Moon June Cho

Pathologic complete response of primary tumor following preoperative chemoradiotherapy for locally advanced rectal cancer: long-term outcomes and prognostic significance of pathologic nodal status (KROG 09-01).

Objective: To investigate long-term outcomes of locally advanced rectal cancer (LARC) patients with postchemoradiotherapy (post-CRT) pathologic complete response of primary tumor (ypT0) and determine prognostic significance of post-CRT pathologic nodal (ypN) status. Background: LARC patients with post-CRT pathologic complete response were suggested to have favorable long-term outcomes, but prognostic significance of ypN status has never been specifically defined in ypT0 patients. Methods: The Korean Radiation Oncology Group collected clinical data for 333 LARC patients with ypT0 following preoperative CRT and curative radical resections between 1993 and 2007. Sphincter preservation surgery and abdominoperineal resection were performed in 283 (85.0%) and 50 (15.0%) patients, respectively. Postoperative chemotherapy was given to 285 (85.6%) patients. Survival was estimated by the Kaplan-Meier method, and the Cox proportional hazard model was used in multivariate analyses. Results: After median follow-up of 43 (range = 14–172) months, 5-year disease-free survival (DFS) was 84.6% and overall survival (OS) was 92.8%. The ypN status was ypT0N0 in 304 (91.3%), ypT0N1 in 22 (6.6%), and ypT0N2 in 7 (2.1%) patients. The ypN status was the most relevant independent prognostic factor for both DFS and OS in ypT0 patients. The 5-year DFS and OS was 88.5% and 94.8% in ypT0N0 patients, and 45.2% and 72.8% in ypT0N+ patients (both, P < 0.001). Conclusions: LARC patients achieving ypT0N0 after preoperative CRT had favorable long-term outcomes, whereas positive ypN status had a poor prognosis even after total regression of primary tumor.

Screening of Brain Metastasis with Limited Magnetic Resonance Imaging (MRI): Clinical Implications of Using Limited Brain MRI During Initial Staging for Non-small Cell Lung Cancer Patients

The purpose of this prospective study was to determine whether using magnetic resonance imaging (MRI) for early screening for brain metastases (BM) can improve quality of life, survival in patients with non-small cell lung cancer (NSCLC). The study group comprised 183 patients newly diagnosed with NSCLC. All patients underwent limited brain MRI and routine workups. The control group comprised 131 patients with NSCLC who underwent limited brain MRI only if they had neurologic symptoms. The incidence of BM was 20.8% (38/183) in the study group and 4.6% (6/131) in the control group. The rate of upstaging based on the MRI data was 13.5% (15/111) overall and 15.9% (11/69) in patients that had been considered initially to be resectable surgically. There was no significant difference in survival outcome between the groups. Patients who had BM alone had a greater overall survival time (49 weeks) than those who had multiple systemic metastases (27 weeks; p=0.0307). In conclusions, limited brain MRI appears to be a useful, cost-effective method to screen for BM at the time of initial staging. And it may facilitate timely treatment of patients with NSCLC and improve their survival and quality of life.

Clinical Experience in Conformal Stereotactic Radiotherapy of Irregularly Shaped Intracranial Tumors

PURPOSE The dosimetric advantages of multiple non-coplanar stationary fields for stereotactic radiotherapy or adiosurgery (SRT/S) are well known. However, this technique is not widely used due to the logistical problems associated with producing and testing customized collimators. We report our experience of SRT/S using multiple non-coplanar stationary fields (conformal SRT/ S). MATERIALS AND METHODS Between August 1997 and February 2002, we performed frameless SRT/S in 63 patients. We chose conformal SRT/S when the tumor was of a very irregular shape or larger than 4 cm. We obtained three pieces of information: 1) the couch translations required to bring the target point to the isocenter, 2) the distance between the stereotaxic markers in the CT study, and the distance between the markers determined from orthogonal beam films, taken in the anterior- posterior and lateral directions, and 3) the rotational movement of the head position between the CT study and actual treatment position. We evaluated two kinds of data: 1) the precision of the isocenter setup, and 2) the reproducibility of the head position in the a) translational and b) rotational components. RESULTS Twenty-six of the 63 patients receiving stereotactic treatment received conformal SRT/S. The precision of the isocenter setup for the conformal SRT/S was x=-0.03+/-0.26 mm, y=0.19+/-0.25 mm and z=-0.20+/-0.27 mm. The reproducibilities of the head position with the conformal SRT/S were 0.5 mm and less than 1degrees C, for the translational and rotational components, in any plane. CONCLUSION We were able to apply conformal stereotactic irradiation, which has a dosimetric advantage, to irregularly shaped intracranial tumors, with precision and reproducibility of head position for the isocenter setup nearly equivalent to that of frame-based SRS or multiple-arc SRT/S.

Survey of the Patterns of Using Stereotactic Ablative Radiotherapy for Early-Stage Non-small Cell Lung Cancer in Korea

Purpose Stereotactic ablative radiotherapy (SABR) is an effective emerging technique for early-stage non-small cell lung cancer (NSCLC). We investigated the current practice of SABR for early-stage NSCLC in Korea. Materials and Methods We conducted a nationwide survey of SABR for NSCLC by sending e-mails to all board-certified members of the Korean Society for Radiation Oncology. The survey included 23 questions focusing on the technical aspects of SABR and 18 questions seeking the participants’ opinions on specific clinical scenarios in the use of SABR for early-stage NSCLC. Overall, 79 radiation oncologists at 61/85 specialist hospitals in Korea (71.8%) responded to the survey. Results SABR was used at 33 institutions (54%) to treat NSCLC. Regarding technical aspects, the most common planning methods were the rotational intensity-modulated technique (59%) and the static intensity-modulated technique (49%). Respiratory motion was managed by gating (54%) or abdominal compression (51%), and 86% of the planning scans were obtained using 4-dimensional computed tomography. In the clinical scenarios, the most commonly chosen fractionation schedule for peripherally located T1 NSCLC was 60 Gy in four fractions. For centrally located tumors and T2 NSCLC, the oncologists tended to avoid SABR for radiotherapy, and extended the fractionation schedule. Conclusion The results of our survey indicated that SABR is increasingly being used to treat NSCLC in Korea. However, there were wide variations in the technical protocols and fractionation schedules of SABR for early-stage NSCLC among institutions. Standardization of SABR is necessary before implementing nationwide, multicenter, randomized studies.