Compared to conventional radiotherapy with photons (CRT), particle therapy (PT) has the potential to inflict maximum damage on tumors with minimum collateral damage to neighboring healthy tissue. Given that the cost of particle therapy (PT) is considerably higher than that of conventional radiotherapy (RT) with photons, it is necessary to establish whether these higher costs are worthwhile in light of the expected advantages. Thus, clear evidence of the situations in which PT outperforms conventional photon treatment is needed. Publications on this topic are rare. The only recent publication has analyzed the results of 37 NSCLC patients of whom 9 were re-irradiated with at least 50 Gy using helical tomotherapy [Kruser in press].