• Radiation Oncology Journal
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• v.12 no.1
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• pp.9-16
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• 1994

Hypothesis that hypoxic tumors should be more responsive to the addition of preferential hypoxic cell cytotoxin SR 4233 (tirapazamine) to fractionated irradiation was tested in the mouse SCCVll carcinoma and RIF-1 sarcoma, Model of hypoxic tumor was established using the tumor bed effect: tumors growing in the preirradiated tissue (preirradiated tumors) were more hypoxic than tumors growing in the unirradiated tissue (unirradiated tumors). When the tumors reached a mean volume of 100 $mm^{3}$, both unirradiated and preirradiated tumors were treated with a fractionated course of 6${\times}$2 Gy in 3 days or 8${\times}$2.5 Gy in 4 days with SR 4233 (0.08 mmol/kg/injection) given 30 minutes before each irradiation or without SR 4233. Compared to the unirradiated tumors, hypoxic preirradiated tumors were approximately 5 times more resistant to fractionated irradiation alone but were approximately 5 times more responsive to SR 4233. Addition of SR 4233 Potentiated the effect of fractionated irradiation in both unirradiated and preirradiated tumors. Potentiation in the preirradiated tumors was morequal to or greater than that in the unirradiated tumors and seemed to be higher for more fractionated treatment. We confirm the hypothesis in a transplantable mouse tumor. Present results suggest that radioresistance of some hypoxic tumors can be overcome with hypoxic cytotoxin.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.35-43
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• 2020

Purpose: This retrospective study compares higher-dose whole-brain radiotherapy (hdWBRT) with reduced-dose WBRT (rdWBRT) in terms of clinical efficacy and toxicity profile in patients treated for primary central nervous system lymphoma (PCNSL). Materials and Methods: Radiotherapy followed by high-dose methotrexate (HD-MTX)-based chemotherapy was administered to immunocompetent patients with histologically confirmed PCNSL between 2000 and 2016. Response to chemotherapy was taken into account when prescribing the radiation dose to the whole brain and primary tumor bed. The whole brain dose was ≤23.4 Gy for rdWBRT (n = 20) and >23.4 Gy for hdWBRT (n = 68). Patients manifesting cognitive disturbance, memory impairment and dysarthria were considered to have neurotoxicity. A median follow-up was 3.62 years. Results: The 3-year overall survival (OS) and progression-free survival (PFS) were 70.0% and 48.9% with rdWBRT, and 63.2% and 43.2% with hdWBRT. The 3-year OS and PFS among patients with partial response (n = 45) after chemotherapy were 77.8% and 53.3% with rdWBRT, and 58.3% and 45.8% with hdWBRT (p > 0.05). Among patients with complete response achieved during follow-up, the 3-year freedom from neurotoxicity (FFNT) rate was 94.1% with rdWBRT and 62.4% with hdWBRT. Among patients aged ≥60 years, the 3-year FFNT rate was 87.5% with rdWBRT and 39.1% with hdWBRT (p = 0.49). Neurotoxicity was not observed after rdWBRT in patients aged below 60 years. Conclusion: rdWBRT with tumor bed boost combined with upfront HD-MTX is less neurotoxic and results in effective survival as higher-dose radiotherapy even in partial response after chemotherapy.

• Journal of Korean Neurosurgical Society
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• v.56 no.2
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• pp.98-102
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• 2014

Objective : The purpose of this study was to assess the feasibility and clinical efficacy of motor evoked potential (MEP) monitoring for supratentorial tumor surgery. Methods : Between 2010 and 2012, to prevent postoperative motor deterioration, MEP recording after transcranial stimulation was performed in 84 patients with supratentorial brain tumors (45 males, 39 females; age range, 24-80 years; median age, 58 years). MEP monitoring results were correlated with postoperative motor outcome compared to preoperative motor status. Results : MEP recordings were stable in amplitude (<50% reduction in amplitude) during surgery in 77 patients (91.7%). No postoperative motor deficit was found in 66 out of 77 patients with stable MEP amplitudes. However, postoperative paresis developed in 11 patients. False negative findings were associated with edema in peri-resectional regions and postoperative bleeding in the tumor bed. MEP decrease in amplitude (>50%) occurred in seven patients (8.3%). However, no deficit occurred postoperatively in four patients following preventive management during the operation. Three patients had permanent paresis, which could have been associated with vascular injury during tumor resection. Conclusions : MEP monitoring during supratentorial tumor surgery is feasible and safe. However, false negative MEP results associated with postoperative events may occur in some patients. To achieve successful monitoring, collaboration between surgeon, anesthesiologist and an experienced technician is mandatory.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.120-126
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• 2000

