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Oncologic Surgery and Intraoperative Radiation Therapy (IORT) in Management of Unplanned Excision of Extremity Soft-Tissue Sarcoma (STS)
Poster Viewing Abstracts S765
Volume 90 Number 1S Supplement 2014 Gastman: None. M.A. Fritz: None. A.T. Vidimos: None. S.A. Koyfman: None.
3406 Oncologic Surgery and Intraoperative Radiation Therapy (IORT) in Management of Unplanned Excision of Extremity Soft-Tissue Sarcoma (STS) C.L. Tinkle, R.J. O’Donnell, V. Weinberg, and A.R. Gottschalk; University of California San Francisco, San Francisco, CA Purpose/Objective(s): Optimal management of patients with extremity STS treated with unplanned non-oncologic surgical excision is not clearly defined. We sought to investigate the efficacy and morbidity of limbsparing oncologic re-resection with IORT for patients who previously underwent unplanned excision of extremity STS. Materials/Methods: A retrospective review identified twenty-two consecutively treated patients with extremity STS treated with IORT following oncologic limb-sparing surgery after an initial unplanned excision from September 2000 to July 2011. All patients had localized disease at the time of IORT. The median age was 36 years, with 8 patients (36%) under the age of 18. Tumor depth was superficial in 10 patients (45%) and deep in 12 patients (55%), and high grade tumors (Coindre grade 2-3) were found in 18 patients (81%). Close (<2mm) or positive margins at IORT were found in 6 patients (27%) and median tumor size was 2.6 cm (range 0.3 - 8.1 cm). The most common histologies were synovial sarcoma and fibrosarcoma (41% and 18%, respectively). The median IORT dose was 1250 cGy (range 1000-1500 cGy). Adjuvant external beam radiation therapy (EBRT) was given to 7 patients (32%) with a median dose of 5400 cGy (range 4500 - 6000 cGy), while no patient received EBRT prior to IORT. Perioperative chemotherapy was delivered to 4 patients (18%). The Kaplan-Meier product limit method was used to estimate disease control and survival and toxicity was reported according to CTCAE v4.0 guidelines. Results: With a median duration of follow-up from surgery and IORT of 54.4 months (range 12 - 141 mos.), 3 patients developed a local recurrence with 1 patient subsequently undergoing amputation. The 5-year Kaplan-Meier estimates for local control (LC) were 84% (95% CI 58-95%); for amputation-free were 95% (95% CI 72-99%); for metastasis-free control (MFC) were 95% (95% CI 72-99%); for disease-free survival (DFS) were 79% (95% CI 5292%); and for overall survival (OS) was 94% (95% CI 63-99%). Of evaluable patients, Grade 3 or higher acute (90 days or less from IORT) and late toxicities were reported for 3 (16%) and 4 (25%) patients, respectively. In all but one patient, observed toxicity improved or resolved. Conclusions: While oncologic re-resection is commonly employed, the timing and technique of radiation therapy in further management of unplanned extremity STS resection is less well established. Review of our institutional approach of oncologic limb-sparing re-resection in combination with IORT reveals excellent local control with acceptable morbidity. This technique offers a method of delivering focal therapy to achieve local control for the majority of patients, while obviating or allowing relatively reduced dose adjuvant EBRT. Author Disclosure: C.L. Tinkle: None. R.J. O’Donnell: None. V. Weinberg: None. A.R. Gottschalk: None.
