• Radiation Oncology Journal
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• v.16 no.3
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• pp.265-274
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• 1998

Purpose : This prospective study has been conducted to assess the value of three dimensional conformal radiation therapy (3DCRT) for lung cancer and to determine its potential advantage over current treatment approaches. Specific aims of this study were to 1) find the most ideal 3DCRT technique 2) establish the maximum tolerance dose that can be delivered with 3DCRT and 3) identify patients at risk for development of radiation pneumonitis. Materials and Methods : Beginning in Nov. 1994, 95 patients with inoperable non-small cell lung cancer (stage I; 4, stage II; 1, stage IIIa; 14, stage IIIb; 76) were entered onto this 3D conformal trial Areas of known disease and elective nodal areas were initially treated to 45 Gy and then using 3DCRT technique 65 to 70 Gy of total dose were delivered to the gross disease. Sixty nine patients received 65 Gy of total dose and 26 received 70 Gy Seventy eight patients (82.1$\%$) also received concurrent MVP chemotherapy. 3DCRT plans were compared with 2D plans to assess the adequacy of dose delivery to target volume, dose volume histograms for normal tissue, and normal tissue complication Probabilities (NTCP). Results : Most of plans (78/95) were composed of non-coplanar multiple (4-8) fields. Coplanar segmented conformal therapy was used in 17 pateints, choosing the proper gantry angle which minimize normal lung exposure in each segment. 3DCRT gave the full dose to nearly 100$\%$ of the gross disease target volume in all patients. The mean NTCP for ipsilateral lung with 3DCRT (range; 0.17-0.43) was 68$\%$ of the mean NTCP with 2D treatment planning (range; 0.27-0.66). DVH analysis for heart showed that irradiated volume of heart could be significantly reduced by non-coplanar 3D approach especially in the case of left lower lobe lesion. Of 95 patients evaluable for response, 75 (79$\%$), showed major response including 25 (26$\%$) with complete responses and 50 (53$\%$) with partial responses. One and two rear overall survivals of stage III patients were 62.6$\%$ and 35.2$\%$ respectively. Twenty percent (19/95) of patients had pneumonitis; Eight patients had grade 1 pneumonitis and 11 other patients had grade 2. Comparison of the average of NTCP for lung showed a significant difference between patients with and without radiation pneumonitis. Average NTCP for Patients without complication was 62$\%$ of those with complications. Conclusions : This study showed that non-coplanar multiple fields (4-8) may be one of the ideal plans for 3DCRT for lung cancer. It also suggested that 3DCRT may provide superior delivery of high dose radiation with reduced risk to normal tissue and that NTCP can be used as a guideline for the dose escalation.

• Radiation Oncology Journal
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• v.25 no.2
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• pp.79-92
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• 2007

[ $\underline{Purpose}$ ]: For the first time, a nationwide survey in the Republic of Korea was conducted to determine the basic parameters for the treatment of esophageal cancer and to offer a solid cooperative system for the Korean Pattern of Care Study database. $\underline{Materials\;and\;Methods}$: During $1998{\sim}1999$, biopsy-confirmed 246 esophageal cancer patients that received radiotherapy were enrolled from 23 different institutions in South Korea. Random sampling was based on power allocation method. Patient parameters and specific information regarding tumor characteristics and treatment methods were collected and registered through the web based PCS system. The data was analyzed by the use of the Chi-squared test. $\underline{Results}$: The median age of the collected patients was 62 years. The male to female ratio was about 91 to 9 with an absolute male predominance. The performance status ranged from ECOG 0 to 1 in 82.5% of the patients. Diagnostic procedures included an esophagogram (228 patients, 92.7%), endoscopy (226 patients, 91.9%), and a chest CT scan (238 patients, 96.7%). Squamous cell carcinoma was diagnosed in 96.3% of the patients; mid-thoracic esophageal cancer was most prevalent (110 patients, 44.7%) and 135 patients presented with clinical stage III disease. Fifty seven patients received radiotherapy alone and 37 patients received surgery with adjuvant postoperative radiotherapy. Half of the patients (123 patients) received chemotherapy together with RT and 70 patients (56.9%) received it as concurrent chemoradiotherapy. The most frequently used chemotherapeutic agent was a combination of cisplatin and 5-FU. Most patients received radiotherapy either with 6 MV (116 patients, 47.2%) or with 10 MV photons (87 patients, 35.4%). Radiotherapy was delivered through a conventional AP-PA field for 206 patients (83.7%) without using a CT plan and the median delivered dose was 3,600 cGy. The median total dose of postoperative radiotherapy was 5,040 cGy while for the non-operative patients the median total dose was 5,970 cGy. Thirty-four patients received intraluminal brachytherapy with high dose rate Iridium-192. Brachytherapy was delivered with a median dose of 300 cGy in each fraction and was typically delivered $3{\sim}4\;times$. The most frequently encountered complication during the radiotherapy treatment was esophagitis in 155 patients (63.0%). $\underline{Conclusion}$: For the evaluation and treatment of esophageal cancer patients at radiation facilities in Korea, this study will provide guidelines and benchmark data for the solid cooperative systems of the Korean PCS. Although some differences were noted between institutions, there was no major difference in the treatment modalities and RT techniques.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.247-256
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• 2008

