title: Beams arrangement in non-small cell lung cancer (NSCLC) according to PTV and dosimetric parameters predictive of pneumonitis.
abstract: The aim of this study is to propose and validate an original new class of solutions for three-dimensional conformal radiation therapy (3DCRT) treatment planning for non-small cell lung cancer (NSCLC) according to the different patterns of disease presentation (on the basis of tumor location and volume) and to explore beams arrangement (planar or no-planar solutions) to respect dose constraints to the lung parenchyma. Benchmarks matched to validate the new approach are interuser reproducibility and saving on planning time. Tumor location was explored and specific categories created according to the tumor volume and location. Therefore, by applying planar and no-planar 3D plans, we searched for an optimization of the beams arrangement for each category. Dose-volume histograms (DVHs) were analyzed and a plan comparison performed. Results were then validated (class solution planning confirmation) by applying the same strategy to another group of patients. This has been realized at two dose levels (50.4 and 59.4 Gy). Fifty-nine patients were enrolled in this dosimetric study. In the first 27 patients ("exploratory sample") three main planning target volume location categories were identified according to the pattern of the disease presentation: (1) centrally located; (2) peripheral T and mediastinal N (P+N); and (3) superior sulcus. Original class solutions were proposed for each location category. On the next 32 patients ("validation sample"), the treatment planning started directly with the recommended approach. Mean V(20 Gy) value was 18.8% (SD +/- 7.25); mean V(30 Gy):12% (SD +/- 4.05); and mean lung dose: 11.6 Gy (SD +/- 5.77). No differences between the two total dose level groups were observed. These results suggest a simple and reproducible tool for treatment planning in NSCLC, allowing interuser reproducibility and cutting down on planning time.
authors.affiliation: Radiotherapy Unit, Campus Bio-Medico University, Rome, Italy. s.ramella@unicampus.it
authors.forename: Sara
authors.initials: S
authors.lastname: Ramella
authors.forename: Lucio
authors.initials: L
authors.lastname: Trodella
authors.forename: Tommaso Claudio
authors.initials: TC
authors.lastname: Mineo
authors.forename: Eugenio
authors.initials: E
authors.lastname: Pompeo
authors.forename: Maria A
authors.initials: MA
authors.lastname: Gambacorta
authors.forename: Francesco
authors.initials: F
authors.lastname: Cellini
authors.forename: Marzia
authors.initials: M
authors.lastname: Ciresa
authors.forename: Michele
authors.initials: M
authors.lastname: Fiore
authors.forename: Carlo
authors.initials: C
authors.lastname: Greco
authors.forename: Diego
authors.initials: D
authors.lastname: Gaudino
authors.forename: Gerardina
authors.initials: G
authors.lastname: Stimato
authors.forename: Angelo
authors.initials: A
authors.lastname: Piermattei
authors.forename: Alfredo
authors.initials: A
authors.lastname: Cesario
authors.forename: Rolando M
authors.initials: RM
authors.lastname: D'Angelillo
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D015203:Reproducibility of Results