Evaluation of Prognostic Factors for the Parotid Cancer Treated With Surgery and Postoperative Radiotherapy

Objectives@#. To investigate the prognostic factors and treatment outcomes of primary parotid carcinoma treated with surgery and postoperative radiotherapy (PORT). @*Methods@#. We reviewed retrospectively 57 patients with primary parotid carcinoma who were treated with surgery and PORT between 2005 and 2014. Superficial parotidectomy was performed in 19 patients, total parotidectomy in 10 patients, and total parotidectomy with lymph node dissection in 28 patients PORT on the tumor bed was performed in 41 patients, while PORT on tumor bed and ipsilateral cervical lymph nodes was performed in 16 patients. @*Results@#. With a median follow-up of 66 months, the 5-year overall survival, disease-free survival, locoregional control, and distant control rates were 77.0%, 60.2%, 77.6%, and 72.8%, respectively. The 5-year overall survival by stage was 100%, 100%, 80.0%, and 46.4% in stage I, II, III, and IV, respectively. Recurrences at primary lesions were found in seven patients, while at cervical nodes in six patients. Distant recurrences were developed in 12 patients. No patient with the low and intermediate histologic grade developed distant failure. As prognostic factors, the histologic grade for overall survival (P=0.005), pathological T-stage (P=0.009) and differentiation grade (P=0.009) for disease-free survival, pathological T-stage for locoregional control (P=0.007), and lympho-vascular invasion (P=0.023) for distant recurrence were significant on multivariate analysis. @*Conclusion@#. This study revealed that differentiation grade, histologic grade, pathological T-stage, and lympho-vascular invasion were significant independent prognostic factors on clinical outcomes.

Intensity-modulated radiotherapy for stage I glottic cancer: a short-term outcomes compared with three-dimensional conformal radiotherapy

PURPOSE: To investigate the differences in treatment outcomes between two radiation techniques, intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT).MATERIALS AND METHODS: We retrospectively analyzed 160 (IMRT = 23, 3DCRT = 137) patients with stage I glottic cancer treated from January 2005 through December 2016. The IMRT was performed with TomoTherapy (16 patients), volumetric-modulated arc therapy (6 patients), and step-and-shoot technique (1 patient), respectively. The 3DCRT was performed with bilateral parallel opposing fields. The median follow-up duration was 30 months (range, 31 to 42 months) in the IMRT group and 65 months (range, 20 to 143 months) in the 3DCRT group.RESULTS: The 5-year overall survival and 3-year local control rates of the 160 patients were 95.7% and 91.4%, respectively. There was no significant difference in 3-year local control rates between the IMRT and 3DCRT groups (94.4% vs. 91.0%; p = 0.587). Thirteen of 137 patients in the 3DCRT group had recurrences. In the IMRT group, one patient had a recurrence at the true vocal cord. Patients treated with IMRT had less grade 2 skin reaction than the 3DCRT group, but this had no statistical significance (4.3% vs. 21.2%; p = 0.080).CONCLUSION: IMRT had comparable outcomes with 3DCRT, and a trend of less acute skin reaction in stage I glottic cancer patients

Prognostic significance of lymphovascular invasion in patients with prostate cancer treated with postoperative radiotherapy

