ESTRO 36 Abstract Book

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S632 ESTRO 36
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No pulmonary or cardiac toxicity was observed.
Although the series is not homogeneus, there was no
significant difference in the incidence of acute or late
toxicity in pts that underwent or not to chemotherapy.
Conclusion
In our seriesHRT is well tollerated with a good toxicity
profile and a good cosmetic result. There is no clear
evidence that chemotherapy has an impact to acute or
late skin toxicity after HRT.
In our analysis we can not evaluate the role that have
sequential boost in causing late toxicity.
EP-1162 Non surgical breast conserving treatment
using a new radiosensitizer
T. Shimbo1, K. Yoshida1, N. Yoshikawa1, H. Yoshioka1, M.
Nakata 1, Y. Narumi 1, T. Komori1, H. Matsutani1, T.
Hamada 1, Y. Uesugi2
1 Osaka Medical College, Radiation Oncology, Osaka,
Japan
2 Kansai University of Welfare Sciences, Medical
treatment for health, Kashihara, Japan
Purpose or Objective
The purpose of this clinical study was to clarify a non-
surgical breast-conserving therapy (BCT) using a new
radiosensitizing agent for the early stage breast cancer
patients who rejected surgery. This new radiosensitizer,
named KORTUC (Kochi Oxydol-Radiation Therapy for
Unresectabe Carcinomas) containing 0.5% hydrogen
peroxide and 0.83% sodium hyaluronate has been
developed for intra-tumoral injection in various tumors.
Hydrogen peroxide is the only agent known to be capable
of inactivating antioxidative enzymes and producing
oxygen when applied topically to tumor tissues. By the
addition of sodium hyaluronate, which makes the solution
more viscous and slows the degradation of hydrogen
peroxide, allowing long-acting radiosensitization of the
local tumor tissue.
Material and Methods
A total of five early stage breast cancer patients (stage I,
2; stage II, 3) who rejected surgery were enrolled in the
KORTUC trial after providing a fully informed consent. The
mean age of the patients was 67.5 years (range; 38-
80). The tumor size was 24.6mm (range; 14-47). A
maximum of 6 mL of the radiosensitizar agent was
injected into breast tumor tissue twice a week under
ultrasonographic guidance. We used hypo-fractionated
radiotherapy with conventional linear accelerator. Forty-
four Gy in 16 fractions were irradiated for whole breast
and ipsilateral axillary region with tangential field, and an
additional electron boost of 9Gy in 3fractions were
delivered for primary tumor site.
Results
Treatment was well tolerated with minimal adverse
effects in all patients. No patients showed any significant
complications other than mild dermatitis. Three patients
with estrogen receptor-positive tumors were also started
on hormone therapy following KORTUC treatment. All
patients showed clinically complete response (cCR). The
mean duration of a follow-up was 15.6 months
(5/23/26/27/44 months), respectively. All patients were
alive with no evidence of disease at present. The mean
period taken to confirm cCR on the breast contrast-
enhanced CT, MRI or PET-CT was approximately 8.2
months. Cosmetically, all patients evaluated as having an
excellent appearance in their ipsilateral breast.
Conclusion
Non-surgical BCT (KORTUC-BCT) can be performed safely
and effectively for patients with early stage breast cancer.
KORTUC-BCT can be one of the treatment options to
breast cancer patients who rejected surgery.
EP-1163 A Prospective Evaluation of Lumpectomy
Cavity Volume Changes During Whole Breast
Radiotherapy
B. Barney1, G. Martinez1, R. Hecox1, J. Clark 1
1Intermountain Health Care, Radiation Oncology, Provo,
USA
Purpose or Objective
A significant percentage of female post-lumpectomy
breast cancer patients treated with whole breast
radiotherapy (WBRT) have a lumpectomy cavity seroma on
the initial CT simulation. Our purpose was to prospectively
evaluate for changes in the size of the postoperative
tumor bed during a course of WBRT, prior to the
lumpectomy cavity boost (LCB).
Material and Methods
This prospective study was approved by the IRB, and
informed consent was given by 20 women prior to study
enrollment. All patients underwent breast conserving
surgery and received a recommendation for LCB following
WBRT by the treating physician. The median patient age
was 63 years (range, 41-84). Most patients (n=19, 95%) had
Stage 0, I, or II breast cancer. There was no standardized
dose or fractionation for WBRT or the boost; these
decisions were left to the treating physician’s discretion.
Regional lymph nodes were treated as per standardized
guidelines. When chemotherapy was required, it preceded
WBRT.
Each patient underwent initial CT simulation (CT1) at a
median 39 days (range, 11-216) from surgery. Twelve
women (60%) had a lumpectomy cavity seroma on CT1,
and 8 (40%) did not. All patients underwent a second CT
simulation (CT2) approximately 1 week before the LCB
began. Median time from CT1 and CT2 was 30 days (range,
21-42). The LCB volume was immediately contoured on
CT1 based on surgical clips, presence/location of seroma,
and surgical findings. Without referencing CT1 LCB
contours, the treating physician then contoured a
modified LCB volume once CT2 was obtained, using the
same factors for CT1 LCB delineation.
We prospectively compared LCB volumes from CT1 and
CT2 across the cohort and within seroma/no seroma
subgroups. Univariate analysis of several factors
potentially associated with a change in LCB volume from
CT1 to CT2, including time from surgery to CT1 (≤40 days
vs >40 days), time from CT1 to CT2 (≤30 days vs >30 days),
and presence of seroma on CT1, was performed.
Results
The median LCB volumes on CT1 and CT2 for the entire
cohort were 20.1 and 8.5 cm3, respectively. Most patients
(n=17, 85%) experienced a reduction (rather than
increase) in the LCB volume from CT1 to CT2. For patients
with seromas, median LCB volumes on CT1 and CT2 were
36.0 and 8.8cm3, respectively, representing a volume
reduction of >75% over the course of WBRT. For patients
without seromas, median LCB volumes on CT1 and CT2
were 11.8 and 8.0cm3, respectively, representing a
volume reduction of 32% during WBRT. On univariate
analysis, only the presence of seroma was associated with
a significant change in LCB volume during WBRT.
Conclusion
Most patients experienced a change in the size of the LCB
volume during WBRT. Patients with seroma experienced
a more dramatic volume reduction than those
without. We recommend that women who will undergo
LCB and have a seroma at the time of initial CT simulation
undergo a re-simulation to plan the LCB boost towards the
end of the WBRT course.