Distinct Cellular Calcium Metabolism in Radiation-sensitive RKO Human Colorectal Cancer Cells

Radiation therapy for variety of human solid tumors utilizes mechanism of cell death after DNA damage caused by radiation. In response to DNA damage, cytochrome c was released from mitochondria by activation of pro-apoptotic Bcl-2 family proteins, and then elicits massive Ca2+ release from the ER that lead to cell death. It was also suggested that irradiation may cause the deregulation of Ca2+ homeostasis and trigger programmed cell death and regulate death specific enzymes. Thus, in this study, we investigated how cellular Ca2+ metabolism in RKO cells, in comparison to radiation-resistant A549 cells, was altered by gamma (gamma)-irradiation. In irradiated RKO cells, Ca2+ influx via activation of NCX reverse mode was enhanced and a decline of [Ca2+]i via forward mode was accelerated. The amount of Ca2+ released from the ER in RKO cells by the activation of IP3 receptor was also enhanced by irradiation. An increase in [Ca2+]i via SOCI was enhanced in irradiated RKO cells, while that in A549 cells was depressed. These results suggest that gamma-irradiation elicits enhancement of cellular Ca2+ metabolism in radiation-sensitive RKO cells yielding programmed cell death.

Surgical Approach for Oropharyngeal Cancer / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: In order to eradicate the disease and preserve function of oropharynx and facial contour, appropriate surgical approach should be chosen for surgical treatment of oropharyngeal cancer. This study was performed to evaluate the usefulness and effectiveness of various surgical approaches in the surgical treatment of oropharyngeal cancer. SUBJECTS AND METHOD: We analyzed 65 patients with oropharyngeal cancer who underwent surgery as a primary treatment from Jan. 1994 to Jun. 2009, retrospectively. Primary tumor site, TNM stage, surgical approach, management of neck, reconstruction method, complication, recurrence rate were analyzed to assess advantages and disadvantages of various surgical approaches. RESULTS: The surgical approaches applied were transoral approach in 25, mandibulotomy in 23, lower cheek flap in 4, trans-pharyngeal in 9, and mandibular lingual releasing approach in 4. Most of T1 lesion was resected by transoral approach (65.0%). For advanced T3 and T4, mandibulotomy was mainly used. Lateral pharyngotomy and mandibular lingual release approach were used for the surgery of moderate size of oropharyngeal cancer. The locoregional recurrence rate did not differ according to different surgical approaches with regard to T and N stages. CONCLUSION: Transoral approach is very useful for the most of small oropharyngeal cancer. Mandibulotomy provides most wide surgical view for advanced T3, T4 oropharyngeal cancer.

Surgical Approach for Oral Cavity Cancer / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: In the treatment of oral cancer, appropriate surgical approaches should be chosen in order to eradicate cancer while preserving the function of oral cavity and facial contour. This study was performed to evaluate the usefulness and effectiveness of various surgical approaches in the surgical treatment of oral cancer. SUBJECTS AND METHOD: A total of 112 oral cancer patients, excepting those with lip cancer, and who underwent surgery from 1994 to Aug 2008, were enrolled. We reviewed medical records retrospectively and analyzed the primary sites, stage, surgical approaches, management of mandible and neck, reconstruction methods, recurrence and survival rates. RESULTS: Of the 112 patients, 64 were transoral, 23 pull-through, 6 mandibular lingual releasing, 6 upper cheek flap , 5 lower cheek flap , 6 mandibulotomy and 2 visor flap approach. Most of T1, T2 lesions could be resected by transoral (71.6%) or pull-through approach (21.0%). In the advanced T3, T4 lesions, transoral (21.9%), pull-through (37.5%), cheek flap (21.9%), mandibulotomy (15.6%) were used. There was no statistically significant difference with respect to locoregional recurrence and survival rate according to surgical approach. CONCLUSION: The transoral approach was the effective method for the surgery of T1, T2 and part of T3 oral cancer. The pull-through or mandibular lingual releasing approach was the effective method of surgery for T2, T3 tongue or floor of mouth (FOM) cancer while avoiding mandibulotomy.

The Treatment Outcome of Hypopharynx Cancer : Surgery versus Organ Preservation Therapy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Hypopharynx cancer usually presents with late stage diseases requiring radical resection including total laryngectomy with reconstruction resulting in severe functional deficits. In order to preserve organ function, chemotherapy in combination with radiotherapy was introduced and it showed similar treatment. The aim of this study is to compare the treatment outcomes of surgery and organ preservation therapy. SUBJECTS AND METHOD: A retrospective review of 55 patients who were diagnosed with hypopharynx cancer and underwent curative treatment from 1994 to 2006 was performed. Patients who underwent surgery or surgery plus postoperative radiotherapy were assigned to surgical treatment group and patients who underwent radiotherapy or radiotherapy with chemotherapy were assigned to organ preservation therapy group. RESULTS: Surgical treatment group consisted of 29 patients (52.7%) and organ preservation therapy group consisted of 26 patients (47.3%). The overall 5 year survival rate was 34%. The survival rate was decreased significantly according to the N stage (p=0.02). There was no statistically significant difference in 5 year survival rates between the two groups. The larynx preservation rate was 35.8% for the organ preservation therapy group and 44% for the conservation surgery group. CONCLUSION: Treatment of hypopharynx cancer could be individualized according to the status of diseases.

