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Factors Influencing Eligibility for Breast Boost Using Non-Invasive Image-Guided Breast Brachytherapy
Abstracts / Brachytherapy 13 (2014) S15eS126 PBSI. Using DR avoids uncertainties associated with poor seroma visualization on post-implant scans and with inter-operator variability when rigid registration is utilized. Reflection of visible post-implant changes and accurate deformation of implanted surgical clips demonstrate the reliability of the deformable registration technique.
S81
reducing the implant extension and keeps all advantages (dosimetric and proper selection patients for APBI) of the classic MIBB technique.
PD75 Minimally Invasive Intraoperative Multicatheter Breast Implant for Perioperative High-Dose-Rate Brachytherapy in Early Breast Cancer Treated With Conservative Surgery Mauricio Cambeiro, MD, Javier Aristu, MD, Marta Moreno, MD, Leire Arbea, MD, Alicia Olarte, MD, German Valtue~na, MD, Fernando Martinez-Regueira, MD, Natalia Rodriguez-Spiteri Sagredo, MD, Begona Olartecoechea, MD, Luis Javier Pina Insausti, MD, Jesus Javier Sola Gallego, MD, Rafael Martinez-Monge, MD. Radiation Oncology, Clinica Universitaria de Navarra, Pamplona, Spain. Purpose: To assess the safety and feasibility of MIOMBI in breast conservative surgery of breast cancer. Multicatheter Interstitial Breast Brachytherapy (MIBB) is an effective and safe technique for Accelerated Partial Breast Irradiation (APBI) in properly selected breast cancer patients treated with conservative surgery. MIBB technique allows reach the highest dose conformity and sparing healthy tissue ability respect of different APBI methods (Balloon, 3DCRT and Intraoperative Radiotherapy). MIBB is usually performed as closedcavity procedure. This condition allows proper selection patients for APBI according to definitive pathological features but has some disadvantages since implies a second operation room visit for patient, determine a indirect visualisation of tumor bed with the consequently risk to make a geographical error dimmed frequently by performing extensive implants. Minimally Invasive Intraoperative Multicatheter Breast Implant (MIOMBI) represents an alternative to classic MIBB procedure with potential logistics, clinical and cosmetics advantages. Materials and Methods: Patients with early breast cancer candidates for conservative surgery were eligible for MIOMBI technique with 6F flexible catheters. Perioperative high-dose-rate brachytherapy (PHDRBT) was delivered as APBI (3.4 Gy for 10 in five days) in patients who met low- and intermediate-risk criteria according to GEC ESTRO recommendations, (women older than 40 years, infiltrating ductal carcinoma less than 2 cm with extensive intraductal carcinoma less than 25%, pN0, free margins more than 2mm and intraductal carcinoma less than 3 cm.) Those patients who did not meet previous criteria receive PHDRBT as anticipatory boost (4 fractions of 3.4 Gy in two days BAT) followed by hypofractionated whole breast irradiation 39.9 Gy in 15 fractions. Results: From April 2010 to July 2013 101 consecutive breast cancer patients have been treated with conservative surgery and MIOMBI. The median time for MIOMBI procedure was 25 minutes. The median of number of catheter employed was 9 (4-14). No intraoperative complications were observed. Major complications RTOG grade 3-4 (acute and late) was observed only in one patient (1%) who suffered bleeding complication after implant remove. Infection (mastitis or abscess) was observed in 3 patients (2%). Fat necrosis with no symptoms was observed in 2 patients. PHDRBT was delivered as APBI in 64 patients (60%) and as a boost in 34 (40%). The median of CTV-T (clips zone plus 2 cm) was 41 cc with a median D90 of 3.27 Gy (96%) and DHI in CTV-T of 0.71. The median V100 and V150 was 60cc and 13cc, respectively, with a median DHI of 0.76. Median D10 in high-risk skin zone was 1.91 Gy (56%). With a median followup of 22 months (2-34) no (local, elsewhere, regional or distant) failure was observed. Cosmetic outcomes were evaluated in 46 of 64 APBI treatments (71%) with excellent and good results in 61% and 37%, respectively, and fair in 2%. Conclusions: Minimally invasive intraoperative multicatheter breast implant (MIOMBI) for perioperative high-dose-rate brachytherapy (PHDRBT) avoids a second surgical procedure, allows direct visualisation of tumor bed
