PO-415 LOCAL CONTROL, SURVIVAL AND COMPLICATIONS OF SOFT TISSUE SARCOMAS TREATED WITH LOW OR HIGH DOSE RATE BRACHYTHERAPY

World Congress of Brachytherapy 2012 PO-414 A CASE-CONTROL STUDY OF PATIENTS WITH HEAD AND NECK SQUAMOUS CELL CARCINOMA TREATED WITH PDR BRACHYTHERAPY A. Haddad1, D. Peiffert1, V. Harter2, J.F. Betala2, I. Buchheit3, P. Graff1, M. Lapeyre4 1 Centre Alexis Vautrin, Department of radiotherapy, Vandoeuvre-lesNancy, France 2 Centre Alexis Vautrin, Department of medical statistics, Vandoeuvre-les-Nancy, France 3 Centre Alexis Vautrin, Department of physics, Vandoeuvre-les-Nancy, France 4 Centre Jean Perrin, Department of radiotherapy, Clermont Ferrand, France Purpose/Objective: PDR brachytherapy combines the radiobiological benefits of low-dose rate delivery with the radioprotection and optimization advantages of HDR brachytherapy. Practice in our department has been progressively shifting away from continuous LDR Iridium192 wires to PDR dose delivery. We set out to evaluate the local control and toxicity outcomes of this technique in patients with head and neck squamous cell carcinoma. Materials and Methods: 36 consecutive head and neck patients treated with PDR brachytherapy were randomly matched to 72 control patients treated with LDR brachytherapy. Patients were excluded if they were previously irradiated to the same site. Patients were matched based on T stage (1/2 Vs 3/4), tumour site (oral cavity Vs oropharynx), and use of surgery and/or external beam radiotherapy as part of the management strategy. Local control and the incidence of soft tissue and osteonecrosis were retrospectively evaluated and compared between the two groups. Results: Baseline patient and tumour characteristics were well balanced between the two groups. Male to female ratio was 3:1, and mean age was 57 yrs. Oral cavity cancers predominated at 81%. Overall T-stage distribution was 46, 44, 6 and 3% for T1, 2, 3 and 4, respectively. 75% of patients received brachytherapy post-operatively, either alone or as a boost after external beam radiotherapy (EBRT), while 14% underwent curative EBRT followed by a brachytherapy boost and 11% were treated with brachytherapy exclusively. PDR patients received a slightly lower mean dose than LDR patients, but had a slightly higher rate of R0 resections. Median follow-up was 59 and 30 months for LDR and PDR patients, respectively. 3-yr actuarial local control rates were 97 and 94% for LDR and PDR patients, respectively. Crude rates of soft tissue and osteonecrosis were 33% and 22% for LDR and PDR, respectively, although Kaplan-Meier estimates at 3 yrs found that this difference was not statistically significant. Dose rate however was correlated with the incidence of late necrosis for both groups: each increase of 1 cGy per hour (or per pulse) was associated with a 3-4% increase in the relative risk of such toxicity. Conclusions: We conclude that PDR brachytherapy in head and neck squamous cell carcinoma yields comparable results to LDR treatment. However, the ability to prescribe the desired dose rate and to optimize the dose distribution may result in lower complication rates. Furthermore, this technique decreases the exposure risk to medical personnel, altogether making it the technique of choice in our department. PO-415 LOCAL CONTROL, SURVIVAL AND COMPLICATIONS OF SOFT TISSUE SARCOMAS TREATED WITH LOW OR HIGH DOSE RATE BRACHYTHERAPY A. Paul1, E. Melian2, M. Surucu2, M. Kwasny3, M. Shoup4, C. Godellas4, D. Vandevender4, A. Sethi2, G. Aranha4 1 Loyola University Medical Center and Rosalind Franklin University of Medicine and Science, Radiation Oncology, Maywood IL, USA 2 Loyola University Medical Center, Radiation Oncology, Maywood IL, USA 3 Northwestern University, Department of Preventive Medicine, Chicago IL, USA 4 Loyola University Medical Center, Surgery, Maywood IL, USA Purpose/Objective: Soft tissue sarcomas (STS) are rare tumors and radiation therapy has played a major role in their treatment. This retrospective analysis reviews the rates of local control, survival, and significant complications (acute and chronic) of patients who received