PURPOSE: To determine prognostic significance of lymphovascular invasion (LVI) in prostate cancer patients who underwent adjuvant or salvage postoperative radiotherapy (PORT) after radical prostatectomy (RP) MATERIALS AND METHODS: A total of 168 patients with prostate cancer received PORT after RP, with a follow-up of ≥12 months. Biochemical failure after PORT was defined as prostate-specific antigen (PSA) ≥0.2 ng/mL after PORT or initiation of androgen deprivation therapy (ADT) for increasing PSA levels regardless of the value. We analyzed the clinical outcomes including survivals, failure patterns, and prognostic factors affecting the outcomes. RESULTS: In total, 120 patients (71.4%) received salvage PORT after PSA levels were >0.2 ng/mL or owing to clinical failure. The 5-year biochemical failure-free survival (BCFFS), clinical failure-free survival (CFFS), distant metastasis-free survival (DMFS), overall survival, and cause-specific survival rates were 78.3%, 94.3%, 95.0%, 95.8%, and 97.3%, respectively, during a follow-up range of 12–157 months (median: 64 months) after PORT. On multivariate analysis, PSA level of ≤1.0 ng/mL at the time of receiving PORT predicted favorable BCFFS, CFFS, and DMFS. LVI predicted worse CFFS (p = 0.004) and DMFS (p = 0.015). Concurrent and/or adjuvant ADT resulted in favorable prognosis for BCFFS (p < 0.001) and CFFS (p = 0.017). CONCLUSION: For patients with adverse pathologic findings, PORT should be initiated as early as possible after continence recovery after RP. Even after administering PORT, LVI was an unfavorable predictive factor, and further intensive adjuvant therapy should be considered for these patients.

Treatment results of radiotherapy following CHOP or R-CHOP in limited-stage head-and-neck diffuse large B-cell lymphoma: a single institutional experience

PURPOSE: This study evaluated outcomes of radiotherapy (RT) after chemotherapy in limited-stage head-and-neck diffuse large B-cell lymphoma (DLBCL). MATERIALS AND METHODS: Eighty patients who were treated for limited-stage head-and-neck DLBCL with CHOP (n = 43) or R-CHOP (n = 37), were analyzed. After chemotherapy, RT was administered to the extended field (n = 60) or the involved field (n = 16), or the involved site (n = 4). The median dose of RT ranged from 36 Gy in case of those with a complete response, to 45–60 Gy in those with a partial response. RESULTS: In all patients, the 5-year overall survival (OS) and disease-free survival (DFS) rates were 83.9% and 80.1%, respectively. In comparison with the CHOP regimen, the R-CHOP regimen showed a better 5-year DFS (86.5% vs. 73.9%, p = 0.027) and a lower rate of treatment failures (25.6% vs. 8.1%, p = 0.040). The volume (p = 0.047) and dose of RT (p < 0.001) were significantly reduced in patients treated with R-CHOP compared to that in those treated with CHOP. CONCLUSION: The outcomes of RT after chemotherapy with R-CHOP were better than those of CHOP regimen for limited-stage head-and-neck DLBCL. In patients treated with R-CHOP, a reduced RT dose and volume might be feasible without increasing treatment failures.

Treatment outcomes of neoadjuvant concurrent chemoradiotherapy followed by esophagectomy for patients with esophageal cancer

PURPOSE: To evaluate treatment outcomes and determine prognostic factors in patients with esophageal cancer treated with esophagectomy after neoadjuvant chemoradiotherapy (NCRT). MATERIALS AND METHODS: We retrospectively evaluated 39 patients with esophageal cancer who underwent concurrent chemoradiotherapy followed by esophagectomy between 2002 and 2012. Initial clinical stages of patients were stage IB in 1 patient (2.6%), stage II in 5 patients (12.9%), and stage III in 33 patients (84.6%). RESULTS: The median age of all the patients was 62 years, and the median follow-up period was 17 months. The 3-year overall survival (OS) rate was 33.6% in all the patients. The 3-year locoregional recurrence-free survival (LRFS) rate was 33.7%. In multivariate analysis with covariates of age, the Eastern Cooperative Oncology Group performance status, hypertension, diabetes mellitus, tumor length, clinical response, clinical stage, pathological response, pathological stage, lymphovascular invasion, surgical type, and radiotherapy to surgery interval, only pathological stage was an independent significant prognostic factor affecting both OS and LRFS. The complications in postoperative day 90 were pneumonia in 9 patients, anastomotic site leakage in 3 patients, and anastomotic site stricture in 2 patients. Postoperative 30-day mortality rate was 10.3% (4/39); the cause of death among these 4 patients was respiratory failure in 3 patients and myocardial infarction in one patient. CONCLUSION: Only pathological stage was an independent prognostic factor for both OS and LRFS in patients with esophageal cancer treated with esophagectomy after NCRT. We could confirm the significant role of NCRT in downstaging the initial tumor bulk and thus resulting in better survival of patients who gained earlier pathological stage after NCRT.

