123. Regional treatment of locally advanced melanoma and soft tissue sarcomas of the extremities with isolated limb perfusion in hyperthermic conditions with alfa-tumour necrotic factor and mephalan – Our experience in eleven years

772 gastrointestinal stromal tumours (GIST). Neo-adjuvant imatinib treatment is strongly advised in patients with locally advanced disease, where the risk of incomplete resection, tumour spill or significant postoperative morbidity is high. In metastatic GIST imatinib is considered treatment of primary choice, followed by secondary surgery in responding patients. In this study, the outcome of patients who were operated for a gastric GIST was investigated. Methods: Patients surgically treated for a gastric GIST at our institute in the past twelve years (1999-2011) were included in this study. Patient-, tumour-, and treatment characteristics were retrieved from patient files from a prospective database. Results: A consecutive series of 47 patients was identified: 17 patients were treated with primary surgery (group 1) and 30 patients received imatinib prior to surgery (group 2). Median tumour size was 5.0 cm (range 1.5-9.0 cm) in group 1, and 13.5 cm (range 3.0-29 cm) in group 2. Most patients had local disease, but seven patients in group 2 had metastatic GIST. Neo-adjuvant imatinib treatment led to a 25% reduction in tumour size. Microscopically complete resection (R0) was achieved in all patients in group 1, and in 27 patients (90%) in group 2. Wedge, partial and total gastric resection was required in 7 (41%), 10 (59%) and none of the patients (0%) in group 1, compared to 3 (10%), 13 (43%) and 4 patients (13%) in group 2. Multiple organ resection was performed in 10 patients (34%) in group 2. Postoperative complications (0% in group 1 and 20% in group 2), were transient with one complication in group 2 necessitating re-intervention. Stratified for extent of resection, there was no significant difference in complication rate between the two groups. At a median follow-up of 30 months, 1 patient (6%) in group 1 and 5 patients (17%) in group 2 had recurrent disease. Four patients died of GIST. In all these 4 patients, either the resection had been irradical or tumour spill had occurred and three of them had radiologic progressive disease at the time of surgery. Median survival was not reached in either group. Conclusions: In this surgical series of gastric GIST patients, neo-adjuvant imatinib led to a reduction in tumour size, with no significant increase in the postoperative complication rate after correction for the extent of surgery. Irradical resection, tumour spill and progressive disease at the time of surgery were associated with poor prognosis. 121. Dose optimization for near-infrared fluorescence sentinel lymph node mapping in melanoma patients F.P.R. Verbeek1, J.R. van der Vorst1, B.E. Schaafsma1, R.J. Swijnenburg1, M. Hutteman1, G.J. Liefers1, J.V. Frangioni2, C.J.H. van de Velde1, A.L. Vahrmeijer1 1 Leiden University Medical Center, Surgery, Leiden, The Netherlands 2 Beth Israel Deaconess Medical Center Harvard Medical School, Hematology/Oncology Medicine, Boston, USA Background: Regional lymph node involvement is the most important prognostic factor in cutaneous melanoma. Since only 20% of melanoma patients have occult nodal disease and would benefit from a regional lymphadenectomy, the sentinel lymph node (SLN) biopsy was introduced. NIR fluorescence has been hypothesized to improve SLN mapping. The objective was to assess the potential of intraoperative near-infrared (NIR) fluorescence imaging to improve SLN mapping in melanoma patients and to establish the optimal dose of indocyanine green adsorbed to human serum albumin (ICG:HSA). Material and methods: Fifteen consecutive cutaneous melanoma patients underwent the standard SLN procedure using 99mtechnetium-nancolloid and patent blue. In addition, intraoperative NIR fluorescence imaging was performed after injection of 1.6 mL of 600, 800, 1000 or 1200 mM of ICG:HSA in four quadrants around the primary excision scar. Results: NIR fluorescence SLN mapping was successful in 14 of 15 patients. In one patient, no SLN could be identified using either conventional methods or NIR fluorescence. A total of 30 SLNs (average 2.0, range 1-7) were detected, 30 radioactive (100%), 27 blue (73%), and 30 NIR fluorescent (100%). With regard to the effect of concentration on SBR a trend (P ¼ 0.066) was found favouring the 600, 800 and 1000 mM groups over the 1200 mM group.

