Earticle

Background Open thyroidectomy is conventionally performed at the anterior side of neck, which is a body part with a comparatively great degree of open exposure; due to this, postoperative scarring may cause distress in patients. We aimed to compare the effects of ablative and nonablative fractional laser treatments on thyroidectomy scars. We examined medical records in a retrospective manner and analyzed scars based on their digital images by using the modified Manchester Scar Scale (mMSS). Methods Between February 2012 and May 2013, 55 patients with thyroidectomy scars were treated with ablative (34 patients) or nonablative (21 patients) fractional laser. Each patient underwent 4 laser treatment sessions in 3-4 week intervals, 1-2 months postoperatively. Scar improvement was assessed using patient images and the mMSS scale. Results The mean decrease in scar score was 3.91 and 3.47 in the ablative and nonablative groups, respectively; the reduction between 2 groups did not exhibit any significant difference (P=0.16). We used the scale once again to individually evaluate scar attributes. The nonablative group accounted for a considerably higher color score value (P=0.03); the ablative group accounted for a considerably higher contour score value (P<0.01). Patient satisfaction was high and no complications occurred. Conclusions Both types of fractional laser treatments can be used successfully for thyroidectomy scar treatment with minimal complications; however, results indicate that higher effectiveness may be obtained from the use of ablative and nonablative lasers for hypertrophic scars and early erythematous scars, respectively. Therefore, the appropriate laser for scar treatment should be selected according to its specific characteristics.

Purpose: Fractional microneedle radiofrequency (FMR) systems are used to treat inflammatory acne and scarring. Nonetheless, few controlled studies have combined this treatment with the traditional ablative fractional laser (AFL). We aimed to assess the safety and efficacy of the combination of FMR and AFL versus AFL alone in treating acne and acne scars. Materials and Methods: In this 20-week, randomized, split-face study, 23 Korean patients with facial acne and acne scars under went FMR and AFL treatments. One half of each patient’s face was randomly assigned to receive FMR+AFL, whereas the other half received AFL alone. Treatments were administered in three consecutive sessions at 4-week intervals. This study investigated the severity of inflammatory acne, acne scars, individual lesion counts, depressed scar volumes, as well as patient and physician satisfaction. In addition, five patients underwent skin biopsy, and sebum output was measured. Results: The FMR+AFL treatment demonstrated superior efficacy compared to AFL alone in terms of inflammatory acne and acne scar grading, lesion counts, and subjective satisfaction. The side effects were minimal and well-tolerated in both groups. Immuno histochemical findings from skin biopsy samples revealed that the application of FMR+AFL could induce an inhibitory effect on sebum secretion at the molecular level. Conclusion: FMR combined with AFL is a well-tolerated and effective treatment modality for inflammatory acne and acne scarring.

Background: Recent reports have shown that intralesional botulinum toxin type-A (BTX-A) works on scar cosmesis. Objective: To evaluate the clinical efficacy of combination treatment of laser and BTX-A injection and compare the effects of conventional intralesional injection and intra- and perilesional BTX-A injection on fibrotic thyroidectomy scars. Methods: Patients with fibrotic thyroidectomy scars showing insufficient responses to previous ablative fractional laser (AFL) treatment were enrolled. Combination treatment with AFL and BTX-A injection was performed. Patients who received intra/perilesional BTX-A injections were classified into group A. Group B was patients in whom the injection was performed only intralesionally. The improvement was assessed based on the Vancouver Scar Scale (VSS). Results: A total of 24 patients was included. Statistically significant improvement in pliability and total VSS score after the combination treatment were observed in overall patient group. Subgroup analysis demonstrated that pliability, height, and total VSS improved significantly in group A. In group B, only pliability significantly improved. Conclusion: BTX-A injection combined with AFL can provide better relief for the previously treated fibrotic thyroidectomy scars. Injection of BTX-A not only into the scar itself, but also into perilesional muscles that can exert tension on the scar site may provide additional benefit in flattening scar height.

The factors that influence ablation resistance in fiber composites are properties of the reinforced fiber and matrix, plugging quantity of fiber, geometrical arrangement, crack, pore size, and their distributions. To examine ablation resistance according to distribution of crack and pore size that exist in carbon/carbon composites, this study produced various sizes of unit cells of preforms. They were densified using high pressure impregnation and carbonization process. Reinforced fiber is PAN based carbon fiber and composites were heat-treated up to $2800^{\circ}C$. The finally acquired density of carbon/carbon composites reached more than $1.932\;g/cm^3$. The ablation test was performed by a solid propellant rocket engine. The erosion rate of samples is below 0.0286 mm/s. In conclusion, in terms of ablation properties, the higher degree of graphitization is, the more fibers that are arranged vertically to the direction of combustion flame are, and the less interface between reinforced fiber bundle and matrix is, the better ablation resistance is shown.

