Optimal High-Dose-Rate Brachytherapy Fractionation Scheme After Keloid Excision: A Retrospective Multicenter Comparison of Recurrence Rates and Complications

Analysis of the Efficacy of Surgical Excision Combined with Electron Beam Therapy for Keloids

This study aimed to investigate the incidence and impact of patient characteristics and timing of postoperative electron beam therapy on the treatment efficacy of keloids. A total of 66 patients with keloids underwent surgical treatment and postoperative electron beam therapy. Follow-up was conducted for 43 patients, and treatment efficacy was analyzed for 39 patients. Statistical analysis was used to analyze incidence characteristics and effects of patient characteristics and timing of electron beam therapy on treatment efficacy. The study included 66 patients with 133 keloids. The timing of electron beam therapy significantly impacted treatment efficacy, with higher efficacy observed when performed 0-2 days after surgery compared to 3-5 days after surgery. Keloids are more common in women aged 20-40 years. The timing of electron beam therapy significantly impacted treatment efficacy, with higher efficacy observed when performed 0-2 days after surgery compared to 3-5 days after surgery.

A Single-Institution Review of the Use of Radiation in the Adjuvant and Definitive Management of Keloids

AIMS

Many individuals suffer from keloids that are refractory to standard treatment modalities, including surgical excision alone. Radiation therapy can be used to reduce the risk of recurrent keloids post-operatively, as well as be used as primary treatment for keloids not amenable to surgical resection. The purpose of this study was to review our institutional experience of radiation therapy for keloid management.

MATERIALS AND METHODS

A retrospective review of patients treated with radiation therapy for keloids between 2014 and 2020 at our institution was performed.

RESULTS

A total of 70 keloids in 41 patients were treated. For the 55 keloids treated with post-operative radiation therapy (16Gy delivered in 2 fractions), 82.5% (33/40) of evaluable lesions did not recur. Among the 15 keloids treated with definitive radiation therapy (24Gy delivered in 3 fractions), 78.6% (11/14) of evaluable keloids showed complete flattening, and 14.3% (2/14) had partial flattening. Both acute and late toxicities were mild, with only a single instance of grade 3 toxicity (dermatitis).

CONCLUSION

Our study confirms that radiation therapy has a role in reducing the risk of keloid recurrence post-operatively, and plays an important role in the definitive management of unresectable keloids.

Post-operative KEloids iRradiation (POKER): does the surgery/high-dose interventional radiotherapy association make a winning hand?

PURPOSE

To report the results involving post-operative interventional radiotherapy (POIRT) in a homogenous cohort of patients affected by keloid and treated at a single institution with the same fractionation schedule.

PATIENTS AND METHODS

Inclusion criteria were: surgery with a histopathological diagnosis of keloid, subsequent high-dose rate interventional radiotherapy (HDR-IRT)-12 Gy in 4 fractions (3 Gy/fr) twice a day-and follow-up period ≥ 24 months.

RESULTS

One-hundred and two patients and a total of 135 keloids were eligible for the analyses. Median follow-up was 64 [IQR: 25-103] months. Thirty-six (26.7%) recurrences were observed, 12-months and 36-months cumulative incidence of recurrence were 20.7% (95% CI 12.2-28.5) and 23.8% (95% CI 14.9-31.7) respectively. History of spontaneous keloids (HR = 7.00, 95% CI 2.79-17.6, p < 0.001), spontaneous cheloid as keloid cause (HR = 6.97, 95% CI 2.05-23.7, p = 0.002) and sternal (HR = 10.6, 95% CI 3.08-36.8, p < 0.001), ear (HR = 6.03, 95% CI 1.71-21.3, p = 0.005) or limb (HR = 18.8, 95% CI 5.14-68.7, p < 0.001) keloid sites were significantly associated to a higher risk of recurrence.

CONCLUSIONS

The findings support the use of surgery and POIRT as an effective strategy for controlling keloid relapses. Further studies should focus on determining the optimal Biologically Effective Dose and on establishing a scoring system for patient selection.

