ESTRO 36 Abstract Book

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S42 ESTRO 36 2017
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previous radiotherapy/brachytherapy or follow-up < 12
months. 5-year relapse free survival was estimated. Cox
regression model was used to find any factors associated
with local control.
Results
Ninety eight patients (56 females/42 males) were
analyzed in this retrospective study. Median age was 72
years (45-91). 112 primary and 43 post surgery lesions to
total of 167 were treated with surface brachytherapy.
Median of lesions’ greatest dimension was 2 cm (0.2-8).
Median total dose was 45 Gy (30-50 Gy) with dose per
fraction of 5 Gy. Dose was specified 0.3-0.5 cm from the
surface of the applicator. Median follow-up was 54 months
(12-95). 5-year local relapse-free survival was 94%. Single
factor linked to local failure was lesion localization in the
concha and/or external acoustic meatus (HR-2.6; 1.4-3.8;
p-0.0000).
Conclusion
Surface HDR brachytherapy is very effective for the
treatment of basal cell caner. Lesions localized in the
concha/external acoustic meatus should be managed
carefully.
OC-0084 Results of excision and 13 Gy single dose HDR
brachytherapy for keloids
C. Hafkamp1, O. Lapid2, R. Dávila Fajardo1, A. Van de
Kar2 , C. Koedooder1, L. Stalpers 1, B. Pieters1
1 Academic Medical Center P.O. Box, Radiation Oncology,
Amsterdam, The Netherlands
2 Academic Medical Center P.O. Box, Plastic and
Reconstructive Surgery, Amsterdam, The Netherlands
Purpose or Objective
To investigate the outcome of a single dose of 13 Gy HDR
given postoperatively for the treatment of keloids.
Surgical treatment of keloids results in high recurrence
rates of 50-80%. Therefore surgical resection is often
combined with radiotherapy. We report the result in terms
of both local control and cosmesis.
Material and Methods
Between 2007 and 2015, 61 patients were treated for 72
keloids. All patients were contacted to participate.
All patients had a surgical excision followed by 13 Gy HDr
brachytherapy within 4 hours. Usually a single catheter
was placed in the wound bed with dose prescribed at 4-7
mm from the source axis. In some cases a volume implant
was applied according to the Paris-system geometry and
dosimetry or the dose was prescribed at dose points on the
skin.
A recurrence was defined as an elevation of the scar
outside the initial wound. Cosmetic assessment was
according to the Patient and Observer Scar Assessment
Scale (POSAS). The POSAS score can range from 6-60,
higher scores correspond with worse scarring.
Results
Twenty-four patients (39%) with 29 keloids consented to
participate in the study. The median age at treatment was
31 years (15 – 64 years). The median follow-up period was
53 months, (19 – 95 months). The most frequent
localization was the ear (n=14). Recurrence was reported
for 7 (24.1%) out of 29 keloids. Two recurrences were
localized presternally, two on one ear, one in the neck,
one abdominal and one on the shoulder.
Patients scored on average 24.3 for their total POSAS score
(range 6 – 52) and the observer scored on average 14.6
(range 6 – 42) (Figure 1). Patients scored stiffness as the
most bothersome side effect followed by thickness. The
observer gave the highest score to overall impression
followed by surface area.
Conclusion
Compared to favorable reports in the literature, typically
reporting about 10% recurrence rates, we found a high
recurrence rate of 24% following excision and
brachytherapy for keloids. This may be explained by our
much longer follow-up of at least 1.5 years, and a more
stringent and objective definition of response by the
POSAS patient and observer reported outcome. Our results
may have been further negatively biased by selection;
despite repeated invitations, the willingness to
participate was very low, partly explained by the poorer
socio-economic background of the patients. Publication
bias may also have deterred publication of less favorable
results, and stresses the need of prospective multicenter
trials with a uniform scoring system.
OC-0085 In search for the optimal HDR brachytherapy
radiation scheme after excision in keloid treatment.
E. Bijlard1, G.M. Verduijn2, J.X. Harmeling1, H. Dehnad3,
M.A.M. Mureau1
1Erasmus Medical Center Rotterdam Daniel den Hoed
Cancer Center, Plastic Surgery, Rotterdam, The
Netherlands
2Erasmus Medical Center Rotterdam Daniel den Hoed
Cancer Center, Radiation Oncology, Rotterdam, The
Netherlands
3University Medical Center Utrecht, Radiation oncology,
Utrecht, The Netherlands
Purpose or Objective
Keloids are benign lesions that can cause physical
symptoms and disturbing appearance. Excision with
radiation is considered the most effective treatment
option for recurrent keloids. Previously a BED of 30Gy was
reported as the minimal effective dose to prevent keloid
recurrence, this was based mainly on external radiation
(EBRT) studies. In a recent review high dose rate (HDR)
brachytherapy achieves favorable outcome over EBRT.
The included studies used different radiation schemes.
The optimal scheme for HDR brachytherapy in keloid
treatment preventing recurrences and treatment side
effects needs to be determined.
Material and Methods
We retrospectively collected patient and keloid
characteristics, information on complications, and (partial
or full) keloid recurrence of all patients who received
excision with HDR brachytherapy in center 1 from 2010 to
May 2014 and in center 2 from 2009 to 2014. In case
follow-up was insufficient or information was missing,
telephone interviews were performed. Center 1 used 9 Gy
2 hours postoperatively and 9 Gy 6 hours later. Center 2
used 6 Gy six hours postoperatively, followed by additional
2x6 Gy a day later. Center 3 has recently published a
prospective cohort, in detail, using 6 Gy 4 hours
postoperatively and 6 Gy the next day. We compared
results of all 3 centers. All centers used an Ir192 HDR
source.
Results
Comparing the 3 centers no significant differences were
found in recurrence rates (full recurrence 9.3%, 3.1%, 8.6%
p=0.31, no recurrence 79%, 77%, 91% p=0.169 for center 1,