L. Arbea

Time to loading and locoregional control in perioperative high-dose-rate brachytherapy: The tumor bed effect revisited.

PURPOSE To determine whether the time to loading (TTL) affects locoregional control. METHODS AND MATERIALS Locoregional control status was determined in 301 patients enrolled in several perioperative high-dose-rate brachytherapy (PHDRB) prospective studies conducted at the University of Navarre. The impact of the time elapsed from catheter implantation to the first PHDRB treatment (TTL) was analyzed. Patients treated with PHDRB alone (n = 113), mainly because of prior irradiation, received 32 Gy in eight twice-a-day treatments or 40 Gy in 10 twice-a-day treatments for negative or close/positive margins, respectively. Patients treated with PHDRB + external beam radiation therapy (EBRT) (n = 188) received 16 Gy in four twice-a-day treatments or 24 Gy in six twice-a-day treatments for negative or close/positive margins followed by 45 Gy of EBRT in 25 treatments. RESULTS After a median followup of 6.5 years (range, 2-13.6+), 113 patients have failed (37.5%), 65 in the PHDRB-alone group (57.5%) and 48 in the combined PHDRB + EBRT group (25.5%). Patients who started PHDRB before Postoperative Day 5 had a 10-year locoregional control rate of 66.7% and patients who started PHDRB on Postoperative Day 5 or longer had a 10-year locoregional control rate of 51.8% (p = 0.009). Subgroup analysis detected that this difference was only observed in the recurrent cases treated with PHDRB alone (Subset 2; n = 99; p = 0.004). No correlation could be detected between locoregional control rate and TTL in the other patient subsets although a trend toward a decreased locoregional control rate after a longer TTL was observed when they were grouped together (p = 0.089). CONCLUSIONS Patients should start PHDRB as soon as possible to maximize locoregional control especially in those recurrent cases treated with PHDRB alone. The time effect in other disease scenarios is less clear.

SIB-IMRT with concomitant chemotherapy-cetuximab after induction chemotherapy for locally-advanced-head-and-neck squamous cell carcinomas

SIB-IMRT with concomitant chemotherapy-cetuximab after induction chemotherapy for locally-advanced-headand-neck squamous cell carcinomas M. Rodriguez-ruiz1, J. Lopez-picazo2, A. Olarte1, L. Arbea1, J. Alcalde3, M. Cambeiro1, M. Idoate4, T. Labiano-miravalles5, J. Aristu1, L. Ramos6, M. Garcia-velloso7, R. Martinez-monge1, M. Moreno-jimenez1 1 Clinica Universitaria de Navarra, Radiation Oncology 2 Clinica Universitaria de Navarra, Medical Oncology 3 Clinica Universitaria de Navarra, Otorhinolaryngology 4 Clinica Universitaria de Navarra, Anatomical Pathology 5 Hospital de Navarra, Anatomical Pathology 6 Clinica Universitaria de Navarra, Medical Physics 7 Clinica Universitaria de Navarra, Nuclear Medicine

Intra-operative radiotherapy in conservative treatment of primary soft tissue sarcomas

Introduction. Conservative surgery (CS) and postoperative radiotherapy (EBRT) is a well-established treatment for primary soft tissue sarcomas (pSTS). Radiation dose effect has been described as improved factor in control disease. Intraoperative radiotherapy allowed deliver high radiation dose selectively. Purpose. To evaluate the patterns of failure and toxicity of CS and Intraoperative Electron Beam Radiotherapy (IOERT) or Perioperative High Dose-Rate Brachytherapy (PHDRB) in pSTS of the extremities and trunk. Methods and materials. Patients were treated with CS combined IOERT or PHDRB plus EBRT. Adjuvant chemotherapy was given in high-grade tumours. Results. 103 patients were retrospectively analysed. Patients received either IOERT (n = 35, 34%) or PHDRB (n = 68, 66%) plus EBRT. The median size was 7.5 cm. Location were in extremities 80 (77.7%) and trunk 23 (22.3%). AJCC stage I–IIA were documented in 33 (32%) and IIB–III in 69 (67%). Margins was free or close in 80 (77.7%) and affected in 23 (22.3%). Mayor complications acute or late (Toxicity Grade 3–5) was documented in 30 patients (29.1%) 15 out of 35 (42%) in IOERT and 15 out of 68 (22%) in HDRBT patients. After a median follow-up of 75.7 months the 5-year rates of DFS, LRC, DC and OS were 62%, 80%, 73% and 90%, respectively. Univariate analysis of LRC, DFS, DC and OS showed for free margins compared with affected an significance improved 5-year control rates (88% vs. 49%), (70% vs. 27%), (79% vs. 52%) and (84% vs. 64) respectively. Univariate analysis of DC and OS showed for tumour lower than 9.5 cm compared with higher an improved 5-year control rates (80% vs. 55%, p = 0.02) and (95% vs. 80%, p = 0.04) respectively. No differences in 5-year LRC rates between IOERT and PHDRB were observed. Conclusions. Margins and tumour size are the most important prognostic factor in pSTS treated with CS and intra-operative radiotherapy plus EBRT.