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Evaluation of Hypofractionated Adjuvant Radiotherapy for Early Breast Cancer: A Prospective Randomized Study
I. J. Radiation Oncology d Biology d Physics
S76
Volume 75, Number 3, Supplement, 2009
Conclusions: Treatment efficacy and cosmesis 5 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI or whole-breast irradiation with similar follow-up and risk factors for IBTR. To our knowledge, this represents the largest group of patients treated with contemporary APBI with 5-years of follow-up. Author Disclosure: F.A. Vicini, None; P. Beitsch, None; C. Quiet, None; A. Keleher, None; D. Garcia, None; H. Snider, None; M. Gittleman, None; V. Zannis, None; B. Haffty, None; H. Kuerer, None.
160
Outcomes following Accelerated Partial Breast Irradiation in Patients with ASTRO Consensus Statement Cautionary Features
D. R. McHaffie1, R. R. Patel2, J. B. Adkison1, R. K. Das1, G. M. Cannon1 1 Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI, 2Department of Human Oncology, University of Wisconsin School of Medicine and Public Health and Western Radiation Oncology, Mountain View, CA
Purpose/Objective(s): In June 2008, ASTRO commissioned a task force to address selection criteria for the use of accelerated partial breast irradiation (APBI). In the recently published consensus statement, a group was defined for which caution in the use of APBI should be exercised at this point in time due to limited data. In this analysis, we reviewed the outcomes in this cohort of potentially higher risk patients. Materials/Methods: Between March 2001 and June 2006, a total of 322 consecutive patients were treated with HDR APBI at the University of Wisconsin. A total of 136 patients were identified that met the ASTRO cautionary criteria: 86 patients (63.2%) age 50–59, 32 patients (23.5%) with pure DCIS, 17 patients (12.5%) with EIC, 13 patients (9.6%) with tumors 2.1–3 cm, 11 patients (8.1%) ER negative, 10 patients (7.4%) with lobular histology, and 10 patients (7.4%) with margins \2 mm. Thirty-eight (27.9%) patients possessed multiple cautionary factors. All patients received 32–34 Gy in 8–10 b.i.d. fractions using multicatheter (93.4%) or MammoSite balloon (6.6%) brachytherapy. Results: With a median follow-up of 60 months (range, 1.3–92.4 months), there were 5 in-breast tumor recurrences (3 local and 2 locoregional). Two of 5 patients were successfully salvaged with mastectomy and had no evidence of disease at last follow-up. The 6-year actuarial local control rate is 95.2% ± 4.1%, with a latency to local recurrence ranging from 24–50 months. Including contralateral events, the 6-year disease-free survival is 89.6% with a cause-specific survival and overall survival of 97.6% and 95.3%, respectively. There were no ipsilateral failures among 32 patients with DCIS, with an actuarial local recurrence rate of 0% vs. 6.1% for patients with invasive carcinoma (p = 0.24). Among 104 patients with Stage I or II invasive carcinoma, the actuarial local recurrence rate for patients considered cautionary by virtue of age alone is 0% vs. 12.7% in those deemed cautionary due to histopathologic or surgical factors (p = 0.018). Local recurrences were observed in 1/17 patients with EIC, 2/11 with ER - tumors, 1/10 with margins \2 mm, 2/10 with lobular histology, and 2/13 with tumor size 2.1–3 cm. Conclusions: Although locoregional recurrences remained low at 6 years for the entire cohort, our experience suggests that patients with EIC, ER-, close margins, lobular histology, and tumor 2.1–3 cm should be approached with caution until prospective, randomized data become available given the higher rate of local recurrence within this group. In the absence of these surgical or histopathologic cautionary factors, however, those aged 50–59 do not appear to be at significant risk of local recurrence, indicating potential suitability for treatment with APBI. The absence of IBTR observed among those with DCIS also supports the use of APBI in this cohort of patients. Author Disclosure: D.R. McHaffie, None; R.R. Patel, BrachySolutions, Inc., F. Consultant/Advisory Board; J.B. Adkison, None; R.K. Das, None; G.M. Cannon, None.
