Radiation Oncology/Benign/Keloid

Current revision (unreviewed)

[edit] Natural history

Recurrence rate of 50-80% after surgery. Recurrence rate reduced to 50% with intralesional steroid therapy. RT reduces recurrence rate to 12-28%.

No universally accepted treatment protocol
Modalities: surgery, radiation, pressure therapy, cryotherapy, intralesional injections of corticosteroids, interferon, fluorouracil, topical silicone, and pulse-dye laser treatment
Surgery only has recurrence rate of 50-80%
Post-op RT
- Success rate 75-90% within 10 year follow-up; however, a recent Dutch study had 70+% recurrence within 2 year, in sharp disagreement with prior studies
- Usually surgical excision followed immediately with RT
- Usually 3-4 fractions daily in 3-4 Gy/fx; however, recent Dutch meta-analysis suggests that dose is insufficient for long-term control, and should use BED of >30 Gy (e.g. 13/1, 16/2, 18/3)
- Sites with high rates of recurrence (eg. high-tension areas) should be treated with escalated dosage

Meta-analysis

Utrecht; 2005 PMID 16254707 -- "Biologically effective doses of postoperative radiotherapy in the prevention of keloids. Dose-effect relationship." (Kal HB, Strahlenther Onkol. 2005 Nov;181(11):717-23.)
- Meta-analysis, 18 studies. Recurrence rate for surgery only 50-80%
- BED: Recurrence rate decreased as a function of BED, if >30 Gy recurrence was <10%. No difference with high stretch tension sites
- Conclusion: For effective therapy, need a reasonably high dose (BED >=30 Gy, for example 13/1, 16/2, 18/3 or 27/1 LDR), within 2 days of surgery

Single Institution

Utrecht; 2007 (Netherlands)(1998-2004) PMID 17967309 -- "Postoperative high-dose-rate brachytherapy in the prevention of keloids." (Veen RE, Int J Radiat Oncol Biol Phys. 2007 Nov 15;69(4):1205-8.)
- Retrospective. 35 patients with 54 keloids (earlobe/auricle n=23, sternum n=17, others n=14), treated with HDR BT. First dose with 6 hours after surgery, 2 additional doses next day 6 hours apart.
- Outcome: 45% recurrence after HDR 4/1 + 6/2; 3% recurrence after HDR 6/1 + 8/2; no recurrence after HDR 18/3. Better cosmetic results after higher doses
- Conclusion: HDR effective; recommend 3 x 6 Gy

Amsterdam, 2007 (Netherlands) PMID 17519728 -- "The results of surgical excision and adjuvant irradiation for therapy-resistant keloids: a prospective clinical outcome study." (Van de Kar AL, Plast Reconstr Surg. 2007 Jun;119(7):2248-54.
- Retrospective. 21 patients with 32 keloids. RT 12 Gy in 3-4 fxs. Mean F/U 19 months
- Recurrence (elevation of the lesion not confined to the original wound area): 72%
- Conclusion: RT may not be as efficacious as suggested by other studies

U. Washington, 1989 (1966-87) - PMID 2745211 — "Radiation therapy following keloidectomy: a 20-year experience." Kovalic JJ et al. Int J Radiat Oncol Biol Phys. 1989 Jul;17(1):77-80.
- 75 pts with 113 keloids with follow-up mean time of 9.7 yrs. 74% involved earlobe. 60% no prior treatment. Superficial X-rays used in 89%, 12 Gy in 3 fx over 3 days most common.
- Control rate 73%. Failure 19% if no prior treatment, 42% if recurrent.
- Toxicity: No treatment-related complications. 5% mild hyperpigmentation. Carcinogenesis never reported to their knowledge
- Prognostic: Higher recurrence in those >2cm, previous therapy, in men. No advantage to starting treatment within 24 hrs versus more than 1 day (range 4-21 days). Mean time to recurrence 12.8 months

London, 1999 PMID 10703484 -- "The risks of treating keloids with radiotherapy." (Botwood N, Br J Radiol. 1999 Dec;72(864):1222-4.)
- Case report. 20F with severe chest burns, then developed keloids. RT 13/5 to bilateral chest wall. At age 57, L invasive BCA with LN-. At age 59 R invasive multifocal BCA.
- Lit review conclusion: No carcinogenicity reported thus far. Causal relationship in this case strong. Two other potential patients reviewed, although causality in one is suspect, and other probably received too high a dose by today's standards

UT San Antonio, 2006 PMID 16730305 -- "The role of radiation therapy in benign diseases." (Eng TY, Hematol Oncol Clin North Am. 2006 Apr;20(2):523-57.)