• Korean Journal of Head & Neck Oncology
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• v.29 no.2
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• pp.58-61
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• 2013

Early glottic cancer can be effectively treated with surgery or radiotherapy showing the comparable treatment results. Since radiation therapy may be better in terms of voice preservation, it tends to be preferred in early glottic cancer. Most common recurrence site is glottis after radiation therapy and complete remission of glottic primary site followed by local recurrence limited to neck is very rare. The authors are reporting a patient with regional recurrence of central neck lymph nodes after radiation therapy for T1a glottic cancer.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.493-504
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• 1997

Background : Non-small cell lung cancer is one of the most frequent cause of death due to cancer in men, and its incidence among women is rapidly increasing. Although there has been a recent surge of interest in combined modality therapy for stageIII non-small cell lung cancer(NSCLC), the optimal treatment is still not well established. Thoracic irradiation has long been the gold standard for locally advanced unresectable NSCLC. However, although conventional radiotherapy(XRT) can palliate symptom and improve local control of disease, it has at most only a modest effect on survival. Recently, cisplatin(cis-diamminedichloroplatinum) has been reported to enhance the cell-killing effect of radiation For patients with unresectable NSCLC, cisplatin-based concurrent chemoradiotherapy(CCRT) had the advantage of therapeutic response over XRT alone and therapeutic side effect more commonly occurred in CCRT group in EORTC(European Organization for Research and Treatment of Cancer) and other trials. Objectives : We compared therapeutic response, compliance, and side effects between CCRT and XRT in patients with advanced NSCLC. Patients and Method : Thirty patients with biopsy-proven inoperable NSCLC were randomized to one of two treatment arms. Arm A consisted of XRT, radiotherapy for 4~6 weeks(1.8 Gy given 20~33 times, in five fractions a week), and arm B consisted of CCRT, radiotherapy for 2 weeks(3 Gy given to times, in five fractions a week), followed by 3 week rest period and then radiotherapy 2 more weeks(2.5 Gy given 10 times, in five fractions a week), combined with 6mg cisplatin per square meter, given daily before radiotherapy. We evaluate therapeutic response, compliance, change of performance status, side effects, and radiation pneumonitis by using the author's made scoring system. Results : There was no significant difference in therapeutic response and compliance. But there was a significantly lower laboratory complication and radiation pneumonitis in CCRT group (p < 0.05). There's significant negative correlation between stage and therapeutic response score in both groups(R=0.353, p < 0.05) In both groups, patients with squamous cell carcinoma had a tendency to higher therapeutic response score than those with adenocarcinoma. Conclusion : There was no difference between CCRT and XRT in respect to therapeutic response and compliance. But CCRT had a advantage of decreased side effects.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2393-2398
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• 2012

Objectives: The purpose of this study was to evaluate the geometric accuracy of thoracic anatomic landmarks as target surrogates of intrapulmonary tumors for manual rigid registration during image-guided radiotherapy (IGRT). Methods: Kilovolt cone-beam computed tomography (CBCT) images acquired during IGRT for 29 lung cancer patients with 33 tumors, including 16 central and 17 peripheral lesions, were analyzed. We selected the "vertebrae", "carina", and "large bronchi" as the candidate surrogates for central targets, and the "vertebrae", "carina", and "ribs" as the candidate surrogates for peripheral lesions. Three to six pairs of small identifiable markers were noted in the tumors for the planning CT and Day 1 CBCT. The accuracy of the candidate surrogates was evaluated by comparing the distances of the corresponding markers after manual rigid matching based on the "tumor" and a particular surrogate. Differences between the surrogates were assessed using 1-way analysis of variance and post hoc least-significant-difference tests. Results: For central targets, the residual errors increased in the following ascending order: "tumor", "bronchi", "carina", and "vertebrae"; there was a significant difference between "tumor" and "vertebrae" (p = 0.010). For peripheral diseases, the residual errors increased in the following ascending order: "tumor", "rib", "vertebrae", and "carina"; There was a significant difference between "tumor" and "carina" (p = 0.005). Conclusions: The "bronchi" and "carina" are the optimal surrogates for central lung targets, while "rib" and "vertebrae" are the optimal surrogates for peripheral lung targets for manual matching of online and planned tumors.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.1-16
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• 2002