Efficacy of surgical resection and ultra-reduced tension suture combined with superficial radiation in keloid treatment

BACKGROUND

There are many available treatment options for keloid; however, single treatments are usually less effective. Therefore, more scientifically rational and effective combined treatment methods should be sought to solve the pain associated with keloids.

AIM

To explore the efficacy and safety of surgical resection and ultra-reduced tension suture combined with superficial radiation as keloid treatment.

METHODS

Fifteen keloid patients admitted to Qingdao Eighth People's Hospital from June 2020 to January 2022 were enrolled in this retrospective analysis. All patients underwent a comprehensive treatment approach comprising surgical resection, ultra-reduced tension suture incision, and superficial radiation therapy within 24 h postoperatively. The modified Vancouver Scar Scale (mVSS) and Patient and Observer Scar Assessment Scale (POSAS) were used to evaluate the treatment effect, whereas the efficacy, adverse effects, and recurrence rate were observed according to the 12-mo follow-up after treatment.

RESULTS

The mVSS and POSAS scores at 1 and 6 mo after combination treatment decreased compared to before treatment (P < 0.001), and the overall response rate was 93.3%. Only one case recurred, yielding a 6.7% recurrence rate. The incidence of local chromour sedimentation rate in 1-3 mo after radiotherapy was 33.3% (5 patients), all subsiding after 6-9 mo, without complications, such as delayed wound healing or dermatitis.

CONCLUSION

Surgical resection, super subtraction sutures, and superficial radiotherapy are treatment methods with short courses, low recurrence rates, and good safety profiles.

The Role of Radiation Therapy in Adult and Pediatric Keloid Management: A National Survey of Radiation Oncologists

INTRODUCTION

Radiation therapy is a promising modality for treating keloids after surgical excision. However, it is currently not standard practice among physicians because of concern surrounding the risk of radiation-induced secondary cancers, especially among pediatric patients. There is minimal research assessing the complications for radiation therapy in keloid management.

AIM

The goal of this study was to determine radiation oncologists' perspectives about the utility and appropriateness of radiation therapy for keloid management in both adult and pediatric patients. This study also aimed to characterize radiation modality, dose, fractionation, and secondary complications observed by providers.

METHODS

An electronic survey was delivered to 3102 members of the American Society for Radiation Oncology. The survey subjects were radiation oncologists who are currently practicing in the United States. Rates of responses were analyzed.

RESULTS

A total of 114 responses from practicing radiation oncologists were received. Of these, 113 providers (99.1%) supported radiation therapy for keloid management in adults, whereas only 54.9% supported radiation therapy for pediatric patients. Of 101 providers that treated adults in the past year, the majority used external beam: electrons (84.2%), applied 3 fraction regimens (54.4%), and delivered radiation within 24 hours postexcision (45.5%). In pediatric patients, only 42 providers reported treating at least 1 patient. The majority used electron beam radiation (76.2%), applied 3 faction regimens (65%), and delivered radiation on the same day of keloid excision (50.0%) The main concern when treating pediatric patients were risk of secondary malignancy (92.1%).

CONCLUSION

Although radiation therapy appears to be a widely accepted adjuvant treatment option for adults with keloids, the use of radiation therapy for pediatric patients is less widely accepted because of concerns regarding secondary malignancy. The findings suggest additional studies need to be carried out to assess the risk of those complications.

Therapeutic and prophylactic effects of radiation therapy in the management of recurrent granulation tissue induced tracheal stenosis: a review on the role of Endobronchial brachytherapy and external beam radiation therapy

PURPOSE

Granulation tissue-induced tracheal stenosis (mainly secondary to intubation or lung transplantation) is one of the most common etiologies of benign airway obstructions. Recurrence rates after standard treatment options (surgical resection and/or endobronchial interventions) can inadvertently worsen the stricture through the stimulation of more granulation tissue generation (via increased fibroblast activity and roliferation). Low-dose radiotherapy could be a promising tool to prevent granulation tissue formation after surgery and/or endobronchial interventions regarding its established role in the treatment of keloids or hypertrophic scars, two benign diseases with similar a pathophysiology to tracheal stenosis. This study reviews case reports and small series that used endobronchial brachytherapy (EBBT) or external beam radiotherapy (EBRT) for the management of refractory granulation tissue-induced tracheal stenosis after surgery and/or endobronchial interventions.

