Bristow, Bonnie

Ji, Chen

Loblaw, Andrew

McGuffin, Merrylee

Elsevier - Publisher Connector 

116: Fighting Prostate Cancer with our Eyes Open: Impact of MRI Staging on Risk Assessment and Radiation Therapy 

CARO 2016                                                                                                                                                                  S43 
_________________________________________________________________________________________________________ 
in Ontario (ONT) and to develop recommendations to ensure all 
patients to have equitable access to MR-guided brachytherapy 
(MRgBT) for cervical cancer. 
Methods: A qualitative phone interview was designed by the GYN 
CoP working group to survey the current state of ccBT in the 
province. Questions were developed to inquire about the current 
use of image-guided ccBT and the associated referral processes, 
the usage of MR imaging in ccBT and the current use of image-
guided interstitial GYN BT. All ONT cancer centres offering 
radiation treatments to GYN cancers were included. Two group 
members conducted and audio recorded the telephone 
interviews from May to November 2015 and analyzed all 
recordings and summarized the data. 
Results: Thirteen (n = 13) ONT cancer centres were interviewed. 
Of these, three centres do not offer ccBT, five centres offer CT-
guided ccBT, four centres offer a combination of CT-MR-guided 
ccBT and one centre offers strictly MR-guided ccBT. The three 
centres that do not offer ccBT have established referral 
processes with three tertiary cancer centres in ONT respectively. 
However, there is no standardized referral process, referral 
timing, or method of communication. Other practices vary 
throughout the centres. Three of 13 centres suggested 
developing a file portal to standardize and facilitate the sharing 
of external beam and BT plans, distributions and images. All CT-
guided ccBT centres except one have plans to develop MRgBT. 
The tertiary centres mentioned above are also the only centres 
that offer interstitial GYN BT. They are located in the 
southwestern part of the province. Of these, one centre offers 
CT-guided and two centres offer MR-guided interstitial GYN BT. 
There is currently no standardized guideline to identify patient 
candidates for interstitial GYN BT. 
Conclusions: This study demonstrated that models of shared 
care exist and are functioning in ONT. While referral processes 
are functioning well, some areas represent opportunities for 
improvement. Future work is needed by the GYN CoP to improve 
referral processes and to develop consensus on indications for 
interstitial brachytherapy. This will ensure all patients in ONT 
have access to this high quality brachytherapy.  
 
114 
PATIENT POSITIONING AND MARK-UP OPTIMIZATION FOR 
PERMANENT BREAST SEED IMPLANT (PBSI)  
Ruth Karchewski-Welter1, Karen Long1, Elizabeth Watt2, Siraj 
Husain2, Tyler Meyer2 
1Tom Baker Cancer Centre, Calgary, AB 
2University of Calgary, Calgary, AB 
 
Purpose: To determine the optimal patient positioning and most 
reliable measurements for placement of skin marks during the 
mark-up procedure prior to PBSI brachytherapy for breast 
cancer. 
Methods and Materials: A retrospective chart review was 
conducted among patients who had imaging assessments to 
determine eligibility for PBSI following breast conserving surgery 
for Stage 0-1 breast cancer. Eligible patients had received CT 
imaging to determine the size and location of the seroma. 
Patients had treatment plans created, with a CT reference 
marker placed on the medial aspect of the nipple and tattoos 
consistent with standard institutional practice for external beam 
radiation treatments (EBRT). For patients receiving PBSI, skin 
markings were placed on the patient’s breast to map the 
implant, on the morning of the procedure. The interval from 
planning CT to implant date was two to four weeks. For this 
study, mark-up and delivery data were documented and 
deviations between planning CT and implant data for PBSI, were 
reviewed to determine the most reliable measurements for 
patient positioning and mark-up. 
Results: Among 40 patients initially assessed for PBSI, 27 
proceeded to implant and 13 ineligible patients (seroma too 
large or close to skin) had EBRT. The EBRT set-up tattoos used in 
PBSI were observed to have significant deviations from the 
planning CT, due to the variation in arm placement between the 
two treatment modalities. Measurements to determine the 
fiducial entry point referencing the nipple marker were 
determined to have a mean deviation of < 1 mm while those from 
the table top to the tattoo was 6mm and from the table top to 
the fiducial was 8 mm. 
Conclusions: Two-thirds of patients assessed were eligible and 
received PBSI. Temporary markings should be used at the time 
of assessment CT with permanent tattoos applied only after of 
the treatment modality is finalized. Measurements from the 
table are less reliable than those referencing the nipple marker. 
Set-up variations on the table top, possibly due to loose tissue 
and patient rotation, make measurements referencing patient’s 
markings the most reliable. 
 
