Helical Tomotherapy for Treating Supraclavicular and Internal Mammary Nodal Chain in Breast Cancer
Moujhuri Nandi, Anurupa Mahato, Indranil Mallick, Rimpa Achari and Sanjoy Chatterjee
World Journal of Surgical Medical and Radiation Oncology 2013, 2:10
To describe one of the first clinical experiences of treating the Internal mammary chain (IMC) and supraclavicular fossa (SCF) using helical tomotherapy (HT), with brachial plexus sparing where necessary.
Three breast cancer cases in whom both SCF and IMC irradiation was required were planned and treated using HT to a dose of 50Gy in 25 fractions or equivalent. In one case dose escalation to the SCF was required to treat clinically palpable node. Inverse planning dose constraints were applied to PTVs and OARs.
HT plans achieved adequate target coverage for all three PTVs in the three cases; mean HI of 1.09, 1.08 and 1.11 and mean CI of 0.6, 0.5 and 0.6 for chest wall, SCF and IMC were obtained respectively. The mean heart dose achieved was 11.8Gy, 18.0Gy and 6.2 Gy for the three cases respectively. The mean heart dose of the second case was higher as it involved bilateral chest wall and IMC irradiation. Mean V20Gy for ipsilateral and contralateral lung was 25.9% and 2.5% respectively. Mean dose of contralateral breast (in two cases) was 5.1Gy. Skin acute toxicity was Grade I in all three cases. At a median follow up of 1 year, all three patients are locoregionally controlled.
Helical tomotherapy is a technique where complex volume treatment in breast cancers could be delivered with adequate homogeneity and conformity indices and high capabilities of critical organ sparing. Further long term studies are required to assess local control and late toxicity.