Evaluation of Setup Errors at the Skin Surface Position for Whole Breast Radiotherapy of Breast Cancer Patients

We used image-processing software to analyze the setup errors at the skin surface position of breast cancer patients (n=66) who underwent post-operative whole breast irradiation at our hospital in 2014-2015. The sixty-six digital reconstructed radiographs (DRR) were created at the treatment planning for each patient. The lineacgraphies (n=377) were taken after the patients’ setup during radiotherapy. The lineacgraphies and DRR were superimposed at the skin surface position for each patient with the image-processing software. We measured the deviations of the isocenters for the nipple-lung (X) direction and craniocaudal (Y) direction and the deviation of the rotation angle of the XY axes between the lineacgraphy and DRR on the superimposed images. The systematic error (μ, Σ) and random error (σ) were calculated from the X and Y deviations and rotation angle deviation. The μ of X, Y, and rotation angle were 0.01 mm, −1.2 mm, and 0.05°, respectively. The Σ of X, Y, and rotation angle were 1.8 mm, 1.5 mm, and 0.9°, respectively. The σ of X, Y, and rotation angle were 2.0 mm, 1.5 mm, and 1.0°, respectively. Our analyses thus revealed that evaluations using image-processing software at the skin surface position in routine breast radiotherapy result in sufficiently small setup errors

Estimation of radioactivity in single photon emission computed tomography for sentinel lymph node biopsy in a torso phantom study

Objectives: Number of lymph nodes to be removed are determined from residual counts. Estimating residual radioactivity in lymphatic nodes before a biopsy in advance is useful for reducing surgical operation time. The purpose of this study was to estimate total radioactivity of a small hot spot in single-photon emission computed tomography (SPECT) of a torso phantom. Methods: Cross-calibration study was performed to convert counts in SPECT images to radioactivity. A simulation study was performed to estimate the size of volume of interest (VOI) covering a hot spot corrupted with full width at half maximum (FWHM) between 8 and 16 mm. The estimation of total radioactivity was validated in a torso phantom study using small sources. Results: True radioactivity was approximately equal to integrated values of hot spots using the VOI with a diameter of 40 mm in our simulation study. The difference was less than18% in cases of more than 9.4 kBq. Conclusions: The total radioactivity in small sources simulating a typical sentinel node was estimated from SPECT images using a VOI of 40 mm in a torso phantom study. Because the difference from actual values were less than 10% on average when radioactivities were more than 9.4 kBq, the total radioactivity of a lymph node can be estimated in a clinical examination

Successful treatment of COVID‐19‐related acute respiratory distress syndrome with a rare blood type: A case report

Extracorporeal membrane oxygenation is indispensable for critically severe COVID-19 patients. However, it would be inapplicable to patients with a rare blood type or blood transfusion refusal. In that case, severely conservative fluid management with the sacrifice of renal functions and hydrocortisone therapy should be considered for better oxygenation

New field‑in‑field with two reference points method for whole breast radiotherapy: Dosimetric analysis and radiation‑induced skin toxicities assessment

The usefulness of the field‑in‑field with two reference points (FIF w/ 2RP) method, in which the dose reference points are set simultaneously at two positions in the irradiation field and the high‑dose range is completely eliminated, was examined in the present study with the aim of decreasing acute skin toxicity in adjuvant breast radiotherapy (RT). A total of 573 patients with breast cancer who underwent postoperative whole breast RT were classified into 178 cases with wedge (W) method, 142 cases with field‑in‑field without 2 reference points (FIF w/o 2RP) method and 253 cases with FIF w/ 2RP method. Using the FIF w/ 2RP method, the high‑dose range was the lowest among the three irradiation methods. The planning target volume (PTV) V105% and the breast PTV for evaluation (BPe) V105% decreased to 0.09 and 0.10%, respectively. The FIF w/ 2RP method vs. the FIF w/o 2RP method had a strong association (η) with PTV V105% (η=0.79; P<0.001) and BPe V105% (η=0.76; P<0.001). The FIF w/ 2RP method had a significant impact on lowering the skin toxicity grade in weeks 3 and 4, and increasing the occurrence of skin toxicity grade 0. The FIF w/ 2RP method vs. the W method had a moderate association with skin toxicity grade at week 3 (η=0.49; P<0.001). Using the FIF w/ 2RP method, the high‑dose range V105% of the target decreased to 0%, and skin adverse events were decreased in conjunction. For patients with early‑stage breast cancer, particularly patients with relatively small‑sized breasts, the FIF w/ 2RP method may be an optimal irradiation method

Investigation into the Effect of Breast Volume on Irradiation Dose Distribution in Asian Women with Breast Cancer