PD76 Factors Influencing Eligibility for Breast Boost Using Non-Invasive Image-Guided Breast Brachytherapy Jaroslaw T. Hepel, MD1,2, Kara L. Leonard, MD1,2, Jessica R. Hiatt, MS1, Thomas A. DiPetrillo, MD1,2, David E. Wazer, MD1,2. 1Radiation Oncology, Rhode Island Hospital, Brown University, Providence, RI; 2 Tufts Medical Center, Tufts University, Boston, MA. Purpose: The intact breast presents a challenge for targeting of the tumor bed (TB) due to patient, breast, and respiratory motion. Non-invasive image-guided breast brachytherapy (NIBB) allows for accurate targeting of the TB for breast boost by utilizing breast immobilization and imageguidance. However, not all patients are ideal candidates for this technique. We evaluated our clinical experience using NIBB to indentify patient and anatomic factors which predict suitability for this technique. Materials and Methods: Consecutive patients with early stage breast cancer treated with breast conserving therapy were evaluated from April to November 2013. Only patients who were candidates for boost were included in this analysis. Patients with very small breast size (cup size A or smaller) for whom breast immobilization could not be achieved using NIBB were treated with en face electrons. All other patients underwent simulation for NIBB boost. NIBB was delivered using the AccuBoost System (Advanced Radiation Therapy, Inc., Billerica, MA). Patients who were found to be ineligible for NIBB boost on simulation underwent boost treatment with en face electrons or 3D conformal photons. The rate of eligibility for NIBB, reasons for ineligibility, and related patient and anatomic factors were analyzed. Results: Fifty-two patients were evaluated of which 6 patients were ineligible for NIBB due to small breast size. Of the remaining patients who underwent simulation for NIBB boost, 33 patients (72%) were treated with NIBB. The most common reasons for ineligibility were absence of identifiable TB (n55), inability to position the patient/breast to adequately target the TB (n54), posterior TB location (n53), and discomfort during breast compression (n51). The likelihood of being eligible for NIBB boost was dependent on breast size and breast quadrant. The eligibility for NIBB according to breast cup size was: # A (0%), B (50%), C (71%), D-DD (77%), and ODD (80%), p50.002. The eligibility based on breast quadrant was: retroareolar/central (100%), upper outer (72%), upper inner (67%), lower outer (38%), lower inner (25%), p50.07. For patients with a posterior TB, located along the chest wall, 73% were good candidates for NIBB. This was not statistically different compared to a non-posterior location, p50.2. For patients without clips defining the TB only 45% were candidates for NIBB as compared with 79% of patients who had clips, p50.05. Conclusions: NIBB boost is feasible in the majority of patients. Patients with larger breast size and a tumor bed located in the central breast or upper outer quadrant are more likely to be good candidates. Posterior TB
S82
Abstracts / Brachytherapy 13 (2014) S15eS126
location can be challenging for NIBB but the majority of patients are still candidates. Surgical clips are very helpful in defining the tumor bed for boost and greatly increase the likelihood of eligibility for NIBB.
T&B versus SAVI are clinically meaningful in terms of local control and/ or cosmetic outcomes.
PD78 PD77 Dosimetric Comparison and Early Clinical Outcomes of Interstitial Versus Strut Assisted Volume Implant (SAVI) for Accelerated Partial Breast Irradiation Mitchell Kamrava, MD, Sang-June Park, PhD, Ben Noor, BS, D. Jeffrey Demanes, MD. University of California Los Angeles, Los Angeles, CA.
Clinical Experience with a Miniature Accelerated Partial Breast Irradiation Device: A 5-Year Single Institution Comprehensive Study S¸erban Morcovescu, MS, DABR1, Jeffery Douglas Morton, MD1, Y. Elle Boleware, MS1, Perry Kerri, MD2. 1Radiation Oncology, Texas Oncology Denton, Denton, TX; 2North Texas Hospital, Denton, TX.
