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The goal of this phase II trial was to evaluate safety and efficacy of a tandem autologous hematopoietic cell transplantation (auto-HCT) using sequentially total marrow irradiation (TMI) at the dose of 12 Gy (4 Gy on days -3, -2, and -1) and melphalan 200 mg/m2 for patients with multiple myeloma (MM). TMI was performed using helical tomotherapy. Additional "boosts" (total 24 Gy) were applied for patients with active lesions as revealed by PET-FDG. Fifty patients with median age 58 years (41-64 years) were included and received tandem auto-HCT. TMI resulted in absolute neutropenia in all patients. Grade 3 infections were reported in 30% patients. Other toxicities were rare. Proportion of patients who achieved at least very good partial response increased from 46% before the first auto-HCT to 82% after tandem transplantation. Complete remission rates changed from 10% to 42%, respectively. The probabilities of overall and progression-free survival at 5 years were 74% and 55%, respectively. No patient died without progression. We conclude that conditioning with TMI ± PET-guided "boosts" represents personalized treatment approach in MM and is characterized by very good toxicity profile. Tandem auto-HCT using TMI in sequence with high-dose melphalan appears safe with encouraging early efficacy.
Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Myeloma , Adult , Bone Marrow , Humans , Melphalan , Middle Aged , Multiple Myeloma/therapy , Transplantation Conditioning , Transplantation, Autologous , Treatment OutcomeABSTRACT
AIM: The aim of this study is to answer the question whether the calculated dose distributions for HD and Millennium collimators (Varian Medical Systems) are equivalent for large treatment volumes. BACKGROUND: Modern biomedical linacs are equipped with multileaf collimators where leaves can be of different widths. Thinner leaves allow better fit to desired (tumor) shape. At the same time, however, the maximum size of the field that can be obtained with the collimator is also reduced. Varian Medical Systems HD and Millennium collimators can be a good sample. They have 40 cm or 22 cm × 40 cm maximal field size at the isocenter, respectively. MATERIALS AND METHODS: This paper presents the comparison of selected statistical and dosimetric parameters achieved for treatment plans where the beams for a HD collimator had to be merged because of the size of the tumor volume. RESULTS AND DISCUSSION: Achieved results show that, independently from irradiated volume, there is no statistically significant difference for calculated dose distributions, integral doses, MU values and coefficients evaluating dose distributions for HD and Millennium collimators. CONCLUSIONS: Results show that both types of collimators can be used interchangeably for preparing the treatment plans for large tumor volume without quality reduction of the prepared treatment plan.
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Purpose: Evaluation of the 18-fluorodeoxy-glucose positron emission tomography-computed tomography (18-FDGPET/ CT) for gross tumor volume (GTV) delineation in gastric cancer patients undergoing radiotherapy. Methods: In this study, 29 gastric cancer patients (17 unresectable and 7 inoperable) were initially enrolled for radical chemoradiotherapy (45Gy/25 fractions + chemotherapy based on 5 fluorouracil) or radiotherapy alone (45Gy/25 fractions) with planning based on the 18-FDG-PET/CT images. Five patients were excluded due to excess blood glucose levels (1), false-negative positron emission tomography (1) and distant metastases revealed by 18-FDG-PET/CT (3). The analysis involved measurement of metabolic tumor volumes (MTVs) performed on PET/CT workstations. Different threshold levels of the standardized uptake value (SUV) and liver uptake were set to obtain MTVs. Secondly, GTVPET values were derived manually using the positron emission tomography (PET) dataset blinded to the computed tomography (CT) data. Subsequently, GTVCT values were delineated using a radiotherapy planning system based on the CT scans blinded to the PET data. The referenced GTVCT values were correlated with the GTVPET and were compared with a conformality index (CI). Results: The mean CI was 0.52 (range, 0.12-0.85). In 13/24 patients (54%), the GTVPET was larger than GTVCT, and in the remainder, GTVPET was smaller. Moreover, the cranio-caudal diameter of GTVPET in 16 cases (64%) was larger than that of GTVCT, smaller in 7 cases (29%), and unchanged in one case. Manual PET delineation (GTVPET) achieved the best correlation with GTVCT (Pearson correlation = 0.76, p <0.0001). Among the analyzed MTVs, a statistically significant correlation with GTVCT was revealed for MTV10%SUVmax (r = 0.63; p = 0.0014), MTVliv (r = 0.60; p = 0.0021), MTVSUV2.5 (r = 0.54; p = 0.0063); MTV20%SUVmax (r = 0.44; p = 0.0344); MTV30%SUVmax (r = 0.44; p = 0.0373). Conclusion: 18-FDG-PET/CT in gastric cancer radiotherapy planning may affect the GTV delineation.
