International Journal of Radiation Oncology Biology Physics最新文献

Objective: To evaluate the efficacy and safety of docetaxel/cisplatin chemotherapy followed by pelvic radiation therapy after staging surgery in patients with high-risk endometrial cancer.

Methods: In this open-label, single-arm, phase 2 trial conducted at two South Korean centers, we enrolled patients with histologically confirmed endometrial cancer who had undergone staging surgery. Inclusion criteria were based on FIGO Staging 2009: stage I patients with ≥2 risk factors (grade 3, positive lymphovascular invasion, more than half of myometrium invasion); stage IB and II patients with clear cell or serous adenocarcinoma; stage II patients post-type 1 hysterectomy; and patients at stage III. Patients underwent three cycles of chemotherapy with docetaxel (70 mg/m2) and cisplatin (60 mg/m2) followed by pelvic radiation therapy ranging from 45 to 50.4 Gy. Disease status and adverse events were evaluated using RECIST 1.1 and CTCAE 4.0, respectively, with scheduled imaging and assessments throughout the study.

Results: A total of 62 patients were included in this study and were followed for a median duration of 65 months (IQR: 48-86). The progression-free survival rates at 1, 3, and 5 years were 98.4%, 86.9%, and 79.1%, respectively. The overall survival rates at 1, 3, and 5 years were 98.4%, 96.4%, and 96.4%, respectively. Following chemotherapy, 62.9% of patients developed severe neutropenia, with 3.2% having grade 3 or 4 anemia. Common mild side effects included nausea (58.1%) and alopecia (38.7%). Post-radiation, 16.7% experienced grade 3 neutropenia, and a few had grade 1 or 2 anemia (3.3%), with most other side effects being mild and no critical toxicities reported.

Conclusion: Patients with endometrial cancer with high-risk factors could benefit from adjuvant chemotherapy using docetaxel/cisplatin, followed by radiation therapy, with manageable toxicities.

Purpose: To develop a deep learning (DL) method exploiting active learning and source-free domain adaptation for gross tumor volume (GTV) delineation in nasopharyngeal carcinoma (NPC), addressing the variability and inaccuracy when deploying segmentation models in multi-center and multi-rater settings.

Materials and methods: 1057 MRI scans of NPC patients from five hospitals were retrospectively collected and annotated by experts from the same medical group with consensus for multi-center adaptation evaluation. One dataset was used for model development (source domain), with the remaining four for adaptation testing (target domains). Meanwhile, another 170 NPC patients with annotations delineated by four independent experts were built for multi-rater adaptation evaluation. We evaluated the pre-trained model's migration ability to the four multi-center and four multi-rater target domains. Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95) and other metrics were used for quantitative evaluations.

Results: In the adaptation of dataset5 to other datasets, our source-free active learning adaptation method only requires limited labeled target samples (only 20%) to achieve a median DSC ranging from 0.70 to 0.86 and a median HD95 ranging from 3.16mm to 7.21mm for four target centers, and 0.78 to 0.85 and 3.64mm to 6.00mm for four multi-rater datasets. For DSC, our results for three of four multi-center datasets and all multi-rater datasets showed no statistical difference compared to the fully supervised U-Net model (P-values > 0.05) and significantly surpassed comparison models for three multi-center datasets and all multi-rater datasets (P-values < 0.05). Clinical assessment showed that our method-generated delineations can be used both in multi-center and multi-rater scenarios after minor refinement (revision ratio < 10% and median time < 2 minutes).

Conclusion: The proposed method effectively minimizes domain gaps and delivers encouraging performance compared with fully supervised learning models with limited labeled training samples, offering a promising and practical solution for accurate and generalizable GTV segmentation in NPC.

Introduction: Brain metastases (BMs) affect an increasing number of cancer patients and are typically managed with stereotactic radiosurgery (SRS). Our institution advocates the use of Personalized Ultrafractionated Stereotactic Adaptive Radiotherapy (PULSAR), where radiation is delivered in high-dose pulses at extended intervals allowing for treatment adaptation and easy concurrent systemic therapy integration. We explore the integration of PULSAR with central nervous system (CNS)- active drugs (CNS-aDs).

Methods: This study involved a retrospective evaluation of patients treated with PULSAR using Gamma Knife from 2018-2024. We collected demographic, clinical, and specific treatment details, outcomes such as local failure (LF) and toxicity rates. Cumulative incidence analysis for local failure and toxicity, considering death a competing risk, and Kaplan-Meier survival analysis for overall survival (OS) were conducted.