Results of Radiation Therapy for Squamous Cell Carcinoma of the Esophagus / 대한방사선종양학회지

PURPOSE: This study was designed to evaluate the effectiveness and prognostic factors for patients treated with postoperative radiation therapy following surgery or with radiation therapy alone for squamous cell carcinoma of the esophagus. MATERIALS AND METHODS: We retrospectively analyzed 132 esophageal cancer patients treated with postoperative radiation therapy following surgery or patients who were treated with radiation therapy alone at our institution from 1989 to 2006. Thirty-five patients had stage II disease, 88 patients had stage III disease and nine patients had stage IV disease. Tumors were located at the upper esophagus in 18 patients, the mid esophagus in 81 patients and the distal esophagus in 33 patients. Sixty patients were treated with radiation therapy alone and 72 patients were treated with postoperative radiation therapy following surgery. Eight patients received a dose less than 40 Gy and 78 patients received a dose of 40 to 50 Gy. The remaining 46 patients received a dose of 50 to 60 Gy. The majority of patients who underwent postoperative radiation therapy received a dose of 45 Gy. RESULTS: Actuarial survival rates for all of the patients at two years and five years were 24% and 5%, respectively. The median survival time was 11 months. Survival rates for patients who underwent postoperative RT at two years and five years were 29% and 8%, respectively. The corresponding survival rates for patients who received radiation alone were 18% and 2%, respectively. Survival rates at two years and five years were 43% and 15% for stage II disease, 22% and 2% for stage III disease and 0% and 0% for stage IV disease, respectively; these findings were statistically significant. Two-year survival rates for patients with upper, middle and distal esophageal cancer were 19, 29% and 22%, respectively. Although there was a trend of slightly better survival for middle esophageal tumors, this finding was not statistically significant. Complete response to radiation was achieved in 13 patients (22%) and partial response to radiation was achieved in 40 patients (67%) who received radiation alone. No response to radiation was noted in seven patients (12%). A statistically significant difference in survival rates was seen between patients that had a complete response and patients that had a partial response. Two-year survival rates for patients that had a complete response versus patients that had a partial response were 31% and 17%, respectively. There were no survivors for patients with no response as determined at two-year follow-up. CONCLUSION: We conclude that radiation therapy is an effective treatment for esophageal cancer. Stage and response to radiation therapy were noted to be prognostic factors. A more effective treatment modality is needed to improve long term survival because of the relatively dismal prognosis for this tumor.

The 1998, 1999 Patterns of Care Study for Breast Irradiation after Mastectomy in Korea / 대한방사선종양학회지

PURPOSE: To determine the patterns of evaluation and treatment in patients with breast cancer after mastectomy and treated with radiotherapy. A nationwide study was performed with the goal of improving radiotherapy treatment. MATERIALS AND METHODS: A web-based database system for the Korean Patterns of Care Study (PCS) for 6 common cancers was developed. Randomly selected records of 286 eligible patients treated between 1998 and 1999 from 17 hospitals were reviewed. RESULTS: The ages of the study patients ranged from 20 to 80 years (median age 44 years). The pathologic T stage by the AJCC was T1 in 9.7% of the cases, T2 in 59.2% of the cases, T3 in 25.6% of the cases, and T4 in 5.3% of the cases. For analysis of nodal involvement, N0 was 7.3%, N1 was 14%, N2 was 38.8%, and N3 was 38.5% of the cases. The AJCC stage was stage I in 0.7% of the cases, stage IIa in 3.8% of the cases, stage IIb in 9.8% of the cases, stage IIIa in 43% of the cases, stage IIIb in 2.8% of the cases, and IIIc in 38.5% of the cases. There were various sequences of chemotherapy and radiotherapy after mastectomy. Mastectomy and chemotherapy followed by radiotherapy was the most commonly performed sequence in 47% of the cases. Mastectomy, chemotherapy, and radiotherapy followed by additional chemotherapy was performed in 35% of the cases, and neoadjuvant chemoradiotherapy was performed in 12.5% of the cases. The radiotherapy volume was chest wall only in 5.6% of the cases. The volume was chest wall and supraclavicular fossa (SCL) in 20.3% of the cases; chest wall, SCL and internal mammary lymph node (IMN) in 27.6% of the cases; chest wall, SCL and posterior axillary lymph node in 25.9% of the cases; chest wall, SCL, IMN, and posterior axillary lymph node in 19.9% of the cases. Two patients received IMN only. The method of chest wall irradiation was tangential field in 57.3% of the cases and electron beam in 42% of the cases. A bolus for the chest wall was used in 54.8% of the tangential field cases and 52.5% of the electron beam cases. The radiation dose to the chest wall was 45~59.4 Gy (median 50.4 Gy), to the SCL was 45~59.4 Gy (median 50.4 Gy), and to the PAB was 4.8~38.8 Gy, (median 9 Gy) CONCLUSION: Different and various treatment methods were used for radiotherapy of the breast cancer patients after mastectomy in each hospital. Most of treatment methods varied in the irradiation of the chest wall. A separate analysis for the details of radiotherapy planning also needs to be followed and the outcome of treatment is needed in order to evaluate the different processes.