Purpose: There are several brachytherapy methods available for accelerated partial breast irradiation (APBI). Interstitial tube and button (T&B) has been utilized the longest but newer single entry channel devices have become more widely adopted because they are considered easier to deploy. The SAVI device is the most similar to the interstitial approach because it has multiple struts that sit on the edge of the lumpectomy cavity. We compared our recent contemporaneous experience with (dosimetry and early clinical outcomes) with these two devices. Materials and Methods: We prospectively collected data on patients treated with either SAVI or T&B APBI at our institution between 2010 and 2013. NSABP B39 target volumes and dosimetry constraints were applied. The mean dose was 34 Gy delivered twice daily for 10 fractions. Dosimetry parameters included: PTV volume (cc), minimum cavity to skin distance (mm), Target: D90 (%), V90 (%), V95 (%), V100 (%), V150 (%), V200 (%), Dose Heterogeneity Index (DHI) (%), Breast: V100% (cc), V150% (cc), V200% (cc), DHI (%), V50% (%), Normal tissue: skin D0.1cc (%), Pectoralis D0.1 cc (%), Ribs D0.1cc (%), Ipsilateral lung D0.1 cc (%). A paired t-test was used to detect significant differences between the methods. Results: There were 71 patients (37 SAVI and 34 TþB) whose mean age was 61 (þ/-11) years. Average tumor size was 1.2 (þ/- 0.6) cm. Histologies were 39 IDC (55%), 4 ILC (6%),4 ITC (6%), and 24 DCIS (34%). Tumor markers were positive as follows: ER 96%, PR 90%, and Her2 4%. According to ASTRO consensus guidelines the patients were suitable 25%, cautionary 54% and unsuitable 21%. Adjuvant antiestrogen therapy was administered to 62% and adjuvant chemotherapy to 4% of patients. Table 1 presents a dosimetry comparison of T&B versus SAVI. With a median followup of 20.0 months there has been 1 regional recurrence, but no local or distant failures. Conclusions: There are significant differences between T&B and SAVI dosimetry particularly with repect to the DHI both within the target and the normal breast. As expected with this cohort of patients with short followup there have been no local recurrences noted. Longer followup is needed to determine whether the observed dosimetric differences between
Purpose: Strut-based applicators have become an alternative to balloontype applicators in accelerated partial breast irradiation (APBI), and were increasingly used at our practice since early 2008. The applicator studied (Cianna Medical, Aliso Viejo, CA), is the smallest of its kind (6-1mini), and it has skin), chest wall bridge, and the maximum doses to critical structures (skin and chest-wall). PTV-to-PTV_EVAL volume reductions coefficients (VR) were also evaluated and discussed, in light of their impact on reported conformity indexes (CI) and dose homogeneity indexes (DHI). A detailed dosimetric analysis of different patient strata (grouped on a skin bridge 5 mm intervals) is provided. The implant technique - device entry and orientation vs. breast side and lumpectomy cavity location in breast quadrants - is also discussed from a dosimetric point of view. Results: Lumpectomy cavity volumes averaged 8.41.3cc. PTV_EVAL and PTV volumes averaged 44.77.9cc and 49.93.4cc, respectively. V90 values averaged 98.81.7% (TG43) of the PTV_EVAL volume. Similarly, V95 averaged 97.82.5%, and V100 averaged 95.34.8% across the entire cohort of patients. The V150 ‘‘hotspots’’ averaged 20.66.1cc, while V200 averaged 18.86.6cc. The average minimum skin distance was 13.5mm, but the applicator was used in patients where the skin bridge was as low as 1mm. The average maximum skin dose was 72.8% of the prescription dose. The average minimum rib bridge was 15.2mm, with the shortest of less than 0.3mm, and the average maximum dose to the chest wall of 90.5% of the prescription dose. The TG43 formalism was employed on all dosimetric evaluations. Conclusions: The SAVI6-1mini strut-based device proves to be a highly adaptable and versatile APBI solution for patients with reduced breast and lumpectomy cavity volumes, and skin and/or rib bridges. Inside the framework of a detailed and clear QA program, when it is appropriately elected as the APBI device of choice, optimally implanted, and comprehensively monitored during the course of treatment, this device indeed offers a very effective and highly reproducible tool for the treatment of complex breast cancer cases.
