Herein, we evaluated a capacitor dosimeter under development by a manufacturer, which is designed to monitor the entrance dose in x-ray diagnosis and comprises a silicon x-ray diode (Si-XD), a 0.1 µF ...capacitor, and a dosimeter dock. The Si-XD is a high-sensitivity photodiode optimized for x-ray detection. The dosimeter was charged to 3.30 V using the dock before x-ray irradiation. The charging voltage was reduced by photocurrents flowing through the Si-XD during irradiation, and the discharging voltage was measured. For the fundamental characterization of this capacitor dosimeter, we investigated the x-ray tube-current and tube-voltage dependences of the measured dose using an industrial x-ray tube; the angular dependence was also investigated. A commercially available semiconductor dosimeter (RaySafe ThinX) was used for dose calibration. The doses were proportional to the tube current at a constant tube voltage of 100 kV and increased with increasing tube voltage at a constant tube current of 1.0 mA. The dose difference with respect to the commercially available semiconductor dosimeter was within 1.0% when the tube current was varied and it was within 3.0% when the tube voltage was varied. In the angular dependence measurement, a difference of up to 6.0% was observed as the angle varied from 0° to 355° in steps of 5°. The dose-calibration results indicated that the determination of the initial charging voltage was important for dose conversion using the capacitor dosimeter.
Abstract
In patients with various cancers, modified Glasgow prognostic score (mGPS) before treatment has predicted prognoses after antitumor therapy. This study aimed to assess whether pretreatment ...mGPS also has predictive value in patients with muscle-invasive bladder cancer (MIBC) after radiotherapy. A retrospective review accumulated 98 consecutive MIBC patients treated with definitive 3D-conformal radiotherapy from January 2011 to December 2016 in a single center. It included cT2-4bN0-3M0 patients with a median age of 79 years (range: 49 to 95 years). Radiotherapy was delivered at 60–66 Gy for bladder cancer. Patients were categorized in terms of their pretreatment serum albumin and C-reactive protein (CRP) values as mGPS_0, mGPS_1, and mGPS_2. Among them, cumulative overall survival (OS) rates were compared by Kaplan–Meier plots with log-rank tests. The number of patients with mGPS_0, mGPS_1, and mGPS_2 were 40, 40, and 18, respectively. The median follow-up time for all patients was 19 months (range: 2–73 months). The 2-year OS rate for all patients was 75.7%. The 2-year OS rates for mGPS_0, mGPS_1, and mGPS_2 were 85.1%, 71.3%, and 60.9%, respectively. Kaplan–Meier curves revealed a significantly higher cumulative OS rate for mGPS_0 compared with mGPS_1 and mGPS_2 (P = 0.003). Using multivariate Cox regression analysis, mGPS_0 and good performance status were associated with favorable OS rates, of which mGPS_0 was more significant (Hazard ratio 2.74, 95% CI 1.30–5.57, P = 0.008). Modified Glasgow prognostic score may be a novel biomarker that can predict survival in patients with MIBC after radiotherapy.
Enfortumab vedotin for urothelial carcinoma is a potentially effective anti-tumor drug that can be used in 3rd-line therapy or later, even in relatively advanced stages of the disease. Here, we ...present two cases of treatment using enfortumab vedotin with subsequent radiotherapy for primary lesions, and long-term disease control was achieved. The first case involved a 78-year-old man previously treated with pembrolizumab following gemcitabine plus carboplatin for lower ureteral carcinoma with multiple lung and lymph node metastases. Six months after the initiation of enfortumab vedotin, the primary tumor and metastases notably shrank. However, the primary tumor regrew, and radiotherapy was initiated along with enfortumab vedotin. The second case involved a 60-year-old man who was initially treated with avelumab following gemcitabine plus cisplatin for bladder cancer with multiple lymph node metastases. After two months of enfortumab vedotin, the primary and metastatic lesions shrunk. However, the primary tumor regrew, and radiotherapy was initiated. In both cases, the primary tumor and metastases recorded long-term shrinkage. The combination of radiotherapy and enfortumab vedotin may be an effective treatment option.
This case report highlights the need for clinicians to monitor patients with rhabdomyosarcoma for pancreatic metastasis to ensure that proper treatment is quickly provided, thereby improving ...outcomes.