Neoadjuvant Chemotherapy Followed by Concurrent Chemoradiation in Locally Advanced Head and Neck Squamous Cell Carcinoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Surgery with postoperative radiotherapy has been the standard treatment for locally advanced head and neck squamous cell carcinoma (HNSCC). However, the prognosis still remains dismal. To increase survival rate and organ preservation rate, alternative approach is needed. Incorporating the taxane regimen into the treatment of HNSCC, the new treatment strategy of sequential therapy has been introduced. The purpose of this study is to determine the efficacy of neoadjuvant chemotherapy, followed by concurrent chemoradiotherapy for the HNSCC. SUBJECTS AND METHOD: Between January 2001 and June 2005, 19 patients with HNSCC were treated with neoadjuvant chemotherapy, followed by concurrent chemoradiotherapy. The sites of primary tumors were hypopharynx in eight patients, oropharynx in six patients, and larynx in five patients. Neoadjuvant chemotherapy included 70 mg/m2 of docetaxel on day 1, 70 mg/m2 of cisplantin on day 2 and 800 mg/m2 of 5-fluorouracil on day 2-4. The cycles were repeated every three weeks. Concurrent chemoradiotherapy starts after two cycles of neoadjuvant chemotherapy. Radiation dose was 200 cGy/dayx5/week with a total of 6,000-7,000 cGy, and the concurrent chemotherapy of 20 mg/m2 of docetaxel or 20 mg/m2 of cisplantin was given weekly. RESULTS: The median follow-up was 21 months. The overall 2-year survival rate was 70.1% and the 2-year organ preservation rate was 59.4%. The survival rate and organ preservation rate of larynx cancer patients were higher than those of hypopharynx and oropharynx cancer patients, but it was not statistically significant (p=0.09, 0.16). The patients of the lower stage showed higher survival rate and organ preservation rate, but it was not statistically significant (p=0.19, 0.48). The most common Grade 3 or 4 toxicities of neoadjuvant chemotherapy were leukopenia, anorexia, nausea and vomiting, whereas the most common Grade 3 or 4 toxicities during concurrent chemoradiotherapy were mucositis, stomatitis, and leukopenia. One patient died due to sepsis during treatment. CONCLUSION: Neoadjuvant chemotherapy with three combined regimens followed by concurrent chemoradiotherapy might be effective treatment modality for HNSCC. Further studies with large number of patients and longer follow-up will be needed.

Na+-Ca2+ exchanger modulates Ca2+ content in intracellular Ca2+ stores in rat osteoblasts

Na+ -Ca2+ exchanger (NCX) transports Ca2+ coupled with Na+ across the plasma membrane in a bi-directional mode. Ca2+ flux via NCX mediates osteogenic processes, such as formation of extracellular matrix proteins and bone nodules. However, it is not clearly understood how the NCX regulates cellular Ca2+ movements in osteogenic processes. In this study, the role of NCX in modulating Ca2+ content of intracellular stores ([Ca2+](ER)) was investigated by measuring intracellular Ca2+ activity in isolated rat osteoblasts. Removal of extracellular Na+ elicited a transient increase of intracellular Ca2+ concentration ([Ca2+](i)). Pretreatment of antisense oligodeoxynucleotide (AS) against NCX depressed this transient Ca2+ rise and raised the basal level of [Ca2+](i). In AS-pretreated cells, the expression and activity of alkaline phosphatase (ALP), an osteogenic marker, were decreased. However, the cell viability was not affected by AS-pretreatment. Suppression of NCX activity by the AS-pretreatment decreased ATP-activated Ca2+ release from intracellular stores and significantly enhanced Ca2+ influx via store operated calcium influx (SOCI), compared to those of S-pretreated or control cells. These results strongly suggest that NCX has a regulatory role in cellular Ca2+ pathways in osteoblasts by modulating intracellular Ca2+ content.