A Phase I/II Trial to Evaluate the Technical Feasibility of Partial Breast Irradiation with Three-Dimensional Conformal Radiation Therapy in Korean Women with Stage I Breast Carcinoma: An Initial Report of the Korean Radiation Therapy Oncology Group (KROG / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This prospective study was designed to verify the technical feasibility of partial breast irradiation in breast cancer patients with small breasts, which are commonly encountered in Korean women. MATERIALS AND METHODS: A total of 40 Gy, administered in 10 fractions on consecutive days (one fraction per day), was prescribed to the isocenters of the fields using three-dimensional conformal radiotherapy (3-DCRT). For all patients, treatment planning and dose parameters strictly adhered to the constraints set forth in the Radiation Therapy Oncology Group (RTOG) 0319 protocol. This study was designed such that if fewer than five of the first 42 evaluable patients received unacceptable scores, the treatment would be considered reproducible. RESULTS: Ten treatment plans (23.8%) were determined to have major variations. There was no major variation in planning target volume (PTV) coverage. The ipsilateral and contralateral breast dose limitations were not met in four (9.5%) and four cases (9.5%), respectively. Major variations in ipsilateral and contralateral lung dose limitations were observed in two cases (4.8%). Major variations in the heart and thyroid dose limitations were observed in one (2.4%) and one case (2.4%), respectively. In multivariate analysis, a ratio of PTV to ipsilateral breast volume (PTV/IB) > 0.16 was the only significant factor that statistically affected major variations. CONCLUSION: We concluded that partial breast irradiation using 3-DCRT could not be reproduced in Korean breast cancer patients, particularly small-volumed breast surrogated as PTV/IB > 0.16. The dominant cause was the major variation in surrounding normal breast tissues.

The Role of Radiotherapy in the Treatment of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To assess radiotherapy for patients with early stage gastric mucosa-associated lymphoid tissue (MALT) lymphoma with respect to survival, treatment response, and complications. MATERIALS AND METHODS: Enrolled into this study were 48 patients diagnosed with gastric MALT lymphoma from January 2000 to September 2012. Forty-one patients had low grade and seven had mixed component with high grade. Helicobacter pylori eradication was performed in 33 patients. Thirty-four patients received radiotherapy alone. Ten patients received chemotherapy before radiotherapy, and three patients underwent surgery followed by chemotherapy and radiotherapy. One patient received surgery followed by radiotherapy. All patients received radiotherapy of median dose of 30.6 Gy. RESULTS: The duration of follow-up ranged from 6 to 158 months (median, 48 months). Five-year overall survival and cause-specific survival rates were 90.3% and 100%. All patients treated with radiotherapy alone achieved pathologic complete remission (pCR) in 31 of the low-grade and in three of the mixed-grade patients. All patients treated with chemotherapy and/or surgery prior to radiotherapy achieved pCR except one patient who received chemotherapy before radiotherapy. During the follow-up period, three patients developed diffuse large B-cell lymphoma in the stomach, and one developed gastric adenocarcinoma after radiotherapy. No grade 3 or higher acute or late complications developed. One patient, who initially exhibited gastroptosis, developed mild atrophy of left kidney. CONCLUSION: These findings indicate that a modest dose of radiotherapy alone can achieve a high cure rate for low-grade and even mixed-grade gastric MALT lymphoma without serious toxicity. Patients should be carefully observed after radiotherapy to screen for secondary malignancies.