METHODS AND MATERIALS

Case reports and series (published up to October 2022) that reported outcomes of patients with recurrent granulation tissue-induced tracheal stenosis (after surgery and/or endobronchial interventions) treated by EBBT or EBRT (in definitive or prophylactic settings) were eligible.

RESULTS

Sixteen studies (EBBT: nine studies including 69 patients, EBRT: seven studies including 32 patients) were reviewed. The pooled success rate across all studies was 74% and 97% for EBBT and EBRT, respectively.

CONCLUSIONS

Radiation therapy appears to be effective in the management of selected patients with recurrent/refractory tracheal stenosis. Response to this treatment is usually good, but further studies with a larger number of patients and long-term followup are necessary to determine the optimal technique, dose, and timing of radiation therapy, late complications, the durability of response, and criteria for patient selection.

Hypertrophic Scars and Keloids: Advances in Treatment and Review of Established Therapies

Hypertrophic scars and keloids can have significant detrimental effects on patients both psychosocially and functionally. A careful identification of patient risk factors and a comprehensive management plan are necessary to optimize outcomes. Patients with a history of dystrophic scarring should avoid unnecessary procedures and enhance the wound-healing process using various preventive strategies. As there is no single, fully efficacious treatment modality, prevention remains the best approach in reducing aberrant scar formation. When prevention therapies fail, keloids have been shown to be respond to a variety of therapies including topical and injectable corticosteroids, 5-fluorouracil, radiotherapy, lasers, and surgical excision, all with varying efficacies. As such, management should be tailored to the individual patient's risk factors with the use of combination therapies to reduce recurrence rates. Still, keloid and hypertrophic scar therapies are widely diverse with novel treatment modalities providing alternatives for recurring lesions. Laser-assisted drug delivery, skin priming, and novel topical therapies may provide alternative options for the management of hypertrophic scars and keloids.

Observation of the clinical efficacy of isotope phosphorus-32 dressing combined with diprospan and mucopolysaccharide polysulphate cream in the treatment of keloids

OBJECTIVE

The present study aims to investigate the effectiveness, recurrence, and adverse reaction rates of isotope phosphorus-32 dressings combined with diprospan and mucopolysaccharide polysulphate cream in the treatment of keloids.

METHODS

A total of 80 patients with keloids admitted to the Dermatology Clinic of the Fourth Affiliated Hospital of Harbin Medical University between June 2019 and June 2021 were included in the present study and randomly divided into three groups: Control Group 1 (n = 27), Control Group 2 (n = 25), and the treatment group (n = 28). Patients in Control Group 1 were treated with diprospan combined with mucopolysaccharide polysulphate cream, patients in Control Group 2 were treated with an isotopic phosphorus-32 dressing combined with mucopolysaccharide polysulphate cream, and patients in the treatment group were treated with an isotopic phosphorus-32 dressing combined with diprospan and mucopolysaccharide polysulphate cream. The effectiveness, recurrence, and adverse reaction rates were observed in all three groups.

RESULTS

The treatment group had the most significant decrease in the itching scores. The respective effectiveness, recurrence, and adverse reaction rates were 81.4%, 43.6%, and 74.1% in Control Group 1; 56%, 38.7%, and 64% in Control Group 2; and 96.7%, 11.2%, and 41% in the treatment group. The differences were statistically significant (p < 0.05).

CONCLUSION

An isotope phosphorus-32 dressing combined with diprospan and mucopolysaccharide polysulphate cream keloid treatment delivers a fast onset, good effectiveness, and low recurrence and adverse effect rates.

