specific IgG remained relatively high, but approximately 20% of study population showed seronegativity. Seropositivities and the level of rubella-specific IgG showed the lowest level at 13 years of age and were increased with age after 14 years of age. Further evaluation may be needed to elucidate the cause of these changes of rubella-specific IgG.

  • PDF

Rectal Bleeding and Its Management after Irradiation for Cervix Cancer (자궁경부암 환자에서 방사선치료 후에 발생한 직장출혈과 치료)

  • Chun Mison;Kang Seunghee;Kil Hoon-Jong;Oh Young-Taek;Sohn Jeong-Hye;Jung Hye-Young;Ryu Hee Suk;Lee Kwang-Jae
    • Radiation Oncology Journal
    • /
    • v.20 no.4
    • /
    • pp.343-352
    • /
    • 2002
  • Purpose : Radiotherapy is the main treatment modality for uterine cervix cancer. Since the rectum is in the radiation target volume, rectal bleeding is a common late side effect. This study evaluates the risk factors of radiation induced rectal bleeding and discusses its optimal management. Materials and Methods : total of 213 patients who completed external beam radiation therapy (EBRT) and intracavitary radiation (ICR) between September 1994 and December 1999 were included in this study. No patient had undergone concurrent chemo-radiotherapy. Ninety patients received radiotherapy according to a modified hyperfractionated schedule. A midline block was placed at a pelvic dose of between 30.6 Gy to 39.6 Gy. The total parametrial dose from the EBRT was 51 to 59 Gy depending on the extent of their disease. The Point A dose from the HDR brachytherapy was 28 Gy to 30 Gy $(4\;Gy\times7,\;or\;5\;Gy\times6)$. The rectal point dose was calculated either by the ICRU 38 guideline, or by anterior rectal wall point seen on radiographs, with barium contrast. Rectal bleeding was scored by the LENT/SOMA criteria. For the management of rectal bleeding, we opted for observation, sucralfate enema or coagulation based on the frequency or amount of bleeding. The median follow-up period was 39 months $(12\~86\;months)$. Results : The incidence of rectal bleeding was $12.7\%$ (27/213); graded as 1 in 9 patients, grade 2 in 16 and grade 3 in 2. The overall moderate and severe rectal complication rate was $8.5\%$. Most complications $(92.6\%)$ developed within 2 years following completion of radiotherapy (median 16 months). No patient progressed to rectal fistula or obstruction during the follow-up period. In the univariate analysis, three factors correlated with a high incidence of bleeding an icruCRBED greater than 100 Gy $(19.7\%\;vs.\;4.2\%)$, an EBRT dose to the parametrium over 55 Gy $(22.1\%\;vs.\;5.1\%)$ and higher stages of III and IV $(31.8\%\;vs.\;10.5\%)$. In the multivariate analysis, the icruCRBED was the only significant factor (p>0.0432). The total parametrial dose from the EBRT had borderline significance (p=0.0546). Grade 1 bleeding was controlled without further management (3 patients), or with sucralfate enema 1 to 2 months after treatment. For grade 2 bleeding, sucralfate enema for 1 to 2 months reduced the frequency or amount of bleeding but for residual bleeding, additional coagulation was peformed, where immediate cessation of bleeding was achieved (symptom duration of 3 to 10 months). Grade 3 bleeding lasted for 1 year even with multiple transfusions and coagulations. Conclusion : Moderate and several rectal bleeding occurred in $8.5\%$ of patients, which is comparable with other reports. The most significant risk factor for rectal bleeding was the accumulated dose to the rectum (icruCRBED), which corrected with consideration to biological equivalence. Prompt management of rectal bleeding, with a combination of sucralfate enema and coagulation, reduced the duration of the symptom, and minimized the anxiety/discomfort of patients.

Analysis of the Causes of Subfrontal Recurrence in Medulloblastoma and Its Salvage Treatment (수모세포종의 방사선치료 후 전두엽하방 재발된 환자에서 원인 분석 및 구제 치료)

  • Cho Jae Ho;Koom Woong Sub;Lee Chang Geol;Kim Kyoung Ju;Shim Su Jung;Bak Jino;Jeong Kyoungkeun;Kim Tae_Gon;Kim Dong Seok;Choi oong-Uhn;Suh Chang Ok
    • Radiation Oncology Journal
    • /
    • v.22 no.3
    • /
    • pp.165-176
    • /
    • 2004
  • Purpose: Firstly, to analyze facto in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma, Secondly, to explore an effective salvage treatment for these relapses. Materials and Methods: Two patients who had high-risk disease (T3bMl, T3bM3) were treated with combined chemoradiotherapy CT-simulation based radiation-treatment planning (RTP) was peformed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. Results: Review of radiotherapy Portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume, When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. Conclusion: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.