Role of Postoperative Radiation Therapy in the Management of Cervical Cancer / 대한방사선종양학회지

PURPOSE: To evaluate the effectiveness of postoperative radiation therapy in cervical cancer patients and define the prognostic factors to affect survival rates. MATERIALS AND METHODS: Eighty one patients with cervical cancer who were treated with postoperative radiation therapy following surgery at our institution between May 1992 and April 2000 were retrospectively analyzed. Forty two patients had stage IB disease, 17 had stage IIA disease, and remaining 22 had stage IIB disease, respectively. Histological examination revealed 76 squamous cell carcinoma and 5 adenocarcinoma. Sixty one patients were noted to have stromal invasion greater than 8 mm and 20 patients were noted to have stromal invasion 7 mm or less. Sixteen patients had parametrial invasion and 65 patients did not. Positive vaginal resection margin was documented in only eight patients and positive lymphovascular invasion was in twelve patients. All of the patients were treated with external beam radiation therapy alone. Majority of the patients were treated with 4 field brick technique to encompass whole pelvis. Total of 5,500 cGy was delivered to the primary surgical tumor bed. Minimum follow up period was four years. RESULTS: Actuarial disease free survival rates for entire group of the patients were 95% and 89% at 2 and 5 years, respectively. Five year disease free survival rates for patients with stage IB, IIA, and IIB disease were 97%, 87% and 70%, respectively. Local recurrences were documented in 5 patients. Cumulative local failure rate at 3 years was 6%. Five year disease free survival rates for patients with stromal invasion greater than 8 mm and 7 mm or less were 88% and 92%, respectively (p>0.05). Five year disease free survival rate for patients with parametrial invasion was significantly lower than those with no invasion (72% vs 92%, p<0.05). Also there was significantly lower survival in patients with positive vaginal resection margin, compared with patients with negative resection margin (64% vs 94%, p<0.05). However, lymphovascular invasion was not a statistically significant prognostic factor. Parametrial invasion and positive surgical resection margins were noted to be significant prognostic factors. Conclusions: Postoperative radiation therapy appears to be beneficial in controlling local disease in cervical cancer patients with high pathologic risk factors. Parametrial invasion and positive resection margins were noted to be significant prognostic factors to affect survival and more effective treatment should be investigated in these patients.

The 1998, 1999 Patterns of Care Study for Breast Irradiation After Breast-Conserving Surgery in Korea / 대한방사선종양학회지

PURPOSE: To determine the patterns of evaluation and treatment in the patient with early breast cancer treated with conservative surgery and radiotherapy and to improve the radiotherapy techiniques, nationwide survey was performed. MATERIALS AND METHODS: A web-based database system for Korean Patterns of Care Study (PCS) for 6 common cancers was developed. Two hundreds sixty-one randomly selected records of eligible patients treated between 1998~999 from 15 hospitals were reviewed. RESULTS: The patients ages ranged from 24 to 85 years(median 45 years). Infiltrating ductal carcinoma was most common histologic type (88.9%) followed by medullary carcinoma (4.2%) and infiltrating lobular carcinoma (1.5%). Pathologic T stage by AJCC was T1 in 59.7% of the casses, T2 in 29.5% of the cases, Tis in 8.8% of the cases. Axillary lymph node dissection was performed in 91.2% of the cases and 69.7% were node negative. AJCC stage was 0 in 8.8% of the cases, stage I in 44.9% of the cases, stage IIa in 33.3% of the cases, and stage IIb in 8.4% of the cases. Estrogen and progesteron receptors were evaluated in 71.6%, and 70.9% of the patients, respectively. Surgical methods of breast-conserving surgery was excision/lumpectomy in 37.2%, wide excision in 11.5%, quadrantectomy in 23% and partial mastectomy in 27.5% of the cases. A pathologically confirmed negative margin was obtained in 90.8% of the cases. Pathological margin was involved with tumor in 10 patients and margin was close (less than 2 mm) in 10 patients. All the patients except one recieved more than 90% of the planned radiotherapy dose. Radiotherapy volume was breast only in 88% of the cases, breast+supraclavicular fossa (SCL) in 5% of the cases, and breast+SCL+posterior axillary boost in 4.2% of the cases. Only one patient received isolated internal mammary lymph node irradiation. Used radiation beam was Co-60 in 8 cases, 4 MV X-ray in 115 cases, 6 MV X-ray in 125 cases, and 10 MV X-ray in 11 cases. The radiation dose to the whole breast was 45~9.4 Gy (median 50.4) and boost dose was 8~20 Gy (median 10 Gy). The total radiation dose delivered was 50.4~70.4 Gy (median 60.4 Gy). CONCLUSION: There was no major deviation from current standard in the patterns of evaluation and treatment for the patients with early breast cancer treated with breast conservation method. Some varieties were identified in boost irradiation dose. Separate analysis for the datails of radiotherapy planning will be followed and the outcome of treatment is needed to evaluate the process.