Purpose : Tumor hypoxia can be overcome with hypoxic cytotoxin. In mouse tumor, tirapazamine's efficacy of the potentiating radiation effect was tested by the tumor oxygenation status combined with hype facti on ated rad iotherapy .:The control and hypoxic mouse tumors we established by inoculation of RIF-1 tumor cells into the normal or previously irradiated back and thigh of C3H mice. When the tumors reached a proper size, both the control and hypoxic tumors were given hypefractionated treatments (8fractions/4 days) with saline (0.02 ml/g), tirapazamin (0.08 mM/0.02 ml/kg), irradiation (2.5 Gy), irradiation combined with tirapazamine given 30 minutes prior to each irradiation. The response was evaluated by the growth delay assay by measuring tumor size from day 0 (12 hrs prior to the first fractionation) to the day when the volume had 4-fold increase or cross sectional area had 2-fold increase. Results : Overall growth pattern showed that tirapazamine Potentiated radiation effect in back and thigh tumors grew in the normal and preirradiated tumor bed. With growth delay assay using reference point of initial tumor volume or cross sectional area, tirapazamine potentiated radiation effect 1.9 times for the control and 2.4 times for the hypoxic tumors in back, and 1.85 times for the control and 1.6 times for the hypoxic tumors. With reference of 4-fold increase of the initial volume or 2-fold increase of the cross sectional area, tirapazamine potentiated radiation effect 1.48 times for the control and 2.02 times for the hypxic tumors in back, and 1.85 times for the control and 1.6 times for the hypoxic tumors. Conclusions : Present result indicated that radiation response of hypoxic tumors was potentiated by tirapazamine in the back or thigh tumors grew in the control or preirradiated tumor bed, and potentiation of the hypoxic tumors was eDual to or greater than that of the control tumors in the back or thigh.

• Radiation Oncology Journal
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• v.31 no.3
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• pp.125-130
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• 2013

Purpose: We investigated the role of radiotherapy (RT) for pancreatobiliary neuroendocrine tumors (PB-NETs). Materials and Methods: We identified 9 patients with PB-NETs who received RT between January 2005 and March 2012. Of these 9 patients, 4 were diagnosed with NETs in the pancreas and 5 were diagnosed with NETs in the gallbladder. All patients received RT to the primary tumor or resection bed with a median total irradiation dose of 50.4 Gy, with or without chemotherapy. Results: The tumor response rate and tumor control rate in the RT field were 60% and 100 %, respectively. All 4 patients who underwent surgery had no evidence of disease in the RT field. Of the 5 patients who received RT to the primary gross tumor, 1 had complete response, 2 had partial response, and 2 had stable disease in the RT field. The median time to progression was 11 months. Of the 9 patients, four patients had no progression, and 5 patients had progression of disease (locoregional, 2; distant, 2; locoregional/distant, 1). Of the 4 patients without progression, 3 were treated with RT in adjuvant or neoadjuvant setting, and one received RT to primary tumor. One patient experienced radiation-induced duodenitis at 3 months after concurrent chemoradiation without treatment-related mortality. Conclusion: RT can yield local control for advanced PB-NETs. RT should be considered an essential part of multimodality treatment in management of advanced PB-NETs.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.398-400
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• 2011

Purpose: Subungual tumors are a common cause of nail plate deformity, and may be caused by fibrokeratoma, Koene's tumor and glomus tumors. Neurofibromas, either as part of neurofibromatosis or as a solitary tumor are exceptionally rare in the digits. Methods: A 44-year-old man presented with painless onychodystrophy and nail plate elevation of the right thumb due to a small subungual mass that had started growing 3 years ago. Sensory evaluation of the distal phalanx was normal, and no discoloration nor infection signs were seen. The nail plate was extracted under local anesthesia, and the mass was delicately removed without injury to the nail bed. The nail matrix was repaired with primary closure. Results: Histopathology shows a well circumscribed, cellular tumor with myxoid stroma. Tumor cells were S-100 protein positive, and the patient was diagnosed with myxoid neurofibroma. There has been no sign of recurrence to date, 14 months after the operation. Conclusion: Presentation of cutaneous neurofibromas in the digits is an uncommon finding. They may occur as a manifestation of neurofibromatosis or as a solitary tumor. Subungual neurofibromas are exceptionally rare. To our knowledge, there are only ten reports of solitary subungual neurofibroma unrelated to neurofibromatosis to date. We report a rare case of solitary subungual myxoid neurofibroma of the thumb, that was treated through total excision, with preservation of the nail matrix.

• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.160-167
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• 2011

This study conducts cross-comparison through verification of treatment planning of using beam spoiler and bolus, according to the dose variation of different tumor bed and metastatic lymph node cancers, against ionization and optically stimulated luminescence detectors(OSLDs), in head and neck radiotherapy. Verification of treatment planning examined the feasibility of inserting detectors through simulated solid dry water slabs under identical irradiated conditions from treatment planning system to measure beam spoiler and 0.5, 1 cm bolus. In addition, two detectors were cross-compared for verification of treatment planning accuracy and reliability within ${\pm}$2%. The study found that, given a beam spoiler thickness of 0.5 cm and beam spoiler-to-skin distance of 10 cm subjected to optimal dose distribution given for metastatic lymph node cancers, the bolus low-level skin dose was less, and the tumor bed dose reduced slightly. Additionally, two detectors were cross-compared for accuracy within ${\pm}$1%. Accordingly, The use of beam spoiler was determined that reduces skin side effects and can deliver an optimal dose distribution for tumor, and to apply to future clinical studies should be performed.

