Although dose prediction for intensity modulated radiation therapy (IMRT) has been accomplished by a deep learning approach, delineation of some structures is needed for the prediction. We sought to ...develop a fully automated dose-generation framework for IMRT of prostate cancer by entering the patient CT datasets without the contour information into a generative adversarial network (GAN) and to compare its prediction performance to a conventional prediction model trained from patient contours.
We propose a synthetic approach to translate patient CT datasets into a dose distribution for IMRT. The framework requires only paired-images, i.e., patient CT images and corresponding RT-doses. The model was trained from 81 IMRT plans of prostate cancer patients, and then produced the dose distribution for 9 test cases. To compare its prediction performance to that of another trained model, we created a model trained from structure images. Dosimetric parameters for the planning target volume (PTV) and organs at risk (OARs) were calculated from the generated and original dose distributions, and mean differences of dosimetric parameters were compared between the CT-based model and the structure-based model.
The mean differences of all dosimetric parameters except for D98% and D95% for PTV were within approximately 2% and 3% of the prescription dose for OARs in the CT-based model, while the differences in the structure-based model were within approximately 1% for PTV and approximately 2% for OARs, with a mean prediction time of 5 seconds per patient.
Accurate and rapid dose prediction was achieved by the learning of patient CT datasets by a GAN-based framework. The CT-based dose prediction could reduce the time required for both the iterative optimization process and the structure contouring, allowing physicians and dosimetrists to focus their expertise on more challenging cases.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Highlights • We analyzed the impact of consolidation/tumor ratio (CTR) on the outcomes after SBRT for early lung cancer. • Local control rates were high for patients with a CTR < 1. • Disease-free ...survival rates were associated with the CTR. • CTR effectively predicts outcomes after SBRT.
Abstract
Background
There are few reports from Japan about the outcomes of intensity-modulated radiation therapy for localized prostate cancer. This study was aimed at assessing the efficacy and ...toxicity of intensity-modulated radiation therapy in patients with intermediate- or high-risk prostate cancer.
Methods
We conducted a review of the data, retrieved from our institutional database, of patients who had received intensity-modulated radiation therapy for localized prostate cancer at a radiation dose of 78 Gy in 39 fractions. Data of 201 patients with intermediate-risk prostate cancer and 311 patients with high-risk prostate cancer were analyzed.
Results
The median follow-up period after the completion of intensity-modulated radiation therapy was 100 months (range, 24–154). The rates of cause-specific survival, overall survival, metastasis-free survival and biochemical recurrence-free survival in the intermediate-risk patients were 99, 95, 95 and 94% at 5 years and 99, 91, 90 and 86% at 8 years, respectively; the corresponding rates in the high-risk patients were 100, 97, 91 and 84% at 5 years and 96, 92, 84 and 76% at 8 years, respectively. The crude incidence of late grade 2–3 genitourinary toxicity was 28.1%, and that of late grade 3 genitourinary toxicity was 2.0%. The crude incidence of late grade 2 gastrointestinal toxicity was 5.1%, and there were no cases of late grade 3 gastrointestinal toxicity.
Conclusions
Our data demonstrated that intensity-modulated radiation therapy is effective for patients with localized intermediate-risk or high-risk prostate cancer while having minimal toxicity.
This study evaluated the efficacy and toxicity of IMRT in 512 patients with locaized prostate cancer, and we demonstrated that clinical outcomes were satisfactory.
To explore a more effective treatment for localized nasal natural killer (NK)/T-cell lymphoma, we conducted a phase I/II study of concurrent chemoradiotherapy.
Treatments comprised concurrent ...radiotherapy (50 Gy) and 3 courses of dexamethasone, etoposide, ifosfamide, and carboplatin (DeVIC). Patients with a newly diagnosed stage IE or contiguous IIE disease with cervical node involvement and a performance status (PS) of 0 to 2 were eligible for enrollment. The primary end point of the phase II portion was a 2-year overall survival in patients treated with the recommended dose.
Of the 33 patients enrolled, 10 patients were enrolled in the phase I portion and a two thirds dose of DeVIC was established as the recommended dose. Twenty-seven patients (range, 21 to 68; median, 56 years) treated with the recommended dose showed the following clinical features: male:female, 17:10; stage IE, 18; stage IIE, 9; B symptoms present, 10; elevated serum lactate dehydrogenase, 5; and PS 2, 2. With a median follow-up of 32 months, the 2-year overall survival was 78% (95% CI, 57% to 89%). This compared favorably with the historical control of radiotherapy alone (45%). Of the 26 patients assessable for a response, 20 (77%) achieved a complete response, with one partial response. The overall response rate was 81%. The most common grade 3 nonhematologic toxicity was mucositis related to radiation (30%). No treatment-related deaths were observed.