Results: Analysis included 109 lesions treated with PULSAR, predominantly in patients with lung and breast cancer. The median follow-up was 1.72. Median OS was not reached. The 1- and 2-year LF rates were 5% and 8.9%, respectively, and 3.4% and 5.5% with concurrent CNS-aDs (cCNS-aDs). BMs > 2 cm had LF rates of 9.4% at two years. No LFs were observed in BMs > 2 cm treated with the combined PULSAR+CNS-aDs approach at 2.5 years. Univariate analysis indicated CNS-aD and radioresponsive histologies were associated with decreased LR rates. The two-year grade 3+ toxicity rate for PULSAR was 8.7%, with no increase in toxicity with cCNS-aDs.

Conclusion: The integration of PULSAR with CNS-aDs appears to offer excellent local control for larger brain metastases with limited toxicity. These promising results merit further prospective investigation to validate the findings and potentially establish new treatment protocols.

Purpose: Historically, spot scanning proton therapy (SSPT) treatment planning utilizes dose volume constraints and linear-energy-transfer (LET) volume constraints separately to balance tumor control and organs-at-risk (OARs) protection. We propose a novel dose-LET volume constraint (DLVC)-based robust optimization (DLVCRO) method for SSPT in treating prostate cancer to obtain a desirable joint dose and LET distribution to minimize adverse events (AEs).

Methods: DLVCRO treats DLVC as soft constraints that control the shapes of the dose-LET volume histogram (DLVH) curves. It minimizes the overlap of high LET and high dose in OARs and redistributes high LET from OARs to targets in a user defined way. Ten prostate cancer patients were included in this retrospective study. Rectum and bladder were considered as OARs. DLVCRO was compared with the conventional robust optimization (RO) method. Plan robustness was quantified using the worst-case analysis method. Besides the dose-volume histogram (DVH) indices, the analogous LET-volume histogram (LETVH), extra-biological-dose (the product of per voxel dose and LET)-volume histogram (xBDVH) indices characterizing the joint dose/LET distributions and DLVH indices were also used. The Wilcoxon signed rank test was performed to measure statistical significance.

Results: In the nominal scenario, DLVCRO significantly improved joint distribution of dose and LET to protect OARs compared with RO. The physical dose distributions in targets and OARs are comparable. In the worst-case scenario, DLVCRO markedly enhanced OAR protection (more robust) while maintaining almost the same plan robustness in target dose coverage and homogeneity.

Conclusion: DLVCRO upgrades 2D DVH-based to 3D DLVH-based treatment planning to adjust dose/LET distributions simultaneously and robustly. DLVCRO is potentially a powerful tool to improve patient outcomes in SSPT.

Purpose: Radiation oncologists are known to be burdened with prior authorization and insurance denials more than other medical specialties. This analysis sought to use publicly available data and determine whether Medicare Advantage (MA) plans are inappropriately denying Radiation Therapy (RT) services more than other health services.

Methods and materials: Data from the Appeals Decision Search on the Centers for Medicare & Medicaid Services (CMS) website were extracted from 2022 through June 2024. The data contain appeal decisions from a third-party Independent Review Entity (IRE), which uses Medicare coverage guidelines to determine appropriateness of a denial. Percentages of inappropriate denials were calculated for RT services and all health services. Chi-squared test was used to compare inappropriate denial levels between RT and everything else. Decisions were also filtered by "keyword" and "condition" to analyze trends in treatment modalities and diagnosis, respectively.

Results: RT services were inappropriately denied 15.04%, 18.69%, and 16.01% for 2022, 2023 and 2024, respectively, while inappropriate denials for all health services were only 4.69%, 5.28% and 3.44%, respectively. Overall, since 2022, 274 out of 1576 RT appeals were inappropriately denied (17.39%), while only 20,195 out of 433,788 total appeals were inappropriately denied for all health services (4.66%). The difference was statistically significant for all three years and for the entire time period, with all p values <.00001. Using keywords Brachytherapy, Stereotactic Body Radiation Therapy (SBRT), Proton and Intensity Modulated Radiation Therapy (IMRT) inappropriate denial rates varied at 12.75%, 26.11%,13.02% and 41.06%, respectively, from 2022-2024. Prostate cancer appeals for protons had particularly low rates of inappropriate denial at 3.45%, while breast cancer appeals for IMRT had particularly high rates of inappropriate denial at 82.14%.

Conclusion: MA plans are inappropriately denying RT services more than non-RT services. These data warrant urgent policy changes to prevent Medicare-eligible patients from being inappropriately denied access to cancer treatments.

Purpose: To present a two-stage framework that robustly extracts and maps reliable lung ventilation surrogates based on subregional respiratory dynamics (SRD) measured from four-dimensional computed tomography (4DCT) images, with comprehensive consideration of spatial and temporal heterogeneity in the ventilation process over the respiratory cycle.

