Cases report of unicentric Castleman’s disease: revisit of radiotherapy role

노오규,이상욱,이제환,김상윤,김청수,최은경,김종훈,안승도 대한방사선종양학회 2013 Radiation Oncology Journal Vol.31 No.1

Castleman’s disease or angiofollicular lymph node hyperplasia is a rare lymphoproliferative disorder. Complete surgical resection was recommended in unicentric Castleman’s disease. Radiotherapy was considered alternative therapeutic option. However, there have been consistent favorable responses to radiotherapy. We also experienced two cases of uncentric Castleman’s disease salvaged successfully with radiotherapy. This paper described these cases and reviewed the literature about Castleman’s disease treated with radiotherapy. Reviewed cases showed that radiotherapy is a successful treatment option in unicentric Castleman’s disease. Furthermore, our report confirms the radiotherapy role in uncentric Castleman’s disease.

절제 불가능한 식도암의 근치적 항암화학방사선치료의 성적

노오규(O Kyu Noh),제형욱(Hyoung Uk Je),김성배(Sung Bae Kim),이진혁(Gin Hyug Lee),박승일(Seung Il Park),이상욱(Sang-wook Lee),송시열(Si Yeol Song),안승도(Seung Do Ahn),최은경(Eun Kyung Choi),김종훈(Jong Hoon Kim) 대한방사선종양학회 2008 Radiation Oncology Journal Vol.26 No.4

