Paolo Montemaggi MD, Presenter: Nothing to Disclose

Patrizia Guerrieri MD, Abstract Co-Author: Nothing to Disclose

Ivan Fazio, Abstract Co-Author: Nothing to Disclose

Giovanna Evangelista MD, Abstract Co-Author: Nothing to Disclose

Letizia Barone Tonghi MPH, Abstract Co-Author: Nothing to Disclose

Vittorio Caputo MPH, Abstract Co-Author: Nothing to Disclose

Boris Abbate MPH, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

LDI is beneficial in BC radiotherapy. However, it presents several technical problems due to the anatomic complexity of the involved volumes. We present data from a mono institution study to evaluate technical problems,VA and homogeneity, medium term LC.

Since January 2002 to December 2002,850 consecutive patients (pts) with BC entered a in house protocol in which pts with either one of the following: a) >4 positive nodes (PN), massive or extra capsular node invasion (MI), <13 nodes in the surgical specimen, were scheduled to receive LDI at the time of tangential fields. Total mastectomy accounted for 170 cases (20%), while 680 (80%) did receive a conservative surgical approach. LDI was done in 154 cases (18.1%) because one of the following: 4 to 5 PN 46 pts (30% of 154), 6 to 10 PN 62 pts (40%), more than 10 PN 23 pts (15%), MI 23 pts (15%);MI was also present in 92 pts (69%) as a concomitant feature. LDI was carried out either with 4 isocentric fields technique (4F), (131 cases, 85%), or trough a modified extended tangential fields technique (MT) (23 cases, 15%). A cumulative analysis of the dose distribution was done utilizing DVH and biological evaluation (TCP and NTCP). Local control data are projected at 5 years.

Differences were observed in VA in favour of 4F technique, when evaluated through DVH analysis. 4F technique allowed a better PTV coverage (17%) than MT. Humeral head V50 was smaller for 4F technique 30% to 60%) than MT; dose-homogeneity index showed a 10% dose variation inside PTV for 4F with a minimum dose to sopraclavicular nodes (SN) >45 Gy as compared to a dose variation of 30% or more with MT with a minimum dose to SN ranging 25 to 30 Gy. As far as LC we had 2 SN failures in MT group, TCP and NTCP were also in favour of 4F while no patient did yet relapse in FT group.

LDI in BC represents a technical challenge for radiation oncologists. Dosimetric analysis shows that 4F technique represents a feasible and effective method of treatment. Even if other techniques may be used, volumes coverage and dose homogeneity support the superiority of 4F technique, pending statistically significant data on clinical end results.

Montemaggi, P, Guerrieri, P, Fazio, I, Evangelista, G, Barone Tonghi, L, Caputo, V, Abbate, B, et al, , Irradiation of Lymphatic Drainage (LDI) in the Treatment of Breast Carcinoma (BC): Clinical Indications, Technical Problems, Volumes Analysis (VA), and Local Control (LC)--Results of a Mono Institution Study.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4412784.html