Dataset Information

Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton.

ABSTRACT:

Objectives

In a previous study of hepatic toxicity, the following three factors were identified to predict the benefits of proton beam therapy (PBT) for hepatocellular carcinomas (HCCs) with a maximum diameter of ≤5 cm and Child-pugh grade A (CP-A): number of tumors (1 vs ≥2), the location of tumors (hepatic hilum or others), and the sum of the diameters of lesions. The aim of this study is to analyze the association between these three factors and hepatic toxicity.

Methods

We retrospectively reviewed patients of CP-A treated with PBT or photon stereotactic body radiotherapy (X-ray radiotherapy, XRT) for HCC ≤5 cm. For normal liver dose, the V5, V10, V20 (volumes receiving 5, 10, and 20 Gy at least), and the mean dose was evaluated. The albumin-bilirubin (ALBI) and CP score changes from the baseline were evaluated at 3 and 6 months after treatment.

Results

In 89 patients (XRT: 48, PBT: 41), those with two or three (2-3) predictive factors were higher normal liver doses than with zero or one (0-1) factor. In the PBT group, the ALBI score worsened more in patients with 2-3 factors than those with 0-1 factor, at 3 months (median: 0.26 vs 0.02, p = 0.032) and at 6 months (median: 0.35 vs 0.10, p = 0.009). The ALBI score change in the XRT group and CP score change in either modality were not significantly different in the number of predictive factors.

Conclusion

The predictive factor numbers predicted the ALBI score change in PBT but not in XRT.

Advances in knowledge

This study suggest that the number of predictive factors previously identified (0-1 vs 2-3) were significantly associated with dosimetric parameters of the normal liver in both modalities. In the proton group, the number of predictive factors was associated with a worsening ALBI score at 3 and 6 months, but these associations were not found in the photon SBRT group.

SUBMITTER: Uchinami Y

PROVIDER: S-EPMC10078862 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature

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Publications

Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton.

Uchinami Yusuke Y Katoh Norio N Abo Daisuke D Morita Ryo R Taguchi Hiroshi H Fujita Yoshihiro Y Kanehira Takahiro T Suzuki Ryusuke R Miyamoto Naoki N Takao Seishin S Matsuura Taeko T Sho Takuya T Ogawa Koji K Orimo Tatsuya T Kakisaka Tatsuhiko T Kobashi Keiji K Aoyama Hidefumi H

The British journal of radiology 20230123 1144

<h4>Objectives</h4>In a previous study of hepatic toxicity, the following three factors were identified to predict the benefits of proton beam therapy (PBT) for hepatocellular carcinomas (HCCs) with a maximum diameter of ≤5 cm and Child-pugh grade A (CP-A): number of tumors (1 vs ≥2), the location of tumors (hepatic hilum or others), and the sum of the diameters of lesions. The aim of this study is to analyze the association between these three factors and hepatic toxicity.<h4>Methods</h4>We ret ...[more]

PMID: 36633335

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Project description:PurposeTo predict the organ at risk (OAR) dose levels achievable with proton beam therapy (PBT), solely based on the geometric arrangement of the target volume in relation to the OARs. A comparison with an alternative therapy yields a prediction of the patient-specific benefits offered by PBT. This could enable physicians at hospitals without proton capabilities to make a better-informed referral decision or aid patient selection in model-based clinical trials.Methods and materialsSkull-base tumors were chosen to test the method, owing to their geometric complexity and multitude of nearby OARs. By exploiting the correlations between the dose and distance-to-target in existing PBT plans, the models were independently trained for 6 types of OARs: brainstem, cochlea, optic chiasm, optic nerve, parotid gland, and spinal cord. Once trained, the models could estimate the feasible dose-volume histogram and generalized equivalent uniform dose (gEUD) for OAR structures of new patients. The models were trained using 20 patients and validated using an additional 21 patients. Validation was achieved by comparing the predicted gEUD to that of the actual PBT plan.ResultsThe predicted and planned gEUD were in good agreement. Considering all OARs, the prediction error was +1.4 ± 5.1 Gy (mean ± standard deviation), and Pearson's correlation coefficient was 93%. By comparing with an intensity modulated photon treatment plan, the model could classify whether an OAR structure would experience a gain, with a sensitivity of 93% (95% confidence interval: 87%-97%) and specificity of 63% (95% confidence interval: 38%-84%).ConclusionsWe trained and validated models that could quickly and accurately predict the patient-specific benefits of PBT for skull-base tumors. Similar models could be developed for other tumor sites. Such models will be useful when an estimation of the feasible benefits of PBT is desired but the experience and/or resources required for treatment planning are unavailable.

