Postoperative radiotherapy in the management of keloids

Double enhancement effect of a surface dose with tungsten rubber bolus in photon radiotherapy for keloids and superficial tumors

To clarify the dosimetric characteristics of a real-time variable shape rubber-containing tungsten (STR) bolus in a clinical plan and investigate the efficacy of the STR bolus in photon radiotherapy for keloids and other superficial tumors. A 5 mm gel bolus or 1 mm STR bolus was placed on a solid water phantom. Tangential irradiation was performed using a TomoTherapy Radixact-X9 and 6 MV X-ray flattening-filter-free beam, and the surface dose was measured with radiochromic film. Clinical-like plans (TomoDirect; TD and TomoHelical; TH) were applied with the same geometry and the dose distributions were measured. The increase in surface dose by the build-up effect and backscatter was 37.7% and 8.0% for the gel bolus, and 40.5% and 26.4% for the STR bolus, respectively. In the TD and TH plans, the increase in surface dose was 27.4% and 48.3% for the gel bolus, and 39.0% and 63.2% for the STR bolus. Similary, changes in the sagittal plane dose were - 3.9% and 6.1% for the gel bolus, and - 6.3% and 6.9% for the STR bolus. The STR bolus effectively increased the surface dose by the build-up effect and backscatter in photon radiotherapy for keloids and other superficial tumors.

Network Meta-Analysis of Different Clinical Commonly Used Drugs for the Treatment of Hypertrophic Scar and Keloid

Background: There is no uniform treatment for pathological scars, including keloids and hypertrophic scars, in clinic currently. Previously, multiple randomized controlled trials have examined the clinical efficacy of different treatments. Nonetheless, the results are inconsistent, and many treatments have not been directly compared. This makes it difficult to conclude which approach is more favorable, in terms of efficacy and safety, for the treatment of pathological scarring. This study aimed at evaluating the efficacy of different injection and topical treatment strategies for hypertrophic scar and keloid.

Methods: Relevant literature from PubMed, Medline, Embase, Scopus, the Cochrane Central Register of Controlled Trials (CCRCT), and WHO International Clinical Trials Registry Platform (WHO-ICTRP) were searched, from database inception through November 2020. Randomized clinical trials evaluating different treatment strategies of pathological scars, including triamcinolone acetonide (TAC), verapamil (VER), 5-fluorouracil (5-FU), botulinum toxin A (BTA), bleomycin (BLM), and silicone gels were included in the study.

Results: The network meta-analysis included a total of 2,009 patients from 29 studies. A network meta-analysis of injection and topical treatment strategies showed that the efficacy of TAC combined with BTA was best in the treatment of pathological scars. Combination therapies of TAC with 5-FU and TAC with BTA significantly improved the clinical efficiency. However, there was no statistically significant difference between other treatment strategies. The order of efficacy predicted by the surface under the cumulative ranking (SUCRA) curve was as follows: TAC+BTA (82.2%) > TAC+5-FU (69.8%) > BTA (67.3%) > 5-FU+silicone (59.4%) > TAC+silicone (58.3%) > 5-FU (49.8%) > BLM (42.0%) > TAC (26.7%) > VER (26.2%) > silicone (18.3%). There was no publication bias revealed based on the funnel diagram.

Conclusion: This study recommends intralesional injection of TAC-BTA and TAC-5-FU combined therapies. But for patients who cannot tolerate the side effects, the use of silicone gels in combination with TAC is recommended. However, these conclusions need to be further confirmed by more randomized controlled trials.

A retrospective study of hypofractionated radiotherapy for keloids in 100 cases

At present, the consensus on the best treatment for keloids is the combination of clinical and surgical therapies, if necessary, associated with adjuvant radiotherapy like brachytherapy. Whereas, the uniform scheme of radiotherapy in keloids is unclear. Here, we conducting a retrospective analysis to assess the efficacy and safety of a specific treatment regimen (20 Gy in 5 fractions) in keloid patients. We retrospectively analysed the medical records of keloid patients receiving auxiliary postoperative radiotherapy (PORT) treatment from 2009 to 2019. The patients were treated with the hypofractionation method of 20 Gy in 5 fractions. We compared the local control rate and complications, using the chi-square test and logistic regression analyses. After screening, we identified 100 keloid patients in this study, with a median follow-up of 59 months. In this study, the overall local control rate of keloid lesions was 84.8%. After multivariate analyses (primary keloid or not, family history, interval from surgery to irradiation and site), our research showed that primary keloid, site and interval from surgery to irradiation were significantly related to recurrence. Acute radiation injury and late radiation injury accounted for 3% (erythema) and 1% (skin sclerosis) of the total cases, respectively. Our results indicate that a postoperative hypofractionation with radiation dose of 20 Gy in 5 fractions may be effective, easy to accept and safe for keloid patients.

