• Radiation Oncology Journal
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• v.33 no.3
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• pp.242-249
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• 2015

Purpose: The purpose of this study is to compare the dosimetry of electron beam (EB) plans and three-dimensional helical tomotherapy (3DHT) plans for the patients with left-sided breast cancer, who underwent breast conserving surgery. Materials and Methods: We selected total of 15 patients based on the location of tumor, as following subsite: subareolar, upper outer, upper inner, lower lateral, and lower medial quadrants. The clinical target volume (CTV) was defined as the area of architectural distortion surrounded by surgical clip plus 1 cm margin. The conformity index (CI), homogeneity index (HI), quality of coverage (QC) and dose-volume parameters for the CTV, and organ at risk (OAR) were calculated. The following treatment techniques were assessed: single conformal EB plans; 3DHT plans with directional block of left anterior descending artery (LAD); and 3DHT plans with complete block of LAD. Results: 3DHT plans, regardless of type of LAD block, showed significantly better CI, HI, and QC for the CTVs, compared with the EB plans. However, 3DHT plans showed increase in the $V_{1Gy}$ at skin, left lung, and left breast. In terms of LAD, 3DHT plans with complete block of LAD showed extremely low dose, while dose increase in other OARs were observed, when compared with other plans. EB plans showed the worst conformity at upper outer quadrants of tumor bed site. Conclusion: 3DHT plans offer more favorable dose distributions to LAD, as well as improved target coverage in comparison with EB plans.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.228-233
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• 2013

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.

• Radiation Oncology Journal
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• v.35 no.2
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• pp.121-128
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• 2017

Purpose: To report the results of a correlation analysis of skin dose assessed by in vivo dosimetry and the incidence of acute toxicity. This is a phase 2 trial evaluating the feasibility of intraoperative radiotherapy (IORT) as a boost for breast cancer patients. Materials and Methods: Eligible patients were treated with IORT of 20 Gy followed by whole breast irradiation (WBI) of 46 Gy. A total of 55 patients with a minimum follow-up of 1 month after WBI were evaluated. Optically stimulated luminescence dosimeter (OSLD) detected radiation dose delivered to the skin during IORT. Acute toxicity was recorded according to the Common Terminology Criteria for Adverse Events v4.0. Clinical parameters were correlated with seroma formation and maximum skin dose. Results: Median follow-up after IORT was 25.9 weeks (range, 12.7 to 50.3 weeks). Prior to WBI, only one patient developed acute toxicity. Following WBI, 30 patients experienced grade 1 skin toxicity and three patients had grade 2 skin toxicity. Skin dose during IORT exceeded 5 Gy in two patients: with grade 2 complications around the surgical scar in one patient who received 8.42 Gy. Breast volume on preoperative images (p = 0.001), ratio of applicator diameter and breast volume (p = 0.002), and distance between skin and tumor (p = 0.003) showed significant correlations with maximum skin dose. Conclusions: IORT as a boost was well-tolerated among Korean women without severe acute complication. In vivo dosimetry with OSLD can help ensure safe delivery of IORT as a boost.

• Radiation Oncology Journal
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• v.37 no.2
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• pp.73-81
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• 2019