Project description:PurposeAdvanced non-small cell lung cancer (NSCLC) is still a challenging indication for conventional photon radiotherapy. Proton therapy has the potential to improve outcomes, but proton treatment slots remain a limited resource despite an increasing number of proton therapy facilities. This work investigates the potential benefits of optimally combined proton-photon therapy delivered using a fixed horizontal proton beam line in combination with a photon Linac, which could increase accessibility to proton therapy for such a patient cohort.Materials and methodsA treatment planning study has been conducted on a patient cohort of seven advanced NSCLC patients. Each patient had a planning computed tomography scan (CT) and multiple repeated CTs from three different days and for different breath-holds on each day. Treatment plans for combined proton-photon therapy (CPPT) were calculated for individual patients by optimizing the combined cumulative dose on the initial planning CT only (non-adapted) as well as on each daily CT respectively (adapted). The impact of inter-fractional changes and/or breath-hold variability was then assessed on the repeat breath-hold CTs. Results were compared to plans for IMRT or IMPT alone, as well as against combined treatments assuming a proton gantry. Plan quality was assessed in terms of dosimetric, robustness and NTCP metrics.ResultsCombined treatment plans improved plan quality compared to IMRT treatments, especially in regard to reductions of low and medium doses to organs at risk (OARs), which translated into lower NTCP estimates for three side effects. For most patients, combined treatments achieved results close to IMPT-only plans. Inter-fractional changes impact mainly the target coverage of combined and IMPT treatments, while OARs doses were less affected by these changes. With plan adaptation however, target coverage of combined treatments remained high even when taking variability between breath-holds into account.ConclusionsOptimally combined proton-photon plans improve treatment plan quality compared to IMRT only, potentially reducing the risk of toxicity while also allowing to potentially increase accessibility to proton therapy for NSCLC patients.

Project description:BackgroundMost patients diagnosed with renal cancer today present with small renal masses (SRMs). Although these patients have a low risk of dying from their disease and many are followed with active surveillance protocols, a small subset of renal cell carcinomas (RCCs) behave aggressively. Knowledge regarding features of aggressive behavior would enable better adoption of active surveillance strategies among these patients.ObjectiveWe sought to improve prognostic models to predict metastasis-free survival after nephrectomy through focused analyses of clinicopathologic characteristics of SRMs associated with adverse outcomes.Design, setting, and participantsWe identified consecutive patients with surgically resected SRMs (≤4 cm) at the University of Texas Southwestern Kidney Cancer Program between 1998 and 2020. In addition, we evaluated the ability of SRMs to form tumors when implanted in mice, an indicator of tumor aggressiveness.Outcome measurements and statistical analysisWe examined the clinicopathologic factors associated with metastasis including prospectively performed BAP1 immunohistochemistry at our Clinical Laboratory Improvement Amendments laboratory. Multivariable Cox proportional hazard regression was used to predict metastasis-free survival.Results and limitationsA total of 3900 evaluable nephrectomies (from 3674 ethnically diverse patients) were identified, of which 1984 (51%) were SRMs including 1720 RCC. Of these patients with RCC (SRMRCC), 1576 did not have synchronous or metachronous larger RCCs and among these, 37 (2%) developed metastases. SRMRCC that metastasized were significantly enriched for aggressive morphologic phenotypes and engrafted in mice at comparable rates as larger metastatic tumors. BAP1 loss remained significantly associated with metastasis-free survival after accounting for TNM (tumor-node-metastasis) stage and SSIGN (stage, size, grade, and necrosis) score in multivariable analysis.ConclusionsWe identified clinicopathologic features that influence metastasis-free survival for patients with SRMRCC. If validated independently, these data should assist with patient prognosis and help with active surveillance strategies.Patient summaryWe report the identification of features of aggressiveness in small renal tumors that influence the likelihood of metastases after surgery.

Project description:Background Radiotherapy (RT) for thymic epithelial tumors (TET) is indicated postoperatively for advanced/aggressive disease or incomplete resection, or as primary treatment in inoperable patients. In selected patients, proton therapy spares better normal tissues compared to standard photon treatment, and therefore has a high potential to reduce toxicity. The aim of this study is to compare photon and proton plans regarding doses and normal tissue complication probability (NTCP), as a validated surrogate for toxicity. Methods Patients with TET referred for radiotherapy from 08.2019–03.2022 were included. Intensity-modulated proton therapy (IMPT) and volumetric-arc photon therapy (VMAT) plans were compared for mean doses to the lungs (MLD), heart (MHD) and esophagus (MED) (using Wilcoxon signed ranks test), and normal tissue complication probability (NTCP) with endpoints radiation pneumonitis (grade ≥2), cardiac toxicity (major coronary events), acute dysphagia (grade ≥2) and since 03.2022 secondary breast cancer. VMAT plans consisted typically of 2–3 partial 6 MV arcs in the anterior region, and the dose was prescribed to the PTV. IMPT plans were typically administered with 3 or 4 anterior and anterior-oblique beams, using robust optimization. Results Twenty-four TET-patients had a VMAT-IMPT comparison (17 thymoma/4 thymic carcinoma) with Masaoka-Koga stages IIA–IVB. Mean age was 61 years. Average MLD, MHD and MED decreased significantly with IMPT (from 9.4 to 5.4 Gy, from 9.0 tot 6.6 Gy and from 7.4 to 2.0 Gy, respectively). Average NTCP-values for radiation pneumonitis, cardiac toxicity and dysphagia all decreased with IMPT compared to VMAT from 11.6% to 7.1%, from 16.3% to 14.6% and from 15.5% to 3.4%, respectively. Average NTCP-difference favoring proton therapy was 4.5% (range, 0.6% to 15.9%) for radiation pneumonitis, 1.7% (−0.1% to 4.9%) for cardiac toxicity and 12.1% (−0.3% to 43.4%) for dysphagia. Seventeen patients (71%) had a significantly lower NTCP with IMPT for at least one of the endpoints and qualified for reimbursement; 13 of these were treated with protons at our centre. Conclusions IMPT significantly reduced mean doses to lungs, heart and esophagus in all patients compared with VMAT, resulting in a significant reduction of NTCP for at least one endpoint in 71% of patients.

Dataset Information

Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton.

Objectives

Methods

Results

Conclusion

Advances in knowledge

Publications

Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton.

Similar Datasets

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