Deep‐inspiration breath‐hold (DIBH) reduces the radiation dose to the heart and lungs during breast radiotherapy in cancer. However, there is not enough discussion about suitable breathing methods ...for DIBH. Therefore, we investigated the radiation doses and organ and body surface displacement in abdominal DIBH (A‐DIBH) and thoracic DIBH (T‐DIBH). Free‐breathing, A‐DIBH, and T‐DIBH computed tomography images of 100 patients were used. After contouring the targets, heart, and lungs, radiotherapy plans were created. We investigated the heart and lung doses, the associations between the heart and left lung displacements, and the thorax and abdominal surface displacements. No significant differences were observed in the target dose indices. However, the heart and lung doses were significantly lower in A‐DIBH than in T‐DIBH for all the indices; the mean heart and lung doses were 1.69 and 3.48 Gy, and 1.91 and 3.55 Gy in A‐DIBH and T‐DIBH, respectively. The inferior displacement of the heart and the left lung was more significant in A‐DIBH. Therefore, inferior expansion of the heart and lungs may be responsible for the respective dose reductions. The abdominal surface displaced more than the thoracic surface in both A‐DIBH and T‐DIBH, and thoracic surface displacement was greater in T‐DIBH than in A‐DIBH. Moreover, A‐DIBH can be identified because abdominal surface displacement was greater in A‐DIBH than in T‐DIBH. In conclusion, A‐DIBH and T‐DIBH could be distinguished by comparing the abdominal and thoracic surfaces of A‐DIBH and T‐DIBH, thereby ensuring the implementation of A‐DIBH and reducing the heart and lung doses.
To investigate PET/CT registration and quantification accuracy of thoracic lesions of a single 30-second deep-inspiration breath-hold (DIBH) technique with a total-body PET (TB-PET) scanner, and ...compared with free-breathing (FB) PET/CT.
137 of the 145 prospectively enrolled patients finished a routine FB-300 s PET/CT exam and a 30-second DIBH TB-PET with chest to pelvis low dose CT. The total-body FB-300 s, FB-30 s, and DIBH-30 s PET images were reconstructed. Quantitative assessment (SUVmax and SUVmean of lung and other organs), PET/CT registration assessment and lesion analysis (SUVmax, SUVpeak, SUVmean and tumor-background ratio) were compared with Wilcoxon signed-rank tests.
The SUVmax and SUVmean of the lung with DIBH-30 s were significantly lower than those with FB. The distances of the liver dome between PET and CT were significantly smaller with DIBH-30 s than with FB. 195 assessable lesions in 106 patients were included, and the detection sensitivity was 97.9 % and 99.0 % in FB-300 s, and DIBH-30 s, respectively. For both small co-identified lesions (n = 86) and larger co-identified lesions with a diameter ≥ 1 cm (n = 91), the lesion SUVs were significantly greater with DIBH-30 s than with FB-300 s. Regarding lesion location, the differences of the SUVs for the lesions in the lower thorax area (n = 97, p < 0.001) were significant between DIBH-30 s and FB-300 s, while these differences were not statistically significant in the upper thorax (n = 80, p > 0.05). The lesion tumor-to-surrounding-background ratio (TsBR) was significantly increased, both in the upper and lower thorax.
The TB DIBH PET/CT technique is feasible in clinical practice. It reduces the background lung uptake and achieves better registration and lesion quantification, especially in the lower thorax.
Many institutions worldwide currently deliver left breast radiotherapy in free breathing mode, mostly due to the unavailability of a Deep Inspiration Breath Hold technique (DIBH). This study aims at ...quantifying the error in dose delivery (compared to treatment plan) due to respiratory motion in free breathing irradiation of left breast or chest wall. Since subfields often consist in small, fine-tuned, highly targeted fields, slight intrafractional target motion may compromise their subtle benefit. Thus we analyzed the respiratory motion effect on target dose coverage, dose homogeneity and left lung dose.
Treatment plans for twenty left breast or chest wall cancer patients previously treated at our center were retrieved and retrospectively planned with the introduction of an appropriate shift in isocenter location to simulate free breathing target motion.
No clinically significant dosimetric changes were found in all twenty cases when breathing motion was accounted for. Changes in target dose coverage (V95%), in target maximum dose (D2%) and in V20Gy lung dose were respectively less than 1.5%, 0.3% and 2.6%.
