Validation of HDR brachytherapy doses in the treatment of keloid scars using the egs_brachy Monte Carlo application.

Objective. Radiotherapy is a well-known alternative in the treatment of keloid scars to reduce the recurrence of scars. The purpose of this study was to investigate the feasibility and accuracy of dose delivered from a high-dose-rate (HDR) afterloaders in keloid scar brachytherapy using Monte Carlo (MC) simulations and measurements.Approach. Treatment doses and central axis dose profiles were measured using radiophotoluminescence dosimeters and radiochromic films, respectively, with two HDR afterloaders, both using an Ir-192 source, in a phantom made of solid water and polycarbonate sheets. The nominal treatment dose calculated by the AAPM Task Group No. 43 (TG-43) dose model was set to 8.5 Gy at a distance of 0.5 cm laterally from the middle of the source line located in a plastic applicator simulating a 15 cm long surgically removed scar treatment with 30 equally spaced (0.5 cm) source positions. The dose profiles were measured at three different distances from the applicator and the absolute doses at four points at different distances. MC simulations were performed using the egs_brachy, which is based on EGSnrc code system.Main results. The measured and simulated dose profiles match well, especially at 10.0 mm (difference <1%) and 15.0 mm depths (difference <4%), and with a small dose difference at 5.0 mm depth (difference <4%). Point dose measurements agreed well in the dose maximum area (difference <7%) with the simulated dose profiles, although the largest difference near the edge of the profile was <30%. The dose differences between the TG-43 dose model and the MC simulation were small (differences <4%).Significance. Simulated and measured dose levels at a depth of 0.5 cm showed that the nominal treatment dose can be achieved with the utilized setup. The measurement results of the absolute dose agree well with the corresponding simulation results.

A Nomogram with the Keloid Activity Assessment Scale for Predicting the Recurrence of Chest Keloid after Surgery and Radiotherapy.

BACKGROUND: Patients with chest keloids undergoing surgery and adjuvant radiotherapy still have a high recurrence rate, which is a critical problem. The level of keloid activity has not been studied, and a nomogram model for predicting keloid recurrence has not been established in previous studies. METHODS: A total of 145 patients with chest keloids who underwent surgery and radiotherapy between January 2015 and January 2019 at Peking Union Medical College Hospital were included in our study. Demographic and clinical features and the score of KAAS were analyzed. We compared the area under the curve (AUC) and decision curve analysis (DCA) between KAAS and the Vancouver scar scale (VSS) and established a nomogram model for predicting the risk of recurrence. We used bootstrap and calibration plots to evaluate the performance of the nomogram. RESULTS: The KAAS can predict recurrence in patients with chest keloids after surgery and radiotherapy. Areas under the curve (AUCs) of KAAS and VSS were 0.858 and 0.711, respectively (p < 0.001). Decision curve analysis (DCA) demonstrated that the KAAS was better than the VSS. Complications after treatment may be risk factors for keloid recurrence. We created a nomogram by using complications and KAAS. The AUC was 0.871 (95% CI 0.812-0.930). The ROC of the model's bootstrap was 0.865 and was well calibrated. CONCLUSIONS: The KAAS can be used to predict the recurrence and we developed a nomogram for predicting the recurrence of chest keloids after surgery and adjuvant radiotherapy. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Laser Speckle Contrast Imaging for the Objective Assessment of Blood Perfusion in Keloids Treated With Dual-Wavelength Laser Therapy.

BACKGROUND: Most of the widely used methods for the assessment of keloid treatment are subjective grading scales based on the opinion of an individual clinician or patient. There is a growing need for objective methods to evaluate keloid treatment. OBJECTIVE: This study aimed to evaluate the value of laser speckle contrast imaging (LSCI) as an objective method for the assessment of dual-wavelength laser therapy for keloids. METHODS: This prospective study included 21 patients with 54 keloids. All patients were treated with a combined 585-nm pulsed dye laser and 1,064 nm neodymium-doped yttrium aluminum garnet dual-wavelength laser at 4 weeks to 6 weeks intervals. Keloids were assessed using the Vancouver Scar Scale (VSS) and LSCI. RESULTS: The total VSS score significantly decreased after 4 sessions of treatment (p < .05). Blood perfusion in keloids as measured by LSCI was significantly reduced after treatment (p < .05). The improvement of chest keloids in terms of the total VSS score and blood perfusion was significantly greater than that of scapular keloids (p < .05). There was a positive correlation between decreased perfusion and reduced total VSS score (R2 = 0.84). CONCLUSION: Blood perfusion in keloids significantly decreased after dual-wavelength laser therapy. Laser speckle contrast imaging is a promising objective method for assessing the improvement of keloids treated with laser therapy.

A novel conformal superficial high-dose-rate brachytherapy device for the treatment of nonmelanoma skin cancer and keloids.

