Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

A congenital defect of the anterior wall of the external auditory canal (EAC) is known as foramen of Huschke. The tympanic bone is incompletely developed and has a U shape at birth. The foramen of Huschke closes via continuous bone growth, which occurs before the age of 5 years. A persistent foramen of Huschke is an anatomic variation located in the anteroinferior portion of EAC, which can cause ear discomfort with spontaneous temporomandibular joint (TMJ) herniation into the EAC bony defect. We present a case of 50-year-old man who had a symptomatic TMJ herniation through an osseous defect. The physical examination showed a bulging mass of anterioinferior portion of EAC when the patient closed his mouth, which was retracted when the mouth openned. We report a case of surgical reconstruction of the EAC wall defect, and the foramen of Huschke with titanium mesh via preauricular approach along with literature’s review.

Amelanotic melanoma comprises only 1.8~8.1% of malignant melanomas, and is difficult to diagnose clinically due to the lack of the diagnostic evidence of clinical pigmentation. To our knowledge, it is rarely reported, and only 10 cases have been reported in the Korean dermatological literature. It presents rather conflicting features such as a pink or red macule, papule, plaque, or nodule mimicking various benign and malignant conditions; therefore, it is difficult to diagnose. We performed a review of six patients with amelanotic melanoma focusing on differential diagnosis, particularly at the time of the initial visit. Clinical impressions included pyogenic granuloma, dermatofibrosarcoma protuberans, eccrine poroma, epidermal cyst, keloid, pilomatricoma, and squamous cell carcinoma in addition to malignant melanoma. The biopsy specimens were consistent with malignant melanoma with little or no melanin pigment on hematoxylin and eosin and Fontana-Masson stains. Four of the six patients were positive for S-100 and HMB-45, but two patients were positive for S-100 only. We report these cases to remind clinicians of the necessity of including malignant melanoma in the differential diagnosis process when patients show poor and unpredictable responses to treatment after a clinical diagnosis of other benign and malignant conditions.
Biopsy ; Carcinoma, Squamous Cell ; Coloring Agents ; Dermatofibrosarcoma ; Diagnosis ; Diagnosis, Differential* ; Eosine Yellowish-(YS) ; Epidermal Cyst ; Granuloma, Pyogenic ; Hematoxylin ; Humans ; Keloid ; Melanins ; Melanoma ; Melanoma, Amelanotic* ; Pigmentation ; Pilomatrixoma ; Poroma

BACKGROUND AND OBJECTIVES: Pneumatization of air cells in the mastoid bone is decreased in chronic otitis media (COM). A decrease in the size of the external auditory canal (EAC) is also found frequently in patients with COM, but this has been little studied. We compared the size of affected bony EACs and the contralateral side in patients with single-side COM using high-resolution computed tomography. SUBJECTS AND METHODS: In total, 99 patients with single-side COM were included. Four indicators related to the size of the bony EAC and IAC were measured using high-resolution computed tomography: the axial and coronal lengths of the tympanic membrane, the length of the isthmus, and the area of the bony ear canal. We also compared both internal auditory canals as negative controls. These assessments were made by radiologists who were blinded to the objective of this study. RESULTS: In patients with single-side COM, the axial length of the tympanic membrane was significantly shorter than normal, and the volume of the EAC was also significantly smaller. The length of the isthmus of the EAC was shorter on the affected side, but the difference was not significant. The IAC volume showed no difference between the two sides. CONCLUSIONS: COM affects general temporal bony development, including the bony EAC and mastoid bone. Therefore, whether to correct this should be considered when preparing for COM surgery.
Ear Canal* ; Humans ; Mastoid ; Otitis Media* ; Otitis* ; Tympanic Membrane

BACKGROUND: Various systemic agents have been assessed for the treatment of alopecia areata (AA); however, there is a paucity of comparative studies. OBJECTIVE: To assess and compare cyclosporine and betamethasone minipulse therapy as treatments for AA with regard to effectiveness and safety. METHODS: Data were collected from 88 patients who received at least 3 months of oral cyclosporine (n=51) or betamethasone minipulse therapy (n=37) for AA. Patients with ≥50% of terminal hair regrowth in the alopecic area were considered responders. RESULTS: The responder of the cyclosporine group was 54.9% and that of the betamethasone minipulse group was 37.8%. In the cyclosporine group, patients with mild AA were found to respond better to the treatment. Based on the patient self-assessments, 70.6% of patients in the cyclosporine group and 43.2% of patients in the betamethasone minipulse group rated their hair regrowth as excellent or good. Side effects were less frequent in the cyclosporine group. CONCLUSION: Oral cyclosporine appeared to be superior to betamethasone minipulse therapy in terms of treatment effectiveness and safety.
Alopecia Areata* ; Alopecia* ; Betamethasone* ; Cyclosporine* ; Hair ; Humans ; Pulse Therapy, Drug ; Self-Assessment ; Treatment Outcome

