Postoperative Strontium-90 Brachytherapy in the Prevention of Keloids: Results and Prognostic Factors

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.

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.

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 .

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.

Assessing keloid recurrence following surgical excision and radiation

Keloids are a fibroproliferative disorder that can result from a cutaneous injury to the reticular dermis. Recurrence rates as high as 100% have been reported following surgical excision alone. Consequently, a variety of post-surgical techniques have been employed to prevent keloid recurrence, including the use of radiation. Although numerous studies have shown post-excisional X-rays, electron beam, lasers and brachytherapy can reduce the rate of keloid recurrence, numerous inconsistencies, including a wide range of definitions for keloid recurrence, make it difficult to compare study outcomes. The review aims to examine the various means for defining keloid recurrence in clinical trials involving the use of radiation therapy. Searches of the Cochrane Library and PubMed were performed to identify the available information for post-surgical keloid recurrence following radiation therapy. Each identified study was reviewed for patient follow-up and criteria used to define keloid recurrence. The search results included clinical studies with external beam radiation, brachytherapy and superficial radiation therapy. Many studies did not include a definition of keloid recurrence, or defined recurrence only as the return of scar tissue. Other studies defined keloid recurrence based on patient self-assessment questionnaires, symptoms and scar elevation and changes in Kyoto Scar Scale, Japan Scar Workshop Scale and Vancouver Scar Scale scores. The results of this review indicate keloidectomy followed by radiation therapy provide satisfactory recurrence rates; however, clinical studies evaluating these treatments do not describe treatment outcomes or use different definitions of keloid recurrence. Consequently, recurrence rates vary widely, making comparisons across studies difficult. Keloid recurrence should be clearly defined using both objective and subjective measures.

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.

Risk factors of recurrence after postoperative electron beam radiation therapy for keloid: Comparison of long-term local control rate

Aim

To investigate the new risk factors for keloid recurrence after postoperative electron beam radiotherapy (RT) and evaluate the effectiveness of tranilast in combination with electron beam RT by comparing the local control rate.

Background

Identifying patients at high risk of recurrence after postoperative RT for keloids remains a challenge. Besides, no study examined the effectiveness of tranilast in combination with RT after surgery for the prevention of keloids recurrence.

Materials and Methods

This study included 75 lesions in 59 consecutive patients who had undergone postoperative RT at our institute. The follow-up period and prescription of tranilast were examined beside several potential risk factors, such as multiple lesions, size, and shape.

Results

The median follow-up was 72 months (range, 6-147 months). Twenty-one lesions in 17 patients recurred in a median of 12 months after treatment (range, 1-60 months). Local control rates of all 75 lesions were estimated as 93%, 78%, 70%, and 68% at 1, 2, 5, and 10 years. Multiple lesions constituted a significant risk of recurrence (P = 0.03). A larger long axis was significantly related to the recurrence (P < 0.01). Irregular shape was associated with a significantly worse local control rate (P = 0.02). There was no significant difference in the local control rate between patients receiving tranilast and those who did not (P = 0.52).

Conclusions

Multiple lesions and irregular shape were risk factors of keloid recurrence after postoperative electron beam RT. The effectiveness of tranilast was not demonstrated in the study.

Image-guided high-dose-rate intracavitary brachytherapy technique for nasal keloid - a case report

The aim of this study is to report an uncommon case of nasal keloid treated with adaptive image-guided high-dose-rate (HDR) intracavitary brachytherapy. A 34-year-old female presented with nasal keloid after facial trauma was treated with scar resection and HDR intracavitary brachytherapy with a customized eccentric applicator. The total dose was 21 Gy in 6 fractions. During 3 years of follow-up, there was no evidence of recurrence at the local site, and no complications. In conclusion, HDR intracavitary brachytherapy is an effective way to prevent the recurrence of nasal keloids post-surgery.

Radiation Therapy in Keloids Treatment: History, Strategy, Effectiveness, and Complication

Objective:

Radiation therapy combined with surgical excision was considered as one of the most effective treatment plans for keloid lesions. However, there was no unanimity found over present literatures regarding the issue on optimized treatment strategy for keloids. We here provide a comprehensive review over this issue and emphasize on the influencing factors.

Data Sources:

The data analyzed in this review were searched from articles included in PubMed and EMBASE databases.

Study Selection:

The original articles and critical reviews discussing the application of radiation therapy in keloids treatment were selected for this review.

Results:

The application of radiation therapy has transitioned from simple superficial X-ray irradiation to brachytherapy. Furthermore, several factors including radiation type, dose, fraction, interval, and complications were reviewed, and the results revealed that these factors were significant toward clinical outcome at various levels.

Conclusions:

Both past and present evidence support the idea that combination therapy of radiation and surgical therapy is safe and feasible. However, the optimization of treatment strategy was based on different radiation types and should take dose, fractions, interval, and complications into consideration, which will then decrease the rate of recurrence and increase the level of satisfaction.

