Photon Versus Particle Therapy for Recurrent Lung Cancer; a Planning Study Based on a Reference Dataset of Patients.

Patients with lung cancer may develop a second primary tumor or recurrent disease after previous radiotherapy. Surgical salvage therapy is the mainstay of therapeutic options. However, in case of irresectable disease, re-irradiation should be considered. Also in the postoperative setting, re-irradiation is considered after surgical salvage in case of features in the pathology specimen indicating a high risk for subsequent recurrence. However after re-irradiation, there is a high risk of 43% grade 3 (late) toxicity at 5 years (including possible fatal complications) and a relatively low chance of locoregional control of 50% at 5 years. One out of three patients survives re-irradiation without recurrence and severe complications. Improvements in both the risk of radiation-induced complications and the oncological outcome are thus warranted. 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 \[Kruser in press\]. We propose an in silico trial to investigate to what extend proton and 12C-ion therapy decrease the amount of irradiated normal tissue in lung cancer patients treated with radiotherapy after an initial radiotherapy treatment.

Sex

All

Inclusion Criteria:

* Re-irradiation patients for relapsed or second cancers in the left or the right lung
* Received respitory gated CT (4DCT) and PET (4DPET) scans.
* The primary treatment was radiotherapy with a curative intent
* The organs at risk of the primary tumor treatment are the same organs at risk at the secondary treatment
* 18 years or older