Purpose: The purpose of this study is to evaluate anal sphincter preservation rates, survival rates, and prognostic factors in patients with rectal cancer treated with preoperative chemoradiotherapy. Materials and Methods: One hundred fifty patients with pathologic confirmed rectal cancer and treated by preoperative chemoradiotherapy between January 1999 and June 2007. Of the 150 patients, the 82 who completed the scheduled chemoradiotherapy, received definitive surgery at our hospital, and did not have distant metastasis upon initial diagnosis were enrolled in this study. The radiation dose delivered to the whole pelvis ranged from 41.4 to 46.0 Gy (median 44.0 Gy) using daily fractions of $1.8{\sim}2.0\;Gy$ at 5 days per week and a boost dose to the primary tumor and high risk area up to a total of $43.2{\sim}54\;Gy$ (median 50.4 Gy). Sixty patients (80.5%) received 5-fluorouracil, leucovorin, and cisplatin, while 16 patients (19.5%) were administered 5-fluorouracil and leucovorin every 4 weeks concurrently during radiotherapy. Surgery was performed for 3 to 45 weeks (median 7 weeks) after completion of chemoradiotherapy. Results: The sphincter preservation rates for all patients were 73.2% (60/82). Of the 48 patients whose tumor was located at less than 5 cm away from the anal verge, 31 (64.6%) underwent sphincter-saving surgery. Moreover, of the 34 patients whose tumor was located at greater than or equal to 5 cm away from the anal verge, 29 (85.3%) were able to preserve their anal sphincter. A pathologic complete response was achieved in 14.6% (12/82) of all patients. The downstaging rates were 42.7% (35/82) for the T stage, 75.5% (37/49) for the N stage, and 67.1% (55/82) for the overall stages. The median follow-up period was 38 months (range $11{\sim}107$ months). The overall 5-year survival, disease-free survival, and locoregional control rates were 67.4%, 58.9% and 84.4%, respectively. The 5-year overall survival rates based on the pathologic stage were 100% for stage 0 (n=12), 59.1% for stage I (n=16), 78.6% for stage II (n=30), 36.9% for stage III (n=23), and one patient with pathologic stage IV was alive for 43 months (p=0.02). The 5-year disease-free survival rates were 77.8% for stage 0, 63.6% for stage I, 58.9% for stage II, 51.1% for stage III, and 0% for stage IV (p<0.001). The 5-year locoregional control rates were 88.9% for stage 0, 93.8% for stage I, 91.1% for stage II, 68.2% for stage III, and one patient with pathologic stage IV was alive without local recurrence (p=0.01). The results of a multivariate analysis with age (${\leq}55$ vs. >55), clinical stage (I+II vs. III), radiotherapy to surgery interval (${\leq}6$ weeks vs. >6 weeks), operation type (sphincter preservation vs. no preservation), pathologic T stage, pathologic N stage, pathologic overall stage (0 vs. I+II vs. III+IV), and pathologic response (complete vs. non-CR), only age and pathologic N stage were significant predictors of overall survival, pathologic overall stage for disease-free survival, and pathologic N stage for locoregional control rates, respectively. Recurrence was observed in 25 patients (local recurrence in 10 patients, distant metastasis in 13 patients, and both in 2 patients). Acute hematologic toxicity ($\geq$grade 3) during chemoradiotherapy was observed in 2 patients, while skin toxicity was observed in 1 patient. Complications developing within 60 days after surgery and required admission or surgical intervention, were observed in 11 patients: anastomotic leakage in 5 patients, pelvic abscess in 2 patients, and others in 4 patients. Conclusion: Preoperative chemoradiotherapy was an effective modality to achieve downstaging and sphincter preservation in rectal cancer cases with a relatively low toxicity. Pathologic N stage was a statistically significant prognostic factor for survival and locoregional control and so, more intensified postoperative adjuvant chemotherapy should be considered in these patients.