목 적: 절제 불가능한 식도암에서의 근치적 동시항암화학방사선치료의 치료 성적과 재발 양상에 대해 알아보고자 하였다. 대상 및 방법: 1994년 2월부터 2002년 12월까지 서울아산병원에서 절제불가능한 국소진행된 식도암으로 진단 받 거나 내과적으로 수술이 불가능한 식도암으로 진단 받은 후 근치적 목적의 동시항암화학방사선치료를 시행 받은 168명을 대상으로 하였다. 방사선치료는 원발병소와 종격동, 그리고 원발병소와 림프절 전이의 위치에 따라 쇄골 상부림프절과 복강림프절을 포함하여 42∼46 Gy의 외부방사선을 조사하였고, 이후 원발병소와 림프절 전이 부위에는 54∼66 Gy까지 추가 조사하였다. 분할조사 방법은 분할조사선량 1.8∼2 Gy씩 1일 1회 조사하거나, 1.2 Gy씩 1일 2회 조사하였다. 고선량률관내방사선치료를 실시하는 경우에는 Ir-192를 이용한 고선량률 방식으로 3 Gy씩 3∼4회 시행하였다. 항암치료는 5-FU와 cisplatin을 이용하여 동시항암화학방사선치료(5-FU 1,000 mg/m2/day, days 2∼6, 30∼34, cisplatin 60 mg/m2/day, days 1, 29)를 2주기 시행하고 방사선치료 후에 2 주기를 추가하여 시행하였다. 결 과: 분석 가능한 환자는 160명 이었으며, 추적관찰 기간은 1개월에서 149개월(중앙값 10개월)이었다. 환자의 AJCC 병기는 I, II, III, IV 기가 각각 5명(3.1%), 38명(23.8%), 68명(42.5%), 49명(30.6%)이었다. 26명(16.3%)의 환자에서는 9∼12 Gy의 추가 관내방사선치료를 시행하였다. 관내방사선치료를 포함하여 총 40 Gy 이상 조사받은 144명의 환자에서 외부 방사선조사량의 범위는 44.4∼66 Gy (중앙값 59.4)이었고, 총 방사선 조사량의 범위는 44.4∼72 Gy (중앙값 60)이었다. 분석가능한 160명의 환자 중에서 101명(63.1%)에서 재발하였으며, 재발 양상으 로는 국소 재발이 20명(12.5%), 지속적 병변 또는 국소 진행이 61명(38.1%), 원격전이가 15명(9.4%), 국소재발과 원격전이가 함께 있는 경우가 5명(3.1%)이었다. 전체환자의 중앙생존기간은 11.1개월이었고, 2년 및 5년 전체생 존율은 각각 31.8%, 14.2%이었다. 중앙무병 생존기간은 10.4개월이었고, 2년 및 5년 무병생존율은 각각 29.0%, 22.7%이었다. 항암화학방사선치료 후에 종양 반응 및 림프절 병기만이 전체생존율에 유의하게 영향을 미치는 예후인자였다. 방사선 조사량(≥50 Gy vs. <50 Gy), 관내방사선치료의 추가 유무, 분할조사(1회/day vs. 2회/day)에 따른 전체 생존율 및 무병생존율에 유의한 차이는 관찰되지 않았다.결 론: 식도암에서 근치적 동시 항암화학방사선치료의 성적은 다른 연구 결과와 유사한 결과를 보였다. 동시 항암화학 방사선치료 후의 주된 재발 양상은 국소 재발이었다. 방사선 조사량의 증가(≥50 Gy), 고선량률관내방사선치료 및 과분할조사법의 시행은 치료 성적을 향상시키지 못하였다. Purpose: To investigate the treatment outcome and failure patterns after definitive chemoradiation therapy in locally advanced, unresectable esophageal cancer. Materials and Methods: From February 1994 to December 2002, 168 patients with locally advanced unresectable or medically inoperable esophageal cancer were treated by definitive chemoradiation therapy. External beam radiation therapy (EBRT) (42∼46 Gy) was delivered to the region encompassing the primary tumor and involved lymph nodes, while the supraclavicular fossa and celiac area were included in the treatment area as a function of disease location. The administered cone-down radiation dose to the gross tumor went up to 54∼66 Gy, while the fraction size of the EBRT was 1.8-2.0 Gy/fraction qd or 1.2 Gy/fraction bid. An optional high dose rate (HDR) intraluminal brachytherapy (BT) boost was also administered (Ir-192, 9∼12 Gy/3 ∼4 fx). Two cycles of concurrent FP chemotherapy (5-FU 1,000 mg/m2/day, days 2∼6, 30∼34, cisplatin 60 mg/m2/day, days 1, 29) were delivered during radiotherapy with the addition of two more cycles. Results: One hundred sixty patients were analyzable for this review [median follow-up time: 10 months (range 1∼149 months)]. The number of patients within AJCC stages I, II, III, and IV was 5 (3.1%), 38 (23.8%), 68 (42.5%), and 49 (30.6%), respectively. A HDR intraluminal BT was performed in 26 patients. The 160 patients had a median EBRT radiation dose of 59.4 Gy (range 44.4∼66) and a total radiation dose, including BT, of 60 Gy (range 44.4∼72), while 144 patients received a dose higher than 40 Gy. Despite the treatment, the disease recurrence rate was 101/160 (63.1%). Of these, the patterns of recurrence were local in 20 patients (12.5%), persistent disease and local progression in 61 (38.1%), distant metastasis in 15 (9.4%), and concomitant local and distant failure in 5 (3.1%). The overall survival rate was 31.8% at 2 years and 14.2% at 5 years (median 11.1 months). Disease-free survival was 29.0% at 2 years and 22.7% at 5 years (median 10.4 months). The response to treatment and N-stage were significant factors affecting overall survival. In addition, total radiation dose (≥50 Gy vs. <50 Gy), BT and fractionation scheme (qd. vs. bid.) were not significant factors for overall survival and disease-free survival. Conclusion: Survival outcome after definitive chemoradiation therapy in unresectable esophageal cancer was comparable to those of other series. The main failure pattern was local recurrence. Survival rate did not improve with increased radiation dose over 50 Gy or the use of brachytherapy or hyperfractionation.

자궁 내막암의 수술 후 방사선치료 결과

노오규(O Kyu Noh),신성수(Seong Soo Shin),이상욱(Sang-Wook Lee),안승도(Seung Do Ahn),최은경(Eun Kyung Choi),김종혁(Jong-Hyeok Kim),김용만(Yong-Man Kim),남주현(Joo-Hyun Nam),목정은(Jung-Eun Mok),김종훈(Jong Hoon Kim) 대한방사선종양학회 2007 Radiation Oncology Journal Vol.25 No.2