Average SD
SAVI (n534)
P value
PD79
PTV Volume (cc) Cavity to skin distance (mm) Target D90 (%) Target V90 (%) Target V95 (%) Target V100 (%) Target V150 (%) Target V200 (%) Target DHI (%) Breast V100 (cc) Breast V150 (cc) Breast V200 (cc) Breast DIII (%) V50 (%) Skin D0.1cc (%) Pectoralis D0.1 cc (%) Ribs D0.1 cc (%) Ipsilateral lung D0.1 cc
71 7 102 98 96 92 44 22 52 70 31 15 55 19 91 84 61 45
0.08 0.40 0.009 0.25 0.13 0.06 !0.001 !0.001 !0.001 0.84 !0.001 !0.001 !0.001 0.76 !0.001 0.41 0.01 0.002
Feasibility of Permanent Breast Seed Implants in British Columbia: Preliminary Dosimetric and Safety Results Yen Pham, MSc1, Michelle Hilts, PhD2, Deidre Batchelar, PhD2, Juanita M. Crook, MD3, Will Ansbacher, PhD1, Hosam Kader, MD4. 1Medical Physics, BC Cancer Agency - Vancouver Island Centre, Victoria, BC, Canada; 2Medical Physics, BC Cancer Agency - Centre of Southern Interior, Kelowna, BC, Canada; 3Radiation Oncology, BC Cancer Agency - Centre of Southern Interior, Kelowna, BC, Canada; 4Radiation Oncology, BC Cancer Agency - Vancouver Island Centre, Victoria, BC, Canada.
29 7 4 2 3 4 4 3 3 23 10 4 2 7 11 28 20 15
T&B (n531) 59 8 105 98 97 94 24 9 74 71 17 7 75 19 70 77 48 34
31 3 6 2 3 5 3 2 4 34 9 3 2 9 11 44 22 15
Purpose: To present preliminary results from a prospective study to determine the feasibility and safety of permanent breast seed implants as a viable treatment option for women with early stage breast cancer in British Columbia. Materials and Methods: Two centers within the BC Cancer Agency are collaborating on a prospective single arm feasibility study on the use of permanent breast seed implants (PBSI) using palladium-103. Confirmation of the technical feasibility and safety of PBSI is required
S81
reducing the implant extension and keeps all advantages (dosimetric and proper selection patients for APBI) of the classic MIBB technique.
PD75 Minimally Invasive Intraoperative Multicatheter Breast Implant for Perioperative High-Dose-Rate Brachytherapy in Early Breast Cancer Treated With Conservative Surgery Mauricio Cambeiro, MD, Javier Aristu, MD, Marta Moreno, MD, Leire Arbea, MD, Alicia Olarte, MD, German Valtue~na, MD, Fernando Martinez-Regueira, MD, Natalia Rodriguez-Spiteri Sagredo, MD, Begona Olartecoechea, MD, Luis Javier Pina Insausti, MD, Jesus Javier Sola Gallego, MD, Rafael Martinez-Monge, MD. Radiation Oncology, Clinica Universitaria de Navarra, Pamplona, Spain. Purpose: To assess the safety and feasibility of MIOMBI in breast conservative surgery of breast cancer. Multicatheter Interstitial Breast Brachytherapy (MIBB) is an effective and safe technique for Accelerated Partial Breast Irradiation (APBI) in properly selected breast cancer patients treated with conservative surgery. MIBB technique allows reach the highest dose conformity and sparing healthy tissue ability respect of different APBI methods (Balloon, 3DCRT and Intraoperative Radiotherapy). MIBB is usually performed as closedcavity procedure. This condition allows proper selection patients for APBI according to definitive pathological features but has some disadvantages since implies a second operation room visit for patient, determine a indirect visualisation of tumor bed with the consequently risk to make a geographical error dimmed frequently by performing extensive implants. Minimally Invasive Intraoperative Multicatheter Breast Implant (MIOMBI) represents an alternative to classic MIBB procedure with potential logistics, clinical and cosmetics advantages. Materials and Methods: Patients with early breast cancer candidates for conservative surgery were eligible for MIOMBI technique with 6F flexible catheters. Perioperative high-dose-rate brachytherapy (PHDRBT) was delivered as APBI (3.4 Gy for 10 in five days) in patients who met low- and intermediate-risk criteria according to GEC ESTRO recommendations, (women older than 40 years, infiltrating ductal carcinoma less than 2 cm with extensive intraductal carcinoma less than 25%, pN0, free margins more than 2mm and intraductal carcinoma less than 3 cm.) Those patients who did not meet previous criteria receive PHDRBT as anticipatory boost (4 fractions of 3.4 Gy in two days BAT) followed by hypofractionated whole breast irradiation 39.9 Gy in 15 fractions. Results: From April 2010 to July 2013 101 consecutive breast cancer patients have been treated with conservative surgery and MIOMBI. The median time for MIOMBI procedure was 25 minutes. The median of