Brachytherapy in the adjuvant management of keloid scars: literature review

INTRODUCTION

Radiation therapy is a well-recognised modality for the adjuvant treatment of keloid scars. It can be conventionally delivered as external beam using a large apparatus at a distance from the lesion or as brachytherapy with specialised equipment to enable the delivery of treatment in the immediate vicinity of the keloidal tissue.

METHODS

An English literature review was performed with keywords 'brachytherapy' and 'keloid' using the databases PubMed, Embase and Web of Science from their individual dates of inception until June 2017. Studies pertinent to the field are presented in a chronological manner to depict the evolution of different brachytherapy strategies over the last decades. We also discuss considerations relating to the risk of secondary carcinogenesis, which are relevant to shared decision-making in the clinical setting.

DISCUSSION

Low dose rate interstitial brachytherapy was first introduced in the English literature in 1976 and currently appears to have been superseded by more modern approaches, including high dose rate interstitial brachytherapy. This modality compares favourably to more traditional modes of radiotherapy in terms of recurrence as well as rates of symptomatic relief from keloidal symptoms. Superficial brachytherapy was introduced more recently in the relevant literature and appears to be associated with favourable therapeutic outcomes compared to external beam radiation therapy.

CONCLUSION

Brachytherapy is a valid modality of radiotherapy for the adjuvant treatment of keloid scars, with high dose rate interstitial and surface regimens gaining in popularity over recent years. Further research needs to focus on randomised controlled trials to further establish the role of different radiotherapy modalities in keloid scar management.

Keloids and Hypertrophic Scars: A Spectrum of Clinical Challenges

Since their earliest description, keloids and hypertrophic scars have beleaguered patients and clinicians alike. These scars can be aesthetically disfiguring, functionally debilitating, emotionally distressing, and psychologically damaging, culminating in a significant burden for patients. Our current understanding of keloid pathophysiology has grown and continues to advance while molecular biology, genetics, and technology provide ever-deepening insight into the nature of wound healing and the pathologic perturbations thereof. Greater understanding will lead to the development and application of refined therapeutic modalities. This article provides an overview of our current understanding of keloids, highlighting clinical characteristics and diagnostic criteria while providing a comprehensive summary of the many therapeutic modalities available. The proposed mechanism, application, adverse events, and reported efficacy of each modality is evaluated, and current recommendations are summarized.

Treatment of retroauricular keloids: Revision of cases treated at the ENT service of HC/UFPR

Introduction: Keloids are benign tumors arising from abnormal healing of the skin, and there are several procedures available for their treatment.

Objective: The objective of this study was to evaluate the outcomes of patients undergoing treatment of keloids after ear, nose, and throat (ENT) surgeries at our service center.

Method: We conducted thorough, retrospective and prospective analysis of records of patients undergoing treatment of retroauricular keloids at our center.

Results: Nine patients were evaluated, and 6 underwent resection and adjuvant beta-therapy, 2 underwent resection with local application of corticosteroids, and only 1 underwent resection without adjuvant therapy. There was no recurrence of keloids in patients that were treated with beta-therapy in the early postoperative period. One patient had relapsed despite corticosteroid administration and late beta-therapy.

Discussion: Several techniques have been used for the treatment of retroauricular keloids, and beta-therapy is thought to yield the best results, followed by the use of intralesional corticosteroids.

Conclusion: Treatment of retroauricular keloids remains a challenge. While new techniques are being developed, resection followed by early beta-therapy is still the best treatment option.

High-dose-rate brachytherapy for the treatment of recalcitrant keloids: a unique, effective treatment protocol

BACKGROUND

Keloids cause aesthetic disfigurement and physical complaints, mainly pain and pruritus. Treatment of these scars is difficult, with high recurrence rates forming the main issue. Surgical excision with adjuvant radiotherapy is considered the most efficacious treatment. At their institution, the authors have been treating keloids with a high-dose-rate brachytherapy procedure for over 10 years, using a protocol with the lowest total radiation dosage known in the literature.

METHODS

This prospective study included 43 patients of all Fitzpatrick skin types, with 67 keloids in total. After extralesional excision, a radiation scheme of 2 × 6 Gy was administered in two fractions: the first within 4 hours after surgery and the second within 24 hours. Scars were measured and recurrence was judged. Scar appearance was evaluated using the Patient and Observer Scar Assessment Scale.

RESULTS

The recurrence rate was 3.1 percent at a mean follow-up of 33.6 months. A significant average scar surface decrease of 56.7 percent was measured (p = 0.01). Complaints of pain and pruritus decreased by 82.9 and 87.2 percent, respectively. Patients were satisfied with the treatment in 88.6 percent of the cases and with the cosmetic result in 77.1 percent. Pigmentation problems were seen in 21.4 percent of the patients, mostly in Fitzpatrick type V and VI/African American individuals.