A Phase I/II Trial of $DCVac/IR^{(R)}$ Dendritic Cell Immunotherapy Combined with Irradiation in Cases of Refractory Colorectal Cancer with Multiple Liver Metastases (기존의 치료에 반응하지 않는 다발성 간전이 대장암 환자에서 방사선조사와 병합한 수지상세포 면역치료의 1, 2상 임상시험)

  • Choi, Young-Min;Lee, Hyung-Sik;Kwon, Hyuk-Chan;Han, Sang-Young;Choi, Jong-Cheol;Chung, Ju-Seop;Kim, Chang-Won;Kim, Dong-Won;Kang, Chi-Duk
    • Radiation Oncology Journal
    • /
    • v.26 no.2
    • /
    • pp.104-112
    • /
    • 2008
  • Purpose: To assess the toxicity and tumor response induced by $DCVac/IR^{(R)}$ dendritic cell(DC) immunotherapy combined with irradiation for refractory colorectal cancer patients with multiple liver metastases. Materials and Methods: Between May 2004 and November 2006, applicants from a pool of refractory colorectal cancer patients with multiple liver metastases were enrolled. The patients were registered after having signed the informed consent form, which had been approved by the Institutional Review Board from the Dong-A University and Busan National University Hospital. DCs were obtained from peripheral blood of each patient, and then cultured in vitro. A total of $6{\times}10^6$ DCs were packed into a vial($DCVac/IR^{(R)}$, 0.5 ml) at the convenience of each patient's schedule. On the day before and on the day of each vaccination, each patient received a 4 Gy radiation dose to the target tumor. On the day of vaccination, the indicated dose of autologous DCs was injected into the irradiated tumor using ultrasound-guided needle injection procedures. A total of four vaccinations were scheduled at three 2-week intervals and one 4 week interval at the Dong-A University and Busan National University Hospital. If the tumor status was deemed to be stable or responding to therapy, an additional vaccination dose or two was approved at 4 week intervals beyond the fourth immunization. A tolerance test for DCs was conducted by injecting a range of doses($3{\times}10^6\;to\;12{\times}10^6$ DCs) after the 3rd injection. Moreover, the maximal tolerable dose was applied to additional patients. Treatment safety was evaluated in all patients who had at least one injection. Treatment feasibility was evaluated by the 10th week by assessing the response of patients having at least 4 injections. For systemic toxicities, the evaluation was performed using the National Cancer Institute Common Toxicity Criteria, whereas adverse effects were recorded using common WHO toxicity criteria. Results: Of the 24 registered patients, 22 received the DCs injections. Moreover, of the 14 patients that applied for the tolerance test, only 11 patients completed it because 3 patients withdrew their testing agreement. A grade 3 or more side effect, which was possibly related to the DC injection, did not occur in additional patients. The $12{\times}10^6$ DC injection was identified as the maximum tolerable dose, and was then injected in an additional 8 patients. Patients tolerated the injection fairly well, with no fatal side effects. In order to assess the feasibility of DC immunotherapy, the response was evaluated in other hepatic lesions outside of the targeted hepatic lesion. The response evaluation was performed in 15 of the 17 patients who received at least 4 injections. Stable and progressive disease was found in 4 and 11 patients, respectively. Conclusion: The DC-based immunotherapy and radiotherapy is theoretically synergistic for the local control and systemic control. The $DCVac/IR^{(R)}$ immunotherapy combined with irradiation was tolerable and safe in the evaluated cases of refractory colorectal cancer with multiple liver metastases. Future work should include well designed a phase II clinical trials.

EFFECT OF INDUCTION CHEMOTHERAPY ON FLAP SURVIVAL RATE IN MICROSURGERY (종양수술전 화학요법이 미세수술시 피판생존율에 미치는 영향)