number of catheter employed was 9 (4-14). No intraoperative complications were observed. Major complications RTOG grade 3-4 (acute and late) was observed only in one patient (1%) who suffered bleeding complication after implant remove. Infection (mastitis or abscess) was observed in 3 patients (2%). Fat necrosis with no symptoms was observed in 2 patients. PHDRBT was delivered as APBI in 64 patients (60%) and as a boost in 34 (40%). The median of CTV-T (clips zone plus 2 cm) was 41 cc with a median D90 of 3.27 Gy (96%) and DHI in CTV-T of 0.71. The median V100 and V150 was 60cc and 13cc, respectively, with a median DHI of 0.76. Median D10 in high-risk skin zone was 1.91 Gy (56%). With a median followup of 22 months (2-34) no (local, elsewhere, regional or distant) failure was observed. Cosmetic outcomes were evaluated in 46 of 64 APBI treatments (71%) with excellent and good results in 61% and 37%, respectively, and fair in 2%. Conclusions: Minimally invasive intraoperative multicatheter breast implant (MIOMBI) for perioperative high-dose-rate brachytherapy (PHDRBT) avoids a second surgical procedure, allows direct visualisation of tumor bed
PD76 Factors Influencing Eligibility for Breast Boost Using Non-Invasive Image-Guided Breast Brachytherapy Jaroslaw T. Hepel, MD1,2, Kara L. Leonard, MD1,2, Jessica R. Hiatt, MS1, Thomas A. DiPetrillo, MD1,2, David E. Wazer, MD1,2. 1Radiation Oncology, Rhode Island Hospital, Brown University, Providence, RI; 2 Tufts Medical Center, Tufts University, Boston, MA. Purpose: The intact breast presents a challenge for targeting of the tumor bed (TB) due to patient, breast, and respiratory motion. Non-invasive image-guided breast brachytherapy (NIBB) allows for accurate targeting of the TB for breast boost by utilizing breast immobilization and imageguidance. However, not all patients are ideal candidates for this technique. We evaluated our clinical experience using NIBB to indentify patient and anatomic factors which predict suitability for this technique. Materials and Methods: Consecutive patients with early stage breast cancer treated with breast conserving therapy were evaluated from April to November 2013. Only patients who were candidates for boost were included in this analysis. Patients with very small breast size (cup size A or smaller) for whom breast immobilization could not be achieved using NIBB were treated with en face electrons. All other patients underwent simulation for NIBB boost. NIBB was delivered using the AccuBoost System (Advanced Radiation Therapy, Inc., Billerica, MA). Patients who were found to be ineligible for NIBB boost on simulation underwent boost treatment with en face electrons or 3D conformal photons. The rate of eligibility for NIBB, reasons for ineligibility, and related patient and anatomic factors were analyzed. Results: Fifty-two patients were evaluated of which 6 patients were ineligible for NIBB due to small breast size. Of the remaining patients who underwent simulation for NIBB boost, 33 patients (72%) were treated with NIBB. The most common reasons for ineligibility were absence of identifiable TB (n55), inability to position the patient/breast to adequately target the TB (n54), posterior TB location (n53), and discomfort during breast compression (n51). The likelihood of being eligible for NIBB boost was dependent on breast size and breast quadrant. The eligibility for NIBB according to breast cup size was: # A (0%), B (50%), C (71%), D-DD (77%), and ODD (80%), p50.002. The eligibility based on breast quadrant was: retroareolar/central (100%), upper outer (72%), upper inner (67%), lower outer (38%), lower inner (25%), p50.07. For patients with a posterior TB, located along the chest wall, 73% were good candidates for NIBB. This was not statistically different compared to a non-posterior location, p50.2. For patients without clips defining the TB only 45% were candidates for NIBB as compared with 79% of patients who had clips, p50.05. Conclusions: NIBB boost is feasible in the majority of patients. Patients with larger breast size and a tumor bed located in the central breast or upper outer quadrant are more likely to be good candidates. Posterior TB
S82
Abstracts / Brachytherapy 13 (2014) S15eS126
location can be challenging for NIBB but the majority of patients are still candidates. Surgical clips are very helpful in defining the tumor bed for boost and greatly increase the likelihood of eligibility for NIBB.