Construction of High-Density Tissue Microarrays at Low Cost by Using Self-Made Manual Microarray Kits and Recipient Paraffin Blocks

BACKGROUND: Advances of tissue microarray (TMA) technology have enabled simultaneous in situ analysis of biomarker expression in a large number of archived pathology specimens. However, the relatively high cost of TMA construction may hamper many researchers from using this essential tool of modern pathology research. We discuss methods for making TMA kits and recipient blocks for manual construction of high-density TMAs at low cost. METHODS: Ordinary cannula piercing needles, hypodermic needles, bone marrow biopsy needles, metallic ink cartridges of ballpoint pens, and disposable skin biopsy punches were used to construct self-made manual TMA kits. The recipient blocks were manufactured by boring holes in the conventional bare paraffin blocks. A mini electric hand drill and a microcompound table assembled on a drill stand were used to maximize the capacity of the recipient blocks. RESULTS: By using TMA kits made from cannula piercing needles (16- and 18-gauge), it was possible to construct TMAs with 1 mmx140 cores, 0.6 mmx320 cores, 2 mmx70 cores, 3 mmx35 cores, and 5 mmx12 cores. The capacity of the recipient blocks could be dramatically increased by drilling holes. CONCLUSIONS: Construction of TMAs using self-made TMA kits is an inexpensive alternative to construction of TMAs using commercial devices.

Adenocarcinoma with Intraductal Papillary Mucinous Neoplasm Arising in Jejunal Heterotopic Pancreas

A 74-year-old man suffered from jejunal perforation and adhesion to sigmoid colon due to adenocarcinoma associated with intraductal papillary mucinous neoplasm (IPMN) arising in a jejunal heterotopic pancreas. The jejunal lesion showed direct extension to the sigmoid colon, which was mistaken as sigmoid colon cancer by surgeons. Malignant transformation is a rare complication of a heterotopic pancreas. About half of malignancies in reported cases were ductal adenocarcinoma arising in the stomach, and the jejunal location is extremely rare. Furthermore, IPMN is also uncommon finding in a heterotopic pancreas.

Practical Output Dosimetry with Undefined NdwCo-60 of Cylindrical Ionization Chamber for High Energy Photon Beams of Linear Accelerator / 의학물리

For the determination of absorbed dose to water from a linear accelerator photon beams, it needs a exposure calibration factor Nx or air kerma calibration factor Nk of air ionization chamber. We used the exposure calibration factor Nx to find the absorbed dose calibration factors of water in a reference source through the TG-21 and TRS-277 protocol. TG-21 used for determine the absorbed dose in accuracy, but it required complex calculations including the chamber dependent factors. The authors obtained the absorbed dose calibration factor NdwCo-60 for reduce the complex calculations with unknown Ndw only with Nx or Nk calibration factor in a TM31010 (S/N 1055, 1057) ionization chambers. The results showed the uncertainty of calculated Ndw of IC-15 which was known the Nx and Ndw is within -0.6% in TG-21, but 1.0% in TRS-277. and TM31010 was compared the Ndw of SSDL to that of PSDL as shown the 0.4%, -2.8% uncertainty, respectively. The authors experimented with good agreement the calculated Ndw is reliable for cross check the discrepancy of the calibration factor with unknown that of TM31010 and IC-15 chamber.

Granular Cell Astrocytoma: Report of a Case

We report here a rare case of granular cell astrocytoma. A 75-year-old man was admitted to Inha University Hospital with a three-month history of language deterioration. In a magnetic resonance imaging, a 6.5 cm-sized heterogeneous enhancing mass was seen in both the frontal lobes and the anterior genu of the corpus callosum. A stereotactic biopsy was performed. The tumor was composed of large and small round cells with abundant intracytoplasmic granules. The nuclei were bland, round to oval, and often eccentrically located. The cytoplasm of the tumor cells was positive for glial fibrillary acidic protein and S-100 protein.