목 적: 근치적 자궁절제술 후 보조적 방사선 치료를 시행 받은 자궁내막암 환자의 치료 성적 및 예후 인자를 알아 보고자 하였다. 대상 및 방법: 1991년 9월부터 2003년 8월까지 서울아산병원에서 자궁내막암으로 자궁 절제술을 시행한 후 보조적 방사선치료를 받은 76명을 대상으로 하였다. FIGO 병기는 I, II, III기가 각각 41명(53.9%), 12명(15.8%), 23명(30.3%)이었다. 조직분화도는 1이 29명(38.2%), 2가 20명(26.3%), 3이 27명(35.5%)이었다. 방사선치료는 외부방 사선 조사와 강내 조사를 함께 시행한 환자가 42명, 외부 방사선 조사만 시행한 환자가 33명, 강내 조사만 시행한 환자는 1명이었다. 외부 방사선 치료의 조사 선량은 50.4 Gy였으며, 강내 조사는 1회 분할 선량을 4~5 Gy씩 4~6 회 실시하였다. 생존환자의 추적기간은 5개월에서 121개월로서 중앙값은 51개월이었다.결 과: 5년 전체 생존율은 89.6%이었으며, FIGO I기는 96.8%, II기는 91.7%, III기는 75.7%였다. 5년 무병 생존율은 83.7%이었고, FIGO 병기에 따라 I기는 94.8%, II기는 91.6%, III기는 59.8%이었다. 단변량 분석에서 전체 생존율에 유의한 영향을 미치는 인자에는 FIGO 병기, 림프절 양성 유무, 조직분화도였고, 무병 생존율에서는 관계되는인자는 FIGO 병기, 림프절 양성 유무, 림프혈관침범 유무였다. 총 11명에서 재발하였고, 국소재발 1명, 원격전이가 10명이었다. 방사선 치료 후에 중등도 이상의 합병증을 보이는 경우는 없었다. 결 론: 자궁내막암의 수술 후 방사선 치료의 성적은 좋은 결과를 보였다. 그러나 주로 원격전이로 재발하는 양상으로 보이므로 항암치료가 도움이 되리라 생각된다. 따라서 FIGO 병기가 높거나, 림프절 양성이거나, 림프혈관침범이 있거나, 조직 분화도가 높은 고위험 군에서 항암제를 포함한 방사선치료 방법에 대한 연구가 필요할 것으로 판단된다. Purpose: To evaluate the outcome and prognostic factors of postoperative radiotherapy in endometrial carcinoma. Materials and Methods: From September 1991 to August 2003, 76 patients with endometrial carcinoma received postoperative adjuvant radiotherapy after hysterectomy at Asan Medical Center. Stage was classified as FIGO I in 41 (53.9%), II in 12 (53.9%), and III in 23 (30.3%). Histologic grade 1, 2 and 3 were in 29 (38.2%), 20 (26.3%), and 27 (35.5%) respectively. Forty two patients received both external beam radiation therapy (EBRT) and intracavitary radiation (ICR), 34 patients were treated with EBRT or ICR alone. EBRT dose was 50.4 Gy, ICR was performed in 4∼6 fractions with 4∼5 Gy per fraction. Median follow‐up period was 51 (range 5∼ 121) months. Results: Five‐year overall survival was 89.6%. In univariate analysis, statistically significant factors to overall survival were FIGO stage, lymph node metastasis and histologic grade. In disease free survival, FIGO stage, lymph node metastasis and lymphovascular invasion were significant prognostic factors. Recurrence was seen in 11 patients. Of these, systemic failure was in 10 patients. There were no moderate to severe complications after radiation therapy. Conclusion: The outcome of postoperative adjuvant radiotherapy in endometrial carcinoma was good. Main pattern of failure after postoperative radiotherapy was distant metastasis. So, adjuvant chemotherapy may help in improving outcome. Further study on chemotherapy in combined with postoperative radiotherapy will be needed, especially for patients with high risk factors such as high FIGO stage, lymphovascular invasion, and high histologic grade.