This case report highlights the need for clinicians to monitor patients with rhabdomyosarcoma for pancreatic metastasis to ensure that proper treatment is quickly provided, thereby improving outcomes.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
This study investigated the effectiveness and safety of low-dose salvage craniospinal irradiation (CSI) for recurrent germinoma. We retrospectively reviewed long-term tumor control and late ...adverse effects in 15 recurrent germinoma patients treated at our hospital between 1983 and 2019. Following the first recurrence of germinoma, seven were treated with 24–30 Gy of salvage CSI, three underwent non-CSI, and five were treated with only chemotherapy. CSI achieved a significantly better recurrence-free survival rate after the first recurrence compared to other strategies (100% vs 33%, p < 0.001: log-rank test). To evaluate the safety of salvage CSI, we assessed the outcomes at the final follow-up of seven patients who received salvage CSI at first recurrence and three patients who received salvage CSI at second recurrence. The median follow-up period was 220 months after initial treatment. Five patients who received 40–50 Gy of radiation therapy or underwent multiple radiation therapy before salvage CSI were classified into Group A, whereas five patients treated with platinum-based chemotherapy and 24–32 Gy of radiation therapy to the primary site, whole ventricle, or whole brain were classified into Group B. In Group A, one had endocrine dysfunction and the other had visual dysfunction. None were socially independent. Meanwhile, in Group B, no endocrine or visual dysfunction was found, and three patients were socially independent. Salvage CSI achieved excellent tumor control in recurrent germinoma and was safe in patients initially treated with low-dose radiation therapy and chemotherapy.
To monitor patient-surface dose in intensity-modulated radiation therapy (IMRT), developed a novel capacitor dosimeter with a disposable USB-A mini-substrate consisting of a 0.22 μF capacitor and a ...silicon X-ray diode (Si-XD). The capacitor dosimeter consisted of a USB-A mini-substrate and a microcomputer dock. The capacitor in the substrate was charged to 3.30 V using the dock before 4 MV X-ray irradiation. The charging voltage was reduced by photocurrents flowing through the Si-XD during irradiation. After which the substrate was re-inserted into the dock, and the discharging voltage was measured. A Farmer-type ionization chamber (N30013, PTW) was used to convert the discharging voltages into absorbed dose (Gy). The IMRT study was performed using a custom-made head-neck phantom. The decrease in the charging voltage was found to be proportional to the X-ray dose, and the calibrated dose corresponded well to those obtained using the ionization chamber. The surface dose measured on the head-neck phantom were equivalent to those obtained from a treatment planning system. An inexpensive dosimeter with Si-XDs was developed, as a promising too. The results suggest for monitoring patient-surface dose during radiation therapy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PURPOSEWe aimed to assess radiomics approaches for estimating three pulmonary function test (PFT) results (forced expiratory volume in one second FEV1, forced vital capacity FVC, and the ratio of ...FEV1 to FVC FEV1/FVC) using data extracted from chest computed tomography (CT) images. METHODSThis retrospective study included 85 lung cancer patients (mean age, 75 years ±8; 69 men) who underwent stereotactic body radiotherapy between 2012 and 2020. Their pretreatment chest breath-hold CT and PFT data before radiotherapy were obtained. A total of 107 radiomics features (Shape: 14, Intensity: 18, Texture: 75) were extracted using two methods: extraction of the lung tissue (<-250 HU) (APPROACH 1), and extraction of small blood vessels and lung tissue (APPROACH 2). The PFT results were estimated using the least absolute shrinkage and selection operator regression. Pearson's correlation coefficients (r) were determined for all PFT results, and the area under the curve (AUC) was calculated for FEV1/FVC (<70 %). Finally, we compared our approaches with the conventional formula (Conventional). RESULTSFor the estimated FEV1/FVC, the Pearson's r were 0.21 (P =.06), 0.69 (P <.01), and 0.73 (P <.01) for Conventional, APPROACH 1, and APPROACH 2, respectively; the AUCs for FEV1/FVC (<70 %) were 0.67 (95 % confidence interval CI: 0.55, 0.79), 0.82 (CI: 0.72, 0.91; P =.047) and 0.86 (CI: 0.78, 0.94; P =.01), respectively. CONCLUSIONSThe radiomics approach performed better than the conventional equation and may be useful for assessing lung function based on CT images.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To evaluate the long-term efficacy and toxicity of definitive radiochemotherapy for solitary lymph node metastasis after curative surgery of esophageal cancer.