VEGF as a Predictor for Response to Definitive Chemoradiotherapy and COX-2 as a Prognosticator for Survival in Esophageal Squamous Cell Carcinoma

We investigated the patterns of pretreatment expression of the epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) by immunohistochemical staining and determined their correlation with treatment response and survival in 44 patients with esophageal squamous cell carcinoma (ESCC) treated with definitive concurrent chemoradiotherapy (CCRT). The definitive CCRT consisted of a median dose of 54 Gy (range: 40.0-68.4 Gy) and two cycles of concurrent administration of mostly 5-fluorouracil + cisplatinum. High expression of EGFR, VEGF, and COX-2 was found in 79.5%, 31.8%, and 38.6%, respectively. The Cox regression analysis for overall survival (OS) showed that both the treatment response and COX-2 expression were significant. The 3-yr OS rates of patients that achieved a complete response and those that did not were 46.7% and 5.3%, respectively (P = 0.006). The logistic regression analysis for treatment response with various parameters showed that only a high expression of VEGF was significantly associated with a complete response. Unlike other well-known studies, higher expression of VEGF was significantly correlated with a complete response to CCRT in this study. However, higher expression of COX-2 was significantly associated with shorter survival. These results suggest that VEGF might be a predictive factor for treatment response and COX-2 a prognostic factor for OS in patients with ESCC after definitive CCRT.

Analysis on the Calculated Dose in the Lung Radiation Surgery Planning Using TomoTherpay / 의학물리

The applicability and feasibility of TomoTherapy in the lung radiation surgery was analyzed by comparison of the calculated dose distribution in TomoTherapy planning with the results of conventional IMRS (intensity modulated radiation surgery) using LINAC (linear accelerator). The acquired CT (computed tomograph) images of total 10 patients whose tumors' motion were less than 5 mm were used in the radiation surgery planning and the same prescribed dose and the same dose constraints were used between TomoTherapy and LINAC. The results of TomoTherapy planning fulfilled the dose requirement in GTV (gross tumor volume) and OAR (organ at risk) in the same with the conventional IMRS using LINAC. TomoTherapy was superior in the view point of low dose in the normal lung tissue and conventional LINAC was superior in the dose homogeneity in GTV. The calculated time for treatment beam delivery was long more than two times in TomoTherapy compared with the conventional LINAC. Based on the results in this study, TomoTherapy can be evaluated as an effective way of lung radiation surgery for the patients whose tumor motion is little when the optimal planning is produced considering patient's condition and suitability of dose distribution.

Fine Needle Aspiration Cytologic Findings of Angiosarcoma: Report of Two Cases

Angiosarcoma is a rare malignant vascular neoplasm which can arise in any part of the body. Specific recognition of this neoplasm in cytological specimens is difficult in the absence of an ancillary method. Herein, we present the cytologic findings of two cases of angiosarcomas diagnosed on fine needle aspiration cytology. One case is a recurred angiosarcoma in the left chest wall and the other case is a lymphedema-associated angiosarcoma in the left lower leg. The cytologic findings of both cases are similar. Cytologic features that identified this neoplasm as an angiosarcoma included arborizing microtissue fragments, irregular anastomosing vascular spaces lined by atypical cells, microacini, intracytoplasmic lumen, and intracellular red blood cells, marked cell discohesiveness, spindle to ovoid, irregular, hyperchromatic nuclei, and elongated cytoplasmic processes with indistinct borders. This report emphasizes that when aspiration smears show vasoformative features in a bloody background, angiosarcoma should be included in the differential diagnosis.

