Abstract
The results of a portal film investigation regarding patients treated for lung tumors and Hodgkin's lymphoma with 6 and 18 MV X-Rays (from 6/100 and 1800 Clinac Varian) are reported. 150 portal films and 68 simulation films of 68 patients (anterior-posterior (AP) fields) have been collected and analyzed evaluating cranio-caudal and lateral shifts, comparing the patient positioning during therapy with respect to the set-up during simulation. Fields have been divided in 'complex' and 'non-complex' ones: we considered as 'complex' ones the mantle fields for the treatment of Hodgkin's disease and the lung-mediastinum fields which included in the treatment volume the supraclavicular nodes, having a complex 'quasi-mantle' shape. 'Non complex' ones were the fields irradiating the mediastinum and portions of lungs, without including supraclavicular nodes. Mean discrepancies and standard deviations have been respectively -0.1 and 3.6 mm for cranio-caudal shifts and -0.8 and 3.1 mm for lateral shifts. Non complex fields showed a standard deviation not significantly different from that of complex fields. Among the considered patients treated for lung diseases, 8 had CT-based treatment planning. For these patients, all treated with 18 MV X-Rays (except one treated with 6 MV X-Rays), exit dose distributions on the central axial slice have been measured by portal film exit dosimetry (Kodak X-Omat V in localization cassette) and compared with those calculated by our treatment planning system (Cadplan Dosetek Varian), with and without applying inhomogeneity correction algorithms (Batho and Equivalent TAR (ETAR)). Off-axis exit doses in the region corresponding to the lungs have been considered in order to assess an index of accuracy in the calculation of the treatment planning. Results show a mean deviation of -11.5% (σ = 7.4%) between calculated and measured relative exit doses (% (calculated-measured)/calculated) when calculating dose distributions without inhomogeneity correction; of -2.5% (σ = 4.4%) when using the Batho algorithm; of +0.3% (= 2.9%) when using Equivalent TAR algorithm. The study confirms the wide dosimetric possibilities of portal film in-vivo dosimetry (especially in the area of verification of the treatment and of treatment planning systems).
| Original language | English |
|---|---|
| Pages (from-to) | 67-74 |
| Number of pages | 8 |
| Journal | Physica Medica |
| Volume | 11 |
| Issue number | 2 |
| Publication status | Published - 1995 |
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Keywords
- in-vivo dosimetry
- portal films
- quality assurance in radiotherapy
- treatment verification
ASJC Scopus subject areas
- Biophysics
- Physics and Astronomy(all)
Cite this
Treatment verification by portal films in chest and mantle field irradiation. / Fiorino, C.; Uleri, C.; Bolognesi, A.; Rosso, A.; Cattaneo, G. M.; Villa, E.; Calandrino, R.
In: Physica Medica, Vol. 11, No. 2, 1995, p. 67-74.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Treatment verification by portal films in chest and mantle field irradiation
AU - Fiorino, C.
AU - Uleri, C.
AU - Bolognesi, A.
AU - Rosso, A.
AU - Cattaneo, G. M.
AU - Villa, E.
AU - Calandrino, R.
PY - 1995
Y1 - 1995
N2 - The results of a portal film investigation regarding patients treated for lung tumors and Hodgkin's lymphoma with 6 and 18 MV X-Rays (from 6/100 and 1800 Clinac Varian) are reported. 150 portal films and 68 simulation films of 68 patients (anterior-posterior (AP) fields) have been collected and analyzed evaluating cranio-caudal and lateral shifts, comparing the patient positioning during therapy with respect to the set-up during simulation. Fields have been divided in 'complex' and 'non-complex' ones: we considered as 'complex' ones the mantle fields for the treatment of Hodgkin's disease and the lung-mediastinum fields which included in the treatment volume the supraclavicular nodes, having a complex 'quasi-mantle' shape. 'Non complex' ones were the fields irradiating the mediastinum and portions of lungs, without including supraclavicular nodes. Mean discrepancies and standard deviations have been respectively -0.1 and 3.6 mm for cranio-caudal shifts and -0.8 and 3.1 mm for lateral shifts. Non complex fields showed a standard deviation not significantly different from that of complex fields. Among the considered patients treated for lung diseases, 8 had CT-based treatment planning. For these patients, all treated with 18 MV X-Rays (except one treated with 6 MV X-Rays), exit dose distributions on the central axial slice have been measured by portal film exit dosimetry (Kodak X-Omat V in localization cassette) and compared with those calculated by our treatment planning system (Cadplan Dosetek Varian), with and without applying inhomogeneity correction algorithms (Batho and Equivalent TAR (ETAR)). Off-axis exit doses in the region corresponding to the lungs have been considered in order to assess an index of accuracy in the calculation of the treatment planning. Results show a mean deviation of -11.5% (σ = 7.4%) between calculated and measured relative exit doses (% (calculated-measured)/calculated) when calculating dose distributions without inhomogeneity correction; of -2.5% (σ = 4.4%) when using the Batho algorithm; of +0.3% (= 2.9%) when using Equivalent TAR algorithm. The study confirms the wide dosimetric possibilities of portal film in-vivo dosimetry (especially in the area of verification of the treatment and of treatment planning systems).
AB - The results of a portal film investigation regarding patients treated for lung tumors and Hodgkin's lymphoma with 6 and 18 MV X-Rays (from 6/100 and 1800 Clinac Varian) are reported. 150 portal films and 68 simulation films of 68 patients (anterior-posterior (AP) fields) have been collected and analyzed evaluating cranio-caudal and lateral shifts, comparing the patient positioning during therapy with respect to the set-up during simulation. Fields have been divided in 'complex' and 'non-complex' ones: we considered as 'complex' ones the mantle fields for the treatment of Hodgkin's disease and the lung-mediastinum fields which included in the treatment volume the supraclavicular nodes, having a complex 'quasi-mantle' shape. 'Non complex' ones were the fields irradiating the mediastinum and portions of lungs, without including supraclavicular nodes. Mean discrepancies and standard deviations have been respectively -0.1 and 3.6 mm for cranio-caudal shifts and -0.8 and 3.1 mm for lateral shifts. Non complex fields showed a standard deviation not significantly different from that of complex fields. Among the considered patients treated for lung diseases, 8 had CT-based treatment planning. For these patients, all treated with 18 MV X-Rays (except one treated with 6 MV X-Rays), exit dose distributions on the central axial slice have been measured by portal film exit dosimetry (Kodak X-Omat V in localization cassette) and compared with those calculated by our treatment planning system (Cadplan Dosetek Varian), with and without applying inhomogeneity correction algorithms (Batho and Equivalent TAR (ETAR)). Off-axis exit doses in the region corresponding to the lungs have been considered in order to assess an index of accuracy in the calculation of the treatment planning. Results show a mean deviation of -11.5% (σ = 7.4%) between calculated and measured relative exit doses (% (calculated-measured)/calculated) when calculating dose distributions without inhomogeneity correction; of -2.5% (σ = 4.4%) when using the Batho algorithm; of +0.3% (= 2.9%) when using Equivalent TAR algorithm. The study confirms the wide dosimetric possibilities of portal film in-vivo dosimetry (especially in the area of verification of the treatment and of treatment planning systems).
KW - in-vivo dosimetry
KW - portal films
KW - quality assurance in radiotherapy
KW - treatment verification
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M3 - Article
AN - SCOPUS:0029065976
VL - 11
SP - 67
EP - 74
JO - Physica Medica
JF - Physica Medica
SN - 1120-1797
IS - 2
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