| 1. |
- Ask, Anders, et al.
(författare)
-
The potential of proton beam radiation therapy in head and neck cancer.
- 2005
-
Ingår i: Acta oncologica (Stockholm, Sweden). - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:8, s. 876-80
-
Tidskriftsartikel (refereegranskat)abstract
- A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In head and neck cancer, including thyroid cancer, it is assessed that at least 300 patients annually will gain sufficiently from proton beam therapy, both to improve tumour control and to decrease toxicity to compensate for the increased treatment costs using protons.
|
|
| 2. |
- Blomquist, Erik, et al.
(författare)
-
The potential of proton beam radiation therapy in intracranial and ocular tumours
- 2005
-
Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:8, s. 862-70
-
Tidskriftsartikel (refereegranskat)abstract
- A group of oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In intracranial benign and malignant tumours, it is estimated that between 130 and 180 patients each year are candidates for proton beam therapy. Of these, between 50 and 75 patients have malignant glioma, 30-40 meningeoma, 20-25 arteriovenous malformations, 20-25 skull base tumours and 10-15 pituitary adenoma. In addition, 15 patients with ocular melanoma are candidates.
|
|
| 3. |
- Tilly, Nina, et al.
(författare)
-
The influence of RBE variations in a clinical proton treatment plan for a hypopharynx cancer
- 2005
-
Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 50:12, s. 2765-2777
-
Tidskriftsartikel (refereegranskat)abstract
- Currently, most clinical range-modulated proton beams are assumed to have a fixed overall relative biological effectiveness (RBE) of 1.1. However, it is well known that the RBE increases with depth in the spread-out Bragg peak (SOBP) and becomes about 10% higher than mid-SOBP RBE at 2 mm from the distal edge (Paganetti 2003 Technol. Cancer Res. Treat. 2 413-26) and can reach values of 1.3-1.4 in vitro at the distal edge (Robertson et al 1975 Cancer 35 1664-77, Courdi et al 1994 Br. J. Radiol. 67 800-4). We present a fast method for applying a variable RBE correction with linear energy transfer (LET) dependent tissue-specific parameters based on the alpharef/betaref ratios suitable for implementation in a treatment planning system. The influence of applying this variable RBE correction on a clinical multiple beam proton dose plan is presented here. The treatment plan is evaluated by RBE weighted dose volume histograms (DVHs) and the calculation of tumour control probability (TCP) and normal tissue complication probability (NTCP) values. The variable RBE correction yields DVHs for the clinical target volumes (CTVs), a primary advanced hypopharynx cancer and subclinical disease in the lymph nodes, that are slightly higher than those achieved by multiplying the absorbed dose with RBE=1.1. Although, more importantly, the RBE weighted DVH for an organ at risk, the spinal cord is considerably increased for the variable RBE. As the spinal cord in this particular case is located 8 mm behind the planning target volume (PTV) and hence receives only low total doses, the NTCP values are zero in spite of the significant increase in the RBE weighted DVHs for the variable RBE. However, high NTCP values for the non-target normal tissue were obtained when applying the variable RBE correction. As RBE variations tend to be smaller for in vivo systems, this study-based on in vitro data since human tissue RBE values are scarce and have large uncertainties-can be interpreted as showing the upper limits of the possible effects of utilizing a variable RBE correction. In conclusion, the results obtained here still indicate a significant difference in introducing a variable RBE compared to applying a generic RBE of 1.1, suggesting it is worth considering such a correction in clinical proton therapy planning, especially when risk organs are located immediately behind the target volume.
|
|