The Results of Curative Concurrent Chemoradiotherapy for Anal Carcinoma / 대한방사선종양학회지

PURPOSE: To evaluate the predictive factors for treatment response and prognostic factors affecting survival outcomes after concurrent chemoradiotherapy (CCRT) for patients with anal squamous cell carcinoma. MATERIALS AND METHODS: Medical records of forty two patients with histologically confirmed analsquamous cell carcinoma, who had complete CCRT between 1993 and 2008, were reviewed retrospectively. Median age was 61.5 years (39~89 years), and median radiotherapy (RT) dose was 50.4 Gy (30.0~64.0 Gy). A total of 36 patients had equal to or less than T2 stage (85.7%). Fourteen patients (33.3%) showed regional nodal metastasis, 36 patients (85.7%) were treated with 5-fluorouracil (5-FU) plus mitomycin, and the remaining patients were treated by 5-FU plus cisplatinum. RESULTS: The median follow-up time was 62 months (2~202 months).The 5-year overall survival, locoregional relapse-free survival, disease-free survival, and colostomy-free survival rates were 86.0%, 71.7%, 71.7%, 78.2%, respectively. Regarding overall survival, the Eastern Cooperative Oncology Group (ECOG) performance status and complete response were found to be significant prognostic factors on univariate analysis. For multivariate analysis, only the ECOG performance status was significant. No significant factor was found for locoregional relapse-free survival or disease-free survival and similarly for treatment response, no significant factor was determined on logistic regression analysis. There were 7 patients who had local or regional recurrences and one patient with distant metastasis. The only evaluable toxicity in all patients was radiation dermatitis of perianal skin (grade 3), which developed in 4 patients (9.5%) and grade 2 in 22 patients (52.4%). CONCLUSION: This study revealed that patients with a performance score of ECOG 0-1 survived significantly longer than those with a poorer score. Finally, there was no significant predicting factors tested for treatment response.

Aspiration Cytology of Cervical Thymoma: A Case Report

An ectopic cervical thymoma is an uncommon tumor of the neck displaying the same histologic features as a mediastinal thymoma. Because of its unusual location, this mass is often confused as originating from the thyroid. In this report we describe a case of cervical type AB thymoma. Aspiration cytologic smears were highly cellular and revealed irregular tissue fragments, cohesive sheets, and clusters of crowded epithelial cells intermingled with many small lymphocytes. The epithelial cells had oval and spindle shaped bland-looking nuclei and scant cytoplasm with indistinct cell borders. Mitosis, nuclear atypia, and necrosis were not observed. The cells were focally arranged in a nesting pattern. Many small lymphocytes, a few activated lymphocytes, and lymphoid tangles were seen in the background. A cytologic misdiagnosis of "possible carcinoma" was rendered. Therefore, ectopic thymoma should also be considered in fine needle aspiration cytology of a neck mass when the smear shows epithelial and lymphoid components.

Analysis on the Effect of Field Width in the Delineation of Planning Target Volume for TomoTherapy / 의학물리

The Hi-Art system for TomoTherapy allows only three (1.0 cm, 2.5 cm, 5.0 cm) field widths and this can produce different dose distribution around the end of PTV (Planning target volume) in the direction of jaw movement. In this study, we investigated the effect of field width on the dose difference around the PTV using DQA (Delivery quality assurance) phantom and real clinical patient cases. In the analysis with DQA phantom, the calculated dose and irradiated films showed that the more dose was widely spreaded out in the end region of PTV as increase of field width. The 2.5 cm field width showed a 1.6 cm wider dose profile and the 5.0 cm field width showed a 4.2 cm wider dose profile compared with the 1.0 cm field width in the region of 50% of maximum dose. The analysis with four patient cases also showed the similar results with the DQA phantom which means that more dose was irradiated around the superior and inferior end of PTV as an increase of field width. The 5.0 cm field width produced the remarkable high dose distribution around the end region of PTV and we could evaluate the effect quantitatively with the calculation of DVH (Dose volume histogram) of the virtual PTVs which were delineated around the end of PTV in the direction of jaw variation. From these results, we could verify that the margin for PTV in the direction of table movement should be reduced compared with the conventional margin for PTV when the large field such as 5.0 cm was used in TomoTherapy.