Probabilities of Pulmonary and Cardiac Complications and Radiographic Parameters in Breast Cancer Radiotherapy

노오규(O Kyu Noh),박성호(Sung Ho Park),안승도(Seung Do Ahn),최은경(Eun Kyung Choi),이상욱(Sang-Wook Lee),송시열(Si Yeol Song),윤상민(Sang Min Yoon),김종훈(Jong Hoon Kim) 대한방사선종양학회 2010 Radiation Oncology Journal Vol.28 No.1

Purpose: To evaluate the relationship between the normal tissue complication probability (NTCP) of 3- dimensional (3-D) radiotherapy and the radiographic parameters of 2-dimensional (2-D) radiotherapy such as central lung distance (CLD) and maximal heart distance (MHD). Materials and Methods: We analyzed 110 patients who were treated with postoperative radiotherapy for breast cancer. A two-field tangential technique, a three-field technique, and the reverse hockey stick method were used. The radiation dose administered to whole breast or the chest wall was 50.4 Gy, whereas a 45 Gy was administered to the supraclavicular field. The NTCPs of the heart and lung were calculated by the modified Lyman model and the relative seriality model. Results: For all patients, the NTCPs of radiation-induced pneumonitis and cardiac mortality were 0.5% and 0.7%, respectively. The NTCP of radiation-induced pneumonitis was higher in patients treated with the reverse hockey stick method than in those treated by other two techniques (0.0%, 0.0%, 3.1%, p<0.001). The NTCP of radiation-induced pneumonitis increased with CLD. The NTCP of cardiac mortality increased with MHD (R2=0.808). Conclusion: We found a close correlation between the NTCP of 3-D radiotherapy and 2-D radiographic parameters. Our results are useful to reanalyze the previous 2-D based clinical reports about breast radiation therapy complications as a viewpoint of NTCP. 목 적: 정상 장기의 부작용 확률(normal tissue complication probability, NTCP) 모델을 이용하여, 중심폐거리(central lung distance, CLD)와 최대심장거리(maximal heart distance)와 같은 이차원 방사선치료의 방사선학적 지 표들과 삼차원 입체조형방사선치료의 부작용확률 사이의 관계를 평가해 보고자 하였다. 대상 및 방법: 2006년 11월부터 2007년 8월까지 서울아산병원에서 유방암으로 진단받고 수술 후 방사선치료를 시행 받은 110명을 무작위로 추출하여 분석하였다. 방사선치료는 2문 빗면 조사법, 3문 조사법, Reverse HockeyStick법을 사용하였고, 유방 및 흉벽에는 5,040 cGy/28회, 쇄골 상부에는 4,500 cGy/25회로 조사하였고, 유방보존술을 시행한 경우에는 원발 병소에 1,000 cGy/4회의 추가치료를 하였다. 모든 환자에서 전산화단층촬영모의치료를 시행하였고, Eclipse Planning System을 사용하여 선량 계산을 시행 후 폐와 심장의 선량 부피 곡선(dosevolume histogram, DVH)을 추출하였다. 추출된 DVH를 사용하여 modified Lymam model과 relative seriality model을 통해 NTCP를 계산하고 분석하였다.결 과: 전체 환자의 방사선 폐렴과 심장 사망의 NTCP 값은 각각 0.5%, 0.7%로 낮은 수치를 보였다. 방사선 폐렴의 NTCP는 2문 조사법과 3문 조사법에 비해 Reverse Hockey Stick 법에서 높았다(0%, 0%, 3.1%, p<0.001). 방사선 폐렴의 NTCP 값은 중심폐거리가 커질수록 증가하였고, 심장 사망의 NTCP는 최대심장거리가 커질수록 증가하였다(R2=0.808).결 론: 이차원 방사선치료의 방사선학적 지표들과 삼차원 입체조형방사선치료의 NTCP 값 사이에는 밀접한 관계가 있다. 이러한 연관성을 통해 과거의 부작용학률에 대한 자료들을 이차원 방사선치료의 방사선학적 지표들을 이용하여 NTCP 모델의 관점에서 재분석하는데 유용할 것으로 생각된다.

Loss of Heterozygosity at Chromosome 16q Is a Negative Prognostic Factor in Korean Pediatric Patients with Favorable Histology Wilms Tumor: A Report of the Korean Pediatric Hematology Oncology Group (K-PHOG)

박준은,노오규,이용희,최형수,한정우,한승민,류철주,이지원,유건희,구홍회,정선용,성기웅 대한암학회 2020 Cancer Research and Treatment Vol.52 No.2