Concurrent chemoradiotherapy using multidrug resistance-nonrelated agents and etoposide is a safe and effective treatment for localized nasal NK/T-cell lymphoma and warrants further investigation.
To evaluate late cardiopulmonary toxicities after concurrent chemoradiotherapy (CCRT) for esophageal carcinomas.
From February 2002 through April 2005, 74 patients with clinical Stage I-IVB carcinoma ...of the esophagus were treated with CCRT. Sixty-nine patients with thoracic squamous cell carcinoma were the core of this analysis. Patients received 60 Gy of radiation therapy in 30 fractions over 8 weeks, including a 2-week break, and received 2 cycles of fluorouracil/cisplatin chemotherapy concomitantly. Initial radiation fields included primary tumors, metastatic lymph nodes, and supraclavicular, mediastinal, and celiac nodes areas. Late toxicities were assessed with the late radiation morbidity scoring scheme of the Radiation Therapy Oncology Group/European Organiation for Research and Treatment of Cancer.
The median age was 67 years (range, 45-83 years). The median follow-up time was 26.1 months for all patients and 51.4 months for patients still alive at the time of analysis. Five cardiopulmonary toxic events of Grade 3 or greater were observed in 4 patients, Grade 5 heart failure and Grade 3 pericarditis in 1 patient, and Grade 3 myocardial infarction, Grade 3 radiation pneumonitis, and Grade 3 pleural effusion. The 2-year cumulative incidence of late cardiopulmonary toxicities of Grade 3 or greater for patients 75 years or older was 29% compared with 3% for younger patients (p = 0.005).
The CCRT used in this study with an extensive radiation field is acceptable for younger patients but is not tolerated by patients older than 75 years.
Purpose
The Japanese Breast Cancer Society (JBCS) Clinical Practice Guideline was revised in 2018. This article describes the revise points in the section on radiation therapy (RT).
Methods and ...materials
The JBCS formed task force to update the JBCS Clinical Practice Guideline 2015 edition. Background questions (BQs) deal with standard treatments of breast cancer in clinical practice. Clinical questions (CQs) highlight the important treatments in which controversy remains. The task force for RT section addressed the 10 BQs, the 10 CQs, and the 4 Future reseach questions (FQs). For each CQ, systematic literature reviews and meta-analyses were conducted, and recommendations, strength of recommendation and strength of evidence were determined according to the protocol in Morizane et al. (Minds Handbook for Clinical Practice Guideline Development, 2014).
Results
The recommendations, the strength of recommendation and the strength of evidence were determined based on the systematic literature reviews and the meta-analyses for each CQ.
Conclusion
The JBCS updated the Clinical Practice Guideline. RT represents a significant portion of the breast cancer treatment, and these recommendations regarding RT will be useful in individualized, shared decision making between physicians and patients.
This study was aimed at assessing the feasibility and toxicity of using stereotactic body radiation therapy (SBRT) for reirradiation of spinal metastatic tumors. We conducted a retrospective review, ...from our institutional database, of the data of patients who received reirradiation, with overlap of some prescribed isodose lines to the vertebra from the initial radiation therapy, between 2007 and 2019. We identified 40 patients with spinal metastatic tumors, of whom 2 had 2 metastatic vertebral lesions each, totaling up to 42 target lesions. The median dose to spinal cord at the initial radiation therapy was 30 Gy. SBRT based on the intensity-modulated radiation therapy (IMRT) technique was used for reirradiation to spare the spinal cord. All patients received a prescription dose of 25 Gy in 5 fractions to the planning target volume (PTV). Among the 40 cases who had pain, pain relief was obtained in 24 (60%) after reirradiation. Neurologic improvement was obtained in 8 of 15 cases (53%). The adverse events were evaluated using the Common Terminology Criteria for Adverse Events Version 5.0. Reirradiation was well-tolerated, with only 2 patients experiencing adverse events ≥grade 2 in severity, including 1 patient with grade 3 pain, and another patient with grade 3 spinal fracture. None of the patients developed radiation myelopathy. Our data demonstrated that reirradiation of spinal metastasis using SBRT provided effective pain relief and neurologic improvement, with minimal toxicity.
To compare five radiotherapy methods for prostate cancer.