Purpose: There is sparse literature on treatment outcomes research on resectable oral tongue squamous cell carcinoma (OTSCC). The aim of this study was to measure the treatment outcomes, explore the failure patterns, and identify the potential clinicopathological prognostic factors affecting treatment outcomes for resectable OTSCC. Materials and Methods: It is a retrospective analysis of 202 patients with resectable OTSCC who underwent upfront primary surgical resection followed by adjuvant radiotherapy with or without concurrent chemotherapy if indicated. Results: The median follow-up was 35.2 months (range, 1.2 to 99.9 months). The median duration of locoregional control (LRC) was 84.9 months (95% confidence interval, 67.3-102.4). The 3- and 5-year LRC rate was 68.5% and 58.3%, respectively. Multivariate analysis showed that increasing pT stage, increasing pN stage, and the presence of extracapsular extension (ECE) were significantly associated with poorer LRC. The median duration of overall survival (OS) was not reached at the time of analysis. The 3- and 5-year OS rate was 70.5% and 66.6%, respectively. Multivariate analysis showed that increasing pT stage and the presence of ECE were significantly associated with a poorer OS. Conclusion: Locoregional failure remains the main cause of treatment failure in resectable OTSCC. There is scope to further improve prognosis considering modest LRC and OS. Pathological T-stage, N-stage, and ECE are strong prognostic factors. Further research is required to confirm whether adjuvant therapy adds to treatment outcomes in cases with lymphovascular invasion, perineural invasion, and depth of invasion, and help clinicians tailoring adjuvant therapy.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.26-34
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• 2020

Purpose: Intensity-modulated radiotherapy (IMRT) allows for more precise treatment, reducing unwanted radiation to nearby structures. We investigated the safety and feasibility of IMRT for anaplastic ependymoma patients below 3 years of age. Materials and Methods: A total of 9 anaplastic ependymoma patients below 3 years of age, who received IMRT between October 2011 and December 2017 were retrospectively reviewed. The median equivalent dose in 2 Gy fractions was 52.0 Gy (range, 48.0 to 60.0 Gy). Treatment outcomes and neurologic morbidities were reviewed in detail. Results: The median patient age was 20.9 months (range, 12.1 to 31.2 months). All patients underwent surgery. The rates of 5-year overall survival, freedom from local recurrence, and progression-free survival were 40.6%, 53.3%, and 26.7%, respectively. Of the 9 patients, 5 experienced recurrences (3 had local recurrence, 1 had both local recurrence and cerebrospinal fluid [CSF] seeding, and 1 had CSF seeding alone). Five patients died because of disease progression. Assessment of neurologic morbidity revealed motor dysfunction in 3 patients, all of whom presented with hydrocephalus at initial diagnosis because of the location of the tumor and already had neurologic deficits before radiotherapy (RT). Conclusion: Neurologic morbidity is not caused by RT alone but may result from mass effects of the tumor and surgical sequelae. Administration of IMRT to anaplastic ependymoma patients below 3 years of age yielded encouraging local control and tolerable morbidities. High-precision modern RT such as IMRT can be considered for very young patients with anaplastic ependymoma.

• Radiation Oncology Journal
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• v.36 no.4
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• pp.276-284
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• 2018

Purpose: Traditionally, three-dimensional conformal radiation therapy (3D-CRT) is used for neoadjuvant chemoradiation in locally advanced rectal cancer. Intensity-modulated radiation therapy (IMRT) was later developed for more conformal dose distribution, with the potential for reduced toxicity across many disease sites. We sought to use the National Cancer Database (NCDB) to examine trends and predictors for IMRT use in rectal cancer. Materials and Methods: We queried the NCDB from 2004 to 2015 for patients with rectal adenocarcinoma treated with neoadjuvant concurrent chemoradiation to standard doses followed by surgical resection. Odds ratios were used to determine predictors of IMRT use. Univariable and multivariable Cox regressions were used to determine potential predictors of overall survival (OS). Propensity matching was used to account for any indication bias. Results: Among 21,490 eligible patients, 3,131 were treated with IMRT. IMRT use increased from 1% in 2004 to 22% in 2014. Predictors for IMRT use included increased N stage, higher comorbidity score, more recent year, treatment at an academic facility, increased income, and higher educational level. On propensity-adjusted, multivariable analysis, male gender, increased distance to facility, higher comorbidity score, IMRT technique, government insurance, African-American race, and non-metro location were predictive of worse OS. Of note, the complete response rate at time of surgery was 28% with non-IMRT and 21% with IMRT. Conclusion: IMRT use has steadily increased in the treatment of rectal cancer, but still remains only a fraction of overall treatment technique, more often reserved for higher disease burden.