The findings suggest that breast irradiation in free breathing mode does not undermine the dosimetric merits of the field-in-field technique and does not produce clinically significant dosimetric differences in dose delivery for target and lung compared to plan.
•Breathing has a negligible effect on dose delivery accuracy in breast cancer radiotherapy.•Free breathing during breast radiotherapy treatment does not invalidate the use of field-in-field technique.•The dosimetric error from free breathing breast motion during radiotherapy treatment is clinically negligible.
The clinical use of surface imaging has increased dramatically, with demonstrated utility for initial patient positioning, real‐time motion monitoring, and beam gating in a variety of anatomical ...sites. The Therapy Physics Subcommittee and the Imaging for Treatment Verification Working Group of the American Association of Physicists in Medicine commissioned Task Group 302 to review the current clinical uses of surface imaging and emerging clinical applications. The specific charge of this task group was to provide technical guidelines for clinical indications of use for general positioning, breast deep‐inspiration breath hold treatment, and frameless stereotactic radiosurgery. Additionally, the task group was charged with providing commissioning and on‐going quality assurance (QA) requirements for surface‐guided radiation therapy (SGRT) as part of a comprehensive QA program including risk assessment. Workflow considerations for other anatomic sites and for computed tomography simulation, including motion management, are also discussed. Finally, developing clinical applications, such as stereotactic body radiotherapy (SBRT) or proton radiotherapy, are presented. The recommendations made in this report, which are summarized at the end of the report, are applicable to all video‐based SGRT systems available at the time of writing.
Historically, heart dose from left-sided breast radiotherapy has been associated with a risk of cardiac injury. Data suggests that there is not a threshold for the deleterious effects from radiation ...on the heart. Over the past several years, advances in radiation delivery techniques have reduced cardiac morbidity due to treatment. Deep inspiration breath hold (DIBH) is a technique that takes advantage of a more favorable position of the heart during inspiration to minimize heart doses over a course of radiation therapy. In the accompanying review article, we outline several methods used to deliver treatment with DIBH, quantify the benefits of DIBH treatment, discuss considerations for patient selection, and identify challenges associated with DIBH techniques.
Purpose
The use of volumetric modulated arc therapy (VMAT), simultaneous integrated boost (SIB), and hypofractionated regimen requires adequate patient setup accuracy to achieve an optimal outcome. ...The purpose of this study was to assess the setup accuracy of patients receiving left‐sided breast cancer radiotherapy using deep inspiration breath‐hold technique (DIBH) and surface guided radiotherapy (SGRT) and to calculate the corresponding setup margins.
Methods
The patient setup accuracy between and within radiotherapy fractions was measured by comparing the 6DOF shifts made by the SGRT system AlignRT with the shifts made by kV‐CBCT. Three hundred and three radiotherapy fractions of 23 left‐sided breast cancer patients using DIBH and SGRT were used for the analysis. All patients received pre‐treatment DIBH training and visual feedback during DIBH. An analysis of variance (ANOVA) was used to test patient setup differences for statistical significance. The corresponding setup margins were calculated using the van Herk's formula.
Results
The intrafractional patient setup accuracy was significantly better than the interfractional setup accuracy (p < 0.001). The setup margin for the combined inter‐ and intrafractional setup error was 4, 6, and 4 mm in the lateral, longitudinal, and vertical directions if based on SGRT alone. The intrafractional error contributed ≤1 mm to the calculated setup margins.
Conclusion
With SGRT, excellent intrafractional and acceptable interfractional patient setup accuracy can be achieved for the radiotherapy of left‐sided breast cancer using DIBH and modern radiation techniques. This allows for reducing the frequency of kV‐CBCTs, thereby saving treatment time and radiation exposure.
•Lowering the dose to organs at risk is a primary goal in mediastinal lymphoma radiotherapy.•We compared full arc and limited arc plans, with and without the use of breath-hold.•The effect of ...combining limited arc and DIBH is additive or complementary.
Radiotherapy is an effective treatment for mediastinal lymphoma but induces late effects including cardiac toxicity and secondary breast and lung cancer. Therefore reducing the dose to these organs is vital. We compared full arc volumetric modulated arc therapy (F-VMAT) against limited angle ‘Butterfly’ VMAT (B-VMAT) on free breathing (FB) and deep inspiration breath-hold (DIBH) computed tomography scans. The aim was to assess the benefits of B-VMAT over F-VMAT and to establish if the addition of DIBH results is a cumulative benefit.