Lesion Site Is the Key Prognostic Factor for Keloid Patients Receiving Surgery With Adjuvant Radiotherapy

BACKGROUND

Keloid is a benign tumor with high recurrence rate; accordingly, complete surgical excision with adjuvant radiotherapy is one of the most effective treatments. This study reviewed outcomes of keloid patients receiving surgery and adjuvant radiotherapy in Kaohsiung Medical University Hospital.

MATERIALS AND METHODS

All patients received radiation dose with 15 Gy, with their first radiotherapy within 24 hours after surgical excision. The end points were recurrence rate and local recurrence-free interval (LRFI), defined clinically as palpable gross tumor over the treatment site and duration from the last day of radiotherapy to disease recurrence.

RESULTS

From May 2017 to July 2020, 32 patients with 40 keloid lesions were included. The mean age for these patients was 37.6 years, and the median follow-up time was 15.3 months. The overall recurrence rate was 52.5%, and the median LRFI was 9.7 months. Recurrence rates for males and females were 46.7% and 56% ( P = 0.567), respectively; for head and ear, chest, shoulder and upper extremities, and abdomen and back were 12.5%, 61.5%, 63.6%, and 62.5% ( P = 0.093); for lesions over 20 cm 2 and below 20 cm 2 were 62.5% and 50% ( P = 0.527); and for megavoltage electron beam and kilovoltage photon beam were 56.7% and 40% ( P = 0.361), respectively. Patients were further classified into 2 groups by lesion sites, which showed lower recurrence rate ( P = 0.011) and longer LRFI ( P = 0.028) with lesions over the head and ear than other sites.

CONCLUSIONS

We found that lesion site might be a prognostic factor for keloid recurrence. Adjuvant radiation dose escalation for high-recurrence risk areas (other than the head and ear) might be required.

Current advances in the selection of adjuvant radiotherapy regimens for keloid

Keloid is a common benign skin tumor in the outpatient department, and patients are often accompanied by itching and pain. Since the pathogenesis is unknown, the effect of single method treatment is unsatisfactory, and therefore the recurrence rate is high. Therefore, comprehensive treatment is mostly used in clinical treatment. Adjuvant radiotherapy is currently one of the most effective treatments for keloid. After long-term clinical practice, brachytherapy and electron beam radiotherapy has increasingly become the gold standard of treatment, because brachytherapy provides more focused radiation treatment to focal tissue to significantly reduce recurrence rate, and better preserve normal tissue. With the development of new radiotherapy techniques, more options for the treatment of keloid. Currently, adjuvant radiotherapy has been widely recognized, but there is no consensus on the optimal protocol for adjuvant radiotherapy for keloids. This review provides a review of published treatment options and new radiotherapy techniques for adjuvant radiotherapy of keloids and gives a comprehensive evaluation for clinical treatment.

Recurrence of Primary and Secondary Keloids in a Select African American and Afro-Caribbean Population

BACKGROUND

Keloid formation occurs with increased incidence in African Americans and Afro-Caribbeans when compared with other ethnic populations. Although surgical management and nonsurgical management of keloids are mainstays of treatment, there are significant variations within studies comparing the efficacy of intraoperative steroid injection, postoperative radiotherapy, or a combination of both modalities. The purpose of our study is to evaluate the efficacy of different treatment modalities used for treatment of keloids and to determine their recurrence in a select Afro-Caribbean population.

METHODS

A retrospective review of the plastic surgery case list from January 2015 to October 2019 was conducted, with identification of 46 Afro-Caribbean and African American patients with 56 keloids. Each patient was contacted to determine whether they had experienced recurrence of their keloid(s). Eighteen patients were lost to follow-up, resulting in 28 patients with 35 keloids included in our study. The treatment protocol involved surgical excision for all keloids, with selective additional triamcinolone 40 mg/mL injection intraoperatively, immediate postoperative radiotherapy, or intraoperative triamcinolone injection with postoperative radiotherapy. Recurrence rates between the different treatment groups were calculated, and statistical analyses were performed using IBM SPSS Statistics, with a value of P < 0.05 deeming statistical significance.