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.

Efficacy and Safety of Intralesional Triamcinolone Versus Combination of Triamcinolone with 5-Fluorouracil in the Treatment of Keloids and Hypertrophic Scars: A Systematic Review and Meta-analysis

BACKGROUND

Although keloids and hypertrophic scars are common benign hyperproliferative growths of dermal fibroblasts, the clinical problems including physical and psychological problems are significant and impairing, with few proven treatments. Intralesional triamcinolone acetonide (TAC) and combination of TAC with 5-fluorouracil (5-FU) are widely used to treat keloids and hypertrophic scars, but their efficacy and safety remain controversial.

METHODS

We systematically searched MEDLINE, EMBASE, Cochrane Library, and CNKI for relevant trials.

RESULTS

The mean scar height and the erythema score in the TAC + 5-FU group were lower than those in the TAC group after treatment (P < 0.05). The effectiveness based on observer assessment after treatment in the TAC + 5-FU group was superior than that in the TAC group (P < 0.05); further, the subgroup analysis showed the TAC + 5-FU group was also superior than the TAC group in the treatment of hypertrophic scars (P = 0.01), and there were no significant differences in the treatment of keloid (P = 0.12). The effectiveness based on patient self-assessment after treatment in the TAC + 5-FU group was also superior than the TAC group (P < 0.05). The overall complication rate in the TAC + 5-FU group was lower than the TAC group (P < 0.05).

CONCLUSIONS

Combination of TAC with 5-FU is more effective and safer than TAC alone therapy in the treatment of keloids and hypertrophic scars. Data on keloids alone or hypertrophic scars alone are, however, limited. A better understanding of effective after intralesional combination of TAC with 5-FU in the treatment of keloids alone or hypertrophic scars alone is imperative.

LEVEL OF EVIDENCE IV

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Dose Effect in Adjuvant Radiation Therapy for the Treatment of Resected Keloids

PURPOSE

Surgical excision of keloids can result in an insidious cycle of tissue injury and repeat keloid formation unless combined with adjuvant therapy to halt this cycle. We present our results of postoperative radiation therapy for keloids with various dose regimens.

METHODS AND MATERIALS

A retrospective review of 124 patients with 250 keloid lesions treated with postoperative radiation therapy was analyzed. In this institutional review board-approved study, 125 keloids were treated to 20 Gy in 5 fractions and 125 keloids were treated to 12 to 16 Gy in 3 to 4 fractions. Local failure was defined as redevelopment of any clinically apparent keloid at the treated site. The median age was 34 years (14-84 years). Keloids were located on the ear (34%), neck/shoulder (19%), abdomen (13%), chest (10%), face (9%), breast (7%), extremities (4%), and back (3%). Median keloid size was 4 cm (0.5-20 cm).

RESULTS

At a median follow-up of 40 months, the recurrence rate for all lesions was 5.6%. Lesions treated to 20 Gy had a recurrence rate of 1.6% compared with 9.6% with <20 Gy and an odds ratio of 0.16 (P = .02). Upon univariate and multivariate analysis there were no differences in recurrence rate with respect to location, race, gender, age, previously treated lesions, and presence of multiple keloids. The lone predictor for improved control rate was the dose of 20 Gy in 5 fractions compared with less than that. Control rate for lesions treated to a biologically equivalent dose₂ of 35 to 36 Gy₂, 48 to 52.5 Gy₂, and 60 to 72 Gy₂ were 10% (P = .007), 8.9% (P = .16), and 1.6% (P = .02), respectively.

CONCLUSIONS

Surgical excision followed by immediate adjuvant radiation therapy for keloids provides excellent local control and cosmesis. Treatment with a biologically equivalent dose₂ > 60 (20 Gy in 5 fractions) yielded superior local control over lower dose regimens.

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

PURPOSE

To determine the optimal brachytherapy dose and fractionation scheme for keloid treatment.

METHODS AND MATERIALS

Patient cohorts from 3 centers treated with keloid excision followed by 2 × 9 Gy, 3 × 6 Gy, or 2 × 6 Gy high-dose-rate brachytherapy were retrospectively compared regarding recurrence (after at least 12 months' follow-up) and complications (after at least 1 month's follow-up), using logistic regression analyses.

RESULTS

A total of 238 keloids were treated. An overall full recurrence rate of 8.3% was found. After correction for confounders (sex, skin color, keloid location, keloid duration) no statistically significant differences in recurrence rates could be discerned between fractionation schemes. There were 12.8% major and 45.6% minor complication rates. Lower radiation dose resulted in significantly fewer complications (odds ratio 0.35, P=.015).

CONCLUSIONS

After excision of resistant keloids, high-dose-rate brachytherapy with a biological equivalent dose of approximately 20 Gy is recommended, on the basis of low recurrence and complication rates.