• 대한두경부종양학회:학술대회논문집
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• 1990.11a
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• pp.8-10
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• 1990

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5337-5341
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• 2014

Background: The standard therapy for stage I rectum cancer is surgical resection. Currently, there is no strong evidence to suggest that any type of adjuvant therapy is beneficial. The risks of local relapse and distant metastasis are higher in rectal tumors. Therefore, while there is no clearly defined absolute indication for adjuvant therapy in lymph node negative colon cancers, rectum tumors that are T3N0 and higher require adjuvant treatment. Due to the more aggressive nature of rectal cancers, we explored the clinical and pathologic factors that could predict the risk of relapse in Stage I (T1-T2) disease and whether there was any progression-free survival benefit to adjuvant therapy. Materials and Methods: This multicenter study was carried out by the Anatolian Society of Medical Oncology. A total of 178 patients with rectal cancers who underwent curative surgery between January 1994 and August 2012 in 13 centers were included in the study. Patient demographics, including survival data and tumor characteristics were obtained from medical charts. Results: The median age was 58 years (range 26-85 years). Most tumors were well or moderately differentiated. For adjuvant treatment, 13 patients (7.3%) received radiotherapy alone, 12 patients (6.7%) received chemotherapy alone and 15 patients (8.4%) were given chemoradiotherapy. Median follow up was 29 months (3-225 months). Some 42 patients (23.6%) had relapse during follow up; 30 with local recurrence (71.4%) whereas 12 (28.6%) were distant metastases. Among the patients, 5-year DFS was 64% and OS was 82%. Mucinous histology and receiving adjuvant therapy were found to have statistically insignificant correlations with relapse and survival. Conclusions: In our retrospective analysis, approximately one quarter of patients exhibited either local or systemic relapse. The rates of relapse were slightly higher in the patients who had no adjuvant therapy. There may thus be a role for adjuvant therapy in high-risk stage I rectal tumors.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2529-2532
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• 2013

Background: Pelvic exenteration is a procedure which includes enbloc resection of pelvic organs followed by surgical reconstruction. Aims include both cure and palliation but data for pelvic exenteration in Thailand are very limited. Objective: This study was conducted to evaluate characteristics of patients, operative procedure outcomes and complications. Materials and Methods: This retrospective review covered all of the charts of exenteration patients during January 2002 to December 2011. Baseline characteristic of the patients were collected as well as details of clinical results. Results: A total of 13 cases of pelvic exenteration were included. Most underwent total pelvic exenteration (9 cases) and the remainder posterior and anterior exenteration. Their primary cancers were ovarian, cervical and vulva. Mean operative time was 532 minutes (SD 160.2, range 270-750) and estimated blood loss was 2830 ml (1850, 1000-8000). Mean tumor size was 7.33 cm (3.75, 4-15). Mean hospital stay was 35.2 days (29.8, 13-109). The most common post operative complication was urinary tract infection. Overall disease free survival with a negative surgical margin was significantly better than in positive surgical margin patients (p=0.014). Conclusions: Surgical margin was the most significant prognostic factor for disease free survival, in line with earlier studies.

• Korean Journal of Head & Neck Oncology
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• v.36 no.2
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• pp.41-44
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• 2020

Clear cell hidradenoma is a skin adnexal tumor originating from eccrine glands. The risk of local recurrence after surgical resection exceeds 50%, and 6-19% of cases are malignant. The rarity of clear cell hidradenoma and its diverse histological findings make this type of tumor a diagnostic challenge. We present a case of recurrent clear cell hidradenoma of the posterior neck in a 70-year-old woman. The tumor recurred once after complete excision, and did not recur again after 1-cm wide excision and reconstruction with a local bilobed flap. Recurrent clear cell hidradenomas are activated by surgical stimulation, increasing the risk for metastasis. Therefore, we suggest that wide excision with confirmation of a tumor-free margin by frozen-section biopsy should be the first-line treatment for recurrent benign clear cell hidradenoma.