Materials and methods: We retrospectively analyzed three subject cohorts from the VAMPIRE challenge containing 4DCT and reference ventilation imaging (RefVI) scans. Lung subregions were partitioned on the 4DCT end-of-exhale base phase using anatomically constrained simple linear iterative clustering, while sliding-preserved interphase image registrations were performed between the base and other phases. SRDs of breathing-induced volume and intensity changes were tracked across phases utilizing the displacement fields. Voxel-level representations integrating mechanical collapsibility and physiological tissue density (V_SRD) were accordingly constructed from SRDs. Imaging performance of V_SRD as the proposed surrogate ventilation map was studied against RefVI scans and compared to classical biphasic Jacobian maps. The dosimetric performance evaluation was also conducted to assess the clinical benefits of incorporating V_SRD maps into functional lung avoidance radiotherapy (FLA-RT) planning.

Results: The extracted SRD highlighted temporally varying subregional volume and CT intensity changes related to underlying functional physiology and pathologies. For imaging performance, the median Spearman correlation coefficients between V_SRD and RefVI scans were 0.600, 0.582, and 0.561 for the three cohorts, while median Dice similarity coefficients against RefVI scans showing the high(low)-functioning lung regions' concordances, were 0.611(0.626), 0.592(0.620), and 0.601(0.611), superior to biphasic Jacobian maps for both metrics. For dosimetric performance, V_SRD-guided FLA-RT plans achieved significantly better dose sparing of high-functioning lung regions compared to FLA-RT plans based on biphasic Jacobian maps.

Conclusions: V_SRD maps captured spatial and temporal heterogeneity in the ventilation process, providing improved ventilation representations compared to classical algorithms. The capability to extract multidimensional ventilation-correlated image information from widely available 4DCT images showed promise in enhancing personalized FLA-RT implementations.

Purpose: To analyze the effects of adjuvant hormonal therapy (AHT) on time to event following neoadjuvant androgen deprivation therapy (ADT) and ¹²⁵I-transperineal prostate brachytherapy (TPPB), compared with neoadjuvant ADT and TPPB only, in patients with intermediate-risk prostate cancer (IRPC).

Patients and methods: In this multicenter, open-label, phase III randomized controlled trial (SHIP0804), 421 patients with IRPC were randomized to either nine-month AHT (AHT arm) or no AHT (non-AHT arm) after three months of neoadjuvant ADT and TPPB. The primary endpoint was biochemical progression-free survival (BPFS), and secondary endpoints included overall survival (OS) and clinical progression-free survival (CPFS). Prostatic biopsy results 36 months after treatment were evaluated in a correlative investigation (SHIP36B).

Results: With a median follow-up of over 11 years, the 10-year BPFS rates were comparable: 82.9% in the AHT group and 78.4% in the non-AHT group (P = 0.51). Results were consistent across key prognostic indicators such as age at randomization, baseline prostate-specific antigen level, clinical stage, Gleason grade group, number of National Comprehensive Cancer Network intermediate-risk factors, and prostatic volume. The secondary endpoints, including OS and CPFS, were also comparable between the two arms. Grade 3 or higher AEs occurred in 5.4% and 1.4% of patients in the AHT and non-AHT arms, respectively. At 36-month post-TPPB prostate biopsy, only 3.1% of biopsied patients tested positive for residual tumors. There were no deaths due to prostate cancer in either group.

Conclusions: Adding nine-month AHT to TPPB after three-month neoadjuvant ADT did not improve long-term outcomes in patients with IRPC. These findings suggest that moderate-term AHT may not offer substantial benefits and thus should not be considered a standard treatment in this population with IRPC.

Purpose: We aim to determine the current treatment patterns and recommendations among physicians for cutaneous lymphomas and to identify the types of skin lymphomas for which existing radiation regimens need improvement.

Materials/methods: A questionnaire from the European Organisation for Research and Treatment of Cancer (EORTC) was distributed to all members of the Cutaneous Lymphoma Tumour Group and radiation oncology scintific council. This online survey included 13 questions regarding treatment practices for patients with cutaneous lymphoma. The survey was conducted from August 21 to December 18, 2023. Frequency distributions and subgroup comparisons were calculated and analyzed.

Results: We collected 51 completed questionnaires from investigators from 19 countries specializing in cutaneous lymphoma treatment. Radiation doses varied significantly (range, 4-60 Gy). Based on the histologic entity, up to one-third of the investigators delivered hypofractionated regimens (range, 14% - 35%). Reduced-dose radiotherapy was considered by 27% to 63% of investigators. Meanwhile, 18 (35%) investigators considered adapting the radiation dose to the response to immunochemotherapy when treating primary cutaneous diffuse large B-cell lymphomal-leg type. Regarding total skin electron beam therapy, 91% of centres delivered reduced-dose regimens, and 18% of investigators applied ultra-hypofractionated protocols.

Conclusion: Radiotherapy of cutaneous lymphoma patients is highly heterogeneous among EORTC centres. Development of evidence-based recommendations for radiotherapy dose, fractionation, and technique for cutaneous lymphomas is required for optimization and standardization of treatment.