PURPOSE: To evaluate the efficacy of low-dose computed tomography (LDCT) for detecting urinary stones with the use of an iterative reconstruction technique for reducing radiation dose and image noise. MATERIALS AND METHODS: A total of 101 stones from 69 patients who underwent both conventional nonenhanced computed tomography (CCT) and LDCT were analyzed. Interpretations were made of the two scans according to stone characteristics (size, volume, location, Hounsfield unit [HU], and skin-to-stone distance [SSD]) and radiation dose by dose-length product (DLP), effective dose (ED), and image noise. Diagnostic performance for detecting urinary stones was assessed by statistical evaluation. RESULTS: No statistical differences were found in stone characteristics between the two scans. The average DLP and ED were 384.60+/-132.15 mGy and 5.77+/-1.98 mSv in CCT and 90.08+/-31.80 mGy and 1.34+/-0.48 mSv in LDCT, respectively. The dose reduction rate of LDCT was nearly 77% for both DLP and ED (p<0.01). The mean objective noise (standard deviation) from three different areas was 23.0+/-2.5 in CCT and 29.2+/-3.1 in LDCT with a significant difference (p<0.05); the slight increase was 21.2%. For stones located throughout the kidney and ureter, the sensitivity and specificity of LDCT remained 96.0% and 100%, with positive and negative predictive values of 100% and 96.2%, respectively. CONCLUSIONS: LDCT showed significant radiation reduction while maintaining high image quality. It is an attractive option in the diagnosis of urinary stones.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Pilot Projects ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted/*methods ; Reproducibility of Results ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods ; Urinary Calculi/*radiography ; Young Adult

PURPOSE: This study was conducted to evaluate prognostic factors and cancer-specific survival (CSS) in a cohort of 41 patients with urachal carcinoma by use of a Bayesian model-averaging approach. MATERIALS AND METHODS: Our cohort included 41 patients with urachal carcinoma who underwent extended partial cystectomy, total cystectomy, transurethral resection, chemotherapy, or radiotherapy at a single institute. All patients were classified by both the Sheldon and the Mayo staging systems according to histopathologic reports and preoperative radiologic findings. Kaplan-Meier survival curves and Cox proportional-hazards regression models were carried out to investigate prognostic factors, and a Bayesian model-averaging approach was performed to confirm the significance of each variable by using posterior probabilities. RESULTS: The mean age of the patients was 49.88+/-13.80 years and the male-to-female ratio was 24:17. The median follow-up was 5.42 years (interquartile range, 2.8-8.4 years). Five- and 10-year CSS rates were 55.9% and 43.4%, respectively. Lower Sheldon (p=0.004) and Mayo (p<0.001) stage, mucinous adenocarcinoma (p=0.005), and larger tumor size (p=0.023) were significant predictors of high survival probability on the basis of a log-rank test. By use of the Bayesian model-averaging approach, higher Mayo stage and larger tumor size were significant predictors of cancer-specific mortality in urachal carcinoma. CONCLUSIONS: The Mayo staging system might be more effective than the Sheldon staging system. In addition, the multivariate analyses suggested that tumor size may be a prognostic factor for urachal carcinoma.
Adult ; Bayes Theorem ; Carcinoma/*pathology/*therapy ; Disease-Free Survival ; Female ; Follow-Up Studies ; Humans ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Neoplasm Staging ; Prognosis ; Proportional Hazards Models ; Risk Factors ; Treatment Outcome ; Urinary Bladder Neoplasms/*pathology/*therapy

PURPOSE: To evaluate the efficacy of low-dose computed tomography (LDCT) for detecting urinary stones with the use of an iterative reconstruction technique for reducing radiation dose and image noise. MATERIALS AND METHODS: A total of 101 stones from 69 patients who underwent both conventional nonenhanced computed tomography (CCT) and LDCT were analyzed. Interpretations were made of the two scans according to stone characteristics (size, volume, location, Hounsfield unit [HU], and skin-to-stone distance [SSD]) and radiation dose by dose-length product (DLP), effective dose (ED), and image noise. Diagnostic performance for detecting urinary stones was assessed by statistical evaluation. RESULTS: No statistical differences were found in stone characteristics between the two scans. The average DLP and ED were 384.60+/-132.15 mGy and 5.77+/-1.98 mSv in CCT and 90.08+/-31.80 mGy and 1.34+/-0.48 mSv in LDCT, respectively. The dose reduction rate of LDCT was nearly 77% for both DLP and ED (p<0.01). The mean objective noise (standard deviation) from three different areas was 23.0+/-2.5 in CCT and 29.2+/-3.1 in LDCT with a significant difference (p<0.05); the slight increase was 21.2%. For stones located throughout the kidney and ureter, the sensitivity and specificity of LDCT remained 96.0% and 100%, with positive and negative predictive values of 100% and 96.2%, respectively. CONCLUSIONS: LDCT showed significant radiation reduction while maintaining high image quality. It is an attractive option in the diagnosis of urinary stones.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Pilot Projects ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted/*methods ; Reproducibility of Results ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods ; Urinary Calculi/*radiography ; Young Adult