Radiotherapy for Nasopharyngeal Carcinoma / 대한방사선종양학회지

PURPOSE: To evaluate the results of radiation management on recurrence, survival and prognostic factors of patients with nasopharyngeal cancer. MATERIALS AND METHODS: Forty-nine patients, treated for nasopharyngeal cancer by radiotherapy between January 1984 and June 2000, were retrospectively studied. All patients were followed up for at least 2.5 years. Their median age was 52 years (range 17~78). The histological types were 21 squamous cell carcinoma, 25 undifferentiated carcinoma, and 3 adenoid cystic carcinoma. The tumor stages were as follows: T1 in 14 patients, T2 in 24, T3 in 3, and T4 in 8, and N0 in 17 patients, N1 in 15, N2 in 4 and N3 in 13. Stages I, IIa, IIb ,III, IV and IVb were 4, 7, 12, 5, 8, and 13 patients respectively. Radiation doses of 58~70 Gy (median 68.7 Gy) were given to the nasopahryngeal and involved lymphatic areas and of 46~50 Gy to the uninvolved neck areas. RESULTS: The overall 5 and 10-year actuarial and disease free survival rates were 54.53% and 47%, and 55.7% and 45.3%, respectively. The overall five-year survival rates were 100% in stage I , 80% in stage IIa, 59.5% in stage IIIb, 40% in stage III, and 42.2% in stage IV tumors. Twenty-three patients failed either loco-regionally or distantly. Incidences of local failure, regional failure and distant metastasis for the first failure were 20.4%, 8.2% and 20.4%, respectively. Local recurrences were 4.3% in T1, 12.5% in T2, 0% in T3, and 62.5% in T4 lesions. Distant metastasis was seen in 41.2% of N2-3 lesions. Fifty percent of local recurrence appeared within 2 years of treatment at the primary lesion, whereas 70% of distant metastasis appeared within 2 years following treatment. Young age, female, early T stage, N0 stage, and poorly differentiated carcinoma were all related with good survival. However only stage showed statistically significance. CONCLUSION: Based on the results of this study, radiation therapy to nasopharyngeal cancer showed high local recurrence in T4 and increased metastasis in N2-3 lesions. To improve local failure, further radiation doses, such as stereotactic radiation or IMRT radiation, are necessary especially in T4 lesions. The high incidence of distant metastasis in positive lymph node patients, indicates that combined radiation and effective chemotherapeutic agents with appropriated schedule are necessary.

Radiation Therapy for Operable Breast Cancer after Conservative Surgery / 대한방사선종양학회지

PURPOSE: To evaluate the result of conservative management on recurrence, survival and prognostic factors of patient with operable breast cancer. MATERIALS AND METHODS: Fifty three patients, treated for localized breast cancer by lumpectomy or quadrantectomy followed by radiotherapy between January 1985 and December 1996, were retrospectively studied. All patients followed up for at least five years. Their median age was 43 years (range 24~72). The tumor stages were as follows : T1 in 30 patients, T2 in 21, Tis in 2. Thirty-eight patients had negative and 15 had positive axillary nodes. The histological types were 42 infiltrating ductal, 2 infiltrating lobular, and 2 intraductal carcinomas with 7 other histologies. The tumor locations were the outer quadrant in 38 breasts, the inner quadrant in 13 and central in 2. Radiation doses of 46~50 Gy were given to the entire breast areas with additional doses of 14-18 Gy delivered to the tumor bed areas. RESULTS: The overall five and 10 year actuarial and disease free survivals were 94.3 % and 92.4%, 91.2 and 81%, respectively. The overall five year survivals were 100% in stage I and IIa, and 66.7% in stage IIb and IIIa tumors. Seven patients failed either locally or distantly. Incidence of local failure and distant metastasis for the first failure were 7.5% and 5.7%, respectively. Local recurrence appeared within 2 years of treatment at the primary site and after more than 8 years outside of primary lesion, whereas distant metastasis appeared between 2 and 6 years following treatment. The overall recurrences were high at a young age (< or = 35 years), with 5 out of 12 (2 local, 3 distant), and in T2 lesions with 5 out of 21 (1 local, 3 distant, and 1 in both). Distant metastasis was high in the positive axillary lymph node group with 4 out of 15 (26.6%). A high incidence in the axillary node was noted at a young age with 7 out of 12 (58.3%) and in T2 lesions with 8 out of 21 (38.4%). A young age, positive axillary node and large tumor size were all related with poor survival. CONCLUSION: Based on this study, lumpectomy or quadrantectomy, followed by radiation appears to be an adequate therapeutic method in operable breast cancer. A long term follow-up is necessary because a recurrence of breast can occur long time after treatment. The poor prognostic group, especially young patients with an aggressive biological behavior needs more effective treatment modalities to improve their survival.