CONCLUSIONS

The results of this prospective study show a good cosmetic outcome with a low recurrence rate. The unique radiation schedule proves the efficacy and safety of high-dose-rate brachytherapy and suggests the importance of immediate postoperative irradiation. In addition, only one outpatient treatment is required after surgery, enhancing patient convenience.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Adjuvance in refractory keloids using electron beams with a spoiler: Recent results

AIM

To present clinical results of adjuvant irradiation of excised refractory keloid wounds using a novel bolus-free technique developed within our group to irradiate the skin surface with a linear accelerator.

BACKGROUND

The use of a bolus to increase surface dose over a newly excised keloid presents several problems. Previous solutions are unsatisfactory. Our technique is promising but needs to be evaluated in practice.

MATERIALS AND METHODS

Twenty refractory skin keloids in 19 patients were excised and irradiated in Hospital Plató (Barcelona, Spain) using a 6 MeV electron beam with a 4-mm aluminium spoiler. 15 Gy in fractions of 3 Gy were delivered to the excision site plus a safety margin. All patients were examined during the follow-up (median: 40 months, interval: 12-68 months) and toxicities were recovered.

RESULTS

At the end of the follow-up period, 76% of the cases had not recurred, while the complete response rate amounted to 53%. Residual hypertrophic scars were classified as partial responses. After therapy, itching and pain were observed in 30% of the patients, as well as one telangiectasia and two hyperchromatic scars.

CONCLUSION

Our technique avoids using a bolus while combining the benefits of electron beam therapy in keloids (fewer secondary effects, and fewer and shorter treatments) with a dose deposition adequate for skin surface treatments. Our results are in line with the most successful therapies evaluated in the literature, as secondary effects are acceptable and recurrence rates are low.

Postoperative management of keloids: low-dose-rate and high-dose-rate brachytherapy

PURPOSE

We report the experience of the Radiation Oncology Department of the European Institute of Oncology in Milan, Italy, on the adjuvant low-dose-rate (LDR) and high-dose-rate (HDR) interstitial brachytherapy. Brachytherapy might be useful to improve keloids recurrence rate or reduce keloids treatment side effects instead of external beam radiotherapy.

METHODS AND MATERIALS

Data on 70 consecutive patients treated after complete keloid surgical excision were retrospectively analyzed. First 38 patients and 46 keloids were treated with adjuvant LDR brachytherapy and the following 39 patients and 50 keloids underwent HDR treatment. Median delivered dose of LDR therapy was 16 Gy; HDR median dose was 12 Gy. Sixty-four keloids (66.7%) were symptomatic at diagnosis with pain, itching, or stress.

RESULTS

Fourteen relapses over 46 treated keloids (30.4%) were observed in the LDR group and 19 of 50 keloids (38%) in the HDR group (p = 0.521). Recurrence rate was significantly higher in males (p = 0.009), in patients younger than 44 years (p < 0.0001), for arms, neck, and chest wall anatomic sites (p = 0.0001) and for symptomatic keloids (p = 0.017). Aesthetic outcome was better in case of larger keloids (>8 cm) (p = 0.064). Symptomatic relief was achieved in 92% of HDR patients and only 68% of LDR patients (p = 0.032).

CONCLUSIONS

Postoperative brachytherapy is an effective treatment for keloids. In our study, LDR and HDR treatments resulted in similar recurrence rate. Better symptomatic relief was reported in case of HDR treatment compared with the LDR regimen.

Post-keloidectomy irradiation using high-dose-rate superficial brachytherapy

A study was conducted to evaluate the early results of high-dose-rate superficial brachytherapy (HDR-SB) after keloidectomy. Between April 2008 and April 2009, 21 patients with 36 histologically confirmed keloids were treated with postoperative HDR-SB. The tube applicator was placed on the skin to match the area of the surgical wound, and a spacer 5 mm thick was placed between the skin and the applicator. A dose evaluation point was established below 2 mm from skin surface, and 20 Gy was delivered in 4 daily fractions to keloidectomy scars on the anterior chest wall, scapular region, lower jaw and suprapubic region. A dose of 15 Gy was delivered in 3 daily fractions to lesions in other areas. The median follow-up period was 18 months (range, 9 to 29 months). Therapeutic outcome was judged in terms of recurrence, control, or acute side effects. Three keloids (9.7%) in two patients showed local recurrence, with a median time to failure after HDR-SB of 12 months. All recurrences affected the anterior chest wall. Dysraphia occurred in only one patient with an anterior chest wall lesion. Excluding the cases of recurrence, acceptable cosmetic results were achieved. Our results indicate that HDR-SB is effective and safe for preventing recurrence of keloids.