The Carbon/Carbon composite was prepared from 3D carbon fiber preform and coal tar pitch as matrix precursor. In order to evaluate of ablative characteristics of the composite, liquid rocket system was employed Kerosene and liquid oxygen was used as propellants, operating at a nominal chamber pressure of 330 psi and a nominal mixture ratio (O/F) of 2.0. The results of an experimental evaluation were that high density composite exhibited high, while low density composites showed low erosion resistance. The erosion rate against heat flux was highly depended on the density of the materials. The morphology of eroded fiber showed differently according to collision angle with heat flux on the composite. The granular matrix which derived from carbonization pressure of 900 bar was more resistance to heat flux than well-developed flow type matrix.

This study presents an efficient computational methodology to perform ablative thermal response analysis of carbon/phenolic composites by introducing a novel dual-domain technique for heat transfer and gas diffusion physics. Phenomena such as in-depth heat transfer, material decomposition (i.e. pyrolysis), in-depth gas diffusion, and surface recession required for ablation analysis of carbon/phenolic composites are simulated. The proposed method is verified with reference simulation test data from Ablation Workshop for a one-dimensional model under four different combinations with surface heat flux, temperature, pressure boundary conditions, and surface recession conditions verified. A two-dimensional ablation problem was also solved, showing its scalability. Temperatures, recession depth, depth of boundaries between layers, the mass flux of char, and pyrolysis gas are obtained and compared with the reference for all cases.

In metastatic non-small cell lung cancer (NSCLC), the role of radiotherapy (RT) has been limited to palliation to alleviate the symptoms. However, with the development of advanced RT techniques, recent advances in immuno-oncology therapy targeting programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) and targeted agents for epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) translocation allowed new roles of RT in these patients. Within this metastatic population, there is a subset of patients with a limited number of sites of metastatic disease, termed as oligometastasis that can achieve long-term survival from aggressive local management. There is no consensus on the definition of oligometastasis; however, most clinical trials define oligometastasis as having 3 to 5 metastatic lesions. Recent phase II randomized clinical trials have shown that ablative RT, including stereotactic ablative body radiotherapy (SABR) and hypofractionated RT, to primary and metastatic sites improved progression-free survival (PFS) and overall survival (OS) in patients with oligometastatic NSCLC. The PEMBRO-RT study, a randomized phase II study comparing SABR prior to pembrolizumab therapy and pembrolizumab therapy alone, revealed that the addition of SABR improved the overall response, PFS, and OS in patients with advanced NSCLC. The efficacy of RT in oligometastatic lung cancer has only been studied in phase II studies; therefore, large-scale phase III studies are needed to confirm the benefit of local ablative RT in patients with oligometastatic NSCLC. Local intensified RT to primary and metastatic lesions is expected to become an important treatment paradigm in the near future in patients with metastatic lung cancer.

Purpose We compared the local control rate and toxicity of stereotactic ablative radiotherapy (SABR) versus wedge resection for colorectal pulmonary metastases.Materials and Methods We retrospectively reviewed medical charts and imaging of patients treated with SABR or wedge resection between 2010 and 2017 at a single institution.Results A total of 404 patients were treated with local therapy for 528 pulmonary metastatic lesions. While surgery was frequently used upfront for smaller, solitary metastases without other site involvement, SABR was often used for larger, multiple lesions and disease burdens beyond the lungs. The 3-year local control rate was 88.6% following surgery, which was not significantly different from that with SABR at 86.7% (p=0.174). No major postoperative complications or mortality were observed in the surgery group, and 2.8% of patients in the SABR group experienced grade 3-4 radiation pneumonitis.Conclusion SABR was used in patients with a higher risk of progression compared to those undergoing surgery, yet it has similar local control rates to wedge resection.

