Dose and organ displacement comparisons with breast conservative radiotherapy using abdominal and thoracic deep-inspiration breath-holds: A comparative dosimetric study.

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.

Examination of the dose distribution of volumetric modulated arc radiotherapy using a high-definition multi-leaf collimator for breast cancer patients with irradiated regional lymph nodes.

Background: A high-definition multi-leaf collimator (HD-MLC) with 5- and 10-mm fine MLCs is useful for radiotherapy. However, it is difficult to irradiate the mammary gland and supraclavicular region using a HD-MLC because of the narrow field of volumetric modulated arc radiotherapy (VMAT). Therefore, we aimed to evaluate the dose distribution of the VMAT dose using a HD-MLC in 15 patients with left breast cancer undergoing postoperative irradiation of breast and regional lymph nodes, including the internal mammary node. Materials and methods: The following four plans were generated: three-arc VMAT using HD-MLC (HD-VMAT), two tangential arcs and one-arc VMAT using HD-MLC (tHD-VMAT), three-dimensional conformal radiotherapy (3DCRT) using HD-MLC, and two-arc VMAT using the Millennium 120-leaf MLC (M-VMAT). We assessed the doses to the target volume and organs at risk. Results: The target dose distributions were higher for HD-VMAT than 3DCRT. There were no significant differences in the heart mean dose (Dmean) or lung volume receiving 20 Gy (V20 Gy) between HD-VMAT and 3DCRT. The heart Dmean and lung V20 Gy of tHD-VMAT were higher than those of HD-VMAT, and the heart Dmean of M-VMAT was higher than that of HD-VMAT. However, the target doses of tHD-VMAT, M-VMAT, and HD-VMAT were equivalent. Conclusions: In cases of the mammary gland and regional lymph node irradiation, including the internal mammary node in patients with left breast cancer, HD-VMAT was not inferior to M-VMAT and provided a better dose distribution to the target volume and organs at risk compared with 3DCRT and tHD-VMAT.

Factors Involved in the Choice Between Thoracic and Abdominal Deep Inspiration Breath Holds During Left Breast Cancer Radiotherapy.

PURPOSE: Deep inspiration breath hold (DIBH) is used with adjuvant radiation therapy after left breast cancer surgery to reduce radiation dose to the heart. In this study we determined whether thoracic DIBH (T-DIBH) or abdominal DIBH (A-DIBH) should be selected based on patient background. METHODS: Three-dimensional conformal radiation therapy plans were created under the same conditions using free breathing (FB), T-DIBH, and A-DIBH CT scans of patients who had previously undergone treatment at our hospital. RESULTS: A-DIBH decreased the left lung dose compared to FB. In comparing T-DIBH and A-DIBH, the heart maximum and left lung doses were significantly lower in A-DIBH. The differences in the heart mean dose (Dmean) between FB, and T-DIBH and A-DIBH were correlated with the cardiothoracic ratio, heart volume, and left lung volume. The difference in the heart Dmean and the left lung dose of T-DIBH and A-DIBH correlated with the forced vital capacity (FVC). CONCLUSIONS: A-DIBH is preferable over T-DIBH with respect to the heart and left lung doses; however, with respect to the heart Dmean, T-DIBH was more effective in reducing the dose in some cases, and the FVC was a relevant factor in this study.

Effect on Heart and Lung Doses Reduction of Abdominal and Thoracic Deep Inspiratory Breath-hold Assuming Involved-field Radiation Therapy in Patients with Simulated Esophageal Cancer.

PURPOSE: The purpose of this study was to evaluate the lung and heart doses in volumetric-modulated arc therapy (VMAT) using involved-field irradiation in patients with middle-to-lower thoracic esophageal cancer during free breathing (FB), abdominal deep inspiratory breath-hold (A-DIBH), and thoracic DIBH (T-DIBH) images. METHODS: Computed tomography images of A-DIBH, T-DIBH, and FB from 25 patients with breast cancer were used to simulate patients with esophageal cancer. The irradiation field was set at an involved-field, and target and risk organs were outlined according to uniform criteria. VMAT optimization was performed, and lung and heart doses were evaluated. RESULTS: A-DIBH had a lower lung V20 Gy than FB and a lower lung V40 Gy, V30 Gy, V20 Gy than T-DIBH. The heart all dose indices were lower in T-DIBH than FB, and the heart V10 Gy was lower in A-DIBH than FB. However, the heart Dmean was comparable with A-DIBH and T-DIBH. CONCLUSIONS: A-DIBH had significant dose advantages for lungs compared to FB and T-DIBH, and the heart Dmean was comparable to T-DIBH. Therefore, when performing DIBH, A-DIBH is suggested for radiotherapy in patients with middle-to-lower thoracic esophageal cancer, excluding irradiation of the prophylactic area.