  • Kim, Uk-Kyu;Kim, Yong-Deok;Byun, June-Ho;Shin, Sang-Hun;Chung, In-Kyo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.29 no.6
    • /
    • pp.421-429
    • /
    • 2003
  • Purpose : Neoadjuvant chemotherapy is commonly used to treat cancer patients as adjunct treatment, but if the microvascular tissue transfer is performed simulataneously with cancer resection surgery, the induction chemotherapy might affect the survival rate of vascularized free flap. Our study will focus on the effect of induction chemotherapy on the free flaps which were made on white rat abdomen after injection of 5-FU. Materials and Methods: The experimental rat groups were divided into three groups (total 24 rats) as a normal control group, 24 hrs group after 5-FU injection, 3 days group after 5-FU injection. Inferior abdominal island flaps of 8 Sprague Dawley rats on each group were made and immediately were induced into an ischemic state by clamping the supplying inferior epigastric artery and vein with microvascular clamp for a hour to induce a similiar free flap circumstance, then the inferior abdominal skin flaps were reperfused by releasing the clamps. The flaps on abdomen were repositioned and sutured. The experimental data for flap survival rate was collected by digital photo taking, analysed by computer image program to compare with the flap luminosity. The rats were sacrificed at 3 days, 5 days, 7 days after flap preparation and specimens of the flap were taken and stained with H-E staining. The microscopic finding was made under magnification of 200 and 400. Results: 1. Gross findings on each groups showed the healing condition was good as following sequences; normal, 24 hrs group after chemotherapy, 3 days group after chemotherpy. 2. The values of flap luminosity for evaluation of flap survival rate also showed the same sequences as gross findings of healing state. 3. The microscopic findings of epidermis necrosis, inflammation state, dermis fibrosis, vessel change, fatty tissue layer thinning were compared with each group. The 3 days group after chemotherapy showed remarkably poor healing condition compared to other groups. Conclusion: Chemotherapy agents affected the healing process of free flap, but healing condition was recovered spontaneously as post-injection periods passed out. In opposite to our expectation, 3 days group showed the bad flap condition in comparing with 24 hours group which was considered as immatured body circulation state of chemotherapy agent. It showed that 3 weeks in human being after chemotherapy was not proper as timing of microvascular tissue transfer if 3 days group in rat was considered as same healing period of 3 weeks in human being. More delayed healing timing than 3 weeks might be required in clinical application of free tissue transfer.

Postmastectomy Radiotherapy and Chemotherapy in Patients with Breast Cancer (유방절제술을 시행한 유방암 환자에서 방사선과 항암제 치료성적)

  • Ahn Sung-Ja;Chung Woong-Ki;Nam Taek-Keun;Nah Byung-Sik;Song Ju-Young;park Seung-Jin
    • Radiation Oncology Journal
    • /
    • v.22 no.1
    • /
    • pp.17-24
    • /
    • 2004
  • Purpose: To evaluate the treatment outcomes after postmastectomy radiotherapy (PMRT) and chemotherapy in patients with breast cancer. Materials and Methods: The PMRT were retrospectively analyzed in 83 patients with stage II-III female breast cancer treated between 1989 and 1995. The median age was 46 years (range, 23-77): Seventy-seven patients had modified radical mastectomies, 5 radical mastectomies and 1 simple mastectomy. Three patients ($4\%$) had pathologically negative axillae, and the remaining 80 ($96\%$) had positive axillae. Eleven, 23, 44 and 5 patients had pathological stages IIA, IIB, IIIA, and IIIB, retrospectively. Eighty ($96\%$) patients were treated with hockey-stick fields. The median dose of PMRT was 50.4 ey, in 1.8 Gy fractions. Adjuvant systemic chemotherapy was given to 74 patients ($89\%$). CMF-based or doxorubicin-containing regimens were given to 54 patients ($55\%$). The median follow-up time was 82 months (range, 8-171) after the mastectomy. Results: The 5 and 10-year overall survival rates for all patients were 65 and $49\%$, respectively. The univariate and multivariate analyses of the factors affecting the overall survival revealed the stage to be the most significant prognostic factor (p=0.002), followed by the combination of chemotherapy. Thirteen patients $16\%$ developed a LRF, at an interval of 4-84 months after radiotherapy, with a median of 20 months. The only significant prognostic factor affecting LRF was the combination of chemotherapy, in both the univariate and multivariate analyses. With respect to the sequence of chemoradiation, the sequence had no saatistical significance (p=0.90). According to the time interval from mastectomy to the onset of radiotherapy, the LRFR of the patients group treated by RT within or after 6 month postmastectomy 6 months were 14 vs. $27\%$ respectively (p=0.24). One third of the pa41en1s (26/83) developed distant metastasis, in 2-92 months, after radiotherapy, with a median of 21 months. The most commonly involved site was bone in 13 cases. The pathological staging was the only significant prognostic factor in both the univariate and multivariate analyses that affected distant failure. Radiological finding of radiation pneumonitis on a simple chest x-ray was shown in $20\%$ (17/83), with a time interval ranging from 2 to 7 months post-radiotherapy, with a median of 3 months. The stable lung fibrosis settled in 11 patients ($65\%$). Conclusion: It was concluded through this analysis that the combination of PMRT with in chemotherapy resulted in better overall survival and local control than PMRT alone in patients needing PMRT.