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Background: Application of the image-guided radiotherapy (IGRT) system for gastric cancer involving daily verification of patient positioning on the treatment machine allows minimisation of geometrical errors as a consequence of intra- and inter-fraction motion. The purpose of this study was to define the intrafraction motion in gastric cancer patients during a treatment session based on the IGRT system and designation of margins around the clinical target volume CTV (internal target volume ITV) necessary to delineate the planning target volume (PTV). Methods: Twenty gastric cancer patients were analysed. The total radiation dose for each was 45Gy in 25 fractions within 5 weeks. The margins for the PTV were calculated according to van Herk (2004), Stroom and Heijmen (2002) and the International Commission on Radiation Units and Measurements (ICRU) Report 62 formulas based on craniocaudal (Y axis), laterolateral (X axis) and anteroposterior (Z axis) shifts. Results: Delineated margins for the PTV in gastric cancer with the three formulas applied were respectively 0.2, 0.2, and 0.2cm in the lateral plane, 0.3, 0.3, and 0.3cm in the craniocaudal plane and 0.3, 0.3, and 0.2cm in the anteroposterior plane. Conclusions: Recommended margins for the PTV in gastric cancer calculated in this study based on intrafraction motion are 0.3cm, 0.2cm and 0.3cm in the craniocaudal, lateral and anterioposterior directions, respectively. Use of the IGRT system corrects for the motions between factions and allows reduction in ITV-PTV margins. The main advantage of the smaller margins in comparison to the non-IGRT radiotherapy is a reduction in the probability of radiation complications.
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AIM: The purpose of this study was to compare conformal radiotherapy techniques used in the treatment of gastric cancer patients. The study is dedicated to radiotherapy centres that have not introduced dynamic techniques in clinical practice. BACKGROUND: The implementation of multi-field technique can minimise the toxicity of treatment and improve dose distribution homogeneity in the target volume with simultaneous protection of organs at risk (OaRs). Treatment plan should be personalised for each patient by taking into account the planning target volume and anatomical conditions of the individual patient. MATERIALS AND METHODS: For each patient, four different three dimensional conformal plans were compared: 2-field plan, 3-field plan, non-coplanar 3-field plan and non-coplanar 4-field plan. Dose distributions in a volume of 107% of the reference dose, and OaRs such as the liver, kidneys, intestines, spinal cord, and heart were analysed. RESULTS: The mean volume of the patient body covered using the isodose of 107% was 3004.73 cm(3), 1454.28 cm(3), 1426.62 cm(3), 889.14 cm(3) for the 2-field, 3-field, non-coplanar 3-field and non-coplanar 4-field techniques, respectively. For all plans the minimum dose in the PTV volume was at least 95% of the reference dose. The QUANTEC protocol was used to investigate doses in OaRs. CONCLUSIONS: Comparison of 3D conformal radiotherapy techniques in gastric cancer patients indicates that none of the plans can fulfil simultaneously all of the criteria of the tolerance dose in the organs at risk. The implementation of the multi-field technique can minimise the toxicity of treatment and improve dose distribution homogeneity in the target volume with additional protection of organs at risk (OaRs).
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The aim of the present study was to compare the techniques of dynamic intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT) in patients with gastric cancer. Implementation of the IMRT technique does not significantly affect the minimum and maximum dose levels in the planning target volume (PTV), but more effectively protects the critical organs. The study group consisted of 25 patients. The results of the analysis of the conformity index (CI) and the homogeneity index (HI) showed that the doses in the PTV regions were at a comparable level. The CI for the PTV was 0.95 for the 2-field technique, 0.95 for the 3-field technique, 0.96 for the 4-field technique and 0.94 for the IMRT technique. The CIs for these techniques for the clinical target volume (CTV) were 0.96, 0.96, 0.97 and 0.96, respectively, and the CIs for the gross tumor volume (GTV) were 0.99, 0.99, 0.99 and 0.98, respectively. The HI values for the PTV were 1.12 for the 2-field technique, 1.12 for the 3-field technique, 1.09 for the 4-field technique and 1.09 for the IMRT technique, and the HI values for the CTV were 1.12, 1.12, 1.09 and 1.08 for the same techniques, respectively. The HI values for the GTV were 1.09, 1.09, 1.07 and 1.06, respectively, which indicated significantly superior performance in the regions of healthy tissue. Statistical study was based on Friedman's rank analysis of variance to determine the level of reliability of the tested groups of variables (P<0.001). The present study demonstrated that the IMRT technique in the pre-operative radiotherapy of gastric cancer patients results in superior treatment tolerance and reduces the risk of damage to healthy tissue that is in close proximity to the irradiated area.
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INTRODUCTION: The use of fiducial markers in patients undergoing teleradiotherapy increases the precision of treatment under the condition that the marker does not displace itself during this treatment. In order to determine the accuracy of the verification method used to establish patient position, it is necessary to establish the possible marker migration range during planning and treatment with radiation therapy. MATERIAL AND METHOD: An analysis of the migration of GoldAnchorTM fiducial markers implanted in the prostate conducted on a group of 29 patients treated with image-guided radiation therapy at the Radiotherapy Department of the Cancer Centre and Institute of Oncology in Gliwice. The migration value was determined based on a comparison of the marker's location with the use of spiral computer tomography and cone-beam computer tomography done on the treatment device. RESULTS: The average values of the given fiducial marker's migration in the superior-inferior (SI), left-right (LR) and anterior-posterior (AP) directions were: 0.07 cm (SD=0.1 cm); 0.06 cm (SD=0.07 cm) and 0.11 cm (SD=0.11 cm), respectively. The average value of the displacement vector computed according to the Pythagorean theorem and using the Euclidean norm was 0.17 cm with SD= 0.13 cm. CONCLUSION: The analysis indicates that migration of markers implanted in the prostate occurs during radiation treatment planning but probably it is not clinically relevant. Because a correlation was determined between the migration value and the time of carrying out the CT as well as the time that had passed from the implantation to the CBCT examination, it is reasonable to start radiation therapy promptly and to control the marker's location during radiation therapy.