3407 Radiologic and Pathologic Response After Neoadjuvant Radiation Therapy for Myxoid Liposarcoma of the Extremities C.T. Wilke, J. Wilson, C. Ogilvie, E. Cheng, D. Clohisy, J. Yuan, K. Dusenbery, and L. Cho; University of Minnesota, Minneapolis, MN Purpose/Objective(s): Myxoid liposarcomas are relatively radiosensitive with a favorable prognosis following local therapy. Restaging imaging is utilized after neoadjuvant radiation therapy to aid in the surgical plan of care although relatively little is known regarding the correlation of the radiologic and pathologic response. In this study, we examine this correlation in a cohort of patients with pure myxoid liposarcomas following neoadjuvant radiation therapy. Materials/Methods: Medical records were reviewed of 11 consecutive patients with pure myxoid liposarcomas who received neoadjuvant radiation therapy
between 12/2009 and 12/2013. All patients were diagnosed with stage cT1b/T2b N0 M0 disease by core needle biopsy. Each of the patients underwent neoadjuvant external beam radiation therapy alone to a median dose of 5000 cGy in 25 fractions (range: 4500-5000 cGy) followed by wide local excision. All of the tumors occurred in the lower extremities with the thigh being the most common site of occurrence. For each patient, the pre-treatment tumor volume was calculated using a radiation treatment planning system from CT or CT/MRI fusion imaging. The radiographic response was ascertained by measuring the tumor volume on presurgical imaging obtained a median of 15 days (11-29 days) following completion of radiation therapy. The median time to surgery after neoadjuvant radiation therapy was 30 (21-39) days. Pathologic response to neoadjuvant radiation therapy was reviewed and quantified by a single pathologist (JW). Results: The median pre-radiation therapy tumor volume for the 11 myxoid liposarcomas was 251.6 cc (16.8-1250 cc). Following radiation therapy, the median tumor volume had decreased to 160.5 cc (6.6-655 cc) with a median relative reduction of 50.4% (16-80%). Review of the surgical pathology demonstrated a marked tumor response with two of the patients demonstrating a complete response to neoadjuvant radiation therapy. The estimated presence of histologic viable tumor after neoadjuvant radiation therapy was approximately 5% (0-60%). In the study cohort, the pathologic response was often significantly greater than the observed radiographic response and was not strongly correlated with either the relative or absolute reduction in tumor volume nor with the initial tumor size or radiation therapy dose with Pearson’s R of 0.36, 0.28, 0.37 and 0.18 respectively. Conclusions: While a marked pathologic response was noted in the examined cohort, the radiographic response was not strongly predictive of the surgical pathology findings. Additional studies exploring the radiographic correlates, including appropriate time interval for radiologic assessment after radiation therapy, would be helpful to further guide surgical management following neoadjuvant radiation therapy. Author Disclosure: C.T. Wilke: None. J. Wilson: None. C. Ogilvie: None. E. Cheng: None. D. Clohisy: None. J. Yuan: None. K. Dusenbery: None. L. Cho: None.
3408 Outcomes and Prognostic Factors of Stereotactic Body Radiation Therapy for Soft-Tissue Sarcoma Metastases K.W. Merrell,1 S.R. Francis,2 B. Mou,1 C.L. Hallemeier,1 and K.R. Olivier1; 1Mayo Clinic, Rochester, MN, 2University of Utah School of Medicine, Salt Lake City, UT Purpose/Objective(s): Radiobiology studies suggest soft tissue sarcoma (STS) is a radioresistant tumor. Primary therapy for localized and oligometastatic STS is surgical resection, often in combination with radiation therapy (RT). Stereotactic body RT (SBRT) allows delivery of large conformal doses of radiation potentially overcoming radioresistance. We reviewed our institutional outcomes of patients treated with SBRT for metastatic STS. Materials/Methods: A retrospective chart review was performed on 21 patients with 30 metastatic STS lesions who received SBRT at our institution between May 2008 and June 2013. Patients were treated with 3D conformal, static-field or volumetric arc intensity modulated RT. The median dose (cGy) and fractionation of lung, bone, liver and soft tissue was 5000/5, 2400/1, 4250/ 5, and 4000/4, respectively. Tumor response was scored using RECIST v1.1. Toxicity was scored using NCI CTCAE v 4.0. Local control (LC) and overall survival (OS) were estimated using the Kaplan-Meier method. Results: Median age was 49 years (range, 30-85). Median follow-up time was 24 months (range, 3-65). Median tumor size was 24 mm (range, 6145). The most common histologies include pleomorphic sarcoma (n Z 5, 24%), leiomyosarcoma (n Z 4, 19%), and synovial cell sarcoma (n Z 3, 14%) with 95% (n Z 20) being high-grade sarcoma. Sites treated include bone (n Z 11, 36.6%), lung (n Z 15, 50%), liver (n Z 2, 6.7%) and soft tissue (n Z 2, 6.7%). LC at 12, 24, and 48 months was 94.4%, 82.6 and 82.6%, respectively. Rates of complete response, partial response, and stable disease were 6% (n Z 2), 43% (n Z 13), and 47% (n Z 14), respectively. There were two local failures: one after a partial response and one in a patient with progressive disease on the first follow up scan. Univariate analysis demonstrated no association with histologic subtype, tumor size, site treated or RT dose in regards to LC. Median survival was
Volume 90 Number 1S Supplement 2014 Gastman: None. M.A. Fritz: None. A.T. Vidimos: None. S.A. Koyfman: None.
