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- Giantsoudi, D., et al.
(författare)
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A gEUD-based inverse planning technique for HDR prostate brachytherapy : Feasibility study
- 2013
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Ingår i: Medical physics (Lancaster). - : Wiley. - 0094-2405 .- 2473-4209. ; 40:4, s. 041704-
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D-10 or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.
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| 4. |
- Freislederer, P., et al.
(författare)
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Recent advanced in Surface Guided Radiation Therapy
- 2020
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Ingår i: Radiation oncology (London, England). - : Springer Science and Business Media LLC. - 1748-717X. ; 15:1
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Forskningsöversikt (refereegranskat)abstract
- The growing acceptance and recognition of Surface Guided Radiation Therapy (SGRT) as a promising imaging technique has supported its recent spread in a large number of radiation oncology facilities. Although this technology is not new, many aspects of it have only recently been exploited. This review focuses on the latest SGRT developments, both in the field of general clinical applications and special techniques.SGRT has a wide range of applications, including patient positioning with real-time feedback, patient monitoring throughout the treatment fraction, and motion management (as beam-gating in free-breathing or deep-inspiration breath-hold). Special radiotherapy modalities such as accelerated partial breast irradiation, particle radiotherapy, and pediatrics are the most recent SGRT developments.The fact that SGRT is nowadays used at various body sites has resulted in the need to adapt SGRT workflows to each body site. Current SGRT applications range from traditional breast irradiation, to thoracic, abdominal, or pelvic tumor sites, and include intracranial localizations.Following the latest SGRT applications and their specifications/requirements, a stricter quality assurance program needs to be ensured. Recent publications highlight the need to adapt quality assurance to the radiotherapy equipment type, SGRT technology, anatomic treatment sites, and clinical workflows, which results in a complex and extensive set of tests.Moreover, this review gives an outlook on the leading research trends. In particular, the potential to use deformable surfaces as motion surrogates, to use SGRT to detect anatomical variations along the treatment course, and to help in the establishment of personalized patient treatment (optimized margins and motion management strategies) are increasingly important research topics. SGRT is also emerging in the field of patient safety and integrates measures to reduce common radiotherapeutic risk events (e.g. facial and treatment accessories recognition).This review covers the latest clinical practices of SGRT and provides an outlook on potential applications of this imaging technique. It is intended to provide guidance for new users during the implementation, while triggering experienced users to further explore SGRT applications.
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| 8. |
- Mavroidis, P, et al.
(författare)
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Radiobiological and dosimetric analysis of daily megavoltage CT registration on adaptive radiotherapy with Helical Tomotherapy
- 2011
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Ingår i: Technology in cancer research & treatment. - : SAGE Publications. - 1533-0338 .- 1533-0346. ; 10:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Pre-treatment patient repositioning in highly conformal image-guided radiation therapy modalities is a prerequisite for reducing setup uncertainties. In Helical Tomotherapy (HT) treatment, a megavoltage CT (MVCT) image is usually acquired to evaluate daily changes in the patient's internal anatomy and setup position. This MVCT image is subsequently compared to the kilovoltage CT (kVCT) study that was used for dosimetric planning, by applying a registration process. This study aims at investigating the expected effect of patient setup correction using the Hi-Art tomotherapy system by employing radiobiological measures such as the biologically effective uniform dose ([Formula: see text]) and the complication-free tumor control probability ( P+). A new module of the Tomotherapy software (TomoTherapy, Inc, Madison, WI) called Planned Adaptive is employed in this study. In this process the delivered dose can be calculated by using the sinogram for each delivered fraction and the registered MVCT image set that corresponds to the patient's position and anatomical distribution for that fraction. In this study, patients treated for lung, pancreas and prostate carcinomas are evaluated by this method. For each cancer type, a Helical Tomotherapy plan was developed. In each cancer case, two dose distributions were calculated using the MVCT image sets before and after the patient setup correction. The fractional dose distributions were added and renormalized to the total number of fractions planned. The dosimetric and radiobiological differences of the dose distributions with and without patient setup correction were calculated. By using common statistical measures of the dose distributions and the P+ and [Formula: see text] concepts and plotting the tissue response probabilities vs. [Formula: see text] a more comprehensive comparison was performed based on radiobiological measures. For the lung cancer case, at the clinically prescribed dose levels of the dose distributions, with and without patient setup correction, the complication-free tumor control probabilities, P+ are 48.5% and 48.9% for a [Formula: see text] of 53.3 Gy. The respective total control probabilities, PB are 56.3% and 56.5%, whereas the corresponding total complication probabilities, PI are 7.9% and 7.5%. For the pancreas cancer case, at the prescribed dose levels of the two dose distributions, the P+ values are 53.7% and 45.7% for a [Formula: see text] of 54.7 Gy and 53.8 Gy, respectively. The respective PB values are 53.7% and 45.8%, whereas the corresponding PI values are ~0.0% and 0.1%. For the prostate cancer case, at the prescribed dose levels of the two dose distributions, the P+ values are 10.9% for a [Formula: see text] of 75.2 Gy and 11.9% for a [Formula: see text] of 75.4 Gy, respectively. The respective PB values are 14.5% and 15.3%, whereas the corresponding PI values are 3.6% and 3.4%. Our analysis showed that the very good daily patient setup and dose delivery were very close to the intended ones. With the exception of the pancreas cancer case, the deviations observed between the dose distributions with and without patient setup correction were within ±2% in terms of P+. In the radiobiologically optimized dose distributions, the role of patient setup correction using MVCT images could appear to be more important than in the cases of dosimetrically optimized treatment plans were the individual tissue radiosensitivities are not precisely considered.