RESULTS

Our study demonstrates that postoperative recurrence rates of primary and secondary keloids were 43% and 58%, respectively. Results of recurrence rate varied by specific treatment modality; keloid excision yielded a rate of only 54%, keloid excision with postoperative radiation yielded a rate of 83%, keloid excision with intraoperative triamcinolone injection yielded a rate of 33%, and keloid excision with a combination of intraoperative triamcinolone injection and postoperative radiation yielded a rate of 33%.

CONCLUSION

Patients of Afro-Caribbean and African American ethnicity are more heavily affected by the formation of keloids compared with other population groups. Results of varying modalities for keloid management demonstrate that patients who received a combination of excision with intraoperative triamcinolone injection, with or without postoperative radiation, had the lowest recurrence rates compared with other treatment protocols including excision alone and excision with postoperative radiation only.

Adjuvant Radiotherapy for Keloids

Radiotherapy is one of the therapeutic methods for keloids, and the irradiation technique has innovated from superficial X-ray to brachytherapy after decades of clinical practice. At present, the application of adjuvant radiotherapy has been widely accepted by clinicians, while the consensus of optimal adjuvant radiotherapy strategies for keloids has not been reached. Factors such as radiation timing, dose, fractions, and lesion locations may be associated with the clinical outcomes of patients with keloids after radiotherapy while a comprehensive review is lacking. Herein, this review summarized the published literature of adjuvant radiotherapy for keloids involving mechanism, timing, dose, fractions, and complications, etc., which may facilitate clinical decision making.Level of Evidence III 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 .

Silencing circular RNAPTPN12 promoted the growth of keloid fibroblasts by activating Wnt signaling pathway via targeting microRNA-21-5p

Keloid is a skin disease marked by fibroplasia, and fibroblasts viability plays a considerable part in keloid. Our research was devoted to assessing the involvement and mechanism of circPTPN12 in keloid. The level of circPTPN12 and miR-21-5p was estimated by qRT-PCR in keloid tissues and cells. MTT analysis was devoted to evaluating the multiplication of keloid fibroblasts. Additionally, transwell assay was dedicated to verifying cell migration and invasion. Furthermore, keloid fibroblasts apoptosis level was assessed adopting flow cytometry, and the relevancy between miR-21-5p and circPTPN12, miR-21-5p, and SMAD7 was assessed by dual luciferase assay. Similarly, RIP and RNA pull-down assay verified the relevance between genes. Moreover, levels of SMAD7 and proteins concerned in Wnt signaling pathway were appraised by Western blot. The level of circPTPN12 declined in keloid. circPTPN12 knockout could enhance the multiplication, migration, invasion, and decline apoptosis of keloid fibroblasts. Indeed, miR-21-5p could be packed with circPTPN12 sponge, SMAD7 was downstream effect factor of miR-21-5p, and miR-21-5p inhibitors partially reversed the promoting effect of silencing circPTPN12 on keloid formation. Otherwise, the level of SMAD7 was adjusted by circPTPN12 and miR-21-5p. Silencing circPTPN12 targeted miR-21-5p and activated Wnt pathway to accelerate keloid fibroblasts growth. Taken together, silencing circPTPN12 promotes the growth of keloid fibroblasts by activating Wnt pathway targeting miR-21-5p. CircPTPN12 may play a considerable part in keloid formation, which supplies a reference for molecularly targeted therapy keloid.

Clinical status of hospitalized keloid cases from 2013 to 2018

OBJECTS

Keloids are intractable scar diseases and sometimes undergo hospitalization. This study aims to represent current status of keloid management in a national sample of hospitalized scar cases.