3406 Oncologic Surgery and Intraoperative Radiation Therapy (IORT) in Management of Unplanned Excision of Extremity Soft-Tissue Sarcoma (STS) C.L. Tinkle, R.J. O’Donnell, V. Weinberg, and A.R. Gottschalk; University of California San Francisco, San Francisco, CA Purpose/Objective(s): Optimal management of patients with extremity STS treated with unplanned non-oncologic surgical excision is not clearly defined. We sought to investigate the efficacy and morbidity of limbsparing oncologic re-resection with IORT for patients who previously underwent unplanned excision of extremity STS. Materials/Methods: A retrospective review identified twenty-two consecutively treated patients with extremity STS treated with IORT following oncologic limb-sparing surgery after an initial unplanned excision from September 2000 to July 2011. All patients had localized disease at the time of IORT. The median age was 36 years, with 8 patients (36%) under the age of 18. Tumor depth was superficial in 10 patients (45%) and deep in 12 patients (55%), and high grade tumors (Coindre grade 2-3) were found in 18 patients (81%). Close (<2mm) or positive margins at IORT were found in 6 patients (27%) and median tumor size was 2.6 cm (range 0.3 - 8.1 cm). The most common histologies were synovial sarcoma and fibrosarcoma (41% and 18%, respectively). The median IORT dose was 1250 cGy (range 1000-1500 cGy). Adjuvant external beam radiation therapy (EBRT) was given to 7 patients (32%) with a median dose of 5400 cGy (range 4500 - 6000 cGy), while no patient received EBRT prior to IORT. Perioperative chemotherapy was delivered to 4 patients (18%). The Kaplan-Meier product limit method was used to estimate disease control and survival and toxicity was reported according to CTCAE v4.0 guidelines. Results: With a median duration of follow-up from surgery and IORT of 54.4 months (range 12 - 141 mos.), 3 patients developed a local recurrence with 1 patient subsequently undergoing amputation. The 5-year Kaplan-Meier estimates for local control (LC) were 84% (95% CI 58-95%); for amputation-free were 95% (95% CI 72-99%); for metastasis-free control (MFC) were 95% (95% CI 72-99%); for disease-free survival (DFS) were 79% (95% CI 5292%); and for overall survival (OS) was 94% (95% CI 63-99%). Of evaluable patients, Grade 3 or higher acute (90 days or less from IORT) and late toxicities were reported for 3 (16%) and 4 (25%) patients, respectively. In all but one patient, observed toxicity improved or resolved. Conclusions: While oncologic re-resection is commonly employed, the timing and technique of radiation therapy in further management of unplanned extremity STS resection is less well established. Review of our institutional approach of oncologic limb-sparing re-resection in combination with IORT reveals excellent local control with acceptable morbidity. This technique offers a method of delivering focal therapy to achieve local control for the majority of patients, while obviating or allowing relatively reduced dose adjuvant EBRT. Author Disclosure: C.L. Tinkle: None. R.J. O’Donnell: None. V. Weinberg: None. A.R. Gottschalk: None.