Subject(s)
Fiducial Markers , Foreign-Body Migration/diagnostic imaging , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted , Radiotherapy, Image-Guided , Aged , Cone-Beam Computed Tomography , Humans , Male , Prostate/diagnostic imaging , Tomography, Spiral ComputedABSTRACT
AIM: The aim was to provide a dosimetric comparison between IMRT and RapidArc treatment plans with RPI index with simultaneous comparison of the treatment delivery time. BACKGROUND: IMRT and RapidArc provide highly conformal dose distribution with good sparing of normal tissues. However, a complex spatial dosimetry of IMRT and RapidArc plans hampers the evaluation and comparison between plans calculated for the two modalities. RPI was used in this paper for treatment plan comparisons. The duration of the therapeutic session in RapidArc is reported to be shorter in comparison to therapeutic time of the other dynamic techniques. For this reasons, total treatment delivery time in both techniques was compared and discussed. MATERIALS AND METHODS: 15 patients with prostate carcinoma were randomly selected for the analysis. Two competitive treatment plans using respectively the IMRT and RapidArc techniques were computed for each patient in Eclipse planning system v. 8.6.15. RPIwin(®) application was used for RPI calculations for each treatment plan. Additionally, total treatment time was compared between IMRT and RapidArc plans. Total treatment time was a sum of monitor units (MU) for each treated field. RESULTS: The mean values of the RPI indices were insignificantly higher for IMRT plans in comparison to rotational therapy. Comparison of the mean numbers of monitor units confirmed that the use of rotational technique instead of conventional static field IMRT can significantly reduce the treatment time. CONCLUSION: Analysis presented in this paper, demonstrated that RapidArc can compete with the IMRT technique in the field of treatment plan dosimetry reducing the time required for dose delivery.
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The IGRT notion (image guided radiation therapy) comprises all techniques enabling checking and correction of patients position directly before or during an irradiation session. In last years they became a standard in radiotherapy due to decreasing of geographical misses. The aim of our study was a comparison of two IGRT techniques--CBCT and 2D-2D kV performed for prostate cancer patients and a comparison of two immobilization systems used for them. The performed analysis comprises 3582 2D-2D kV and 2110 CBCT IGRT measurements made for 85 prostate cancer patients. Patients were irradiated using thermoplastic masks and two kinds of immobilizing plates. One subgroup of patients was treated using leg supports and second one without them. Mean, maximum, minimum and standard deviation of absolute values of shifts (cm) measured using 2D-2D kV were 0.27, 0.0, 2.8 and 0.33 respectively. For CBCT these same values were 0.31, 0.0, 4.1 and 0.33. Mean, maximum, minimum and standard deviation of real shifts values (cm) measured using 2D-2D kV were -0.01, -2.5, 2.8 and 0.43 respectively. For CBCT these same values were 0.01, -4.1, 2.3 and 0.45. Comparison of shift absolute values distributions for whole analyzed group showed statistically significant difference (p=0.001) between 2D-2D kV and CBCT with higher mean for CBCT (0.31 vs 0.27) and equal standard deviations. Statistically significant difference (p=0.000...) between distributions of measurements in z axis was found (for 2D-2D kV mean 0.16, SD=0.21, for CBCT mean 0.25, SD=0.25). Comparison of absolute shifts values distributions revealed significant difference for CBCT, for two immobilization plates--in x (p=0.001) and y axis (p=0.007). For the small plate in x axis mean was 0.22 (SD=0.2), and for the large one (with an integrated head support) 0.17 (SD=0.2). Comparison of absolute shifts values for sub- groups created dependently on the leg support use, showed significant differences in x axis for 2D-2D kV (p=0.000...); mean in the subgroup irradiated without leg supports was 0.14 (SD=0.14) and for the subgroup without them was 0.19 (SD=0.15) and in x axis for CBCT (p=0.03); mean in the subgroup irradiated without leg supports was 0.18 (SD=0.18) and for the subgroup without them was 0.23 (SD=0.22). Significant difference was also revealed for the whole group of absolute shift values for 2D-2D kV (p=0.01). For the subgroup irradiated without leg supports mean was 0.27 (SD=0.34), and for the subgroup treated with them was 0.27 (SD=0.31). Obtained results permit us to conclude that in the case of prostate cancer patients IGRT based on the bone anatomy visualization, the method of choice should be 2D-2D kV, because it allows for more precise and shorter patient position evaluation and, that during IGRT of prostate cancer patients using a simple thermoplastic immobilization system is sufficient; use of more sophisticated systems with additional supports did not improve the patient immobilization.