115 
PROPOSAL FOR A PERMANENT BREAST SEED IMPLANT (PBSI) 
TRAINING PROGRAM  
Karen Long1, Ruth Karchewski-Welter1, Michael Roumeliotis2, 
Elizabeth Watt2, Tyler Meyer2, Siraj Husain2 
1Tom Baker Cancer Centre, Calgary, AB 
2University of Calgary, Calgary, AB 
 
Purpose: To propose an effective training program for radiation 
therapy teams starting to implement PBSI brachytherapy for 
early stage breast cancer. 
Methods and Materials: A PBSI program requires a 
multidisciplinary team including physicians, physicists, 
dosimetrists, radiation therapists, operating room nurses, 
anesthetists, machinists and administrative personnel. A PBSI 
program was launched in 2013. Multiple CT and ultrasound 
compatible gel phantoms that mimicked breast tissue with 
embedded seromas, were designed and constructed. Physicians 
practiced ultrasound guided needle placement into numerous 
phantoms, with seromas in various locations, to simulate actual 
patient implants. Post-implant CT scans of phantoms were used 
to assess implant accuracy. Observations recorded prospectively 
during the practice implants on phantoms and mock PBSI 
deliveries were used to guide process development, improve 
quality and refine training, education, and experience. 
Results: Based on our development research, results, and 
experience, we suggest that a centre starting a PBSI program 
should have an onsite training course that includes the following 
modules: 
1) PBSI theory: including background, patient eligibility, patient 
assessments and suitability, process from assessment to 
treatment and patient care; 
2) Treatment planning session: including dosimetric goals and 
objectives, hands on clinical case examples with comparison to 
benchmark plans and guided physician evaluation; 
3) Participant observation of a PBSI operating room procedure; 
4) Active involvement of the participants in practice sessions 
with phantoms and realistic operating room scenarios; 
5) Wrap up session: opportunity to share experiences and 
problem solve. Group discussion on how to translate their 
learning to their own practice. Feedback from participants on 
this training program and areas for improvement; and 
6) Follow up: remote pre-plan consults and/or reviews as well as 
post-plan analyses for several cases. 
Conclusions: Effective training with hands on experience 
followed by support after centre implementation will improve 
the learning curve, increase confidence, and assist radiation 
therapy teams to set up a breast brachytherapy program in their 
department. 
 
116 
FIGHTING PROSTATE CANCER WITH OUR EYES OPEN: IMPACT OF 
MRI STAGING ON RISK ASSESSMENT AND RADIATION THERAPY 
Merrylee McGuffin1, Chen Ji2, Bonnie Bristow1, Andrew Loblaw2 
1Sunnybrook Health Sciences Centre, Toronto, ON 
2University of Toronto, Toronto, ON 
 