PURPOSE: To develop a novel conformal superficial brachytherapy (CSBT) device as a treatment option for the patient-specific radiation therapy of conditions including superficial lesions, postsurgical positive margins, Dupuytren's contractures, keloid scars, and complex anatomic sites (eyelids, nose, ears, etc.). METHODS AND MATERIALS: A preliminary CSBT device prototype was designed, built, and tested using readily available radioactive seeds. Iodine-125 (125I) seeds were independently guided to the treatment surface to conform to the target. Treatment planning was performed via BrachyVision Planning System (BPS) and dose distributions measured with Gafchromic EBT3 film. Percent depth dose curves and profiles for Praseodymium-142 (142Pr), and Strontium-90/Yttrium-90 (90Sr-90Y) were also investigated as potential sources. Results achieved with 90Sr-90Y and electron external beam radiation therapy were compared and Monte Carlo N-Particle eXtended 2.6 simulations of 142Pr seeds were validated. RESULTS: BPS was able to predict clinical dose distributions for a multiple seeds matrix. Calculated and measured doses for the 125I seed matrix were 500 cGy and 473.5 cGy at 5 mm depth, and 171.0 cGy and 201.0 cGy at 10 mm depth, respectively. Results of 90Sr-90Y tests demonstrate a more conformal dose than electron EBRT (1.6 mm compared to 4.3 mm penumbra). Measured 142Pr doses were 500 cGy at surface and 17.4 cGy at 5 mm depth. CONCLUSIONS: The CSBT device provides a highly conformal dose to small surface areas. Commercially available BPS can be used for treatment planning, and Monte Carlo simulation can be used for plans using beta-emitting sources and complex anatomies. Various radionuclides may be used in this device to suit prescription depths and treatment areas.

Evaluating keloid recurrence after surgical excision with prospective longitudinal scar assessment scales.

INTRODUCTION: Evaluation tools are used to quantify scar evolution and determine treatment effectiveness. In clinical practice, scar assessment scales are less costly, tend to cover a greater number of aspects related to scar characteristics and can incorporate a patient's opinion in the assessment. However, the scales have not yet been used as an evaluation method for the postoperative recurrence of keloids. OBJECTIVE: The study aims to evaluate the effectiveness of scar rating scales for keloid recurrence after surgical excision. METHODS: Patients (n = 25) with keloids on the trunk were treated by surgical resection and postoperative beta radiation therapy. On the 3rd, 6th, 9th and 12th postoperative months, two specialists classified the lesions qualitatively in recurrent and non-recurrent cases. Furthermore, in the objective evaluation, the items on the Seattle Scar Scale (SSS) and the Stony Brook Scar Evaluation Scale (SBSES) were assessed by specialists, and the patients assessed items on the Patient Scar Assessment Scale (PSAS) for the pre- and postoperative periods. The scars were classified qualitatively as "good" or "poor." RESULTS: Recurrence was observed in 18 patients (72%), according to the specialists' qualitative assessments. The best scores on the SSS and SBSES were given to the non-recurrent (p < 0.001) scars. The highest PSAS values were for the scars classified as "poor" (p < 0.001). There were no differences in the PSAS values for the preoperative period and outcomes for the recurrent scars (p = 0.519). The outcomes showed that the non-recurrent scars had lower values on the PSAS compared to the recurrent scars (p = 0.001) and compared to the preoperative period (p = 0.004). CONCLUSIONS: The PSAS, SSS and SBSES scales were effective methods in distinguishing keloid postoperative recurrence. It is necessary to establish the recurrence cut-off scores for each of the scales according to the treatment used.

Postoperative electron beam radiotherapy for keloids: objective findings and patient satisfaction in self-assessment.

AIM: To evaluate the role of postoperative radiotherapy in the management of keloids. METHODS: Forty-seven patients with a combined total of 60 keloids were treated with 6-MeV electron beam radiotherapy after surgical excision of the keloids. Mean daily fractions of 4 Gy (range, 3-5 Gy) were administered up to a total dose of 16 Gy (range, 12-18 Gy). The median follow-up was 70 months. Patients were asked to complete a questionnaire addressing their satisfaction with the treatment results. This self-assessment was compared with the clinical outcome. RESULTS: Four keloids (7%) relapsed completely, and five recurrences (8%) were classified as limited relapses. All recurrences were observed at sites of high stretch-tension. Keloid-associated symptoms, e.g. itching and pain, were improved in 81%. Hypopigmentation was observed in 29 patients (62%), a mild redness of the scar in eight patients (17%), and grade 1 telangiectasias in two patients (4%). No severe complications or secondary malignancies were observed. Self-assessments did not fully correspond to the clinical examination and recurrence status. Twelve patients were not satisfied with the treatment result, but only two of these relapsed completely. Three relapsed patients described the result of therapy as excellent or good. CONCLUSION: Postoperative electron radiotherapy is well tolerated and very effective in preventing keloid recurrence. To avoid an overestimation of cosmetic outcome, patients should be informed about achievable results before therapy starts.

Results of postoperative (90)Sr radiotherapy of keloids in view of patients' subjective assessment.

BACKGROUND AND PURPOSE: As treatment of keloids is mainly a cosmetic indication, the authors investigated, beyond the recurrence rate, the patients' satisfaction with the result and its correlation with objective medical findings. PATIENTS AND METHODS: 83 keloids of 66 patients had been irradiated after excision by a uniform protocol with 4 x 5 Gy (strontium- 90 [(90)Sr] surface applicator). A questionnaire was developed and sent out in which, above all, the satisfaction with the therapeutic and cosmetic outcome was obtained. These results were correlated with objective parameters and medical findings which were ascertained during an extra follow-up examination. RESULTS: Among 18 of the 41 patients (44%), who had answered the questionnaire, 19 of the 53 keloids treated (36%) had relapsed. 61% of the patients were extremely or mainly satisfied with the therapeutic outcome, 51% extremely or mainly satisfied with the cosmetic outcome. The relief from former keloid-caused symptoms (therapeutic outcome: p = 0.0005; cosmetic outcome: p = 0.0011), the ear as keloid localization (p = 0.0008 and p = 0.0197), and male gender (therapeutic outcome: p = 0.0423) were significantly associated with higher satisfaction. The recurrence rate as well as the extent of radiation side effects had no significant influence on patients' assessment. CONCLUSION: Cosmetic aspects like the dermal side effects and the patients' satisfaction should be taken into account when evaluating the results of radiotherapy in keloids.