Bashir, Shaheena

Koch, Anne

Ng, Sylvia

Rock, Kathy

Elsevier - Publisher Connector 

CARO 2016                                                                                                                                                                  S7 
_________________________________________________________________________________________________________ 
use of RTB after adjuvant breast radiotherapy was 38% in Era 1, 
29% in Era 2 and 76% in Era 3 (p < 0.001). Ten-year LRFS was 
85.3% in Era 1, 93.9% in Era 2 and 91.9% in Era 3. On MVA there 
was a significant decrease in relapse going from Era 1 (pre-HT, 
pre-boost) to Era 2 (HT, no boost) (HR 2.2, p = 0.03), but no 
change in relapse from Era 2 (HT, no boost) to Era 3 (HT and 
boost) (HR 1.0, p = 0.97). For LRFS across all three eras, there 
was no significant difference for patients that received a boost 
(92.9%) and those that did not (88.6%, p = 0.31) but there was a 
significant improvement for ER-positive patients that received 
HT (91.8% versus 81.6%, p = 0.01).  
Conclusions: This study showed that new breast cancer 
therapies were adopted swiftly in response to new clinical 
practice guidelines. The introduction of HT was associated with 
an 8.6% improvement in ten-year LRFS. However, for a 
population of patients that was routinely prescribed HT, no 
improvement in LRFS was observed with the addition of routine 
RTB. RTB causes toxicity and offers no survival benefit; its 
routine use should be re-evaluated in the HT era.  
 
17 
DOES DEEP INSPIRATION BREATH HOLD (DIBH) PRODUCE A 
CLINICALLY MEANINGFUL REDUCTION IN IPSILATERAL LUNG DOSE 
DURING LOCOREGIONAL RADIATION THERAPY FOR WOMEN WITH 
RIGHT-SIDED BREAST CANCER? 
Jessica L Conway1, Leigh Conroy2, Lindsay Harper1, Marie 
Scheifele1, Wendy Smith2, Tannis Graham1, Tien Phan1, Ivo A 
Olivotto2 
1Tom Baker Cancer Centre, Calgary, AB 
2University of Calgary, Calgary, AB  
 
Purpose: To determine whether DIBH produced a clinically 
meaningful reduction in pulmonary dose in comparison to free 
breathing (FB) during adjuvant locoregional radiation (RT) for 
right-sided breast cancer. 
Methods and Materials: Thirty women with Stages 0-I left-sided 
breast cancer and who had both DIBH and FB CT scans as part of 
standard care were included. The right-sided IMC nodes were 
contoured according to ESTRO guidelines on DIBH and FB scans, 
with care taken to ensure comparability between scans. A four-
field, modified-wide tangent RT plan was developed on each 
scan to include the right breast and full regional nodes, including 
a minimum dose of 80% to the IMC volume. The junction between 
the supraclavicular and tangent fields was at the inferior extent 
of the ossified medial clavicle. Treatment plans were calculated 
in Eclipse using the Acuros algorithm version 11. FB and DIBH plan 
metrics were compared using Wilcoxon-signed rank testing. 
Results: IMC coverage was equivalent between DIBH and FB 
plans; V80 was 100% on both plans and D100 was 39.2 and 39.5 
Gy for DIBH and FB, respectively. Twenty-one patients (70%) had 
≥ 5% reduction in ipsilateral lung V20 with DIBH compared to FB. 
The average ipsilateral lung V20 decreased by 7.8% (range: 0 to 
20%; p < 0.001) and the mean lung dose decreased by 3.4 Gy with 
DIBH (range: -0.2 to 9.1; p < 0.001). The right lung absolute V20 
Gy gain from DIBH was larger among 15 patients with the highest 
V20 compared to 15 patients with the lowest V20 on FB (10.1% 
versus 5.6% respectively; p = 0.01). There was a mean reduction 
of 42.3 cc (range: 0 to 178.9; p < 0.001) in the volume of liver 
receiving 50% of the prescription dose. The differences in mean 
heart doses were statistically significant, but not likely clinically 
significant: MHD was 0.88 Gy (range: 0.67 to 1.27) and 1.00 Gy 
(range: 0.75 to 1.48) (p < 0.001) for DIBH and FB, respectively.  
Conclusions: DIBH reduced mean ipsilateral lung V20 by 7.8% and 
mean lung dose by 3.4 Gy. For some patients, the volume of liver 
receiving ≥ 25 Gy can also be reduced with DIBH. DIBH should be 
available as a treatment strategy to reduce right lung V20 
without compromising IMC or supraclavicular nodal coverage for 
patients with right-sided breast cancer during locoregional RT. 
This strategy can be advantageous in cases where the ipsilateral 
V20 on FB approaches 30%, a value that prompts many radiation 
oncologists to exclude IMCs from the RT volume. 
 