S 165 low dose rate (LDR) or high dose rate (HDR) brachytherapy (BRT) at our institution. Materials and Methods: From 1993 to 2011, 33 adult (median age = 58) patients with STS received LDR BRT (n= 9) or HDR (n = 24) as part of initial or salvage local treatment. All patients had radical excision with goal to remove tumor enbloc and simultaneous catheter placement. BRT was started 4-5 days post surgery. LDR was used from 1993-2003 and HDR from 2004-2011. BRT was given with (18) or without (15) external beam radiation (EBRT). Doses for BRT alone were LDR 45 Gy or HDR 34-37 Gy in 10 fractions given twice daily. When BRT was given with EBRT doses were LDR 15-20 Gy over 4 days or HDR 13.6-20.4 Gy in 4-6 fractions given with 45-50.4 Gy in 25-28 fractions EBRT. Kaplan-Meier estimates of local control (LC), overall survival (OS), and disease specific survival (DSS) are presented. Association between LC, acute severe complications (ASC; <6 months), and late severe complications (LSC; ≥6 months) and various parameters was assessed by Fisher’s exact tests, and Cox and logistic regression models. Severe complications were defined as significant infection, wound dehiscence, extended wound healing, and need for another surgical procedure to help close the wound. Results: Thirty-two of 33 patients had high grade tumors. 81% (27/33) had primary tumors. 85% (28/33) had deep tumors with 15% (5/33) having superficial tumors. Pathology consisted of malignant fibrohistocytoma (14), leiomyosarcoma (3), high grade dermatofibrosarcoma (1), extra-osseous osteosarcoma (1), pleomorphic sarcoma (5), round cell sarcoma (2), spindle cell sarcoma (1), myxoid liposarcoma (2), malignant peripheral nerve sheath tumor (1), malignant fibromatosis (1), and synovial sarcoma (2). 17 were located in the trunk, 13 in lower extremity, and 3 in upper. Median size was 6.7 cm (2.0-22.2 cm). Margin status was positive in 21% (7/33), close (< 1mm) in 15% (5/33), initially positive and ultimately negative (cases of either re-excision or need for further margins taken at surgery) 30% (10/33), and negative in 33% (11/33). The median follow up times from diagnosis and BRT delivery were 58.9 and 44.6 months, respectively. The 5 year LC, OS, and DSS were 87%, 77%, and 81%, respectively. There were 15% ASC and 12% LSC. Tumor size was associated with OS, DSS, ASC, and LSC (all p < 0.05). No differences were found in OS, DSS, LC, ASC, or LSC for margin status, BRT modality (LDR vs. HDR), tumor site (trunk vs. extremity) and location (deep vs. superficial). Conclusions: Postoperative BRT with or without EBRT after radical surgery provides satisfactory outcomes in terms of recurrence and acute/late severe complications. Our LDR and HDR local control rates were similar. Tumor size was predictive for OS, DSS, and both early and late complications. PO-416 ADJUVANT INTERSTITIAL BRACHYTHERAPY AFTER SALVAGE NECK DISSECTIONS F. Miccichè1, G. Mattiucci1, L. Tagliaferri1, F. Bussu2, M. Rigante2, N. Dinapoli1, R. Autorino1, G. Almadori2, V. Valentini1, G. Paludetti2 1 Università Cattolica del Sacro Cuore, Radiotherapy, Rome, Italy 2 Università Cattolica del Sacro Cuore, Otorhinolaryngology, Rome, Italy Purpose/Objective: Neck recurrence and progression is the main pattern of failure in head and neck oncology. Neck dissection, with all its variants (selective versus comprehensive), which is an extraordinary operation for the management of primaries, is characterized by issues of radicality in cases of post-irradiation recurrences with extracapsular spread and vessel involvement. On the other hand a regional recurrence after a neck dissection is often not susceptible of a radical surgery. After a salvage surgery for these cases, if a full course of radiotherapy has been already delivered, a second clinically effective dose of external beam radiotherapy leads to high toxicity rates. In the present work we evaluate the outcome of combined salvage surgery on the neck and perioperative brachytherapy. Materials and Methods: Regional recurrences following a full course of radiotherapy were resected by an external approach and plastic tubes were intraoperatively fixed to the surgical bed. The tubes were fixed in a grossly parallel direction to cover all the high risk areas of the surgical bed, both on the tissues to irradiate, by reabsorbable stitches, and to the skin, by buttons and nylon. The irradiation started