Purpose : Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plant for each site of the brain. Therefore we developed several 3 dimensional conformal radiotherapy plans (3D plans) for tumors at each site of brain, compared them with each other, and with 2 dimensional radiotherapy plans. Finally model plans for each site of the brain were decide. Materials and Methods : Imaginary tumors, with sizes commonly observed in the clinic, were designed for each site of the brain and drawn on CT images. The planning target volumes (PTVs) were as follows; temporal $tumor-5.7\times8.2\times7.6\;cm$, suprasellar $tumor-3\times4\times4.1\;cm$, thalamic $tumor-3.1\times5.9\times3.7\;cm$, frontoparietal $tumor-5.5\times7\times5.5\;cm$, and occipitoparietal $tumor-5\times5.5\times5\;cm$. Plans using paralled opposed 2 portals and/or 3 portals including fronto-vertex and 2 lateral fields were developed manually as the conventional 2D plans, and 3D noncoplanar conformal plans were developed using beam's eye view and the automatic block drawing tool. Total tumor dose was 54 Gy for a suprasellar tumor, 59.4 Gy and 72 Gy for the other tumors. All dose plans (including 2D plans) were calculated using 3D plan software. Developed plans were compared with each other using dose-volume histograms (DVH), normal tissue complication probabilities (NTCP) and variable dose statistic values (minimum, maximum and mean dose, D5, V83, V85 and V95). Finally a best radiotherapy plan for each site of brain was selected. Results : 1) Temporal tumor; NTCPs and DVHs of the normal tissue of all 3D plans were superior to 2D plans and this trend was more definite when total dose was escalated to 72 Gy (NTCPs of normal brain 2D $plans:27\%,\;8\%\rightarrow\;3D\;plans:1\%,\;1\%$). Various dose statistic values did not show any consistent trend. A 3D plan using 3 noncoplanar portals was selected as a model radiotherapy plan. 2) Suprasellar tumor; NTCPs of all 3D plans and 2D plans did not show significant difference because the total dose of this tumor was only 54 Gy. DVHs of normal brain and brainstem were significantly different for different plans. D5, V85, V95 and mean values showed some consistent trend that was compatible with DVH. All 3D plans were superior to 2D plans even when 3 portals (fronto-vertex and 2 lateral fields) were used for 2D plans. A 3D plan using 7 portals was worse than plans using fewer portals. A 3D plan using 5 noncoplanar portals was selected as a model plan. 3) Thalamic tumor; NTCPs of all 3D plans were lower than the 2D plans when the total dose was elevated to 72 Gy. DVHs of normal tissues showed similar results. V83, V85, V95 showed some consistent differences between plans but not between 3D plans. 3D plans using 5 noncoplanar portals were selected as a model plan. 4) Parietal (fronto- and occipito-) tumors; all NTCPs of the normal brain in 3D plans were lower than in 2D plans. DVH also showed the same results. V83, V85, V95 showed consistent trends with NTCP and DVH. 3D plans using 5 portals for frontoparietal tumor and 6 portals for occipitoparietal tumor were selected as model plans. Conclusion : NTCP and DVH showed reasonable differences between plans and were through to be useful for comparing plans. All 3D plans were superior to 2D plans. Best 3D plans were selected for tumors in each site of brain using NTCP, DVH and finally by the planner's decision.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.91-98
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• 2011