METHODS

Data of scar-diagnosed cases admitted in 1064 China's tertiary hospitals between 2013 and 2018, were obtained from the Hospital Quality Monitoring System (HQMS) database. Variables analyzed include sex, age, nationality, occupation, hospital department, accompanied symptoms at admission, surgical treatment, length of stay (LOS), and hospitalization cost. The potential risk factors of keloid diagnosis among scar cases were preliminarily identified through the Cochran-Mantel-Haenszel tests and univariate regression analyses.

RESULTS

This study identified 177,586 scar cases including 21,777 keloid cases and 155,809 non-keloid scar cases. The prevalence of scars in the HQMS database was gradually decreased from 0.123% in 2013 to 0.075% in 2018. We found a preponderances of males (54.32%), adults (61.52%), Han nationality (93.38%), and students (17.35%) in scar cases, among whom keloid cases accounted for growing proportions increasing from 9.2% in 2013 to 15.1% in 2018. Comparing non-keloid scar cases, keloid cases consisted of more women (59.1% VS 43.8%), office staffs (13.08% VS 6.75%) and retirees (5.16% VS 2.65%), and less Zhuang (0.79% VS 1.40%) and Hui nationalities (0.76% VS 1.00%), and showed lower incidence of accompanied symptoms (4.51% VS 47.96%) and higher rate of receiving operations (57.96% VS 50.28%, P < 0.001). Both the LOS and cost per hospitalization were lower in keloid cases. Furthermore, the adult and older women, Han and Uyghur nationalities, office staffs and retirees, and admitted in otolaryngology and dermatology departments, were potential predictors of keloid diagnosis among hospitalized scar cases.

CONCLUSION

When viewed at the national level, keloid occupies an important part in scar management in Chinese tertiary hospitals. Demographic and clinical differences between keloids and other scars facilitate understanding and promoting of individualized anti-scar therapeutic strategies.

Timing of Adjuvant Radiotherapy After Keloid Excision: A Systematic Review and Meta-Analysis

BACKGROUND

No consensus exists regarding the appropriate timing of adjuvant radiotherapy administration after surgical excision of keloids.

OBJECTIVE

This study investigated the appropriate timing of adjuvant radiotherapy.

MATERIALS AND METHODS

A systematic review and meta-analysis of randomized controlled trials and observational cohort studies was performed. A pooled estimate of the incidence rate was performed using a random-effects model. Subgroup analyses based on different anatomic region, biologically effective dose, keloid length, and radiotherapy regimen were also conducted.

RESULTS

Sixteen observational cohort studies (1,908 keloid lesions) met the inclusion criteria. The incidence rate was significantly lower in the group treated with electron beam therapy more than 24 hours after surgery (3.80%; 95% confidence interval [CI], 1.78%-8.13%) than that in the group treated with the same therapy within 24 hours of surgery (37.16%; 95% CI, 20.80%-66.37%; p < .0001), but no significant difference was observed between the groups regarding brachytherapy and x-ray treatments.

CONCLUSION

Immediate adjuvant radiotherapy did not significantly reduce the incidence rate of recurrent keloids.

Feasibility of aponeurectomy in combination with perioperative 192Ir high dose rate brachytherapy for Dupuytren's disease

PURPOSE

Partial aponeurectomy (PA) is a standard procedure for Dupuytren's contracture (DC). Here we report a novel approach using surgery combined with perioperative high dose rate (¹⁹²Ir-HDR) brachytherapy.

METHODS AND PATIENTS

From March 2018 until February 2020, thirteen rays of 6 patients with Dupyutren's contractures underwent PA followed by HDR brachytherapy. After removal of fibrous tissue and mobilization of the tendons, one to three catheters per patient were placed intraoperatively. Immediately after surgery, a planning computer tomography with 3D-planning was performed. Then 10-12 Gy were given to 0-2 mm from the catheters' surface and the catheters were removed 6-12 h after brachytherapy.

RESULTS

No complications were observed. The mean contractures were reduced from 55.4° (standard error SE 19.6) to 15.4° (SE 6.7; p < 0.01). One patient showed progressive fibrosis of a nontreated ray during follow-up.