Cytology of Follicular Dendritic Cell Sarcoma on Intraoperative Touch Imprint Smears: A Case Report

Follicular dendritic cell (FDC) sarcoma is a neoplastic proliferation of FDCs. Because its cytologic findings can vary widely, both the cytomorphology and histopathology of FDC sarcoma can impose a significant diagnostic dilemma. We present cytologic features of FDC sarcoma assessed by intraoperative touch imprint. Intra-abdominal lymphadenopathies were noted in 54-year-old male with hepatitis B-virus associated liver cirrhosis. In contrast to cytologic features of classical FDC sarcoma, the tumor cells featured a large epithelioid or Reed-Sternberg cell-like shape scattered in a background with abundant inflammatory cells, which led to a mistaken diagnosis of malignant lymphoma. However, in accordance with cytologic features previously described in the literature, the tumor cells were characterized by a fragile cytoplasm with cytoplasmic processes in dendritic or reticulated patterns reminiscent of the ultrastructural features of FDC. Cytoplasmic features rendering nuclei with a tendency to form clusters or syncytial aggregates associated with reactive lymphocytes appear to be the most valuable finding in diagnosis of FDC sarcoma.

A Retrospective Study of the Radiotherapy Care Patterns for Patients with Laryngeal Cancer and Comparison of Different Korean Hospitals Treated from 1998 through 1999 / 대한방사선종양학회지

PURPOSE: To investigate the care patterns for radiation therapy and to determine inter-hospital differences for patients with laryngeal carcinoma in Korea. MATERIALS AND METHODS: A total of 237 cases of laryngeal carcinoma (glottis, 144; supraglottis, 93) assembled from 23 hospitals, who underwent irradiation in the year of 1998 and 1999, were retrospectively analyzed to investigate inter-hospital differences with respect to radiotherapy treatment. We grouped the 23 hospitals based on the number of new patients annually irradiated in 1998; and designated them as group A (> or =900 patients), group B (> or =400 patients and <900 patients), and group C (<400 patients). RESULTS: The median age of the 237 patients was 62 years (range, 25 to 88 years), of which 216 were male and 21 were female. The clinical stages were distributed as follows: for glottis cancer, I; 61.8%, II; 21.5%, III; 4.2%, IVa; 11.1%, IVb; 1.4%, and in supraglottic cancer, I; 4.3%, II; 19.4%, III; 28.0%, IVa; 43.0%, IVb; 5.4%, respectively. Some differences were observed among the 3 groups with respect to the dose calculation method, radiation energy, field arrangement, and use of an immobilization device. No significant difference among 3 hospital groups was observed with respect to treatment modality, irradiation volume, and median total dose delivered to the primary site. CONCLUSION: This study revealed that radiotherapy process and patterns of care are relatively uniform in laryngeal cancer patients in Korean hospitals, and we hope this nationwide data can be used as a basis for the standardization of radiotherapy for the treatment of laryngeal cancer.

Development of Respiratory Signal Analysis Program for Accurate Phase Reassignment in 4D CT Reconstruction / 의학물리

Patient's respiration can have an effect on movement of tumor range and peripheral organs. Therefore, the respiratory signal was acquired by relation between external markers and movement of patient's abdomen during radiational therapy in order to minimize the effect of respiration. Based on this technique, many studies of rational therapy to irradiate at particular part of stable respiratory signals have executed and they have been clinically applied. Nevertheless, the phase-based method is preferred to the amplitude-based method for the rational therapy related to respiration. Because stabilization of the respiratory signal are limited. In this study, a in-house respiratory signal analysis program was developed for the phase reassignment and the analysis of the irregular respiratory signals. Various irregular respiratory patterns was obtained from clinical experimental volunteers. After then, the in-house program analyzed the factors affecting to phase assignment which is directly related to irradiated sector. Subsequently, accuracy of phase assignment was improved with removement of irregular signals by self-developed algorithm. This study is considered to be useful for not only image reconstruction and elevation of irradiating accuracy through phase assignment of RPM system but also analysis of respiratory signals. Moreover, development of 4D CT image is planed with phantom researches or clinical experiments based on this program.