• Archives of Plastic Surgery
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• v.42 no.3
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• pp.295-301
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• 2015

Background Glomus tumors were first described by Wood in 1812 as painful subcutaneous tubercles. It is an uncommon benign neoplasm involving the glomus body, an apparatus that involves in thermoregulation of cutaneous microvasculature. Glomus tumor constitutes 1%-5% of all hand tumors. It usually occurs at the subungual region and more commonly in aged women. Its classical clinical triad consists of pain, tenderness and temperature intolerance, especially cold sensitivity. This study reviews 15 cases of glomus tumor which were analyzed according to its anatomic location, surgical approach and histologic findings. Methods Fifteen patients with subungual glomus tumors of the hand operated on between January 2006 and March 2013, were retrospectively reviewed. Patients were evaluated preoperatively with standard physical examination including ice cube test and Love's test. Diagnostic imaging consisted of ultrasonography, computed tomography, and magnetic resonance imaging. All procedures were performed with tourniquet control under local anesthesia. Eleven patients underwent excision using the transungual approach, 3 patients using the volar approach and 1 patient using the lateral subperiosteal approach. Results Total of 15 cases were reviewed. 11 tumors were located in the nail bed, 3 in the volar pulp and 1 in the radial aspect of the finger tip. After complete excision, patients remained asymptomatic in the immediate postoperative period. In the long term follow up, patients exhibited excellent cosmetic results with no recurrence. Conclusions Accurate diagnosis should be made by physical, radiologic and pathologic examinations. Preoperative localization and complete extirpation is essential in preventing recurrence and subsequent nail deformity.

• Radiation Oncology Journal
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• v.33 no.4
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• pp.320-327
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• 2015

Purpose: To investigate the treatment outcome and the toxicity of helical tomotherapy (HT) in patients with metastatic colorectal cancer (mCRC). Materials and Methods: We retrospectively reviewed 18 patients with 31 lesions from mCRC treated with HT between 2009 and 2013. The liver (9 lesions) and lymph nodes (9 lesions) were the most frequent sites. The planning target volume (PTV) ranged from 12 to 1,110 mL (median, 114 mL). The total doses ranged from 30 to 70 Gy in 10-30 fractions. When the ${\alpha}/{\beta}$ value for the tumor was assumed to be 10 Gy for the biologically equivalent dose (BED), the total doses ranged from 39 to $119Gy_{10}$ (median, $55Gy_{10}$). Nineteen lesions were treated with concurrent chemotherapy (CCRT). Results: With a median follow-up time of 16 months, the median overall survival for 18 patients was 33 months. Eight lesions (26%) achieved complete response. The 1- and 3-year local progression free survival (LPFS) rates for 31 lesions were 45% and 34%, respectively. On univariate analysis, significant parameters influencing LPFS rates were chemotherapy response before HT, aim of HT, CCRT, PTV, BED, and adjuvant chemotherapy. On multivariate analysis, $PTV{\leq}113mL$ and $BED>48Gy_{10}$ were associated with a statistically significant improvement in LFPS. During HT, four patients experienced grade 3 hematologic toxicities, each of whom had also received CCRT. Conclusion: The current study demonstrates the efficacy and tolerability of HT for mCRC. To define optimal RT dose according to tumor size of mCRC, further study should be needed.

• Radiation Oncology Journal
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• v.35 no.2
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• pp.144-152
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• 2017

Purpose: The role of radiotherapy (RT) was largely deserted after the introduction of platinum-based chemotherapy, but still survival rates are disappointingly low. This study focuses on assessing the clinical efficacy of RT in relation to chemotherapy resistance. Materials and Methods: From October 2002 to January 2015, 44 patients were diagnosed with epithelial ovarian cancer (EOC) and treated with palliative RT for persistent or recurrent EOC. All patients received initial treatment with optimal debulking surgery and adjuvant platinum-based chemotherapy. The biologically effective dose (BED) was calculated with ${\alpha}/{\beta}$ set at 10. Ninety-four sites were treated with RT with a median BED of 50.7 Gy (range 28.0 to 79.2 Gy). The primary end-point was the in-field local control (LC) interval, defined as the time interval from the date RT was completed to the date any progressive or newly recurring disease within the RT field was detected on radiographic imaging. Results: The median follow-up duration was 52.3 months (range 7.7 to 179.0 months). The 1-year and 2-year in-field LC rates were 66.0% and 55.0%, respectively. Comparisons of percent change of in-field tumor response showed similar distribution of responses among chemoresistant and chemosensitive tumors. On multivariate analysis of predictive factors for in-field LC analyzed by sites treated, $BED{\geq}50Gy$ (hazard ratio, 0.4; confidence interval, 0.2-0.9; p = 0.025) showed better outcomes. Conclusion: Regardless of resistance to platinum-based chemotherapy, RT can be a feasible treatment modality for patients with persistent of recurrent EOC. The specific role of RT using updated approaches needs to be reassessed.