Purpose: To assess the usefulness of implanted fiducial markers in the setup of hypofractionated radiotherapy for prostate cancer patients by comparing a fiducial marker matched setup with a pelvic bone match. Materials and Methods: Four prostate cancer patients treated with definitive hypofractionated radiotherapy between September 2009 and August 2010 were enrolled in this study. Three gold fiducial markers were implanted into the prostate and through the rectum under ultrasound guidance around a week before radiotherapy. Glycerin enemas were given prior to each radiotherapy planning CT and every radiotherapy session. Hypofractionated radiotherapy was planned for a total dose of 59.5 Gy in daily 3.5 Gy with using the Novalis system. Orthogonal kV X-rays were taken before radiotherapy. Treatment positions were adjusted according to the results from the fusion of the fiducial markers on digitally reconstructed radiographs of a radiotherapy plan with those on orthogonal kV X-rays. When the difference in the coordinates from the fiducial marker fusion was less than 1 mm, the patient position was approved for radiotherapy. A virtual bone matching was carried out at the fiducial marker matched position, and then a setup difference between the fiducial marker matching and bone matching was evaluated. Results: Three patients received a planned 17-fractionated radiotherapy and the rest underwent 16 fractionations. The setup error of the fiducial marker matching was $0.94{\pm}0.62$ mm (range, 0.09 to 3.01 mm; median, 0.81 mm), and the means of the lateral, craniocaudal, and anteroposterior errors were $0.39{\pm}0.34$ mm, $0.46{\pm}0.34$ mm, and $0.57{\pm}0.59$ mm, respectively. The setup error of the pelvic bony matching was $3.15{\pm}2.03$ mm (range, 0.25 to 8.23 mm; median, 2.95 mm), and the error of craniocaudal direction ($2.29{\pm}1.95$ mm) was significantly larger than those of anteroposterior ($1.73{\pm}1.31$ mm) and lateral directions ($0.45{\pm}0.37$ mm), respectively (p<0.05). Incidences of over 3 mm and 5 mm in setup difference among the fractionations were 1.5% and 0% in the fiducial marker matching, respectively, and 49.3% and 17.9% in the pelvic bone matching, respectively. Conclusion: The more precise setup of hypofractionated radiotherapy for prostate cancer patients is feasible with the implanted fiducial marker matching compared with the pelvic bony matching. Therefore, a less marginal expansion of planning target volume produces less radiation exposure to adjacent normal tissues, which could ultimately make hypofractionated radiotherapy safer.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.1
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• pp.35-41
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• 2006

Purpose: A various find of radiotherapy treatment plans have been made to determine appropriate doses for breasts, chest walls and loco-regional lymphatics in the radiotherapy of breast cancers. The aim of this study was to evaluate the optimum radiotherapy plan technique method by analyzing dose distributions qualitatively and quantitatively. Materials and Methods: To evaluate the optimum breast cancer radiotherapy plan technique, the traditional method(two dimensional method) and computed tomography image are adopted to get breast volume, and they are compared with the three-dimensional conformal radiography (3DCRT) and the intensity modulated radiotherapy (IMRT). For this, the regions of interest (ROI) such as breasts, chest walls, loco-regional lymphatics and lungs were marked on the humanoid phantom, and the computed tomography(Volume, Siemens, USA) was conducted. Using the computed tomography image obtained, radiotherapy treatment plans (XiO 5.2.1, FOCUS, USA) were made and compared with the traditional methods by applying 3DCRT and IMRT. The comparison and analysis were made by analyzing and conducting radiation dose distribution and dose-volume histogram (DVH) based upon radiotherapy techniques (2D, 3DCRT, IMRT) and point doses for the regions of interest. Again, treatment efficiency was evaluated based upon time-labor. Results: It was found that the case of using 3DCRT plan techniques by getting breast volume is more useful than the traditional methods in terms of tumor delineation, beam direction and confirmation of field boundary. Conclusion: It was possible to present the optimum radiotherapy plan techniques through qualitative and quantitative analyses based upon radiotherapy plan techniques in case of breast cancer radiotherapy. However, further studies are required for the problems with patient setup reproducibility arising from the difficulties of planning target volume (PVT) and breast immobilization in case of three-dimensional radiotherapy planning.

• 대한두경부종양학회:학술대회논문집
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• 1998.05a
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• pp.118-120
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• 1998

• Proceedings of the KTCVS Conference
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• 1997.04a
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• pp.61-65
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• 1997

• 대한두경부종양학회:학술대회논문집
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• 2001.05a
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• pp.96-97
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• 2001

• 대한두경부종양학회:학술대회논문집
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• 2002.11a
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• pp.238-242
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• 2002