Predictors of Distant Metastasis after Radical Surgery Followed by Postoperative Radiotherapy with or without Chemotherapy for Oropharyngeal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We investigated the prognostic factors for distant metastasis (DM) in patients with locally advanced oropharyngeal cancer (OPC) treated with surgery and adjuvant radiotherapy with or without concurrent chemotherapy. MATERIALS AND METHODS: Eighty-five patients treated between January 1995 and August 2014 were evaluated retrospectively. Data regarding the pathological tumour and nodal status, human papillomavirus (HPV) status, treatment characteristics, and pretreatment maximum standardized uptake value (SUVmax) of 18-fluoro-2-deoxyglucose positron emission tomography–computed tomography scan (¹⁸F-FDG PET-CT) were evaluated, and their influence on DM and survival outcomes were analyzed. RESULTS: Median follow-up period was 48.0 months. Recurrence was observed in 20 patients, including locoregional recurrence and DM. DM was observed in 13 patients. A multivariate analysis confirmed that the presence of lymphovascular invasion (p=0.031), lower neck lymph node (LN) involvement (p=0.006), SUVmax ≥ 9.7 (p=0.014), and tumour size ≥ 3 cm (p=0.037) significantly affected DM. HPV status was not associated with DM. Perineural invasion (p=0.048), lower neck LNinvolvement (p=0.008), SUVmax ≥ 9.7 (p=0.019), and tumour size ≥ 3 cm (p=0.033) were also significant factors for the DM-free survival rate. CONCLUSION: Lower neck LN involvement, high SUVmax in pretreatment ¹⁸F-FDG PET-CT, and large tumour size were predictive factors for DM in patients of OPC.

Setup Error and Effectiveness of Weekly Image-Guided Radiation Therapy of TomoDirect for Early Breast Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study investigated setup error and effectiveness of weekly image-guided radiotherapy (IGRT) of TomoDirect for early breast cancer. MATERIALS AND METHODS: One hundred and fifty-one breasts of 147 consecutive patients who underwent breast conserving surgery followed by whole breast irradiation using TomoDirect in 2012 and 2013 were evaluated. All patients received weekly IGRT. The weekly setup errors from simulation to each treatment in reference to chest wall and surgical clips were measured. Random, systemic, and 3-dimensional setup errors were assessed. Extensive setup error was defined as 5 mm above the margin in any directions. RESULTS: All mean errors were within 3 mm of all directions. The mean angle of gantry shifts was 0.6degrees. The mean value of absolute 3-dimensional setup error was 4.67 mm. In multivariate analysis, breast size (odds ratio, 2.82; 95% confidence interval, 1.00 to 7.90) was a significant factor for extensive error. The largest significant deviation of setup error was observed in the first week of radiotherapy (p < 0.001) and the deviations gradually decreased with time. The deviation of setup error was 5.68 mm in the first week and within 5 mm after the second week. CONCLUSION: In this study, there was a significant association between breast size and significant setup error in breast cancer patients who received TomoDirect. The largest deviation occurred in the first week of treatment. Therefore, patients with large breasts should be closely observed on every fraction and fastidious attention is required in the first fraction of IGRT.

A Dosimetric Comparative Analysis of TomoDirect and Three-Dimensional Conformal Radiotherapy in Early Breast Cancer / 한국유방암학회지