T&B versus SAVI are clinically meaningful in terms of local control and/ or cosmetic outcomes.
PD78 PD77 Dosimetric Comparison and Early Clinical Outcomes of Interstitial Versus Strut Assisted Volume Implant (SAVI) for Accelerated Partial Breast Irradiation Mitchell Kamrava, MD, Sang-June Park, PhD, Ben Noor, BS, D. Jeffrey Demanes, MD. University of California Los Angeles, Los Angeles, CA.
Clinical Experience with a Miniature Accelerated Partial Breast Irradiation Device: A 5-Year Single Institution Comprehensive Study S¸erban Morcovescu, MS, DABR1, Jeffery Douglas Morton, MD1, Y. Elle Boleware, MS1, Perry Kerri, MD2. 1Radiation Oncology, Texas Oncology Denton, Denton, TX; 2North Texas Hospital, Denton, TX.
Purpose: There are several brachytherapy methods available for accelerated partial breast irradiation (APBI). Interstitial tube and button (T&B) has been utilized the longest but newer single entry channel devices have become more widely adopted because they are considered easier to deploy. The SAVI device is the most similar to the interstitial approach because it has multiple struts that sit on the edge of the lumpectomy cavity. We compared our recent contemporaneous experience with (dosimetry and early clinical outcomes) with these two devices. Materials and Methods: We prospectively collected data on patients treated with either SAVI or T&B APBI at our institution between 2010 and 2013. NSABP B39 target volumes and dosimetry constraints were applied. The mean dose was 34 Gy delivered twice daily for 10 fractions. Dosimetry parameters included: PTV volume (cc), minimum cavity to skin distance (mm), Target: D90 (%), V90 (%), V95 (%), V100 (%), V150 (%), V200 (%), Dose Heterogeneity Index (DHI) (%), Breast: V100% (cc), V150% (cc), V200% (cc), DHI (%), V50% (%), Normal tissue: skin D0.1cc (%), Pectoralis D0.1 cc (%), Ribs D0.1cc (%), Ipsilateral lung D0.1 cc (%). A paired t-test was used to detect significant differences between the methods. Results: There were 71 patients (37 SAVI and 34 TþB) whose mean age was 61 (þ/-11) years. Average tumor size was 1.2 (þ/- 0.6) cm. Histologies were 39 IDC (55%), 4 ILC (6%),4 ITC (6%), and 24 DCIS (34%). Tumor markers were positive as follows: ER 96%, PR 90%, and Her2 4%. According to ASTRO consensus guidelines the patients were suitable 25%, cautionary 54% and unsuitable 21%. Adjuvant antiestrogen therapy was administered to 62% and adjuvant chemotherapy to 4% of patients. Table 1 presents a dosimetry comparison of T&B versus SAVI. With a median followup of 20.0 months there has been 1 regional recurrence, but no local or distant failures. Conclusions: There are significant differences between T&B and SAVI dosimetry particularly with repect to the DHI both within the target and the normal breast. As expected with this cohort of patients with short followup there have been no local recurrences noted. Longer followup is needed to determine whether the observed dosimetric differences between