Usefulness of Gated RapidArc Radiation Therapy Patient evaluation and applied with the Amplitude mode (호흡 동조 체적 세기조절 회전 방사선치료의 유용성 평가와 진폭모드를 이용한 환자적용)

  • Kim, Sung Ki;Lim, Hhyun Sil;Kim, Wan Sun
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.26 no.1
    • /
    • pp.29-35
    • /
    • 2014
  • Purpose : This study has already started commercial Gated RapidArc automation equipment which was not previously in the Gated radiation therapy can be performed simultaneously with the VMAT Gated RapidArc radiation therapy to the accuracy of the analysis to evaluate the usability, Amplitude mode applied to the patient. Materials and Methods : The analysis of the distribution of radiation dose equivalent quality solid water phantom and GafChromic film was used Film QA film analysis program using the Gamma factor (3%, 3 mm). Three-dimensional dose distribution in order to check the accuracy of Matrixx dosimetry equipment and Compass was used for dose analysis program. Periodic breathing synchronized with solid phantom signals Phantom 4D Phantom and Varian RPM was created by breathing synchronized system, free breathing and breath holding at each of the dose distribution was analyzed. In order to apply to four patients from February 2013 to August 2013 with liver cancer targets enough to get a picture of 4DCT respiratory cycle and then patients are pratice to meet patient's breathing cycle phase mode using the patient eye goggles to see the pattern of the respiratory cycle to be able to follow exactly in a while 4DCT images were acquired. Gated RapidArc treatment Amplitude mode in order to create the breathing cycle breathing performed three times, and then at intervals of 40% to 60% 5-6 seconds and breathing exercises that can not stand (Fig. 5), 40% While they are treated 60% in the interval Beam On hold your breath when you press the button in a way that was treated with semi-automatic. Results : Non-respiratory and respiratory rotational intensity modulated radiation therapy technique absolute calculation dose of using computerized treatment plan were shown a difference of less than 1%, the difference between treatment technique was also less than 1%. Gamma (3%, 3 mm) and showed 99% agreement, each organ-specific dose difference were generally greater than 95% agreement. The rotational intensity modulated radiation therapy, respiratory synchronized to the respiratory cycle created Amplitude mode and the actual patient's breathing cycle could be seen that a good agreement. Conclusion : When you are treated Non-respiratory and respiratory method between volumetric intensity modulated radiation therapy rotation of the absolute dose and dose distribution showed a very good agreement. This breathing technique tuning volumetric intensity modulated radiation therapy using a rotary moving along the thoracic or abdominal breathing can be applied to the treatment of tumors is considered. The actual treatment of patients through the goggles of the respiratory cycle to create Amplitude mode Gated RapidArc treatment equipment that does not automatically apply to the results about 5-6 seconds stopped breathing in breathing synchronized rotary volumetric intensity modulated radiation therapy facilitate could see complement.

Changes of the surface roughness depending on immersion time and powder/liquid ratio of various tissue conditioners (수종의 조직 양화재의 침수시간과 분액비에 따른 표면 거칠기의 변화)

  • Kim, Kyung-Soo;Moon, Hong-Suk;Shim, June-Sung;Jung, Moon-Kyu
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.47 no.2
    • /
    • pp.108-118
    • /
    • 2009
  • Statement of problem: Volume stability, microstructure reproducibility and fluidity along with compatibility with dental stone must be in consideration in order to use tissue conditioner as a material for functional impression. There are few studies concerning the influence of time factor in oral condition on surface roughness of the stone and optimal retention period in the oral cavity considering such changes in surface roughness. Purpose: The purpose of this study was to find out the influence of various kinds of tissue conditioner, its powder/liquid ratio and immersion time on surface roughness of the stone. Material and methods: Materials used in this study were the three kinds of tissue conditioners(Coe-Comfort, Visco-Gel, Soft-Liner) and were grouped into three: group R-mixed with standard powder/liquid ratio that was recommended by the manufacturers, group M-mixed with 20% more powder, group L-mixed with 20% less powder. Specimens were made with the size of 20 mm diameter and 2 mm width. Each tissue conditioner specimens were subdivided into 5 groups according to the immersion time(0 hour, 1 day, 3 days, 5 days, 7 days), completely immersed into artificial saliva and were stored under $37^{\circ}C$. Specimens of which the given immersion time elapsed were taken out and were poured with improved stone, making the stone specimens. Surface roughness of the stone specimens was measured by a profilometer. Results: Within the limitation of this study, the following results were drawn. 1. Major influencing factor on surface roughness of the stone model made from tissue conditioner was the retention period(contribution ratio($\rho$)=62.86%, P<.05) of the tissue conditioner in oral cavity to make functional impression. 2. In case of Coe-Comfort, higher mean surface roughness value of the stone model with statistical significance was observed compared to that of Soft-Liner and Visco-Gel as immersion time changes(P<.05). 3. In case of group L(less), higher mean surface roughness value of the stone model with statistical significance was observed compared to that of R(recommended) and M(more) group as immersion time changes(P<.05). Conclusion: We may conclude that as the retention period of time in oral cavity influences surface roughness of the stone model the most and as the kind of tissue conditioner and its P/L ratio may influence also, clinician should well understand the optimal retention period in oral cavity and choose the right tissue conditioner for the functional impression, thus making the functional impression with tissue conditioner usefully.