Purpose This study aimed to determine the role of local ablative radiotherapy (LART) in oligometastatic/oligoprogressive lung ade-nocarcinoma. Materials and Methods Patients (n=176) with oligometastatic lung adenocarcinoma treated with LART were identified, and those treated with LART at the initial diagnosis of synchronous oligometastatic disease (OMD group) or treated with LART when they presented with repeat oligoprogression (OPD group) were included. Results In the OMD group (n=54), the 1- and 3-year progression-free survival (PFS) were 50.9% and 22.5%, respectively, whereas the 1- and 3-year overall survival in the OPD group were 75.9% and 58.1%, respectively. Forty-one patients (75.9%) received LART at all gross disease sites. Tyrosine kinase inhibitor (TKI) use and all-metastatic site LART were significant predictors of higher PFS (p=0.018 and p=0.046, respectively). In patients treated with TKIs at the time of LART (n=23) and those treated with all-metastatic site LART, the 1-year PFS was 86.7%, while that of patients not treated with all-metastatic site LART was 37.5% (p=0.006). In the OPD group (n=122), 67.2% of the patients (n=82) maintained a systemic therapy regimen after LART. The cumulative incidence of changing systemic therapy was 39.6%, 62.9%, and 78.5% at 6 months, 1 year, and 2 years after LART, respectively. Conclusion Aggressive LART can be an option to improve survival in patients with oligometastatic disease. Patients with synchronous oligometastatic disease receiving TKI and all-metastatic site LART may have improved PFS. In patients with repeat oligoprogression, LART might potentially extend survival by delaying the need to change the systemic treatment regimen.

목 적 : 폐암의 정위 절제 방사선 치료(Stereotactic Ablative Radiation Therapy, SABR)시 복부압박을 이용한 치료계획과 양압지속유지기(The Continuous Positive Air Pressure, CPAP)를 이용한 치료계획을 비교, 분석하여 방사선 치료 효과 향상에 기여하고자 한다. 대상 및 방법 : 본원의 폐의 SABR 환자 중 2명을 대상으로 복부 압박 고정 장치(the Body Pro-Lok, BPL)와 CPAP를 이용한 치료 계획을 수립하여, RTOG 0813에서 제안한 parameter들과 균질도(Homogeneity Index, HI), 일치도(Conformity Index, CI)를 통해 치료계획을 분석하였다. 또한 모든 4D CT에서 각 Phase별 계획용 표적 체적(Planning Target Volume, PTV) 중심의 X, Y, Z축 움직임을 분석하고, PTV와 손상위험장기(Organ At Risk, OAR)의 체적과 평균 선량을 구하여 비교하였다. 그리고 4개의 원뿔형빔 전산화단층촬영(Cone Beam Computed Tomography, CBCT)을 이용하여, PTV 중심점과 0°, 90°, 180°, 270° 중 세 방향에서의 흉강내 접점까지의 직선거리를 측정하고, 각 방향에서 평균거리 값과의 차이를 비교하였다. 결 과 : BPL과 CPAP를 사용하여 얻은 치료계획은 모두 RTOG의 권고값을 따랐으며, 균질도와 일치도에서도 큰 차이가 없었다. PTV 중심의 X축, Y축, Z축 움직임은 A 환자의 경우 BPL 사용시 0.49 cm, 0.37 cm, 1.66 cm, CPAP 사용시 0.16 cm, 0.12 cm, 0.19 cm을 보였고, B 환자의 경우 BPL 사용시 0.22 cm, 0.18 cm, 1.03 cm, CPAP 사용시 0.14 cm, 0.11 cm, 0.4 cm을 보였다. CPAP 사용시 BPL 사용시보다 A 환자의 경우 ITV가 46.27% 감소하였고 좌측 폐의 체적이 41.94% 증가하였으며, 평균선량은 심장에서 52.81% 감소하였다. B 환자의 경우 좌측 폐 106.89%, 우측 폐 87.32% 체적이 증가하였고, 평균선량은 위에서 44.30% 감소하였다. 각 방향의 직선거리 값과 평균거리 값과의 최대 차이는 A 환자의 경우 a방향에서 0.05 cm, b방향에서 0.05 cm, c방향에서 0.41 cm 났고, B 환자의 경우 d방향에서 0.19 cm, e방향에서 0.49 cm, f방향에서 0.06 cm 차이가 났다. 결 론 : CPAP 사용시 폐용적의 증가를 통해 표적 근처 OAR의 선량을 BPL 사용시보다 더 효과적으로 감소시킬 수 있으며, 호흡에 따른 종양의 움직임 제한에도 더 효과적으로 기여할 수 있다는 것을 확인하였다. 추후 CPAP의 다양한 부위 적용과 다른 치료기와의 결합을 통해 방사선 치료 효과를 개선시킬 수 있을 것으로 사료된다.