Purpose Loss of heterozygosity (LOH) at chromosomes 1p and 16q is a poor prognostic factor in favorable histology Wilms tumor (FHWT). This study investigated the prevalence of LOH at 1p and 16q and evaluated its prognostic value in Korean children with FHWT. Materials and Methods We analyzed 101 FHWT patients who were diagnosed between 1996 and 2016 in Korean Society of Pediatric Hematology Oncology Group hospitals. Using paraffin-embedded kidney tissue samples sent from each center, we reviewed LOH at 1p and 16q in each patient and assessed the prognostic value of LOH status for clinical parameters affecting event-free survival (EFS). Results Of the 101 patients, 12 (11.9%) experienced recurrence; the 3-year EFS was 87.6%. LOH at 1p or 16q was detected in 19 patients (18.8%), with five having LOH at both 1q and 16q. The frequency of LOH at 1p was higher among younger patients (p=0.049), but there was no difference in LOH prevalence according to tumor stage. In the multivariate analysis, LOH at 16q was a significant negative prognostic factor affecting EFS (3-year EFS, 73.7% vs. 91.1%; hazard ratio, 3.95; p=0.037), whereas LOH at 1p was not (p=0.786). Conclusion LOH at 16q was a significant negative prognostic factor affecting outcome in Korean pediatric FHWT patients. Due to the small sample size of this study, large-scale multicenter trials are warranted to investigate the prognostic value of LOH at 1p and 16q in Korean children with FHWT.

Comparison of concurrent chemoradiotherapy versus sequential radiochemotherapy in patients with completely resected non-small cell lung cancer

김환익,노오규,오영택,전미선,김상원,조오연,허재성 대한방사선종양학회 2016 Radiation Oncology Journal Vol.34 No.3

Purpose: Our institution has implemented two different adjuvant protocols in treating patients with non-small cell lung cancer (NSCLC): chemotherapy followed by concurrent chemoradiotherapy (CT-CCRT) and sequential postoperative radiotherapy (PORT) followed by postoperative chemotherapy (POCT). We aimed to compare the clinical outcomes between the two adjuvant protocols. Materials and Methods: From March 1997 to October 2012, 68 patients were treated with CT-CCRT (n = 25) and sequential PORT followed by POCT (RT-CT; n = 43). The CT-CCRT protocol consisted of 2 cycles of cisplatin-based POCT followed by PORT concurrently with 2 cycles of POCT. The RT-CT protocol consisted of PORT followed by 4 cycles of cisplatin-based POCT. PORT was administered using conventional fractionation with a dose of 50.4–60 Gy. We compared the outcomes between the two adjuvant protocols and analyzed the clinical factors affecting survivals. Results: Median follow-up time was 43.9 months (range, 3.2 to 74.0 months), and the 5-year overall survival (OS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were 53.9%, 68.2%, and 51.0%, respectively. There were no significant differences in OS (p = 0.074), LRFS (p = 0.094), and DMFS (p = 0.490) between the two protocols. In multivariable analyses, adjuvant protocol remained as a significant prognostic factor for LRFS, favouring CT-CCRT (hazard ratio [HR] = 3.506, p = 0.046) over RT-CT, not for OS (HR = 0.647, p = 0.229). Conclusion: CT-CCRT protocol increased LRFS more than RT-CT protocol in patients with completely resected NSCLC, but not in OS. Further studies are warranted to evaluate the benefit of CCRT strategy compared with sequential strategy.

Neonatal Outcomes of Very Low Birth Weight Infants in Korean Neonatal Network from 2013 to 2016

이장훈,노오규,장윤실 대한의학회 2019 Journal of Korean medical science Vol.34 No.5

Background: This study was performed to determine survival and morbidity rates in very low birth weight infants (VLBWIs) in the Korean Neonatal Network (KNN), and to compare neonatal outcomes with those in other countries. Methods: Data were collected for 8,269 VLBWIs with gestational age (GA) ≥ 22 weeks who were born between January 1, 2013 and December 31, 2016, and admitted to the neonatal intensive care units of the KNN. Results: The survival rate of all VLBWIs and of infants with GA 22–23, 24–25, 26–27, 28–29, 30–32, and > 32 weeks were 86% (total), 33%, 65%, 84%, 94%, 97%, and 98%, respectively. The bronchopulmonary dysplasia (BPD) rates of all VLBWIs and of infants with GA 22–23, 24–25, 26–27, 28–29, 30–32, and > 32 weeks were 30% (total), 88%, 64%, 47%, 26%, 14%, and 5%, respectively. The intraventricular hemorrhage rates (≥ grade III) of all VLBWIs and of infants with GA 22–23, 24–25, 26–27, 28–29, 30–32, and > 32 weeks were 10% (total), 45%, 27%, 12%, 5%, 2%, and 1%, respectively. In an international comparison, the survival rate of VLBWIs with GA 24–27 weeks in KNN was lower, and the BPD rate of VLBWIs in the KNN was higher than that of the neonatal networks of other countries. Conclusion: Despite overall improvements in neonatal outcomes, the survival and morbidity rates of more immature infants with GA 22–27 weeks need further improvement. Therefore, it would be necessary to develop more optimal treatment strategies and perform more active quality improvement to further improve neonatal outcomes of VLBWIs in Korea.

Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

조오연,노오규,전미선,박성호,오영택,김미화,박혜진,남상수,허재성 대한방사선종양학회 2013 Radiation Oncology Journal Vol.31 No.1

Purpose: Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. Materials and Methods: From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Results: Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p < 0.001). Mean parotid dose of both glands ≥20 Gy were observed in 15 (28.3%) for CF and in 0 (0.0%) for MF. The whole brain percentage volumes receiving >98% of prescribed dose were 99.7% for CF and 99.5% for MF. Conclusion: Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

Nodal tumor response according to the count of peripheral blood lymphocyte subpopulations during preoperative chemoradiotherapy in locally advanced rectal cancer

허재성,오영택,노오규,전미선,박준은,조성란 대한방사선종양학회 2016 Radiation Oncology Journal Vol.34 No.4

Purpose: The objective of this prospective study was to evaluate the relationship between the circulating lymphocyte subpopulation counts during preoperative chemoradiotherapy (CRT) and tumor response in locally advanced rectal cancer. Materials and Methods: From August 2015 to June 2016, 10 patients treated with preoperative CRT followed by surgery were enrolled. Patients received conventional fractionated radiotherapy (50.4 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. The absolute blood lymphocyte subpopulation was obtained prior to and after 4 weeks of CRT. We analyzed the association between a tumor response and change in the lymphocyte subpopulation during CRT. Results: Among 10 patients, 2 (20%) had evidence of pathologic complete response. In 8 patients with clinically node positive, 4 (50%) had nodal tumor response. All lymphocyte subpopulation counts at 4 weeks after CRT were significantly lower than those observed during pretreatment (p < 0.01). A high decrease in natural killer (NK) cell, count during CRT (baseline cell count − cell count at 4 weeks) was associated with node down staging (p = 0.034). Conclusion: Our results suggest that the change of lymphocyte subset to preoperative CRT may be a predictive factor for tumor response in rectal cancer.

Sustaining Blood Lymphocyte Count during Preoperative Chemoradiotherapy as a Predictive Marker for Pathologic Complete Response in Locally Advanced Rectal Cancer

허재성,전미선,노오규,오영택,서광욱,박준은,조오연 대한암학회 2016 Cancer Research and Treatment Vol.48 No.1

Purpose The objective of this study was to explore the relationship between the circulating lympho- cyte level during preoperative chemoradiotherapy (CRT) and pathologic complete response (pCR) in locally advanced rectal cancer. Materials and Methods From May 2010 to May 2013, 52 patients treated with preoperative CRT followed by surgery, were analysed. Patients received conventional fractionated radiotherapy (50-54 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. Absolute blood lymphocyte counts and their rel- ative percentage in total white blood cell counts were obtained from complete blood count tests performed prior to and after 4, 8, and 12 weeks of CRT. We analysed the association between achieving pCR and change in blood lymphocyte level during CRT, as well as clinical parameters. Results Among 52 patients, 14 (26.9%) had evidence of pCR. Sustaining the blood lymphocyte count during CRT (lymphocyte count at 4 weeks/baseline lymphocyte count > 0.35; odds ratio, 8.33; p=0.02) and initial carcinoembryonic antigen < 4.4 ng/mL (odds ratio, 6.71; p=0.03) were significantly associated with pCR in multivariate analyses. Conclusion Sustaining blood lymphocyte count during preoperative CRT was predictive for pCR in rectal cancer. Further studies are warranted to investigate the association between pathologic responses and circulating lymphocyte count with its subpopulation during preoperative CRT.