We performed a retrospective review of ...35 patients who underwent definitive radiochemotherapy at Tohoku University Hospital between 2000 and 2009 for solitary lymph node metastasis after curative esophagectomy with lymph node dissection for esophageal cancer. Radiotherapy doses ranged from 60 to 66 Gy (median, 60 Gy). Concurrent chemotherapy was platinum based in all patients. The endpoints of the present study were overall survival, cause-specific survival, progression-free survival, irradiated-field control, overall tumor response, and prognostic factors.
The median observation period for survivors was 70.0 months. The 5-year overall survival was 39.2% (median survival, 39.0 months). The 5-year cause-specific survival, progression-free survival, and irradiated-field control were 43.3%, 31.0% and 59.9%, respectively. Metastatic lesion, size of the metastatic lymph node, and performance status before radiochemotherapy were significantly correlated with prognosis. Complete response and partial response were observed in 22.9% and 57.1% of the patients, respectively. There was no Grade 3 or higher adverse effect based on the Common Terminology Criteria for Adverse Events (CTCAE v3.0) in the late phase.
Based on our study findings, approximately 40% of patients with solitary lymph node metastasis after curative resection for esophageal cancer have a chance of long-term survival with definitive radiochemotherapy.
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GEOZS, IJS, NUK, OILJ, UL, UM, UPUK
Background/Objectives: Particle beam therapy (PBT) was approved in April 2018 for head and neck malignancies and has since been introduced as a radical therapy for parotid malignancies. However, its ...prevalence and effectiveness in relation to surgical treatment have not been investigated. Methods: In this study, we evaluated 36 patients with parotid malignancy who underwent surgery (n = 26) or PBT (n = 10) and then analyzed the annual changes in the number of patients, survival rates, and clinical factors affecting prognosis. Results: Of the ten patients who opted for PBT, two and eight patients underwent PBT before and after 2018, respectively. There was a significant difference between these two groups of patients (p = 0.04). Of the ten patients who underwent PBT, five patients were recurrent cases; meanwhile, all twenty-six patients who underwent surgery were receiving initial treatment. Only one patient in each group had local recurrence after the treatment. Conclusions: The use of PBT as a radical therapy for parotid malignancies has been increasing since 2018, and patients with recurrent tumors tended to choose PBT. The outcome of the patients who underwent PBT did not seem to be inferior compared with those of the patients who underwent surgery. The histopathological type was a crucial issue in the outcomes of patients who underwent radical therapy for parotid malignancies.
Esophagectomy remains the mainstay treatment for esophageal cancer, although retrospective studies have suggested that chemoradiotherapy (CRT) is as effective as surgery. To determine whether CRT can ...substitute for surgery as the primary treatment modality, we performed a prospective direct comparison of outcomes after treatment in patients with resectable esophageal cancer who had received CRT and those who had undergone surgery.
Eligible patients had resectable T1-3N0-1M0 thoracic esophageal cancer. After the surgeon explained the treatments in detail, the patients selected either CRT (CRT group) or surgery (OP group). The CRT course consisted of two cycles of cisplatin and fluorouracil with split-course concurrent radiotherapy of 60Gy in 30 fractions. Patients with progressive disease during CRT and/or with persistent or recurrent disease after CRT underwent salvage resection.
Of 99 eligible patients with squamous cell carcinoma registered between January 2001 and December 2005, 51 selected CRT and 48 selected surgery. Of the patients in the CRT group, 13 (25.5%) underwent esophagectomy as salvage therapy. The 3- and 5-year survival rates were 78.3% and 75.7%, respectively, in the CRT group compared with 56.9% and 50.9%, respectively, in the OP group (p = 0.0169). Patients in the OP group had significantly more metastatic recurrence than those in the CRT group.
Treatment outcomes among patients with resectable thoracic esophageal squamous cell carcinoma were comparable or superior after CRT (with salvage therapy if needed) to outcomes after surgery alone.
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GEOZS, IJS, NUK, OILJ, UL, UM, UPUK
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