Purpose : By comparing and analyzing treatment plans using abdominal compression and The Continuous Positive Air Pressure(CPAP) during SABR of lung cancer, we try to contribute to the improvement of radiotherapy effect. Materials & Methods : In two of the lung SABR patients(A, B patient), we developed a SABR plan using abdominal compression device(the Body Pro-Lok, BPL) and CPAP and analyze the treatment plan through homogeneity, conformity and the parameters proposed in RTOG 0813. Furthermore, for each phase, the X, Y, and Z axis movements centered on PTV are analyzed in all 4D CTs and compared by obtaining the volume and average dose of PTV and OAR. Four cone beam computed tomography(CBCT) were used to measure the directions from the center of the PTV to the intrathoracic contacts in three directions out of 0°, 90°, 180° and 270°, and compare the differences from the average distance values in each direction. Result : Both treatment plans obtained using BPL and CPAP followed recommendations from RTOG, and there was no significant difference in homogeneity and conformity. The X-axis, Y-axis, and Z-axis movements centered on PTV in patient A were 0.49 cm, 0.37 cm, 1.66 cm with BPL and 0.16 cm, 0.12 cm, and 0.19 cm with CPAP, in patient B were 0.22 cm, 0.18 cm, 1.03 cm with BPL and 0.14 cm, 0.11 cm, and 0.4 cm with CPAP. In A patient, when using CPAP compared to BPL, ITV decreased by 46.27% and left lung volume increased by 41.94%, and average dose decreased by 52.81% in the heart. In B patient, volume increased by 106.89% in the left lung and 87.32% in the right lung, with an average dose decreased by 44.30% in the stomach. The maximum difference of A patient between the straight distance value and the mean distance value in each direction was 0.05 cm in the a-direction, 0.05 cm in the b-direction, and 0.41 cm in the c-direction. In B patient, there was a difference of 0.19 cm in the d-direction, 0.49 cm in the e-direction, and 0.06 cm in the f-direction. Conclusion : We confirm that increased lung volume with CPAP can reduce doses of OAR near the target more effectively than with BPL, and also contribute more effectively to restriction of tumor movement with respiration. It is considered that radiation therapy effects can be improved through the application of various sites of CPAP and the combination with CPAP and other treatment machines.

Becker’s nevus (BN) is a benign hamartoma that may present as a distressing cosmetic problem. The treatment of BN poses a significant challenge as current therapeutic modalities aresuboptimal and have an increased risk of adverse effects, such as scarring and dyspigmentation. We present the use of non-ablative fractional laser therapy combined with Q-switchedNd:YAG laser as a possible therapeutic option for BN treatment and review relevant literatureto discuss its efficacy and limitations.

Background: Recently, photodynamic therapy (PDT) has been shown to be an effective first-line treatment for actinic keratosis (AK). However, a major limitation of PDT is the long incubation time required to allow penetration of the photosensitizer. Objective: The aim of this study was to assess if pretreatment with an ablative carbon dioxide (CO2)fractional laser can reduce the incubation time of the photosensitizer. Methods: Initially, 29 patients with a total of 34 AK lesions were treated with an ablative CO2 fractional laser at Ajou University Hospital between January and December 2010. Immediately after the laser treatment,topical 20% 5-aminolevulinic acid or methyl-aminolevulinate was applied to the AK lesions and incubated for 70 to 90minutes. Then, the treated areas were illuminated with a red light source. Improvement was clinically or histologically assessed eight weeks after the treatment. Results: In spite of the short incubation time, 24 lesions (70.6%) showed a complete response (CR) within three sessions of PDT (10 lesions a clinical CR and 14 lesions a clinical/histological CR). There were no significant side effects associated with the combination of ablative CO2 fractional laser and PDT. Conclusion:Ablative CO2 fractional laser may be considered an additional treatment option for reducing the incubation time of the photosensitizer in PDT.

Background: Topical photodynamic therapy (PDT) has been increasingly used to treat malignant skin tumors including the Bowen disease. However, patients could be displeased with the long incubation time required for conventional PDT. Objective: We evaluated the efficacy and safety of PDT with a short incubation time of ablative CO2 fractional laser pretreatment for treating Bowen disease. Methods: Ten patients were included. Just before applying the topical photosensitizer, all lesions were treated with ablative CO2fractional laser, following the application of methyl aminolevulinate and irradiation with red light (Aktilite CL 128). Histological confirmation, rebiopsy, and clinical assessments were performed. Adverse events were also recorded. Results: Five of the ten (50%) lesions showed a complete response (CR) within three PDT sessions. After four treatment sessions, all lesions except one penile shaft lesion (90%) achieved clinical and histological CR or clinical CR only. The average number of treatments to CR was 3.70±1.70. The treatments showed favorable cosmetic outcomes and no serious adverse events. Conclusion: The results suggest that pretreatment with an ablative fractional CO2 laser before PDT has similar treatment efficacy and requires a shorter photosensitizer incubation time compared with the conventional PDT method.