CONCLUSIONS

HDR brachytherapy in combination with surgery is feasible and harbors the potential for combined modality therapy to reduce relapse rates of advanced or relapsing DC. Controlled studies are warranted to investigate the role of bimodal therapy compared with PA alone.

Scoping Review of Therapeutic Strategies for Keloids and Hypertrophic Scars

BACKGROUND

Keloids are an abnormal proliferation of scars that can involve large areas of tissue beyond the original injury site. Hypertrophic scars are similar clinically, but do not exceed the original scar limits. These scarring abnormalities can cause noxious symptoms such as pain, tenderness, itching, and ulcerations. The aim of this review is to discuss current therapies for both types of abnormal scarring, and to determine if guidelines can be provided for excisional treatment with adjuvant therapies versus non-excisional methods.

METHODS

A systematic literature search was performed through the Web of Science database. The search revolved around keywords such as "keloid," "hypertrophic scars," and "treatment." Articles were reviewed and screened for inclusion and exclusion criteria. The review focuses on an analysis and summarization of randomized control trials regarding keloid or hypertrophic scar treatments.

RESULTS

The original searches produced 1161 and 1275 articles for keloid and hypertrophic scars, respectively. In total, 316 duplicates were found. After accounting for 2014-2019 publication time, 655 keloid and 893 hypertrophic scar articles were reviewed. This resulted in 15 articles that pertained to treatment and randomized control trials.

CONCLUSIONS

Keloids and hypertrophic scars present a clinical challenge. Based on qualitative review of recurrence, neither excision plus adjuvant therapy or nonsurgical treatments can be recommended preferentially at this time. More research is needed to determine if recurrence rate bias exists between the treatment regimens, as excisional treatment plus adjuvant therapy is reserved for refractory scars.

Interstitial high-dose-rate brachytherapy in the treatment of keloids: Moving toward a volumetric approach

PURPOSE

Brachytherapy (BT) after surgical resection of keloids reduces the risk of local recurrence, but standardization of dose/technique is lacking. Typical keloid BT treatment utilizes a single-channel source prescribed to 5-mm depth. We investigated the dosimetry of a volume-based target definition for interstitial high-dose-rate BT treatment of keloids.

METHODS AND MATERIALS

We retrospectively identified consecutive 14 patients who had a total of 20 keloids treated with interstitial high-dose-rate BT for keloids at our institution between 2004 and 2014. Keloids were treated with a single 8 Gy fraction prescribed to 5 mm beneath the scar within 36 h of surgery. Retrospectively, a 3-mm skin high-risk clinical target volume (HR-CTV) was contoured under the scar for volume-based dose calculations.

RESULTS

Mean (SD) HR-CTV was 3.91 cm³ (3.1) and mean (SD) HR-CTV dose was 11.3 Gy (3.6). Mean D₉₀ (SD) was 62.9% (25.8) and mean V₁₀₀ (SD) was 56.5% (26.4). The mean V₁₅₀ (SD), V₂₀₀ (SD), and V₃₀₀ (SD) were as follows: 37.6% (19.9), 25.1% (14.4), and 11.3% (6.5), respectively. No local failures were reported at 9 months median followup. There were no Grade 2 or higher late toxicities.

CONCLUSIONS

Using a volume-based target definition, a wide range of target coverage was observed. This is likely a consequence of the curvature of the skin and the challenges of keeping the catheter equidistant from the skin across the target. Additional data are needed to define the potential clinical impact on outcomes/toxicities of dosimetric correlates with single-catheter BT keloid treatment.

Surface brachytherapy in the treatment of keloid scars in Mexico

OBJECTIVE

To demonstrate that superficial high-dose-rate (HDR) brachytherapy by means of Leipzig applicators or moulds with catheters is an adjuvant treatment with impact on local control and low toxicity.

BACKGROUND

Keloid scars occur in 5-15 % of cases, secondary to an uncontrolled proliferation of fibroblasts and reduction in the inhibition of growth factors.