PURPOSE: The purpose of this study is to compare dosimetric parameters of intensity-modulated mode of TomoDirect and three-dimensional conformal radiotherapy (3D-CRT) in patients with early breast cancer. METHODS: TomoDirect and 3D-CRT planning were carried out for 26 patients with early breast cancer who had received breast-conserving surgery. A total of 50.4 Gy in 28 fractions were prescribed to the planning target volume. The organs at risk (OAR) such as lung and heart were contoured. Planning target volume (PTV) dose coverage, radiation conformity index (RCI), radical dose homogeneity index (rDHI), and irradiation dose of organs at risk were compared between TomoDirect and 3D-CRT planning. RESULTS: The mean PTV dose (51.65+/-0.37 Gy) and V47.8 (100%) in TomoDirect were significantly higher than the mean PTV dose (50.88+/-0.65 Gy) and V47.8 (89.23%+/-0.06%) in 3D-CRT (all, p<0.001). The RCI value in TomoDirect was significantly better than that in 3D-CRT (1.00 vs. 1.13, p<0.001). However, the rDHI value in TomoDirect was not significantly better than that in 3D-CRT (0.72 vs. 0.67, p=0.056). The mean lung dose and V10, V20, V30, and V40 values of ipsilateral lung in TomoDirect were significantly lower than those in 3D-CRT (all, p<0.05). There is no significant difference in the V10, V20, V30, and V40 values of heart between TomoDirect and 3D-CRT. And the mean dose for heart in TomoDirect was marginally lower than that in 3D-CRT (1.05 Gy vs. 1.62 Gy, p=0.085). The mean dose for left anterior descending coronary artery in left breast cancer was significantly lower in TomoDirect than in 3D-CRT (7.2 Gy vs. 12.1 Gy, p<0.001). CONCLUSION: Compared to 3D-CRT, TomoDirect could result in favorable target coverage while reducing the irradiation dose of the ipsilateral lung for patients with early breast cancer.

Postoperative Radiotherapy Alone Versus Chemoradiotherapy in Stage I-II Endometrial Carcinoma: An Investigational and Propensity Score Matching Analysis / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to compare the results of postoperative adjuvant radiotherapy (RT) and concurrent chemoradiotherapy (CRT) in stage I-II endometrial carcinoma. MATERIALS AND METHODS: We analyzed a total of 64 patients with surgically staged I-II endometrial carcinoma who were treated with postoperative adjuvant RT or concurrent CRT between March 1999 and July 2013. Thirty-two patients who received postoperative RT alone were matched with those who received postoperative CRT (n=32) in accordance to age, stage, and tumor histology. Overall survival and relapse-free survival, as well as toxicity of the RT and CRT arms were evaluated and compared. RESULTS: The 5-year overall survival rate was 90.0% for the RT arm and 91.6% for the CRT arm. There was no significant difference in overall survival between the two treatment arms (p=0.798). The 5-year relapse-free survival rate was 87.2% in the RT arm and 88.0% in the CRT arm. Again, no significant difference in relapse-free survival was seen between the two arms (p=0.913). In a multivariate analysis, tumor histology was an independent prognostic factor for relapse-free survival (hazard ratio, 3.67; 95% of CI, 2.34 to 7.65; p=0.045). Acute grade 3 or 4 hematologic toxicities in the CRT arm were significantly higher than in the RT alone arm (6.2% vs. 31.2%, p=0.010). CONCLUSION: Adjuvant pelvic concurrent chemoradioherapy did not show superior results in overall survival and relapse-free survival compared to RT alone in stage I-II endometrial carcinoma.

Outcome of postoperative radiotherapy following radical prostatectomy: a single institutional experience

PURPOSE: This single institutional study is aimed to observe the outcome of patients who received postoperative radiotherapy after radical prostatectomy. MATERIALS AND METHODS: A total of 59 men with histologically identified prostate adenocarcinoma who had received postoperative radiation after radical prostatectomy from August 2005 to July 2011 in Seoul St. Mary's Hospital of the Catholic University of Korea, was included. They received 45-50 Gy to the pelvis and boost on the prostate bed was given up to total dose of 63-72 Gy (median, 64.8 Gy) in conventional fractionation. The proportion of patients given hormonal therapy and the pattern in which it was given were analyzed. Primary endpoint was biochemical relapse-free survival (bRFS) after radiotherapy completion. Secondary endpoint was overall survival (OS). Biochemical relapse was defined as a prostate-specific antigen level above 0.2 ng/mL. RESULTS: After median follow-up of 53 months (range, 0 to 104 months), the 5-year bRFS of all patients was estimated 80.4%. The 5-year OS was estimated 96.6%. Patients who were given androgen deprivation therapy had a 5-year bRFS of 95.1% while the ones who were not given any had that of 40.0% (p < 0.01). However, the statistical significance in survival difference did not persist in multivariate analysis. The 3-year actuarial grade 3 chronic toxicity was 1.7% and no grade 3 acute toxicity was observed. CONCLUSION: The biochemical and toxicity outcome of post-radical prostatectomy radiotherapy in our institution is favorable and comparable to those of other studies.