Radiation Therapy Alone for Early Stage Non-small Cell Carcinoma of the Lung / 대한방사선종양학회지

PURPOSE: To evaluate the outcome of early stage non-small cell lung cancer patients who were treated with radiation therapy alone and define the optimal radiotherapeutic regimen for these patients. MATERIALS AND METHODS: A retrospective review was performed on patients with sage I or II non-small cell carcinoma of the lung that were treated at our institution between June, 1987 and May, 2000. A total of 21 patients treated definitively with radiation therapy alone were included in this study. The age of the patients ranged from 53 to 81 years with a median of 66 years. All the patients were male. The medical reasons for inoperability were lack of pulmonary reserve, cardiovascular disease, poor performance status, old age, and patient refusal in the decreasing order. Pathological evidence was not adequate to characterize the non-small cell subtype in two patients. Of the remaining 19 patients, 16 had squamous cell carcinoma and 3 had adenocarcinoma. Treatment was given with conventional fractionation, once a day, five times a week. The doses to the primary site ranged from 56 Gy to 69 Gy. No patients were lost to follow-up. RESULTS: The overall survival rates for the entire group at 2, 3 and 5 years were 41, 30 and 21%, respectively. The cause specific survivals at 2, 3 and 5 years were 55, 36 and 25%, respectively. An intercurrent disease was the cause of death in two patients. The cumulative local failure rate at 5 years was 43%. Nine of the 21 patients had treatment failures after the curative radiotherapy was attempted. Local recurrences as the first site of failure were documented in 7 patients. Therefore, local failure alone represented 78% of the total failures. Those patients whose tumor sizes were less than 4 cm had a significantly better 5 year disease free survival than those with tumors greater than 4 cm (0% vs 36%). Those patients with a Karnofsky performance status less than 70 did not differ significantly with respect to actuarial survival when compared to those with a status greater than 70 (25% vs 26%, p>0.05). CONCLUSION: Radiation therapy alone is an effective and safe treatment for early stage non-small cell lung cancer patients who are medically inoperable or refuse surgery. Also we believe that a higher radiation dose to the primary site could improve the local control rate, and ultimately the overall survival rate.

Postoperative Radiotherapy for Non-Small Cell Lung Cancer / 대한방사선종양학회지

PURPOSE: To evaluate effect of postoperative radiotherapy on survival and local control for patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Ninety two NSCLC patients with N1or N2 involvement who were treated with postoperative radiotherapy following surgery with curative intent from May 1987 to October 1999 were retrospectively analyzed. Age of the patients was ranged from 32 to 78 years. According to TNM Stage, 35 patients had Stage II and 57 had Stage III disease. There were 49 patients with N1 involvement and 43 patients with N2 involvement. Fifty six patients were noted to have T1~2 tumors and 36 patients to have T3~4 tumors. Delivered total dose was ranged from 40 to 60 Gy. Majority of patients received 50 Gy or 50.4 Gy. Follow-up period was ranged from 9 month to 7 years with median follow-up of 26 months. RESULTS: Overall survival rates at 3 and 5 years for entire group of patients were 46% and 38%, respectively. Corresponding disease free survival rates were 44% and 36%. There was significant difference in survival between patients with Stage II and Stage III disease (50% vs 28% at 5-year). Five year survival rates for N1 and N2 patients were 52% and 20%, respectively (p<0.05). These were 40% and 34% for patients with T1~2 tumors and T3~4 tumors. There were documented local relapses in 13% of the patients. For patients with N1 and N2 Stage, local relapse rates were 8% and 18%, respectively. CONCLUSION: Our study confirms that postoperative radiotherapy for patients with non-small cell lung cancer improves local control. However, influence of postoperative radiotherapy on long-term survival is less clear. More effective systemic treatment to prevent distant metastasis should be investigated in future study to improve long-term survival.

Optimization of Total Arc Degree for Stereotactic Radiotherapy by Using Integral Biologically Effective Dose and Irradiated Volume / 대한방사선종양학회지

PURPOSE: To find the optimal values of total arc degree to protect the normal brain tissue from high dose radiation in stereotactic radiotherapy planning. METHODS AND MATERIALS: With Xknife-3 planning system & 4 MV linear accelerator, the authors planned under various values of parameters. One isocenter, 12, 20, 30, 40, 50, and 60 mm of collimator diameters, 100degrees, 200degrees, 300degrees, 400degrees, 500degrees, 600degrees of total arc degrees, and 30degrees or 45degrees of arc intervals were used. After the completion of planning, the plans were compared each other using V50 (the volume of normal brain that is delivered high dose radiation) and integral biologically effective dose. RESULTS: At 30degrees of arc interval, the values of V50 had the decreased pattern with the increase of total arc degree in any collimator diameter. At 45degrees arc interval, up to 400degrees of total arc degree, the values of V50 decreased with the increase of total arc degree, but at 500degrees and 600degrees of total arc degrees, the values increased. At 30degreesdegreesof arc interval, integral biologically effective dose showed the decreased pattern with the increase of total arc degree in any collimator diameter. At 45degrees arc interval with less than 40 mm collimator diameter, the integral biologically effective dose decreased with the increase of total arc degree, but with 50 and 60 mm of collimator diameters, up to 400degrees of total arc degree, integral biologically effective dose decreased with the increase of total arc degree, but at 500degrees and 600degrees of total arc degrees, the values increased. CONCLUSION: In the stereotactic radiotherapy planning for brain lesions, planning with 400degrees of total arc degree is optimal. Especially, when the larger collimator more than 50 mm diameter should be used, the uses of 500degrees and 600degrees of total arc degrees make the increase of V50 and integral biologically effective dose. Therefore stereotactic radiotherapy planning using 400degrees of total arc degree can increase the therapeutic ratio and produce the effective outcome in the management of personal and mechanical sources in radiotherapy department.

