Heerim Nam

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.

Prognostic significance of anatomic subsites : Results of radiation therapy for 66 patients with localized orbital marginal zone B cell lymphoma

BACKGROUND AND PURPOSE To evaluate the prognostic significance of anatomic subsites for marginal zone B cell lymphoma confined to the orbit. MATERIALS AND METHODS From 1995 to 2005, 66 patients (80 lesions) with marginal zone B cell lymphoma, confined to the orbit, received radiation therapy at Samsung Medical Center. The most frequent site of involvement was conjunctiva (29 patients) followed by retrobulbar (20 patients), eyelid (10 patients) and lacrimal gland (7 patients). The median follow-up duration was 50 (13-114) months. RESULTS Local relapse developed in two patients, systemic relapse in three, and metachronous relapse in two. The 5-year relapse-free survival rate was 92.0%. A primary tumor located at lacrimal gland was the only poor prognostic factor for relapse (p=0.023, HR=12.263, 95% CI=1.360-110.602). The 5-year actuarial relapse-free survival rate was 57.1% for lacrimal tumor versus 95.8% for non-lacrimal tumors (p=0.002). CONCLUSIONS Localized primary orbital MALT lymphomas respond extremely well to moderate-dose RT, with a high local control rate and durable disease free status. However, primary lacrimal involvement maybe related to future relapse more frequently than other orbital subsites.

18F-fluorodeoxyglucose positron emisson tomography/computed tomography guided conformal brachytherapy for cervical cancer.

PURPOSE To evaluate the feasibility of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT)-guided conformal brachytherapy treatment planning in patients with cervical cancer. METHODS AND MATERIALS Pretreatment FDG-PET/CT was performed for 12 patients with cervical cancer. Brachytherapy simulation was performed after an external-beam radiation therapy median dose of 4140 cGy. Patients underwent FDG-PET/CT scans with placement of tandem and ovoid applicators. The gross tumor volume (GTV) was determined by adjusting the window and level to a reasonable value and outlining the edge of the enhancing area, which was done in consultation with a nuclear medicine physician. A standardized uptake value profile of the tumor margin was taken for each patient relative to the maximum uptake value of each tumor and analyzed. The plan was designed to deliver 400 cGy to point A (point A plan) or to cover the clinical target volume (CTV) (PET/CT plan). RESULTS The median dose that encompassed 95% of the target volume (D95) of the CTV was 323.0 cGy for the point A plan vs 399.0 cGy for the PET/CT plan (P=.001). The maximum standardized uptake values (SUV(max)) of the tumors were reduced by a median of 57% (range, 13%-80%). All but 1 patient presented with discernable residual uptake within the tumors. The median value of the thresholds of the tumors contoured by simple visual analysis was 41% (range, 23%-71%). CONCLUSIONS In this study, the PET/CT plan was better than the conventional point A plan in terms of target coverage without increasing the dose to the normal tissue, making optimized 3-dimensional brachytherapy treatment planning possible. In comparison with the previously reported study with PET or CT alone, we found that visual target localization was facilitated by PET fusion on indeterminate CT masses. Further studies are needed to characterize the metabolic activity detected during radiation therapy for more reliable targeting.

Effects of adjuvant radiotherapy on completely resected gastric cancer: A radiation oncologist's view of the ARTIST randomized phase III trial.

PURPOSE We investigated which subgroups might benefit from adjuvant radiotherapy (RT) and suggested optimal RT targets by analyzing the results of the Adjuvant Chemoradiation Therapy in Stomach Cancer (ARTIST) trial. METHODS We conducted randomized controlled trial in 458 gastric cancer patients. Patients were randomly assigned to XP (6 cycles of capecitabine and) or XPRT (2 cycles of XP+RT 45Gy/25 fraction with capecitabine+2 cycles of XP) groups after D2 resection. Minimum follow-up was 5years. RESULTS During follow-up, 77 patients (33.8%) in the XP arm and 60 (26.1%) in the XPRT arm experienced recurrence. Among these patients, locoregional recurrence (LRR) developed in 44 (9.6%; 29 in XP, 15 in XPRT; P=0.03). The local recurrence rate (4.8%) did not vary between arms. Regional recurrence was the most important difference between the two groups (23 in the XP arm, 5 in the XPRT arm, P<0.001). LRR-free survival (LRRFS) was significantly different between study arms (P=0.03), especially in patients with LN metastasis (P=0.009). CONCLUSIONS Adjuvant RT after D2 resection in gastric cancer reduced LRR, especially in group 3 LNs, and improved LRRFS. Patients with LN metastasis benefited more from the adjuvant RT treatment than the other subgroups.