Purpose: The risk of tumour progression and recurrence is an 
important consideration when treating prostate cancer. Risk 
assessment includes clinical staging through physical 
S44                                                                                     CARO 2016 
_________________________________________________________________________________________________________ 
examination and transrectal ultrasound, CT and/or bone scan 
imaging. Increasingly, multiparametric magnetic resonance 
imaging (mpMRI) is being used to identify the presence, size and 
location of dominant intraprostatic lesions (DIL) for novel 
treatment approaches, such as MR-dose painted brachytherapy. 
This study was done to determine how frequently risk assessment 
was changed after mpMRI and to summarize the dosimetric data 
of DIL coverage for MR-dose painted brachytherapy. 
Methods and Materials: This study was conducted as a 
retrospective chart audit. Staging information, dosimetric data 
and demographics were collected from the electronic patient 
record for prostate cancer patients who had mpMRI staging prior 
to radiotherapy. Pre- and post-mpMRI risk assessment and 
dosimetric data were analyzed using descriptive statistics. 
Univariate analyses of demographic and staging information were 
done to identify factors associated with changes in risk 
assessment. 
Results: In total, 100 patients underwent mpMRI staging. Before 
mpMRI, 12 patients were assessed with low-risk, 47 with 
intermediate- and 41 with high-risk disease. After mpMRI, risk 
assessment changed for 11 patients; four low-risk patients 
changed to intermediate-risk and one low- and six intermediate-
risk patients changed to high-risk. On average, reclassified 
patients had a larger prostate volume (Mean = 48.4cc, StDev = 
10.6 versus Mean = 37.1 cc, StDev = 12.1; p = 0.004). Most 
patients (90/100) had a DIL identified as PiRADs 4 or 5 with an 
average volume of 5.4 cc. The mean boost D90% and V150% to 
the DIL were 131 and 69 respectively. 
Conclusions: Risk assessment changed after mpMRI in a small but 
significant proportion of the patients reviewed in this study. 
mpMRI is an important tool for the identification of intraprostatic 
lesions and the accurate staging of prostate cancer patients prior 
to HDR brachytherapy. 
 
117 
CAN POST-OP DOSIMETRY PREDICT SKIN REACTIONS FOLLOWING 
PARTIAL BREAST RADIATIO TREATMENT USING PERMANENT 
PALLADIUM SEED IMPLANTS? 
Siraj Husain, Elizabeth Watt, Michael Peacock, Karen Long, Tyler 
Meyer 
University of Calgary, Calgary, AB 
 
Purpose: To validate the Hilts et al. (Brachytherapy 
2015;14:970-8) skin dose to 0.2 ccs’ as a metric to estimate skin 
toxicity following breast brachytherapy with a permanent seed 
implant. 
Methods and Materials: Between November 2013 and December 
2015, 25 patients were treated with a permanent Palladium Seed 
Implant breast brachytherapy technique 14 to 16 weeks following 
breast conserving surgery for Stage 0-1 breast cancer. Prescribed 
dose was 90Gy. Pre-op planning parameters were (PTV V100 > 
95%, V200 < 40%, skin dose to 1 cm2 was kept to < 90% of 
prescribed dose). Immediately following the implant (Day 0 CT) 
patients had a CT simulation performed to assess the implant 
quality. Images were transferred to the Mim Symphony 
treatment planning system and deformably registered to the pre-
op plan to create a post op plan. The deformed seroma contour 
was modified by the treating physician where necessary, and 
doses to skin and PTV were evaluated. PTV V200 and CTV V100 
were calculated. Skin dose to 0.2 cc was calculated and 
correlated with clinical signs and symptoms. Cosmetic outcomes 
were evaluated at 2, 4, 8, 16, 26 and 52 weeks post treatment 
using patient reports based on the Harvard Cosmetic Criteria. 
Results: Mean post-op CTV V100 and PTV V200 were 93.2 Gy and 
36.2 Gy with a range of 70.2 Gy to 100 Gy and 15.8 – 62.4 Gy, 
respectively. Mean dose to 0.2 cc of skin was 51.5 Gy with a range 
of 12.2 Gy to 137.2 Gy. At two and four weeks all but one patient 
had excellent cosmesis. At eight weeks, 17, two and one patients 
reported excellent, good, and fair cosmesis. The patient who 
reported fair continued to score fair until 52 weeks at which time 
she reported good. The two patients that scored “good” had 
Grade 1 reaction and by 16 weeks converted back to excellent. 
All patients who scored “excellent” at 16 weeks continued to 
report excellent on their subsequent visits. Only two patients had 
a skin 0.2 cc dose of > 100 Gy and both reported skin reactions 
(Grade 1 for SD 0.2 cc 137.2, and Grade 2 for SD 0.2cc of 108.1 
Gy). One patient with a 0.2 cc skin dose of 34.8 Gy also 
developed a Grade 1 skin reaction. 
Conclusions: Permanent Breast Seed Implant brachytherapy 
delivered in a single fraction caused a low rate of early side 
effects and patient reported cosmetic results were good to 
excellent in this small group of patients. An SD 0.2cc of > 100 Gy 
appeared to predict skin reactions, as only one out of  23 
reported Grade 1 reaction below this level and two out of two 
patients with a dose above this had skin reactions. Further follow 
up is ongoing to assess late effects and dosimetric factors that 
may predict favourable and less favourable outcomes. More data 
is needed to better predict these factors. 
 