During 2005-2018, the data of patients with non-metastatic prostate cancer were retrospectively analysed. Patients were treated with ...high-dose-rate brachytherapy (HDR-BT); low-dose-rate brachytherapy (LDR-BT); or external-beam radiotherapy (EBRT), including conventionally fractionated radiotherapy (CFRT), moderate-hypofractionated radiotherapy (MHRT), and ultra-hypofractionated radiotherapy (UHRT).
In total, 496 patients (149, HDR-BT; 100, LDR-BT; 100, CFRT; 97, MHRT, and 50, UHRT) with a median follow-up of 4.3 years were enrolled. The incidence of grade ≥2 acute genitourinary toxicities was significantly lower with HDR-BT (p<0.001) than with any other radiotherapy. The cumulative incidence of late grade ≥2 genitourinary toxicities was the highest with UHRT and significantly higher (p=0.005) with UHRT than with HDR-BT. Higher symptom score peaks were noted 4 weeks after therapy for LDR-BT than for EBRT.
Physician-recorded toxicities were slightly lower with HDR-BT and patient-reported outcomes tended to be worse with LDR-BT.
Prognosis of patients with localized nasal extranodal natural killer/T‐cell lymphoma, nasal type (ENKL) has been improved by non‐anthracycline‐containing treatments such as concurrent ...chemoradiotherapy (CCRT). However, some patients experience early disease progression. To clarify the clinical features and outcomes of these patients, data from 165 patients with localized nasal ENKL who were diagnosed between 2000 and 2013 at 31 institutes in Japan and who received radiotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin (RT‐DeVIC) were retrospectively analyzed. Progression of disease within 2 years after diagnosis (POD24) was used as the definition of early progression. An independent dataset of 60 patients with localized nasal ENKL who received CCRT at Samsung Medical Center was used in the validation analysis. POD24 was documented in 23% of patients who received RT‐DeVIC and in 25% of patients in the validation cohort. Overall survival (OS) from risk‐defining events of the POD24 group was inferior to that of the reference group in both cohorts (P < .00001). In the RT‐DeVIC cohort, pretreatment elevated levels of serum soluble interleukin‐2 receptor (sIL‐2R), lactate dehydrogenase, C‐reactive protein, and detectable Epstein‐Barr virus DNA in peripheral blood were associated with POD24. In the validation cohort, no pretreatment clinical factor associated with POD24 was identified. Our study indicates that POD24 is a strong indicator of survival in localized ENKL, despite the different CCRT regimens adopted. In the treatment of localized nasal ENKL, POD24 is useful for identifying patients who have unmet medical needs.
One‐quarter of patients with localized NK/T‐cell lymphoma experienced progression of disease within 24 months after diagnosis (POD24) by concurrent chemoradiotherapy (CCRT). POD24 was strongly associated with short overall survival, despite the different CCRT regimens adopted.
Objective: The aim of this study was to investigate the influence of chemoradiotherapy (CRT) on nutritional status and the association between changes in nutritional status and clinical outcomes ...(treatment completion, adverse events, perioperative complications, and relapse-free survival RFS) in patients with locally advanced rectal cancer (LARC).
Methods: In this multicenter, phase II study, 41 patients with LARC underwent CRT for 5 wk, followed by a 6- to 8-wk interval before surgery. Body weight, body mass index (BMI), lean body mass, serum albumin, and prealbumin levels were measured before (pre-), during, and after CRT, and before surgery. Changes in these data and scores on the Malnutrition Universal Screening Tool (MUST) were calculated based on pre-CRT status.
Results: Twelve patients (29.3%) experienced body weight loss (BWL) ≥5% (defined as malnutrition) after CRT (P < 0.001) and before surgery (P = 0.035). Significant changes were seen in serum albumin levels and BMI during and after CRT (P < 0.001), and in MUST scores after CRT (P = 0.003) and before surgery (P = 0.035). Treatment completion was significantly associated with BWL (P = 0.028), MUST score (P = 0.013), and decreased serum albumin level (P = 0.001) after CRT. Regarding adverse events, MUST score before surgery (P = 0.009) and serum albumin level after CRT (P = 0.002) were significantly associated with diarrhea severity. Serum albumin level during CRT was associated with the onset of neutropenia (P = 0.005). No association was found between BWL and RFS.
Conclusions: These findings suggest that malnutrition and changes in nutritional status are not only commonly observed after CRT, but also associated with treatment completion and adverse events.
•This is a prospective study regarding chemoradiotherapy for rectal cancer.•Malnutrition is a common side effect of chemoradiotherapy for rectal cancer.•Malnutrition is associated with treatment completion and adverse events.
PDF