Purpose: Strut-based applicators have become an alternative to balloontype applicators in accelerated partial breast irradiation (APBI), and were increasingly used at our practice since early 2008. The applicator studied (Cianna Medical, Aliso Viejo, CA), is the smallest of its kind (6-1mini), and it has skin), chest wall bridge, and the maximum doses to critical structures (skin and chest-wall). PTV-to-PTV_EVAL volume reductions coefficients (VR) were also evaluated and discussed, in light of their impact on reported conformity indexes (CI) and dose homogeneity indexes (DHI). A detailed dosimetric analysis of different patient strata (grouped on a skin bridge 5 mm intervals) is provided. The implant technique - device entry and orientation vs. breast side and lumpectomy cavity location in breast quadrants - is also discussed from a dosimetric point of view. Results: Lumpectomy cavity volumes averaged 8.41.3cc. PTV_EVAL and PTV volumes averaged 44.77.9cc and 49.93.4cc, respectively. V90 values averaged 98.81.7% (TG43) of the PTV_EVAL volume. Similarly, V95 averaged 97.82.5%, and V100 averaged 95.34.8% across the entire cohort of patients. The V150 ‘‘hotspots’’ averaged 20.66.1cc, while V200 averaged 18.86.6cc. The average minimum skin distance was 13.5mm, but the applicator was used in patients where the skin bridge was as low as 1mm. The average maximum skin dose was 72.8% of the prescription dose. The average minimum rib bridge was 15.2mm, with the shortest of less than 0.3mm, and the average maximum dose to the chest wall of 90.5% of the prescription dose. The TG43 formalism was employed on all dosimetric evaluations. Conclusions: The SAVI6-1mini strut-based device proves to be a highly adaptable and versatile APBI solution for patients with reduced breast and lumpectomy cavity volumes, and skin and/or rib bridges. Inside the framework of a detailed and clear QA program, when it is appropriately elected as the APBI device of choice, optimally implanted, and comprehensively monitored during the course of treatment, this device indeed offers a very effective and highly reproducible tool for the treatment of complex breast cancer cases.
Average SD
SAVI (n534)
P value
PD79
PTV Volume (cc) Cavity to skin distance (mm) Target D90 (%) Target V90 (%) Target V95 (%) Target V100 (%) Target V150 (%) Target V200 (%) Target DHI (%) Breast V100 (cc) Breast V150 (cc) Breast V200 (cc) Breast DIII (%) V50 (%) Skin D0.1cc (%) Pectoralis D0.1 cc (%) Ribs D0.1 cc (%) Ipsilateral lung D0.1 cc
71 7 102 98 96 92 44 22 52 70 31 15 55 19 91 84 61 45
0.08 0.40 0.009 0.25 0.13 0.06 !0.001 !0.001 !0.001 0.84 !0.001 !0.001 !0.001 0.76 !0.001 0.41 0.01 0.002
Feasibility of Permanent Breast Seed Implants in British Columbia: Preliminary Dosimetric and Safety Results Yen Pham, MSc1, Michelle Hilts, PhD2, Deidre Batchelar, PhD2, Juanita M. Crook, MD3, Will Ansbacher, PhD1, Hosam Kader, MD4. 1Medical Physics, BC Cancer Agency - Vancouver Island Centre, Victoria, BC, Canada; 2Medical Physics, BC Cancer Agency - Centre of Southern Interior, Kelowna, BC, Canada; 3Radiation Oncology, BC Cancer Agency - Centre of Southern Interior, Kelowna, BC, Canada; 4Radiation Oncology, BC Cancer Agency - Vancouver Island Centre, Victoria, BC, Canada.
29 7 4 2 3 4 4 3 3 23 10 4 2 7 11 28 20 15
T&B (n531) 59 8 105 98 97 94 24 9 74 71 17 7 75 19 70 77 48 34
31 3 6 2 3 5 3 2 4 34 9 3 2 9 11 44 22 15
Purpose: To present preliminary results from a prospective study to determine the feasibility and safety of permanent breast seed implants as a viable treatment option for women with early stage breast cancer in British Columbia. Materials and Methods: Two centers within the BC Cancer Agency are collaborating on a prospective single arm feasibility study on the use of permanent breast seed implants (PBSI) using palladium-103. Confirmation of the technical feasibility and safety of PBSI is required