118 
IMPACT OF INTERNAL MAMMARY NODE RADIATION ON SURVIVAL 
OF PATIENTS WITH BREAST CANCER: EXTENDED FOLLOW UP OF A 
POPULATION BASED ANALYSIS  
Robert Olson1, Benjamin Maas2, Lovedeep Gondara3, Ryan 
Woods3, Caroline Speers3, Pauline Truong4, Andrea Lo2, Ivo 
Olivotto5, Scott Tyldesley3, Alan Nichol2, Lorna Weir2 
1British Columbia Cancer Agency, Centre for the North, Prince 
George, BC  
2University of British Columbia, Vancouver, BC 
3British Columbia Cancer Agency, Vancouver, BC 
4University of British Columbia, Victoria, BC 
5Tom Baker Cancer Centre, Calgary, AB 
 
Purpose: To extend follow up of a published analysis examining 
the value of the intent to include the internal mammary nodes 
(IMN) in patients with breast cancer receiving adjuvant 
locoregional radiation therapy (RT) to the breast or chest wall 
plus axillary/supraclavicular nodes. 
Methods and Materials: 2413 women with node-positive or 
T3/4pN0 breast cancer, treated with locoregional RT from 2001 
to 2006, were identified using a prospectively maintained, 
population-based database. Intent to include IMN was 
determined by review of charts and RT plans. Kaplan-Meier 
distant relapse-free survival (DRFS), breast cancer specific 
survival (BCSS), and overall survival (OS) were compared 
between the IMN and no-IMN RT groups. Pre-specified subgroup 
analyses of patients with pN1 disease were performed. 
Propensity scores were used to adjust for imbalances in patient, 
tumour, and treatment factors between the two groups. 
Results: Median follow up time was 11.7 years. Forty-one 
percent of subjects received IMN RT. Twelve-year survival 
outcomes among the IMN and no-IMN groups were: DRFS 72.3% 
versus 72.3%, p = 0.85, BCSS 76.4% versus 72.5%, p = 0.41, and 
OS 69.6% versus 63.2%, p = 0.005. Corresponding survival 
comparisons restricted to the pN1 subgroup were: DRFS 83.3% 
versus 80%, p = 0.17, BCSS 86.2% versus 82.7%, p = 0.11, and OS 
79.1% versus 70.5%, p = 0.0003. After adjusting for potential 
confounding factors, the IMN RT group did not have significantly 
different DRFS (hazard ratio [HR] 1.01 (95% confidence interval 
[CI], 0.85-1.19; p = 0.95), BCSS (HR 0.97 (95% CI, 0.81-1.17; p = 
0.77), or OS (HR 0.95; 95% CI, 0.82-1.11; p = 0.53) compared to 
the no-IMN RT group. In the pN1 subgroup, IMN RT was associated 
with non-significant trends for improved survival: DRFS (HR 0.84; 
95% CI, 0.63-1.11; p=0.22), BCSS (HR 0.84; 95% CI, 0.61 -1.14; p 
= 0.26), and OS (HR 0.80; 95% CI, 0.63-1.02; p = 0.08).  
Conclusions: With extended 12-year follow up, the intent to 
include IMN was not associated with significant improvements in 
survival. The survival hazard ratios associated with IMN RT among 
the pN1 cohort, while not statistically significant, appeared 
comparable to those reported in randomized trials, suggesting 
that IMN RT may contribute to improved outcomes in this 
subgroup.  
 
 
 


file:///data/core-remote/dit/data/elsevier/pdf/1e4/aHR0cDovL2FwaS5lbHNldmllci5jb20vY29udGVudC9hcnRpY2xlL3BpaS9zMDE2NzgxNDAxNjMzNTE1MA==.pdf

116: Fighting Prostate Cancer with our Eyes Open: Impact of MRI Staging on Risk Assessment and Radiation Therapy

Abstract

Similar works

Full text

Available Versions

Elsevier - Publisher Connector

Elsevier - Publisher Connector