Practical Radiation Oncology最新文献

Purpose

The purpose of this investigation was to evaluate the clinical applicability of a commercial artificial intelligence–driven deep learning auto-segmentation (DLAS) tool on enhanced iterative cone beam computed tomography (iCBCT) acquisitions for intact prostate and prostate bed treatments.

Methods and Materials

DLAS models were trained using 116 iCBCT data sets with manually delineated organs at risk (bladder, femoral heads, and rectum) and target volumes (intact prostate and prostate bed) adhering to institution-specific contouring guidelines. An additional 25 intact prostate and prostate bed iCBCT data sets were used for model testing. Segmentation accuracy relative to a reference structure set was quantified using various geometric comparison metrics and qualitatively evaluated by trained physicists and physicians. These results were compared with those obtained for an additional DLAS-based model trained on planning computed tomography (pCT) data sets and for a deformable image registration (DIR)-based automatic contour propagation method.

Results

In most instances, statistically significant differences in the Dice similarity coefficient (DSC), 95% directed Hausdorff distance, and mean surface distance metrics were observed between the models, as the iCBCT-trained DLAS model outperformed the pCT-trained DLAS model and DIR-based method for all organs at risk and the intact prostate target volume. Mean DSC values for the proposed method were $\ge$0.90 for these volumes of interest. The iCBCT-trained DLAS model demonstrated a relatively suboptimal performance for the prostate bed segmentation, as the mean DSC value was <0.75 for this target contour. Overall, 90% of bladder, 93% of femoral head, 67% of rectum, and 92% of intact prostate contours generated by the proposed method were deemed clinically acceptable based on qualitative scoring, and approximately 63% of prostate bed contours required moderate or major manual editing to adhere to institutional contouring guidelines.

Conclusions

The proposed method presents the potential for improved segmentation accuracy and efficiency compared with the DIR-based automatic contour propagation method as commonly applied in CBCT-based dose evaluation and calculation studies.

Purpose

Several international groups have published guidelines to identify low-risk breast cancer (BC) patients who are eligible for partial breast irradiation (PBI). These include the American Society for Radiation Oncology (ASTRO), the European Society for Radiotherapy and Oncology (ESTRO), and ESTRO subgroups such as the Intraoperative radiation (IORT) Task Force and Groupe Européen de Curiethérapie (GEC) -ESTRO. Only ASTRO guidelines recommend against the use of PBI in known carriers of germline pathogenic variants (PVs) in BRCA1/2. The aim of this study was to evaluate the proportion of BC patients, subsequently found to be BRCA1/2 PV carriers who would be eligible for PBI based on clinical-pathologic criteria of the above-mentioned international guidelines.

Methods and Materials

Data were extracted from the medical records of consecutive BC BRCA1/2 PV carriers treated at a single institution between 2006 and 2023. Data included patient demographics, tumor characteristics, treatment, and disease outcomes.

Results

Overall, 498 patients with 518 primary tumors were analyzed. Of these, 282 (12 of them with synchronous bilateral disease) presented with unknown genetic status at diagnosis and formed the study cohort. The median age at diagnosis was 42.7 years (range, 23.8-77.9). Based on the recent ASTRO guidelines (not including conditionally recommended criteria), 17 of 294 (5.8%) of the carriers had tumors that would be eligible for PBI, including 3 Her2-positive tumors and 5 patients diagnosed between ages 40 and 49 years. Using the ESTRO IORT and the ACROP-ESTRO PBI criteria, 9 of 294 (3%) would be eligible, whereas with the GEC-ESTRO low-risk criteria, 31 of 294 (10.5%) of the carriers would be eligible, and their intermediate risk criteria would increase eligibility for PBI by an additional 8.2% (overall 18.7%).

Conclusions

Using clinical-pathologic criteria published in international guidelines, 3% to 18% of BRCA1/2 PV carriers will have tumors eligible for PBI. Therefore, especially in populations who are at high risk for being BRCA1/2 PV carriers, we recommend adhering to stricter guidelines. In our cohort, ASTRO, ESTRO-IORT, and ESTRO PBI had the lowest probability of identifying BRCA1/2 PV carriers as eligible for PBI.

H3K27-altered diffuse midline glioma (DMG H3K27-altered) is a relatively newly-designated WHO entity which primarily affects the midline structures of the central nervous system (CNS), including the brainstem (predominantly pontine region), thalamus, midbrain, or spinal cord, and primarily affects children and young adults. Despite the proximity of these tumors to eloquent areas in the CNS, novel stereotactic approaches have facilitated the ability to obtain tissue diagnoses without significant morbidity, providing molecular diagnostic information in more than half of patients. Conventionally fractionated radiation therapy to a total dose of 54-60 Gy in 27-30 fractions and 24 Gy in 12 fractions play a crucial role in the definitive treatment of these tumors in the primary and salvage settings, respectively. Hypofractionated regimens may allow for accelerated treatment courses in selected patients without jeopardizing disease control or survival. The decision to add concurrent or adjuvant systemic therapy mainly relies on the physicians’ experience without solid evidence in the literature in favor of any particular regimen. Recently, novel agents, such as ONC201 have demonstrated promising oncologic outcomes in progressive/recurrent tumors and are currently under investigation in ongoing randomized trials. Given the scarcity of data and well-established guidelines due to the rare nature of the disease, we provide a contemporary overview on the molecular underpinnings of this disease entity, describe the role of radiotherapy and systemic therapy, and present practice management principles based on the published literature.