161
Evaluation of Hypofractionated Adjuvant Radiotherapy for Early Breast Cancer: A Prospective Randomized Study
S. Saha, A. Ghosh Dastidar, A. Gangopadhyay, S. Ghorai Medical College Hospital Calcutta, Calcutta, India Purpose/Objective(s): Upcoming hypothesis of higher fraction sensitivity of breast cancer, owing to presumably lower a/b value, has provoked a number of hypofractionation trials in recent years. This prospective randomized single institute pilot trial aims to evaluate one such hypofractionated schedule of weekly 6 Gy 5 fractions for both, breast conservation (BCT), and also postmastectomy cases (PMRT) against the conventional regimen. Study endpoints are locoregional control, acute and late effects, and cosmetic outcome. Materials/Methods: Between October 2004 and December 2005, 131 early breast cancer patients (T1 = 34, T2 = 97; N1 = 114, N0 = 17) with the histopathology of invasive duct carcinoma were randomized, postsurgery (BCT = 47; mastectomy with axillary clearance = 84) after informed consent to either radiotherapy schedule: 50 Gy/25 fractions/5 weeks (Control arm, n = 62; BCT = 23; and PMRT = 39) or 30 Gy/6 fractions, weekly (Study arm, n = 69; BCT = 24; PMRT = 45). Individualized CT-based planning was done to optimize target coverage and quantify exposure to organs at risk. Central lung distance was recorded in all. For left breast patients, volume of heart irradiated and the volume of heart receiving 5 Gy (V5) were estimated individually from integral DVH. Maximum heart distance (MHD) was measured for majority. Sequential boost was given by HDR implant in 41/47 BCT patients. All patients received FAC chemotherapy for 6 cycles. Locoregional recurrences as well as late toxicity (LENT-SOMA) were recorded in follow-up. Cosmetic outcome (for BCT patients) was evaluated by a panel using a four point (excellent, good, fair, or poor) scale. Results: After a median follow-up of 42 months (minimum = 36 months), 2/23 BCT patients of control arm and 1/24 of study arm had in-breast failure (p = NS) and were salvaged by mastectomy. Among postmastectomy patients, chest wall recurrence was noted in 1/39 of the control arm and none in the study arm. Regional failure was in 3/62 (BCT+PMRT) of control arm and 4/69 of study arm. Grade 1–2 fibrosis was noted in 5/23 BCT patients in the control arm and 7/24 in the study arm (p = NS). Grade 1–2 telengiectasia occurred in 2/23 in control arm vs. 4/24 in the study arm (p = NS). Grade 3 fibrosis was observed in 1 BCT patient in the control arm and in none of the study arm. Regarding cosmetic outcome, 20/23 patients (87%) were good + excellent, 3 fair, and 0 poor in the control arm. Corresponding figures in study arm were 19/24 (80%), 5/24 and 1/24 (p = NS). Conclusions: There was no significant difference in local control or late toxicity in hypofractionated arm compared to conventional arm. Cosmetic outcome was also similar at least in 3-year follow-up. To improve patient compliance and minimize machine time, weekly 5 fractions of 6 Gy each may be an alternative approach as far as safety and efficacy is concerned. Author Disclosure: S. Saha, None; A. Ghosh Dastidar, None; A. Gangopadhyay, None; S. Ghorai, None.
S76
Volume 75, Number 3, Supplement, 2009
Conclusions: Treatment efficacy and cosmesis 5 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI or whole-breast irradiation with similar follow-up and risk factors for IBTR. To our knowledge, this represents the largest group of patients treated with contemporary APBI with 5-years of follow-up. Author Disclosure: F.A. Vicini, None; P. Beitsch, None; C. Quiet, None; A. Keleher, None; D. Garcia, None; H. Snider, None; M. Gittleman, None; V. Zannis, None; B. Haffty, None; H. Kuerer, None.
160
Outcomes following Accelerated Partial Breast Irradiation in Patients with ASTRO Consensus Statement Cautionary Features
D. R. McHaffie1, R. R. Patel2, J. B. Adkison1, R. K. Das1, G. M. Cannon1 1 Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI, 2Department of Human Oncology, University of Wisconsin School of Medicine and Public Health and Western Radiation Oncology, Mountain View, CA
Purpose/Objective(s): In June 2008, ASTRO commissioned a task force to address selection criteria for the use of accelerated partial breast irradiation (APBI). In the recently published consensus statement, a group was defined for which caution in the use of APBI should be exercised at this point in time due to limited data. In this analysis, we reviewed the outcomes in this cohort of potentially higher risk patients. Materials/Methods: Between March 2001 and June 2006, a total of 322 consecutive patients were treated with HDR APBI at the University of Wisconsin. A total of 136 patients were identified that met the ASTRO cautionary criteria: 86 patients (63.2%) age 50–59, 32 patients (23.5%) with pure DCIS, 17 patients (12.5%) with EIC, 13 patients (9.6%) with tumors 2.1–3 cm, 11 patients (8.1%) ER negative, 10 patients (7.4%) with lobular histology, and 10 patients (7.4%) with margins \2 mm. Thirty-eight (27.9%) patients possessed multiple cautionary factors. All patients received 32–34 Gy in 8–10 b.i.d. fractions using multicatheter (93.4%) or