Role of Radiation Therapy for Stage III Thymoma / 대한방사선종양학회지

PURPOSE: To evaluate the effectiveness and tolerance of the postoperative radiation therapy for patients with Stage III thymoma and to define the optimal radiotherapeutic regimen. MATERIALS AND METHODS: We retrospectively analyzed the records of 24 patients with Stage III thymoma who were referred for postoperative radiation therapy in our institution from June, 1987 to May, 1999. Surgical therapy consisted of total resection in one patient, subtotal resection in seventeen, and biopsy alone in six patients. Age of the patients was ranged from 20 to 62 years with mean age of 47 years. Male to female ratio was 14 to 10. Radiation therapy was delivered with linear accelerator producing either 6 MeV or 10 MeV photons. The irradiated volume included anterior mediastinum and known residual disease. The supraclavicular fossae were not irradiated. The delivered total dose was ranged from 30 to 56 Gy. One patient received 30 Gy and eighteen patients received minimum of 50 Gy. Follow up period was ranged from 12 months to 8 years with median follow up of 40 months. RESULTS: The overall local control rate for entire group of patients was 67% at 5 years. The cumulative local failure rates at one, three and five year were 18%, 28% and 33%, respectively. In patients treated with subtotal resection and biopsy alone, local control rate was 76% and 33%, respectively. The actuarial observed survival rate at 5 years was 57%, and actuarial adjusted survival at 5 years was 72%. The difference between 5 year survival rates for patients treated with subtotal resection and biopsy alone was not statistically significant (62% vs 30%). CONCLUSION: We might conclude that postoperative radiation therapy was safe and effective treatment for patients with Stage III thymoma. Postoperative radiation therapy is recommended in cases where tumor margin is close or incomplete resection is accomplished.

Radical Radiotherapy for Carcinoma of the Prostate / 대한방사선종양학회지

PURPOSE: To evaluate effect and tolerance of external beam radiotherapy for carcinoma of the prostate and define the optimal radiotherapeutic regimen. MATERIALS AND METHODS: We retrospectively analyzed the records of 60 patients with prostate cancer who were treated with external beam radiotherapy with curative intent in our institution between September, 1987 and March, 2000. Histologic diagnosis was established by transurethral resection or ultrasonography guided biopsy. The major presenting symptoms were a nodule at routine prostatic examination and frequency and urgency of urination, along with dysuria. The median age was 63 years with range of 51 to 87 years. There were 6 patients in Stage A, 20 in Stage B, 26 in Stage C, and 8 in Stage D1. All patients were treated with megavoltage equipment producing 10 MV photons. The 4 field pelvic brick technique was used to a dose of 45 Gy or 50.4 Gy at 1.8 Gy per day in 5 to 6 weeks, after which a small boost field was delivered 2.0 Gy per day to a total dose of 66 to 70 Gy. The follow-up period ranged from 1 to 8 years. RESULTS: Actuarial 5-year and 7-year survival rates for Stage A, B, C, and D1 were 100% and 84%, 83% and 72%, 67% and 54%, and 40% and 30%, respectively. The corresponding 5-year and 7-year relapse free survival rates were 84% and 84%, 77% and 67%, 48% and 40%, and 33% and 25%, respectively. Relapse free 5-year survival rates for Stage B were 80%, 80%, and 50% for well, moderately, and poorly differentiated tumors, respectively. These were 64%, 44%, and 33% for Stage C, respectively. The local control rates at 5 years were 84%, 85%, 78%, and 60% for Stage A, B, C, and D1, respectively. Mild to moderate complications were observed in 22% of patients. Severe complications requiring surgical procedures were documented in only 3% of patients. CONCLUSION: This study confirms that external beam irradiation is an effective and safe treatment for prostatic cancer, providing long-term local control and good survival with acceptable complications.