Treatment of squamous cell carcinoma of the tonsil involves primary radiation therapy (RT) or surgical resection. Historically, if RT was the primary or adjuvant treatment modality, most of the bilateral retropharyngeal lymph nodes (RPLNs) were treated electively with a therapeutic dose for subclinical disease, regardless of whether radiographically pathologic lymph nodes were seen on initial diagnostic imaging. De-escalation strategies include the incorporation of transoral surgery with the goal to either eliminate or reduce the dose of adjuvant RT or chemotherapy. Transoral surgery does not include elective removal of the RPLNs, and no guideline or outcome paper recommends adjuvant RT specifically to electively treat RPLNs. In this Topic Discussion, we discuss pertinent literature and suggest management decisions. The management decisions discussed in this Topic Discussion pertain to only tonsillar primaries and not those of the soft palate or base of the tongue.

Purpose

Real-time adaptation of thoracic radiation plans is compelling because offline adaptive experiences show that tumor volumes and lung anatomy can change during therapy. We present and analyze a novel adaptive-on-demand (AOD) workflow combining online adaptive radiation therapy (o-ART) on the ETHOS system with image guided radiation therapy delivery on a Halcyon unit for conventional fractionated radiation therapy of locally advanced lung cancer (LALC).

Methods and Materials

We analyzed 26 patients with LALC treated with the AOD workflow, adapting weekly. We timed segments of the workflow to evaluate efficiency in a real-world clinic. Target coverage and organ at risk (OAR) doses were compared between adaptive plans (ADP) and nonadaptive scheduled plans (SCH). Planning robustness was evaluated by the frequency of preplanning goals achieved in ADP plans, stratified by tumor volume change.

Results

The AOD workflow was achievable within 30 minutes for most radiation fractions. Over the course of therapy, we observed an average 26.6% ± 23.3% reduction in internal target volume (ITV). Despite these changes, with o-ART, ITV and planning target volume (PTV) coverage (V100%) was 99.2% and 93.9% for all members of the cohort, respectively. This represented a 2.9% and 6.8% improvement over nonadaptive plans (P < .05), respectively. For tumors that grew >10%, V100% was 93.1% for o-ART and 76.4% for nonadaptive plans, representing a median 17.2% improvement in the PTV coverage (P < .05). In these plans, critical OAR constraints were met 94.1% of the time, whereas in nonadaptive plans, this figure was 81.9%. This represented reductions of 1.32 Gy, 1.34 Gy, or 1.75 Gy in the heart, esophagus, and lung, respectively. The effect was larger when tumors had shrunk more than 10%. Regardless of tumor volume alterations, the PTV/ITV coverage was achieved for all adaptive plans. Exceptional cases, where dose constraints were not met, were due to large initial tumor volumes or tumor growth.

Conclusions

The AOD workflow is efficient and robust in responding to anatomic changes in LALC patients, providing dosimetric advantages over standard therapy. Weekly adaptation was adequate to keep pace with changes. This approach is a feasible alternative to conventional offline replanning workflows for managing anatomy changes in LALC radiation therapy.

Purpose

Patients with cervical cancer undergoing chemoradiation have high symptom burden. We performed an analysis of prospectively collected data on patient-reported outcomes to determine characteristics predictive of poor treatment experience.

Methods and Materials

Between 2021 and 2023, we prospectively collected data on patient-reported outcomes from patients with cervical cancer undergoing definitive chemoradiation. The European Organization for Research and Treatment of Cancer (EORTC)-Quality of Life Question-Core 30 and the EORTC-Quality of Life Question-Cervical Cancer module were completed at baseline (BL) and at the end of treatment (EOT). Poor treatment experience was defined as EOT poor health-related quality of life (HRQOL), low physical function, or significant overall symptom burden. Predictive factors analyzed included demographic, clinical, and disease-specific factors and BL financial toxicity, depression, social function, and emotional function. Receiver operating characteristic analysis provided appropriate predictive cutoff values. Univariable and multivariable (MVA) linear regression analyses were performed.

Results

Forty-nine patients completed BL and EOT questionnaires. Median age was 43 years (range, 18-85 years). Most patients (59%) had stage III disease. BL financial toxicity ≥66.7, depression ≥66.7, social function ≤50, and emotional function ≤58 on the EORTC linear transformed scale of 0 to 100 were significant predictors for poor treatment experience (p ≤ .04) based on receiver operating characteristic analysis. On MVA, poor BL social function was associated with reduced EOT HRQOL (β, −9.3; 95% CI, −16.1 to −2.6; p < .008), decreased physical function (β, −24.4; 95% CI, −36.3 to −12.6; p < .001), and high symptom burden (β, 26.9; 95% CI, 17.5-36.3; p < .001). Earlier disease stage predicted decreased symptom burden (β, −6.7; 95% CI, −13.1 to −0.3; p = .039). BL financial toxicity was a significant predictor in univariable analysis (p = .001-.044) and showed a significant interaction term on MVA (p = .024-.041) for all 3 domains of poor treatment experience. Demographic and treatment-related factors were not predictive.

Conclusions

Patients with cervical cancer with poor BL social function or high financial toxicity were at risk for increased symptom burden and poor HRQOL. Screening for these factors provides an opportunity for early intervention to improve treatment experience.