Reports on irradiation dose distribution in breast cancer radiotherapy with sufficient sample size are limited in Asian patients. Elucidating dose distribution in Asian patients is particularly important as their breast volume differs compared to patients in Europe and North America. Here, we examined dose distribution in the irradiation field relative to breast volume for three irradiation methods historically used in our facility. We investigated the influence of breast volume on each irradiation method for Asian women. A total of 573 women with early-stage breast cancer were treated with breast-conserving surgery and adjuvant radiotherapy. Three methods were compared: wedge (W), field-in-field (FIF), and wedge-field-in-field (W-FIF). In patients with small breast volume, FIF decreased low- and high-dose areas within the planning target volume, and increased optimal dose area more than W. In patients with medium and large breast volumes, FIF decreased high-dose area more than W. The absolute values of correlation coefficients of breast volume to low-, optimal-, and high-dose areas and mean dose were significantly lower in FIF than in W. The correlation coefficients of V107% were 0.00 and 0.28 for FIF and W, respectively. FIF is an excellent irradiation method that is less affected by breast volume than W in Asian breast cancer patients

Higher Serum Brain-Derived Neurotrophic Factor Levels Are Associated With a Lower Risk of Cognitive Decline: A 2-Year Follow Up Study in Community-Dwelling Older Adults

ObjectiveTo assess the relationship of serum brain-derived neurotrophic factor (BDNF) levels with the subsequent short-term decline in cognitive functioning in community-dwelling older adults.DesignTwo-year prospective, observational study.Setting and ParticipantsThe study included 405 adults aged 65–84 years, initially free of a dementia diagnosis who were living in Tokyo, Japan.MethodsParticipants underwent health assessments at baseline (2011) and follow-up (2013). Serum BDNF levels and scores from the Montreal Cognitive Assessment-Japanese version (MoCA-J) were systematically measured. Logistic regression was used to estimate the odds of cognitive decline between baseline and follow-up assessments in the full MoCA-J scale (operationally defined as a decrease of two or more points), as well as in MoCA-J subscales (decline of one or more points in a specific subscale), as a function of serum BDNF level, adjusting for baseline demographics, prevalent chronic diseases, and baseline cognitive scores.ResultsAmong individuals who performed worse on the full MoCA-J at baseline (i.e., scores in the bottom quartile [≤21], which is consistent with a mild cognitive impairment status), but not among those who performed better (top 3 quartiles), those with highest baseline serum BDNF levels (top quartile) had lower odds of subsequent decline in the full MoCA-J scale than those with lowest (bottom quartile); i.e., odds ratio (OR): 0.10 (95% confidence interval [CI]: 0.02–0.62; p = 0.013). Regarding MoCA-J subscales, adjusted odds of decline in the executive function subscale, but not in the other five subscales, were substantially low among those with highest baseline serum BDNF levels (top quartile), as compared to those with the lowest (bottom quartile), i.e., OR: 0.27 (95% CI:0.13–0.60; p &lt; 0.001).Conclusion and ImplicationsHigher serum BDNF levels were associated with a lower risk of decline in cognitive function in a sample of community-dwelling older Japanese adults. Risk varied across cognitive subdomains and according to baseline cognition. This warrants further research to evaluate the added-value of serum BDNF in health promotion initiatives directed toward cognitive decline prevention in community-dwelling older adults

Dose-Volume Parameters Predict Radiation Pneumonitis after Surgery with Induction Concurrent Chemoradiotherapy for Non-small Cell Lung Cancer

To clarify the relationship between dose-volume histogram (DVH) parameters and radiation pneumonitis (RP) after surgery in cases of non-small cell lung cancer (NSCLC) treated with induction concurrent chemoradiotherapy (CCRT). Patients with NSCLC treated with induction CCRT (chemotherapy: cisplatin and docetaxel; radiotherapy: 2.0 Gy fractions once daily for a total of 46 Gy) before surgery were reviewed. We calculated the percentage of lung volume receiving at least 20 Gy (V20) and the mean lung dose (MLD) for the total lung volume and the lung remaining after resection. Factors affecting the incidence of RP at grade 2 or higher (≥ G2 RP) were analyzed. Eighteen of 49 patients (37%) experienced ≥G2 RP. The V20 and MLD for the lung remaining after resection (V20r and MLDr) were significant predictors according to the multivariate analysis (p=0.007 and 0.041, respectively). The incidence of ≥G2 RP was 8% in patients with V20r<10%, and 13% in patients with MLDr<5.6 Gy, respectively. The optimal approach to reduce the rate of postoperative RP in patients with induction CCRT for NSCLC is to keep the V20r below 10% and/or the MLDr below 5.6 Gy in the radiotherapy planning