MammoSite balloon (6.6%) brachytherapy. Results: With a median follow-up of 60 months (range, 1.3–92.4 months), there were 5 in-breast tumor recurrences (3 local and 2 locoregional). Two of 5 patients were successfully salvaged with mastectomy and had no evidence of disease at last follow-up. The 6-year actuarial local control rate is 95.2% ± 4.1%, with a latency to local recurrence ranging from 24–50 months. Including contralateral events, the 6-year disease-free survival is 89.6% with a cause-specific survival and overall survival of 97.6% and 95.3%, respectively. There were no ipsilateral failures among 32 patients with DCIS, with an actuarial local recurrence rate of 0% vs. 6.1% for patients with invasive carcinoma (p = 0.24). Among 104 patients with Stage I or II invasive carcinoma, the actuarial local recurrence rate for patients considered cautionary by virtue of age alone is 0% vs. 12.7% in those deemed cautionary due to histopathologic or surgical factors (p = 0.018). Local recurrences were observed in 1/17 patients with EIC, 2/11 with ER - tumors, 1/10 with margins \2 mm, 2/10 with lobular histology, and 2/13 with tumor size 2.1–3 cm. Conclusions: Although locoregional recurrences remained low at 6 years for the entire cohort, our experience suggests that patients with EIC, ER-, close margins, lobular histology, and tumor 2.1–3 cm should be approached with caution until prospective, randomized data become available given the higher rate of local recurrence within this group. In the absence of these surgical or histopathologic cautionary factors, however, those aged 50–59 do not appear to be at significant risk of local recurrence, indicating potential suitability for treatment with APBI. The absence of IBTR observed among those with DCIS also supports the use of APBI in this cohort of patients. Author Disclosure: D.R. McHaffie, None; R.R. Patel, BrachySolutions, Inc., F. Consultant/Advisory Board; J.B. Adkison, None; R.K. Das, None; G.M. Cannon, None.
161
Evaluation of Hypofractionated Adjuvant Radiotherapy for Early Breast Cancer: A Prospective Randomized Study
S. Saha, A. Ghosh Dastidar, A. Gangopadhyay, S. Ghorai Medical College Hospital Calcutta, Calcutta, India Purpose/Objective(s): Upcoming hypothesis of higher fraction sensitivity of breast cancer, owing to presumably lower a/b value, has provoked a number of hypofractionation trials in recent years. This prospective randomized single institute pilot trial aims to evaluate one such hypofractionated schedule of weekly 6 Gy 5 fractions for both, breast conservation (BCT), and also postmastectomy cases (PMRT) against the conventional regimen. Study endpoints are locoregional control, acute and late effects, and cosmetic outcome. Materials/Methods: Between October 2004 and December 2005, 131 early breast cancer patients (T1 = 34, T2 = 97; N1 = 114, N0 = 17) with the histopathology of invasive duct carcinoma were randomized, postsurgery (BCT = 47; mastectomy with axillary clearance = 84) after informed consent to either radiotherapy schedule: 50 Gy/25 fractions/5 weeks (Control arm, n = 62; BCT = 23; and PMRT = 39) or 30 Gy/6 fractions, weekly (Study arm, n = 69; BCT = 24; PMRT = 45). Individualized CT-based planning was done to optimize target coverage and quantify exposure to organs at risk. Central lung distance was recorded in all. For left breast patients, volume of heart irradiated and the volume of heart receiving 5 Gy (V5) were estimated individually from integral DVH. Maximum heart distance (MHD) was measured for majority. Sequential boost was given by HDR implant in 41/47 BCT patients. All patients received FAC chemotherapy for 6 cycles. Locoregional recurrences as well as late toxicity (LENT-SOMA) were recorded in follow-up. Cosmetic outcome (for BCT patients) was evaluated by a panel using a four point (excellent, good, fair, or poor) scale. Results: After a median follow-up of 42 months (minimum = 36 months), 2/23 BCT patients of control arm and 1/24 of study arm had in-breast failure (p = NS) and were salvaged by mastectomy. Among postmastectomy patients, chest wall recurrence was noted in 1/39 of the control arm and none in the study arm. Regional failure was in 3/62 (BCT+PMRT) of control arm and 4/69 of study arm. Grade 1–2 fibrosis was noted in 5/23 BCT patients in the control arm and 7/24 in the study arm (p = NS). Grade 1–2 telengiectasia occurred in 2/23 in control arm vs. 4/24 in the study arm (p = NS). Grade 3 fibrosis was observed in 1 BCT patient in the control arm and in none of the study arm. Regarding cosmetic outcome, 20/23 patients (87%) were good + excellent, 3 fair, and 0 poor in the control arm. Corresponding figures in study arm were 19/24 (80%), 5/24 and 1/24 (p = NS). Conclusions: There was no significant difference in local control or late toxicity in hypofractionated arm compared to conventional arm. Cosmetic outcome was also similar at least in 3-year follow-up. To improve patient compliance and minimize machine time, weekly 5 fractions of 6 Gy each may be an alternative approach as far as safety and efficacy is concerned. Author Disclosure: S. Saha, None; A. Ghosh Dastidar, None; A. Gangopadhyay, None; S. Ghorai, None.