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| 9. |
- Mavroidis, Panayiotis, et al.
(författare)
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Radiobiological and Dosimetric Analysis of Daily Megavoltage CT Registration on Adaptive Radiotherapy with Helical Tomotherapy
- 2011
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Ingår i: Technology in Cancer Research & Treatment. - 1533-0346 .- 1533-0338. ; 10:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Pre-treatment patient repositioning in highly conformal image-guided radiation therapy modalities is a prerequisite for reducing setup uncertainties. In Helical Tomotherapy (HT) treatment, a megavoltage CT (MVCT) image is usually acquired to evaluate daily changes in the patient's internal anatomy and setup position. This MVCT image is subsequently compared to the kilovoltage CT (kVCT) study that was used for dosimetric planning, by applying a registration process. This study aims at investigating the expected effect of patient setup correction using the Hi-Art tomotherapy system by employing radiobiological measures such as the biologically effective uniform dose (<(D)double over bar>) and the complication-free tumor control probability (P.). A new module of the Tomotherapy software (Tomo Therapy, Inc, Madison, WI) called Planned Adaptive is employed in this study. In this process the delivered dose can be calculated by using the sinogram for each delivered fraction and the registered MVCT image set that corresponds to the patient's position and anatomical distribution for that fraction. In this study, patients treated for lung, pancreas and prostate carcinomas are evaluated by this method. For each cancer type, a Helical Tomotherapy plan was developed. In each cancer case, two dose distributions were calculated using the MVCT image sets before and after the patient setup correction. The fractional dose distributions were added and renormalized to the total number of fractions planned. The dosimetric and radiobiological differences of the dose distributions with and without patient setup correction were calculated. By using common statistical measures of the dose distributions and the P, and <(D)double over bar> concepts and plotting the tissue response probabilities vs. <(D)double over bar> a more comprehensive comparison was performed based on radiobiological measures. For the lung cancer case, at the clinically prescribed dose levels of the dose distributions, with and without patient setup correction, the complication-free tumor control probabilities, P. are 48.5% and 48.9% for a <(D)double over bar>(ITV) of 53.3 Gy. The respective total control probabilities, P(B) are 56.3% and 56.5%, whereas the corresponding total complication probabilities, P(I) are 7.9% and 7.5%. For the pancreas cancer case, at the prescribed dose levels of the two dose distributions, the P. values are 53.7% and 45.7% for a <(D)double over bar>(ITV) of 54.7 Gy and 53.8 Gy, respectively. The respective PB values are 53.7% and 45.8%, whereas the corresponding P, values are similar to 0.0% and 0.1%. For the prostate cancer case, at the prescribed dose levels of the two dose distributions, the P. values are 10.9% for a <(D)double over bar>(ITV) of 75.2 Gy and 11.9% for a D(ITV) of 75.4 Gy, respectively. The respective PB values are 14.5% and 15.3%, whereas the corresponding P, values are 3.6% and 3.4%. Our analysis showed that the very good daily patient setup and dose delivery were very close to the intended ones. With the exception of the pancreas cancer case, the deviations observed between the dose distributions with and without patient setup correction were within +/- 2% in terms of P(+). In the radiobiologically optimized dose distributions, the role of patient setup correction using MVCT images could appear to be more important than in the cases of dosimetrically optimized treatment plans were the individual tissue radiosensitivities are not precisely considered.
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