BACKGROUND

What is a keloid?

A keloid is a benign fibroproliferative growth resulting from a connective tissue response to a variety of proposed factors such as surgery, burns, trauma, inflammation, foreign body reactions, endocrine dysfunction, and occasional spontaneous occurrence.

Is there a racial predilection for keloid formation?

Yes. People of African descent are more likely to be predisposed to keloid formation than other ethnic groups. Any skin insult (piercings, lacerations, infected skin lesions, surgery) can cause keloid formation in predisposed individuals. Less commonly, lesions can occur de novo.

Name 3 common locations for keloids.

Keloids most commonly affect areas of increased skin tension such as the ears, neck, jaw, presternal chest, shoulders, and upper back.

Name 3 Sx commonly associated with keloids.

Keloids can be asymptomatic but often are pruritic, tender to palpation, or occasionally cause pain.

WORKUP/STAGING

What is the difference between a keloid and a hypertrophic scar?

Hypertrophic scars may initially appear similar to keloids but do not extend beyond the margins of the scar. Keloids are more infiltrative and can cause a local reaction such as pain and inflammation. Hypertrophic scars are much less likely to recur after resection.

TREATMENT/PROGNOSIS

What are the indications for RT in keloid Tx?

The indications for RT in keloid Tx include demonstrated recurrence after resection, marginal or incomplete resection, an unfavorable location, or a larger lesion.

Within what timeframe should RT be given postop after keloid resection?

PORT for keloids should be initiated within 24 hrs after resection.

What is the typical target RT volume for keloid Tx?

The typical target RT volume for keloid Tx is scar + a 1-cm safety margin.

What is the typical RT dose and fractionation for keloids?

The typical RT dose and fractionation for keloids is 12–16 Gy in 3–4 fx. Single doses of 7.5–10 Gy are also effective. (Ragoowansi R et al., Plast Reconstr Surg 2003) Some series suggest that a dose of at least 9 Gy is required to maximize the benefit from RT. (Lo T et al., Radiother Oncol 1990; Doornbos J et al., IJROBP 1990) Another series from Pittsburgh suggests that doses of at least 5–6 Gy per fx for 3 fx may be needed for 90%–95% control for earlobe keloids and 7–8 Gy per fx for 3 fx may be needed for similar control at other sites. (Flickinger J, IJROBP 2011)

What RT modalities can be used in the Tx of keloids?

For RT Tx of keloids, the most common modalities are lower megavoltage electrons, kilovoltage photons, or brachytherapy.

Name 7 Tx options for keloids other than surgery and RT.

Tx options for keloids other than surgery and RT include steroid injections, pressure earrings, silicone gel sheeting, cryosurgery, laser therapy, imiquimod, and injections of fluorouracil or verapamil.

What is the recurrence rate for keloids after PORT?

The recurrence rate for keloids after PORT is typically 10%–35%. This can vary depending on the size, location, extent of excision, etiology, and other factors.

Is there any randomized data comparing surgery + RT against surgery + steroid injection?

Yes. A prospective randomized trial conducted by Sclafani A et al. looked at a series of 31 pts, comparing PORT vs. intralesional steroid injection. The recurrence rate after surgery + RT was 12.5%; the recurrence rate after surgery + steroid injection was 33%. (Dermatol Surg 1996)

For unresectable keloids, what is the efficacy of using RT alone?

Malaker K et al. looked at 86 keloids in 64 pts treated with RT alone. 97% had significant regression 18 mos after completing radiotherapy. 63% of the pts surveyed were very happy with the outcome of their Tx. (Clin Oncol 2004)

TOXICITY

What are the most common side effects after RT for keloids?

The most common side effects of RT for keloids are hyperpigmentation, pruritus, and erythema.

Is there a risk of radiation-induced malignancy after treatment for keloid?

There are a few anecdotal reports in the medical literature of malignant tumors developing in association with radiotherapy for keloid formation, but this outcome is extremely rare. Caution is warranted and risks should be discussed when considering radiotherapy for keloids in the very young and in particular for lesions involving the chest or breast tissue in young females. (Botwood N et al., Br J Radiol 1999)

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