F-VMAT and B-VMAT plans were calculated for 20 consecutive patients (15 females) with mediastinal lymphoma on both FB and DIBH scans. The planning target volume V95% was kept comparable between all plans while reducing organ doses as much as possible.
B-VMAT significantly reduced low lung doses (V5–10), while F-VMAT was better for higher lung doses (V20–30). DIBH further improved lung doses for both types of plans. DIBH B-VMAT produced the lowest mean lung dose. With FB, heart doses were slightly higher for B-VMAT but the maximum difference was small (0.8% for V20) and only statistically significant for V10-20. The mean heart dose increased by only 0.1 Gy. The addition of DIBH however significantly reduced heart doses. While DIBH F-VMAT had the lowest heart doses, the difference was small compared with DIBH B-VMAT. B-VMAT significantly reduced breast V4 while DIBH reduced the V10.
B-VMAT and DIBH are both effective in reducing organ doses and the dosimetric benefit is additive for some parameters and complementary for others.
This clinical study aimed to evaluate lung cancer patients’ ability to perform deep inspiration breath‐hold (DIBH) during CT simulation and throughout the treatment course of stereotactic body ...radiation therapy (SBRT). In addition, target sizes, organ at risk (OAR) sizes, and doses to the respective volumes in filter‐free volumetric‐modulated arc therapy plans performed under free‐breathing (FB) and DIBH conditions were evaluated. Twenty‐one patients with peripheral lesions were included, of which 13 were eligible for SBRT. All patients underwent training for breath‐hold during CT, and if they complied with the requirements, two CT scans were obtained: CT scan in DIBH and a four‐dimensional CT scan in FB. The treatment plans in FB and DIBH were generated, and the dose parameters and volume sizes were compared. The endpoints for evaluation were patient compliance, target dose coverage, and doses to the OARs. This clinical study showed high patient DIBH compliance during both CT simulation and treatment for patients with lung cancer. A significant reduction in target volumes was achieved with SBRT in DIBH, in addition to significantly decreased doses to the heart, chest wall, and lungs. DIBH in SBRT of lung lesions is feasible, and a routine to manage intra‐fractional deviation should be established upon implementation.
•Reproducibility/Stability of MANIV-DIBH is non-inferior to surface-guided DIBH.•A better cardiopulmonary protection is achieved with mechanical ventilation.•Comfort and treatment time with MANIV are ...similar to surface-guided DIBH.•MANIV enables better inter-fraction heart repositioning.
Deep inspiration breath-hold (DIBH) protects critical organs-at-risk (OARs) for adjuvant breast radiotherapy. Guidance systems e.g. surface guided radiation therapy (SGRT) improve the positional breast reproducibility and stability during DIBH. In parallel, OARs sparing with DIBH is enhanced through different techniques e.g. prone position, continuous positive airway pressure (CPAP). By inducing repeated DIBH with the same level of positive pressure, mechanically-assisted and non-invasive ventilation (MANIV) could potentially combine these DIBH optimizations.
We conducted a randomized, open-label, multicenter and single-institution non-inferiority trial. Sixty-six patients eligible for adjuvant left whole-breast radiotherapy in supine position were equally assigned between mechanically-induced DIBH (MANIV-DIBH) and voluntary DIBH guided by SGRT (sDIBH). The co-primary endpoints were positional breast stability and reproducibility with a non-inferiority margin of 1 mm. Secondary endpoints were tolerance assessed daily via validated scales, treatment time, dose to OARs and their inter-fraction positional reproducibility.
Differences between both arms for positional breast reproducibility and stability occurred at a sub-millimetric level (p < 0.001 for non-inferiority). The left anterior descending artery near-max dose (14,6 ± 12,0 Gy vs. 7,7 ± 7,1 Gy, p = 0,018) and mean dose (5,0 ± 3,5 Gy vs. 3,0 ± 2,0 Gy, p = 0,009) were improved with MANIV-DIBH. The same applied for the V5Gy of the left ventricle (2,4 ± 4,1 % vs. 0,8 ± 1,6 %, p = 0,001) as well as for the left lung V20Gy (11,4 ± 2,8 % vs. 9,7 ± 2,7 %, p = 0,019) and V30Gy (8,0 ± 2,6 % vs. 6,5 ± 2,3 %, p = 0,0018). Better heart’s inter-fraction positional reproducibility was observed with MANIV-DIBH. Tolerance and treatment time were similar.
Mechanical ventilation provides the same target irradiation accuracy as with SGRT while better protecting and repositioning OARs.
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