High Dose Involved Field Radiation Therapy as Salvage for Loco-Regional Recurrence of Non-Small Cell Lung Cancer

Purpose To determine the effectiveness of salvage radiation therapy (RT) in patients with loco-regional recurrences (LRR) following initial complete resection of non-small cell lung cancer (NSCLC) and assess prognostic factors affecting survivals. Materials and Methods Between 1994 and 2007, 64 patients with LRR after surgery of NSCLC were treated with high dose RT alone (78.1%) or concurrent chemo-radiation therapy (CCRT, 21.9%) at Samsung Medical Center. Twenty-nine patients (45.3%) had local recurrence, 26 patients (40.6%) had regional recurrence and 9 patients (14.1%) had recurrence of both components. The median RT dose was 54 Gy (range, 44-66 Gy). The radiation target volume included the recurrent lesions only. Results The median follow-up time from the start of RT in survivors was 32.0 months. The rates of in-field failure free survival, intra-thoracic failure free survival and extra-thoracic failure free survival at 2 years were 52.3%, 33.9% and 59.4%, respectively. The median survival after RT was 18.5 months, and 2-year overall survival (OS) rate was 47.9%. On both univariate and multivariate analysis, the interval from surgery till recurrence and CCRT were significant prognostic factors for OS. Conclusion The current study demonstrates that involved field salvage RT is effective for LRR of NSCLC following surgery.

The effects of radiation therapy on height and spine MRI characteristics in children with neuroblastoma

PURPOSE To investigate the effect of radiotherapy (RT) on height and spine using magnetic resonance imaging (MRI) analysis in children with neuroblastoma and to identify parameters related to patient height. METHODS AND MATERIALS We performed a retrospective cohort study of neuroblastoma patients treated between January 1997 and December 2007. Twenty-seven children were enrolled. Whole spine MRI was completed and height percentiles were compared with national growth charts. RESULTS The median ages were 28, 43, and 126 months at diagnosis, RT, and analysis, respectively. All of the enrolled children received local RT, and 15 patients received total body irradiation (TBI). Median growth percentiles were 67.0, 54.0, and 4.9 at diagnosis, RT, and analysis, respectively. The number of irradiated vertebrae (P=0.009) and having undergone TBI (P=0.03) were significantly associated with shorter stature. Among the MRI parameters for irradiated vertebrae, signal intensity was higher (P=0.05) and more heterogeneous (P=0.02) in T1-weighted images and roundness was lower (P=0.03) in T2-weighted images. CONCLUSIONS Height of children with neuroblastoma was significantly affected by RT. The number of irradiated vertebrae and having undergone TBI were significantly associated with lower height. Irradiated spine showed changes in both signal and shape on MRI.

Clinical outcomes of tissue expanders on adjuvant radiotherapy of resected retroperitoneal sarcoma.

Abstract We investigated the efficacy and safety of a tissue expander (TE) for adjuvant radiotherapy (RT) of resected retroperitoneal sarcoma (RPS). This study was conducted with 37 patients with RPS who received resection with or without TE insertion followed by RT from August 2006 to June 2012 at Samsung Medical Center. Among the 37 patients, TE was inserted in 19. The quality of TE insertion was evaluated according to the correlation of clinical target volume and retroperitoneal surface volume covered by TE and was defined as follows: excellent, ≥85%; good, 70% to 85%; fair, 50% to 70%; and poor, <50%. The median follow-up period after surgery was 47.9 months (range, 5.5–85.5 months). The quality of TE insertion was excellent in 7 (36.8%), good in 5 (26.3%), fair in 4 (21.0%), and poor in 3 (16.7%) patients. A significantly higher biologically equivalent dose (BED, &agr;/&bgr; = 10) was used in patients who had TE insertion (median, 64.8 vs. 60.0 Gy, P = 0.01). Local control was 39.7%, and overall survival was 76.4% at 5 years. Local control was significantly higher in patients who received ≥65 Gy of BED, 100.0% in contrast to 22.8% (P = 0.01). One patient with a history of multiple tumor resections showed abdominal infection with duodenal perforation of uncertain cause but had the potential of being related to TE and/or RT. Otherwise there were no ≥grade III acute or late toxicities. TE for adjuvant RT in RPS is feasible for delivering a higher RT dose with acceptable toxicity.

Clinical outcomes in cervical cancer patients treated by FDG-PET/CT-based 3-dimensional planning for the first brachytherapy session.