Prognostic Significance of Serum Carcinoembryonic Antigen Normalization on Survival in Rectal Cancer Treated with Preoperative Chemoradiation / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this retrospective study was to identify factors predictive of survival in rectal cancer patients who received surgery with curative intent after preoperative chemoradiotherapy (CRT). MATERIALS AND METHODS: Between July 1996 and June 2010, 104 patients underwent surgery for rectal cancer after preoperative CRT. The median dose of radiotherapy was 50.4 Gy (range, 43.2 to 54.4 Gy) for 6 weeks. Chemotherapy was a bolus injection of 5-fluorouracil and leucovorin for the first and last week of radiotherapy (n=84, 77.1%) or capecitabine administered daily during radiotherapy (n=17, 16.3%). Low anterior resection (n=86, 82.7%) or abdominoperineal resection (n=18, 17.3%) was performed at a median 47 days from the end of radiotherapy, and four cycles of adjuvant chemotherapy was administered. The serum carcinoembryonic antigen (CEA) level was checked at initial diagnosis and just before surgery. RESULTS: After a median follow-up of 48 months (range, 9 to 174 months), 5-year disease free survival (DFS) was 74.5% and 5-year overall survival (OS) was 86.4%. Down staging of T diagnoses occurred in 32 patients (30.8%) and of N diagnoses in 40 patients (38.5%). The CEA change from initial diagnosis to pre-surgery (high-high vs. high-normal vs. normal-normal) was a statistically significant prognostic factor for DFS (p=0.012), OS (p=0.002), and distant metastasis free survival (p=0.018) in a multivariate analysis. CONCLUSION: Patients who achieve normal CEA level by the time of surgery have a more favorable outcome than those who retain a high CEA level after preoperative CRT. The normalization of CEA levels can provide important information about the prognosis in rectal cancer treatment.

Tumor bed volumetric changes during breast irradiation for the patients with breast cancer

PURPOSE: The aim of this study was to evaluate changes in breast tumor bed volume during whole breast irradiation (WBI). MATERIALS AND METHODS: From September 2011 to November 2012, thirty patients who underwent breast-conserving surgery (BCS) followed by WBI using computed tomography (CT) simulation were enrolled. Simulation CT scans were performed before WBI (CT1) and five weeks after the breast irradiation (CT2). The tumor bed was contoured based on surgical clips, seroma, and postoperative change. We retrospectively analyzed the factors associated with tumor bed volumetric change. RESULTS: The median tumor bed volume on CT1 and CT2 was 29.72 and 28.6 mL, respectively. The tumor bed volume increased in 9 of 30 patients (30%) and decreased in 21 of 30 patients (70%). The median percent change in tumor bed volume between initial and boost CT was -5%. Seroma status (p = 0.010) was a significant factor in tumor bed volume reduction of 5% or greater. However, patient age, body mass index, palpability, T stage, axillary lymph node dissection, and tumor location were not significant factors for tumor bed volumetric change. CONCLUSION: In this study, volumetric change of tumor bed cavity was frequent. Patients with seroma after BCS had a significant volume reduction of 5% or greater in tumor bed during breast irradiation. Thus, resimulation using CT is indicated for exquisite boost treatment in breast cancer patients with seroma after surgery.

Dosimetric evaluation of Tomotherapy and four-box field conformal radiotherapy in locally advanced rectal cancer

PURPOSE: To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer. MATERIALS AND METHODS: Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, V(n Gy), D(min), D(max), radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose. RESULTS: Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p = 0.001). But, V(26.25 Gy) and V(27.5 Gy) were not significantly different between the two modalities. Tomotherapy showed higher D(max) and lower D(min). The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT. CONCLUSION: In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.