Postoperative Radiotherapy for Intracranial Meningioma / 대한방사선종양학회지

PURPOSE: To evaluate the effectiveness and tolerance of postoperative external radiotherapy for patients with intracranial meningiomas. MATERIALS AND METHODS: The records of thirty three patients with intracranial meningiomas who were treated with postoperative external irradiation at our institution between Feb, 1988 and Nov, 1999 were retrospectively analyzed. Median age of patients at diagnosis was 53 years with range of 17 to 68 years. Sites of involvement were parasagital, cerebral convexity, sphenoid ridge, parasellar and tentorium cerebelli. Of 33 evaluated patients, 15 transitional, 10 meningotheliomatous, 4 hemangiopericytic, 3 atypical and 1 malignant meningioma were identified. Four patients underwent biopsy alone and remaining 29 patients underwent total tumor resection. A dose of 50 to 60 Gy was delivered in 28-35 daily fractions over a period of 5 to 7 weeks. Follow-up period ranged from 12 months to 8 years. RESULTS: The actuarial survival rates at 5 and 7 years for entire group of patients were 78% and 67%, respectively. The corresponding disease free survival rates were 73% and 61%, respectively. The overall local control rate at 5 years was 83%. One out of 25 patients in benign group developed local failure, while 4 out of 8 patients in malignant group did local failure (p<0.05). Of 4 patients who underwent biopsy alone, 2 developed local failure. There was no significant difference in 5 year actuarial survival between patients who underwent total tumor resection and those who did biopsy alone. Patients whose age is under 60 showed slightly better survival than those whose age is 60 or older, although this was not statistically significant. There was no documented late complications in any patients. CONCLUSION: Based on our study, we might conclude that postoperative external beam radiotherapy tends to improve survival of patients with intracranial meningiomas comparing with surgery alone.

Postoperative Radiotherapy for Low Grade Glioma of the Brain / 대한방사선종양학회지

PURPOSE: To evaluate the effectiveness and tolerance of postoperative external beam radiotherapy for patients with low grade glioma of the brain and define the optimal radiotherapeutic regimen. MATERIALS AND METHODS: Between June, 1985 and May, 1998, 72 patients with low grade gliomas were treated with postoperative radiotherapy immediately following surgery. Median age was 37 years with range of 11 to 76 years. Forty one patients were male and 31 patients were female with male to female ratio of 1.3:1. Of those patients, 15 underwent biopsy alone and remaining 57 did subtotal resection. The distribution of the patients according to histologic type was as follows: astrocytomas-42 patients (58%), mixed oligodendrogliomas-19 patients (27%), oligodendrogliomas-11 patients (15%). Two patients were treated with whole brain irradiation followed by cone down boost and remaining 70 patients were treated with localized field with appropriate margin. All of the patients were treated with conventional once a day fractionation. Most of patients received total tumor dose of 5000~5500 cGy. RESULTS: The overall 5 and 7 year survival rates for entire group of 72 patients were 61% and 50%. Corresponding disease free survival rates for entire patients were 53% and 45%, respectively. The 5 and 7 year overall survival rates for astrocytomas, mixed oligodendrogliomas, and oligodendrogliomas were 48% and 45%, 76% and 56%, and 80% and 52%, respectively. Patients who underwent subtotal resection showed better survival rates than those who did biopsy alone. The overall 5 year survival rates for subtotal resection patients and biopsy alone patients were 67% and 43%, respectively. Forty six patients who were 40 years or younger survived better than 26 patients who were 41 years or older (overall survival rate at 5 years, 69% vs 45%). Although one patient was not able to complete the treatment because of neurological deterioration, there was no significant treatment related acute toxicities. CONCLUSION: Postoperative radiotherapy was safe and effective treatment for patients with low grade gliomas. However, we probably need prospective randomized trial to define optimal treatment timing and schedule for low grade gliomas and select patient group for different treatment philosophies.

Postoperative External Beam Radiotherapy for Medulloblastoma / 대한방사선종양학회지

PURPOSE: This study was performed to evaluate the effectiveness and tolerance of craniospinal irradiation for patients with medulloblastoma and to define the optimal radiotherapeutic regimen. MATERIALS AND METHODS: We retrospectively analyzed the records of 43 patients with medulloblastoma who were treated with external beam craniospinal radiotherapy at our institution between May, 1984 and April, 1998. Median follow up period was 47 months with range of 18 to 86 months. Twenty seven patients were male and sixteen patients were female, a male to female ratio of 1.7 : 1. Surgery consisted of biopsy alone in 5 patients, subtotal excision in 24 patients, and gross total excision in 14 patients. All of the patients were treated with craniospinal irradiation. All of the patients except four received at least 5,000 cGy to the posterior fossa and forty patients received more than 3,000 cGy to the spinal cord. RESULTS: The overall survival rates at 5 and 7 years for entire group of patients were 67% and 56%, respectively. Corresponding disease free survival rates were 60% and 51%, respectively. The rates of disease control in the posterior fossa were 77% and 67% at 5 and 7 years. Gross total excision and subtotal excision resulted in 5 year overall survival rates of 76% and 66%, respectively. In contrast, those patients who had biopsy alone had a 5 year survival rate of only 40%. Posterior fossa was a component of failure in 11 of the 18 recurrences. Seven recurrences were isolated to the posterior fossa. Four patients had neuraxis recurrences, three had distant metastasis alone and four had multiple sites of failure, all involving the primary site. CONCLUSION: Craniospinal irradiation for patients with medulloblastoma is an effective adjuvant treatment without significant treatment related toxicities. There is room for improvement in terms of posterior fossa control, especially in biopsy alone patients. The advances in radiotherapy including hyperfractionation, stereotactic radiosurgery and 3D conformal radiotherapy would be evolved to improve the tumor control rate at primary site.