Comparing the toxicity and disease control rate of radiotherapy for prostate cancer between salvage settings after high-intensity focused ultrasound therapy and initial settings.

The purpose of this retrospective study was to compare the toxicity and disease control rate of radiotherapy for prostate cancer in salvage settings after high-intensity focused ultrasound (HIFU) therapy (HIFU cohort) with those in radical settings (non-HIFU cohort). From 2012 to 2020, 215 patients were identified for this study and 17 were treated in the salvage settings after HIFU. The median follow-up time was 34.5 months (range: 7-102 months, inter-quartile range [IQR]: 16-64 months). Genitourinary (GU) and gastrointestinal (GI) adverse events were evaluated in acute and late periods with Common Terminology Criteria for Adverse Events version 5, and the rates of biochemical-clinical failure free survival (BCFS) and overall survival (OS) were estimated. The cumulative incidence of late GU Grade 2 or greater toxicity after five years was significantly different between the non-HIFU and HIFU cohorts with rates of 7.3% and 26.2%, respectively (P = 0.03). Regarding GI Grade 2 or greater toxicity, there was no significant difference between the two cohorts. The 5y-BCFS was 84.2% in the non-HIFU cohort and 69.5% in the HIFU cohort with no significant difference (P = 0.10) and the 5y-OS was 95.9% and 92.3%, respectively (P = 0.47). We concluded that the possibility of increased late GU Grade 2 or greater should be considered when applying salvage radiotherapy for local recurrence after HIFU.

Persistent left superior vena cava with absent right superior vena cava in adults: CT and clinical findings.

PURPOSE: Persistent left superior vena cava (PLSVC) with absent right superior vena cava (ARSVC) is rare. We evaluated CT and clinical findings of adults with ARSVC. MATERIALS AND METHODS: Our study included 11 adults with ARSVC (mean age, 63 ± 17 years). We evaluated CT findings of the azygos vein system and coronary sinus (CS) using thin slice data of > 64 MDCT. Arrhythmia and congenial heart disease were assessed. We compared the CS diameters between the ARSVC group and the control group of 120 adults with normal vena cava (mean age, 60 ± 4 years). RESULTS: Adults with ARSVC had no azygos vein arch and the hemiazygos vein continued to PLSVCs via the superior intercostal vein. Eight adults had arrhythmia including conduction disturbance and one arrhythmia was associated with atrial septal defect. All adults with ARSVC had dilated CS larger than 11 mm. The mean diameter of the CS in the ARSVC group was 18.4 mm, and that of the control group was 6.8 mm. CS diameter in the ARSVC group was larger than that in the control group (p < 0.001). CONCLUSION: Adults with ARSVC had dilated CS and no azygos vein arch. Four adults had conduction disturbance.

Cutaneous Metastases from Testicular Diffuse Large B-cell Malignant Lymphoma and Bowen Disease: 18F-FDG PET-CT Findings.

Here, we report the case of cutaneous metastases from testicular diffuse large B-cell malignant lymphoma (DLBCL) concurrent with Bowen disease evaluated with 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT). A 60-year-old male underwent orchiectomy to remove his left testicle because of DLBCL. Multiple skin lesions appeared 1 month postoperatively. Furthermore, an intractable erythematous plaque localized to the right lower leg was present from 2 years before the operation. 18F-FDG PET-CT images revealed multiple skin lesions with marked FDG uptakes in the face, neck, and thigh of this patient, as well as a lower leg lesion with minimal FDG uptake. Biopsy of both lesions revealed cutaneous metastases from DLBCL and Bowen disease (BD) of the lower leg lesion. 18F-FDG PET-CT images following chemotherapy and resection of BD demonstrated no FDG uptake.