 
18 
LOCAL CONTROL IN YOUNG WOMEN WITH EARLY-STAGE BREAST 
CANCER TREATED WITH HYPOFRACTIONATED WHOLE BREAST 
RADIOTHERAPY  
Kathy Rock, Sylvia Ng, Shaheena Bashir, Anne Koch 
University of Toronto, Toronto, ON 
 
Purpose: Randomized clinical trials have shown equivalent local 
control for patients with early-stage breast cancer (BC) treated 
with conventional fractionation (CF) or hypofractionated (HF) 
adjuvant whole breast radiotherapy (WBRT). However, women 
less than 50 years of age have been underrepresented in these 
trials, and controversy still remains in relation to optimal 
fractionation schedule in this patient group. Our institutional 
policy allows for both schedules, therefore we compared local 
control in young women following breast-conserving surgery 
(BCS), and identified factors associated with recommendation of 
CF or HF schedule. 
Methods and Materials: Two hundred and seventy-one women 
under 50 years of age with early-stage invasive BC (pT1-T2, pN0) 
treated from September 2009 to December 2013 were identified 
from an institutional database. BCS was followed by adjuvant CF 
(50 Gy in 25 fractions) or HF (40 or 42.4 Gy in 16 fractions) WBRT, 
followed by a boost to the tumour bed of 10-16 Gy in in 5-8 
fractions. Data on tumour characteristics and adjuvant systemic 
therapies were collected. Length of follow up was calculated 
from the completion date of radiotherapy (RT) to the date of 
most recent imaging or clinical review in which disease status 
was recorded. 
Results: Two hundred and twenty-seven (83.8%) patients were 
treated with HF and 44 (16.2%) with CF WBRT. Median follow up 
was 2.9 years (range 0-5.8 years) and median age was 42.8 years 
(range 19-49 years). Most patients had invasive ductal carcinoma 
(94%), unifocal (86%), Grade 1 or 2 (65%) and ER positive (88%) 
disease, of which 81% received adjuvant endocrine therapy. 
Lymphovascular invasion was associated in 16%, 54% received 
adjuvant systemic chemotherapy, 14% had HER2-positive disease 
and 8.5% of cases were triple negative (TN). Local control was 
achieved in 225 (99.1%) and 43 (97.7%) patients in the HF and CF 
groups, respectively. The mean age (± standard deviation) of 
patients receiving HF was 43.5 ± 4.5 years, and 39.3 ± 7.5 years 
for the CF group (p < 0.01). On univariate analysis, age greater 
than 40 years was associated with a higher likelihood of receiving 
HF WBRT (OR = 2.52, 95% CI 1.32-4.87), and patients with TN 
disease were 67% more likely to receive CF WBRT (OR = 0.33, 95% 
CI 0.13-0.87). No other differences were identified between the 
CF and HF groups, including receipt of systemic therapies. 
Conclusions: Young women with early-stage BC treated with HF 
WBRT following BCS obtained excellent local control that was 
comparable to CF WBRT. At our institution, HF was more likely 
to be recommended for women over 40 years of age or for non-
TN BC in this patient population. HF WBRT shortens total 
treatment time, is more convenient for patients and may be 
considered for women less than 50 years of age. 
 
19 
POPULATION-BASED ASSESSMENT OF RELATIONSHIP BETWEEN 
VOLUME OF PRACTICE AND OUTCOMES IN HEAD AND NECK 
CANCER PATIENTS  
Mary McLay1, Adrienne Stedford1, Emily Yurkowski2, Scott 
Matlock1, Robert Olson1 
1University of British Columbia, Vancouver, BC 
2University of Northern British Columbia, Prince George, BC 
 
Purpose: Recent literature has suggested that higher volumes of 
practice are associated with better survival outcomes for head 
and neck cancer (HNC) patients. Some limitations in these 
studies, however, include looking at the volume of practice on a 
cancer centre level, not a provider level, and not controlling for 
rurality of patient residence. The primary objective of this study 
was to evaluate the effect of treatment centre on the overall 
survival (OS) and cancer-specific survival (CSS) of HNC patients 


18: Local Control in Young Women with Early-Stage Breast Cancer Treated with Hypofractionated whole Breast Radiotherapy 

Rock, K

Ng, S

Bashir, S

Koch, CA

White Rose Research Online

Local Control in Young Women With Early-Stage Breast Cancer Treated With Hypofractionated Whole-Breast Radiation Therapy

K. Rock

S. Ng

S. Bashir

C.A. Koch

Crossref

International Journal of Radiation Oncology*Biology*Physics

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18: Local Control in Young Women with Early-Stage Breast Cancer Treated with Hypofractionated whole Breast Radiotherapy

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