MATERIAL AND METHODS

Retrospective, longitudinal and descriptive study in patients with keloid scars who were treated with superficial HDR brachytherapy in the General Hospital of Mexico between November 2009 and December 2013.

RESULTS

Eighty patients were evaluated, and the mean follow-up was 22.18 months (range 8-48). The anatomic site treated was the ear in 72 patients (90.0 %), anterior thorax in 5 patients, retroauricular region in 2, and abdomen region in 1 patient. The application was performed 24 h after surgery; the dose for 79 patients (99 %) was 1500 cGy/3 fractions, and 1 received 500 cGy in 1 fraction. Adequate healing occurred in 76 patients (95 %), and the local failure was 5 % (95 % CI). Acute toxicity occurred in 15 % (12 patients) with grade 1 radioepithelitis. Chronic toxicity occurred in 22 patients (27.5 %) with grade 1 hypopigmentation and 18 patients (22.5 %) with grade 1 fibrosis. The cosmetic result was good in 72 patients (90 %). During follow-up, 2 patients presented recurrence, and 2 patients persisted.

CONCLUSIONS

Treatment with superficial brachytherapy in keloid scars using a mould with catheters or a Leipzig applicator is a therapeutic option that results in 95 % local control and low toxicity.

Retrospective study of immediate postoperative electron radiotherapy for therapy-resistant earlobe keloids

Keloid resection followed by adjuvant radiotherapy is the most efficacious treatment for keloids. However, for earlobe keloids, an optimal protocol for the total dose and fractions of adjuvant radiation has not yet been established. We retrospectively analyzed the efficacy and safety of immediate three-fraction electron radiotherapy after operation for resistant earlobe keloids. From 2011 to 2017, three-fraction electron radiotherapy with single dose of 5 Gy was given postoperatively to 23 patients with 30 keloids in our hospital. The first fraction of adjuvant radiotherapy was administered within 2 h of surgery, and the other two sessions were completed within the next day or two. Five (16.7%) primary keloids and 25 (83.3%) recurrent keloids were examined in this study. The primary endpoint was the local control rate, which was 86.7% after a median follow-up of 26 months (14–93 months). Secondary endpoints were acute and late procedure-related complications, and no severe complications were observed after combination therapy. Our results suggest that three-fraction electron radiotherapy after excision within 2 days of surgery is a safe and effective protocol for the prevention of earlobe keloid recurrence that can also improve patient compliance and comfort.

Subdermal injection of hyaluronic acid to decrease skin toxicity from radiation delivered with low-dose-rate brachytherapy for cancer patients

Purpose

To study the feasibility of hyaluronic acid (HA) injection to increase the distance between skin and radioactive sources, and dose reduction of skin during low-dose-rate (LDR) brachytherapy.

Material and methods: A total of 11 patients with subdermal malignant tumors were enrolled in this study. HA was injected after I-125 seed implantation, and dosimetric parameters were calculated by a brachytherapy treatment planning system (BTPS). The distance of the new space between radioactive sources and skin was measured on computed tomography (CT) and magnetic resonance imaging (MRI). Clinical signs were observed and followed up for every patient.

Results

After HA injection, the average of newly generated maximum distance was 1.0 cm along the entire length of the tumor. The D₉₀ and V₁₀₀ did not significantly change for tumors before or after injection (p = 0.39, p = 0.50, respectively). The maximum dose to a relatively small volume (0.1 cc) of the skin (OAR-Max) decreased from 100.66 Gy to 61.20 Gy (p < 0.05), and the mean skin dose (OAR-Mean) decreased from 49.20 Gy to 17.27 Gy (p < 0.05) after injection. On follow-up CT and MRI, HA was quite stable in shape and position for nearly 6 months.

Conclusions

Our study results showed that an additional 1.0 cm distance between the radioactive source and skin could be induced by HA injection in patients with subdermal tumor, and this distance could significantly decrease the skin dose in LDR brachytherapy. In addition, no obvious toxicity and side effects were produced by HA injection. Therefore, hyaluronic acid injection is a safe and effective technique.