3407 Radiologic and Pathologic Response After Neoadjuvant Radiation Therapy for Myxoid Liposarcoma of the Extremities C.T. Wilke, J. Wilson, C. Ogilvie, E. Cheng, D. Clohisy, J. Yuan, K. Dusenbery, and L. Cho; University of Minnesota, Minneapolis, MN Purpose/Objective(s): Myxoid liposarcomas are relatively radiosensitive with a favorable prognosis following local therapy. Restaging imaging is utilized after neoadjuvant radiation therapy to aid in the surgical plan of care although relatively little is known regarding the correlation of the radiologic and pathologic response. In this study, we examine this correlation in a cohort of patients with pure myxoid liposarcomas following neoadjuvant radiation therapy. Materials/Methods: Medical records were reviewed of 11 consecutive patients with pure myxoid liposarcomas who received neoadjuvant radiation therapy
between 12/2009 and 12/2013. All patients were diagnosed with stage cT1b/T2b N0 M0 disease by core needle biopsy. Each of the patients underwent neoadjuvant external beam radiation therapy alone to a median dose of 5000 cGy in 25 fractions (range: 4500-5000 cGy) followed by wide local excision. All of the tumors occurred in the lower extremities with the thigh being the most common site of occurrence. For each patient, the pre-treatment tumor volume was calculated using a radiation treatment planning system from CT or CT/MRI fusion imaging. The radiographic response was ascertained by measuring the tumor volume on presurgical imaging obtained a median of 15 days (11-29 days) following completion of radiation therapy. The median time to surgery after neoadjuvant radiation therapy was 30 (21-39) days. Pathologic response to neoadjuvant radiation therapy was reviewed and quantified by a single pathologist (JW). Results: The median pre-radiation therapy tumor volume for the 11 myxoid liposarcomas was 251.6 cc (16.8-1250 cc). Following radiation therapy, the median tumor volume had decreased to 160.5 cc (6.6-655 cc) with a median relative reduction of 50.4% (16-80%). Review of the surgical pathology demonstrated a marked tumor response with two of the patients demonstrating a complete response to neoadjuvant radiation therapy. The estimated presence of histologic viable tumor after neoadjuvant radiation therapy was approximately 5% (0-60%). In the study cohort, the pathologic response was often significantly greater than the observed radiographic response and was not strongly correlated with either the relative or absolute reduction in tumor volume nor with the initial tumor size or radiation therapy dose with Pearson’s R of 0.36, 0.28, 0.37 and 0.18 respectively. Conclusions: While a marked pathologic response was noted in the examined cohort, the radiographic response was not strongly predictive of the surgical pathology findings. Additional studies exploring the radiographic correlates, including appropriate time interval for radiologic assessment after radiation therapy, would be helpful to further guide surgical management following neoadjuvant radiation therapy. Author Disclosure: C.T. Wilke: None. J. Wilson: None. C. Ogilvie: None. E. Cheng: None. D. Clohisy: None. J. Yuan: None. K. Dusenbery: None. L. Cho: None.
3408 Outcomes and Prognostic Factors of Stereotactic Body Radiation Therapy for Soft-Tissue Sarcoma Metastases K.W. Merrell,1 S.R. Francis,2 B. Mou,1 C.L. Hallemeier,1 and K.R. Olivier1; 1Mayo Clinic, Rochester, MN, 2University of Utah School of Medicine, Salt Lake City, UT Purpose/Objective(s): Radiobiology studies suggest soft tissue sarcoma (STS) is a radioresistant tumor. Primary therapy for localized and oligometastatic STS is surgical resection, often in combination with radiation therapy (RT). Stereotactic body RT (SBRT) allows delivery of large conformal doses of radiation potentially overcoming radioresistance. We reviewed our institutional outcomes of patients treated with SBRT for metastatic STS. Materials/Methods: A retrospective chart review was performed on 21 patients with 30 metastatic STS lesions who received SBRT at our institution between May 2008 and June 2013. Patients were treated with 3D conformal, static-field or volumetric arc intensity modulated RT. The median dose (cGy) and fractionation of lung, bone, liver and soft tissue was 5000/5, 2400/1, 4250/ 5, and 4000/4, respectively. Tumor response was scored using RECIST v1.1. Toxicity was scored using NCI CTCAE v 4.0. Local control (LC) and overall survival (OS) were estimated using the Kaplan-Meier method. Results: Median age was 49 years (range, 30-85). Median follow-up time was 24 months (range, 3-65). Median tumor size was 24 mm (range, 6145). The most common histologies include pleomorphic sarcoma (n Z 5, 24%), leiomyosarcoma (n Z 4, 19%), and synovial cell sarcoma (n Z 3, 14%) with 95% (n Z 20) being high-grade sarcoma. Sites treated include bone (n Z 11, 36.6%), lung (n Z 15, 50%), liver (n Z 2, 6.7%) and soft tissue (n Z 2, 6.7%). LC at 12, 24, and 48 months was 94.4%, 82.6 and 82.6%, respectively. Rates of complete response, partial response, and stable disease were 6% (n Z 2), 43% (n Z 13), and 47% (n Z 14), respectively. There were two local failures: one after a partial response and one in a patient with progressive disease on the first follow up scan. Univariate analysis demonstrated no association with histologic subtype, tumor size, site treated or RT dose in regards to LC. Median survival was