PURPOSE: This study was conducted to evaluate prognostic factors and cancer-specific survival (CSS) in a cohort of 41 patients with urachal carcinoma by use of a Bayesian model-averaging approach. MATERIALS AND METHODS: Our cohort included 41 patients with urachal carcinoma who underwent extended partial cystectomy, total cystectomy, transurethral resection, chemotherapy, or radiotherapy at a single institute. All patients were classified by both the Sheldon and the Mayo staging systems according to histopathologic reports and preoperative radiologic findings. Kaplan-Meier survival curves and Cox proportional-hazards regression models were carried out to investigate prognostic factors, and a Bayesian model-averaging approach was performed to confirm the significance of each variable by using posterior probabilities. RESULTS: The mean age of the patients was 49.88+/-13.80 years and the male-to-female ratio was 24:17. The median follow-up was 5.42 years (interquartile range, 2.8-8.4 years). Five- and 10-year CSS rates were 55.9% and 43.4%, respectively. Lower Sheldon (p=0.004) and Mayo (p<0.001) stage, mucinous adenocarcinoma (p=0.005), and larger tumor size (p=0.023) were significant predictors of high survival probability on the basis of a log-rank test. By use of the Bayesian model-averaging approach, higher Mayo stage and larger tumor size were significant predictors of cancer-specific mortality in urachal carcinoma. CONCLUSIONS: The Mayo staging system might be more effective than the Sheldon staging system. In addition, the multivariate analyses suggested that tumor size may be a prognostic factor for urachal carcinoma.
Adult ; Bayes Theorem ; Carcinoma/*pathology/*therapy ; Disease-Free Survival ; Female ; Follow-Up Studies ; Humans ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Neoplasm Staging ; Prognosis ; Proportional Hazards Models ; Risk Factors ; Treatment Outcome ; Urinary Bladder Neoplasms/*pathology/*therapy

BACKGROUND AND OBJECTIVES: Sudden sensorineural hearing loss (SSNHL) is commonly defined as a loss of at least 30 dB in three contiguous frequencies occurring within 3 days. Systemic steroid administration has become the most widely accepted treatment option for SSNHL. Since viral infection and vascular compromise are considered specific causes of SSNHL, antiviral agents, anticoagulants, and stellate ganglion block have been used for its treatment, although the evidence of their effectiveness is weak. The present study evaluated the hearing recovery rate in the combination therapy group (systemic steroids, antiviral agent, anticoagulants, and stellate ganglion block) in comparison with patients treated with systemic steroids alone. SUBJECTS AND METHODS: A total of 85 patients diagnosed with SSNHL were treated with combination therapy (group A, 46 patients) or systemic steroids only (group B, 39 patients). Hearing improvement was defined as a hearing gain of more than slight improvement using Siegel's criteria. All patients were treated with a 10-day course of systemic steroids (10-mg dexamethasone for 5 days, followed by tapering for 5 days). Acyclovir, heparin, and stellate ganglion block were included in the group A treatment regimen. RESULTS: The overall rate of hearing improvement was 60.9% (28/46 patients) in group A, which was significantly higher than that (38.5%, 15/39 patients) in group B. The distribution of prognostic factors was not significantly different between the two groups with the exception of the degree of initial hearing loss, which was more severe in group A. Upon analysis according to prognostic factors, group A showed a better hearing improvement recovery rate than group B in patients with hearing loss >70 dB, age >41 years, dizziness, and early treatment (<1 week). CONCLUSIONS: Thus SSNHL patients treated with combination therapy have a higher likelihood of hearing improvement than those treated with systemic steroids alone.
Acyclovir ; Anticoagulants ; Antiviral Agents ; Dexamethasone ; Dizziness ; Hearing ; Hearing Loss ; Hearing Loss, Sensorineural ; Heparin ; Humans ; Stellate Ganglion ; Steroids