Breast treatments with Axxent equipment.Comparison with Mammosite for skin, lung and heart dose

Gandia, A. ; Lozares, S. ; Font-Gomez, J.A. (Universidad de Zaragoza) ; Molina, G. ; Ibañez, R. (Universidad de Zaragoza) ; Garcia-Mur, M.C. ; Villa, D.

Resumen: Poster Session [EP-1314]
Purpose or Objective We have treated 250 patients at our center from May 2015 to September 2017 for breast cancer with Axxent (Xoft Inc.) intraoperativ e radiotherapy (IORT) following the inclusion parameters of the TARGIT study, in this work we compare the doses in the skin of the first 150 patients treated with the 50 kVp source with the skin doses they would have received using the Mammosite kit using an Ir192 source. Material and Methods To the 250 patients treated in our center after removing the tumor, the appropriate balloon size is chosen to cover the tumor area with a dose of 20 Gy on the ball oon surface, the sizes used range fro m 30-65 cm3, after which it is verified that the distance to skin from the 3 closest points of the balloon i s less than 10 mm and then the treatment is carried out with an average duration of 10.3 minutes being the volumes of 30 and 35 cm3 the most used due to the inclusion criteria of the procedure. Treatment plans are previously per formed in a Brachyvision treatment planning system (TPS) (Varian Inc.) for each of the possible volumes. In tur n, another plan is calculated with the Mammosite applicator and Ir192 source, from which the skin dose of each control point is estimated, compared to our results. We present also the cases of acute dermatitis seen for these first 150 patients in a time less than 6 months after the surgical act and irradiation. Results The differences in maximum skin dose for bot h types of treatment are 8.1 ± 1.2 Gy for the case of Mammosite and 5.7 ± 1.5 Gy for patients treated with electronic source, due to the difference in the depht dos e percentage of both types of treatment (Image 1). This, in turn, explains the very few cases of acute dermatitis at 6 months (8 cases of grade 2 and 2 cases of grade 3) (Image 2) with no recurrence to date.We also show the mean and maximum doses (expressed as percentage of prescribed dose) for the left lung and heart in cases of left breast tumor for the volumes of 30 and 35 cm3, which are the most common volumes in our hospital (70% of cases):
LEFT LUNG (Left Breast tratment) AXXENT MAMMOSITE
Maximun Dose (%PD) 20.4% 29.9%
Mean Dose (%PD) 1.0% 3.9%
HEART (Left Breast tratment) AXXENT MAMMOSITE
Maximun Dose (%PD) 4.1% 10.4%
Mean Dose (%PD) 0.8% 3.3%
Conclusion It is concluded that the IORT treatments performed with the Axxent equipment with electronic source are a good alternative to those performed with Ir192 and our 250 patients treated to date to the good results presented by other centers are joined.In additi on to the low skin toxicity, there is no recurrence in patients treated so far, which makes us very optimistic about the results.

Idioma: Inglés

DOI: 10.1016/S0167-8140(18)31624-4

Año: 2018

Publicado en: RADIOTHERAPY AND ONCOLOGY 127, Suppl. 1 (2018), S721
ISSN: 0167-8140

Factor impacto JCR: 5.252 (2018)

Categ. JCR: RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING rank: 14 / 129 = 0.109 (2018) - Q1 - T1
Categ. JCR: ONCOLOGY rank: 46 / 229 = 0.201 (2018) - Q1 - T1

Factor impacto SCIMAGO: 2.023 - Hematology (Q1) - Radiology, Nuclear Medicine and Imaging (Q1) - Oncology (Q1)

Tipo y forma: Comunicación congreso (Versión definitiva)

Área (Departamento): Área Radiol. y Medicina Física (Dpto. Pediatría Radiol.Med.Fís)