ABSTRACTS Conclusions: This study demonstrates feasibility and accuracy of SLN mapping using NIR fluorescence and ICG:HSA in melanoma patients. NIR fluorescence has a high accuracy in SLN detection and adds the value of percutaneous lymphatic drainage and in some cases percutaneous SLN identification. Considering safety, cost, and pharmacological characteristics, an ICG:HSA concentration of 600 mM appears optimal for SLN mapping in cutaneous melanoma. 123. Regional treatment of locally advanced melanoma and soft tissue sarcomas of the extremities with isolated limb perfusion in hyperthermic conditions with alfa-tumour necrotic factor and mephalan e Our experience in eleven years D.R. Jose Farre Alegre 1 , M. Duarte LLanos1 , D.R. Manuel Sureda Gonzalez1, D.R. Pere Bretcha Boix1, D.R. Joseba Rebollo Liceaga1, M. Antonio Ballester 1 , M. Aurora Crespo 1 , D.R. Carlos Dussan Luberth1, M. Israel Gutierrez1, D.R. Antonio Burgarolas Masllorens1 1 Hospital Usp San Jaime, Cirugıa General Y Del Aparato Digestivo, Alicante, Spain Aim: To evaluate our experience in the treatment of bulky tumours, multicentric, satellite lesions and in transit metastases of melanoma and unresectable soft tissue sarcomas through isolated limb perfusion with mephalan and alfa-tumour necrotic factor with a multidisciplinary approach. Material and methods: Between November 2001 and March 2012 thirty three patients were treated (13 men and 20 women), with a median age of 59 years (range:14-82 y) diagnosed in five cases of sarcoma and twenty eight cases of stage III -IV melanoma. The procedure consist on performing a dissection and isolation of iliac or axillary vessels of the affected limb, followed by cannulation of the respective artery and vein , connexion to a perfusion system (Performer MedtronicÒ)and applying a tourniquet in the upper side of the limb to achieve a complete isolation of the systemic circulation. The perfusion is done with mephalan (60 minute) and TNF a (90 minutes). Every perfusion is developed under hyperthermic condition (39o Celsius) and monitored using thermometer probes placed in the subcutaneous and intramuscular tissues. Monitoring of leakage is performed with a gamma detection probe placed on the precordial, having previously instilled 99m TC-Albumin microcoloide (Vasculocis) in the perfusion system. Results: In two cases the perfusion could not be completed due to high leakage. The median leakage was 5,6% (range:0-28%). Objective response was observed in 93% of the patients: complete in 17 cases (52%), partial response in 14 patients (42%) and in two cases we did not observe any response (6%). Progression free survival was 7 month (0 - 77 months +) and median survival post-perfusion was 24 month (7-87months +). 91% of the amputations were avoided. At present there are ten patients alive (two patients with sarcoma and eight with melanoma disease): six without evidence of disease, two with systemic progression and two with local progression who are receiving treatment. Conclusions: The isolated perfusion of the limb with chemotherapy and hyperthermia has proved to be a feasible and safe technique under a multidisciplinary approach. It has shown to be a very effective procedure to achieve a proper local control and to prevent the amputation of the affected limb. Our results are comparable to those of the literature.

124. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with peritoneal sarcomatosis e A single institution experience A. Sommariva1, S. Pasquali2, P. del Fiore1, M.C. Montesco3, P.G. Pilati2, A. Vecchiato1, S. Mocellin2, M. Rastrelli1, D. Nitti2, C.R. Rossi1 1 Veneto Institute of Oncology IOV e IRCCS, Melanoma and Sarcoma Unit, Padova, Italy