AbstractThe aim of the study was to evaluate the treatment outcomes in cervical cancer patients treated with 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT)-guided 3-dimensional brachytherapy (3D-BT) planning for the first brachytherapy session.We retrospectively analyzed 87 patients with cervical cancer who received definitive radiotherapy (RT). Primary tumor size was ⩽4 cm in 22 patients (25.3%), >4 cm and ⩽6 cm in 45 patients (51.7%), and >6 cm in 20 patients (23.0%). The median total dose of external beam RT was 50.4 (50.4–60.4) Gy. FDG-PET/CT-guided 3D-BT with an iridium-192 source was performed. The clinical target volume (CTV) for 3D-BT included the entire cervix and the abnormal FDG-uptake with a 1-cm expansion. A planned total dose was 24 Gy at 4 Gy per insertion 3 times per week using a tandem and 2 ovoids.The mean D95 and D90 for the CTV were 73.4 (±5.9) Gy and 77.9 (±6.9) Gy, respectively (EQD2, &agr;/&bgr;=10). The D2cc for the rectum and bladder was 374 (±97.4) cGy and 394 (±107.6) cGy per fraction, respectively. The EQD2 (&agr;/&bgr;=3) for the D2cc was 74.5 (±12.4) Gy for the rectum and 77.3 (±14.6) Gy for the bladder. The median follow-up period was 40 (8–61) months. The 3-year overall survival (OS), progression-free survival (PFS), and local control (LC) rates were 84.7%, 72.1%, and 89.2%, respectively. The 3-year LC rate was 100% for tumors ⩽ 4 cm, 91.1% for tumors > 4 cm and ⩽ 6 cm, and 70.5% for tumors > 6 cm (P = 0.014). Local failure developed in 9 patients. Three patients had local failures outside of the CTV. Grade 1, 2, and 3 rectal bleeding developed in 5, 4, and 2 patients, respectively. One patient experienced rectovaginal fistula.FDG-PET/CT-guided 3D-BT planning is a feasible approach, which showed favorable clinical outcomes.

High-dose radiation therapy alone by moderate hypofractionation for patients with thoracic esophageal squamous cell carcinoma.

Abstract We conducted retrospective analyses to investigate the clinical outcome of thoracic esophageal cancer patients who were treated with high-dose radiation therapy (RT) alone by moderate hypofractionation due to medical unfitness or refusal to receive either surgery or chemo-radiotherapy. Between May 2003 and April 2013, 70 patients were treated with high-dose RT alone with curative aim. The planned total RT dose was 60 Gy in daily 3.0 Gy per fraction. We evaluated the survival outcome, toxicities, and prognostic factors affecting patients’ survival. At the time of analysis, 32 patients experienced disease progression. The 2-year overall survival (OS), cancer-specific survival (CSS) and local control (LC) rates were 52.1%, 57.8%, and 68.2%, respectively. Among them, 25 patients had superficial (cT1a-b) esophageal cancers, and the 2-year OS, CSS, and LC rates were 80.0%, 87.3%, and 81.6%, respectively. Multivariate analysis revealed that cT disease (P < 0.001) and tumor location (P = 0.022) were the significant factors for OS. The incidence of grade 3 or higher toxicities were 9.9%, including grade 3 esophagitis (2 patients, 2.8%) and grade 4 or 5 trachea-esophageal fistula (5 patients, 7.1%). High-dose RT alone by moderate hypofractionation had led to reasonable clinical outcomes at acceptable toxicity risk in thoracic esophageal cancer patients who are medically unfit or refuse surgery or chemotherapy, especially for the patients having superficial lesion.

A simple DVH generation technique for various radiotherapy treatment planning systems for an independent information system

In recent years, the use of a picture archiving and communication system (PACS) for radiation therapy has become the norm in hospital environments and has been suggested for collecting and managing data using Digital Imaging and Communication in Medicine (DICOM) objects from different treatment planning systems (TPSs). However, some TPSs do not provide the ability to export the dose-volume histogram (DVH) in text or other format. In addition, plan review systems for various TPSs often allow DVH recalculations with different algorithms. These algorithms result in inevitable discrepancies between the values obtained with the recalculation and those obtained with TPS itself. The purpose of this study was to develop a simple method for generating reproducible DVH values by using the TPSs. Treatment planning information, including structures and delivered dose, was exported in the DICOM format from the Eclipse v8.9 or the Pinnacle v9.6 planning systems. The supersampling and trilinear interpolation methods were employed to calculate the DVH data from 35 treatment plans. The discrepancies between the DVHs extracted from each TPS and those extracted by using the proposed calculation method were evaluated with respect to the supersampling ratio. The volume, minimum dose, maximum dose, and mean dose were compared. The variations in DVHs from multiple TPSs were compared by using the MIM software v6.1, which is a commercially available treatment planning comparison tool. The overall comparisons of the volume, minimum dose, maximum dose, and mean dose showed that the proposed method generated relatively smaller discrepancies compared with TPS than the MIM software did compare with the TPS. As the structure volume decreased, the overall percent difference increased. The largest difference was observed in small organs such as the eye ball, eye lens, and optic nerve which had volume below 10 cc. A simple and useful technique was developed to generate a DVH with an acceptable error from a proprietary TPS. This study provides a convenient and common framework that will allow the use of a single well-managed storage solution for an independent information system.