A compelling body of non-randomized evidence has established stereotactic ablative lung radiotherapy (SABR) as a standard of care for medically inoperable patients with peripheral early-stage non-small cell lung cancer (NSCLC). This convenient outpatient therapy, which is typically delivered in 3-8 fractions, is also well tolerated by elderly and frail patients, makes efficient use of resources and is feasible using standard commercial equipment. The introduction of lung SABR into large populations has led to an increased utilization of radiotherapy, a reduction in the proportion of untreated patients and an increase in overall survival. In selected patients, the same ablative technology can now achieve durable local control of NSCLC metastases in a variety of common locations including the adrenal glands,bone, brain, and liver. At the same time as this, advances in prognostic molecular markers and targeted systemic therapies mean that there is now a subgroup of patients with stage IV NSCLC and a median survival of around 2 years. This creates opportunities for new trials that incorporate SABR and patient-specific systemic strategies. This selective mini-review focuses on the emerging role of SABR in patients with early-stage and oligometastatic NSCLC.

This paper discusses the development of the English preposition from and its English corresponding particle pwuthe from a grammaticalization perspective. From and pwuthe are grammatical markers in Present-day English and Korean to denote an ablative concept that typically develops from COME FROM, DEPART, MOVE (OUT), and LEAVE. This interesting phenomenon of semantic change involves an antonymization, in which the meanings of the source and the result are compared. Examination of the bizarre semantic development of from and pwuthe suggests a grammaticalization process that is largely enabled by the conceptual mechanisms along the event schema, and presents an explication for the peculiar relationship between allative (i.e. goal-oriented) and ablative (i.e. source) concepts based on the cognitive forces that operate in language use. To do this, cognitive enabling mechanisms such as metaphor, metonymy, and subjective frame-of-focus variation (Rhee 2000) are invoked as major forces to cause the semantic changes. Additional discussions on distributional characteristics are designed to support the semantic and syntactic distributions of these markers and their degree of grammaticality within the category.

Background : Skin injuries, such as lacerations due to trauma, are relatively common, and patients are very concerned about the resulting scars. Recently, the use of ablative and non-ablative lasers based on the fractional approach has been used to treat scars. In this study, the authors demonstrated the efficacy and safety of ablative fractional resurfacing (AFR) for traumatic scars using a 2,940-nm erbium: yttrium-aluminum-garnet (Er:YAG) laser for traumatic scars after primary repair during the early posttraumatic period. Methods : Twelve patients with fifteen scars were enrolled. All had a history of facial laceration and primary repair by suturing on the day of trauma. Laser therapy was initiated at least 4 weeks after the primary repair. Each patient was treated four times at 1-month intervals with a fractional ablative 2,940-nm Er:YAG laser using the same parameters. Posttreatment evaluations were performed 1 month after the fourth treatment session. Results : All 12 patients completed the study. After ablative fractional laser treatment, all treated portions of the scars showed improvements, as demonstrated by the Vancouver Scar Scale and the overall cosmetic scale as evaluated by 10 independent physicians, 10 independent non-physicians, and the patients themselves. Conclusions : This study shows that ablative fractional Er:YAG laser treatment of scars reduces scars fairly according to both objective results and patient satisfaction rates. The authors suggest that early scar treatment using AFR can be one adjuvant scar management method for improving the quality of life of patients with traumatic scars.

Rhee, Seongha. 2007. On Interrelation of Instrumental and Ablative. Discourse and Cognition 14.3, 131-153. This paper addresses the issues surrounding the close relationship between Instrumental and Ablative across languages. This inter-categorial relationship is widespread across both time and space. This close relationship often results in case syncretism, and creates the difficulties of case labeling due to lack of isomorphy. This intimate relationship becomes more complicated when the source lexemes from which the two forms are grammaticalized are considered. For instance, Instrumental typically develops from such lexical items as MEET, WAY, MOVE, USE, HOLD, TAKE, SIDE, FLANK, and DEPART, whereas Ablative typically develops from COME FROM, DEPART and LEAVE. This poses an interesting question since some of the semantics of the two source group lexemes is largely antonymous. This calls for the need of evaluating the well-known source determination hypothesis (Bybee et al. 1994) and semantic persistence (Hopper 1991). It is suggested in this paper that grammaticalization process is largely enabled by the conceptual mechanisms along the event schema, a process largely not mindful of semantic clashes between the source and the target meanings, or between the resultant grammatical meanings, unlike the claims of avoidance of antonymy and of form-function isomorphy. This paper presents an explication on this peculiar relationship, based on the cognitive forces that operate in language use from a grammaticalization perspective. In addition to the traditional cognitive mechanisms of semantic change, this paper illustrates how different conceptualization on an event schema can bring forth diverse grammatical markers.