Practical Radiation Oncology最新文献

Traditionally, renal cell carcinoma (RCC) was considered a radioresistant tumor, thereby limiting definitive radiation therapy management options. However, several recent studies have demonstrated that stereotactic body radiation therapy (SBRT) can achieve high rates of local control for the treatment of primary RCC. In the setting of expanding use of SBRT for primary RCC, it is crucial to provide guidance on practical considerations such as patient selection, fractionation, target delineation, and response assessment. This is particularly important in challenging scenarios where a paucity of evidence exists, such as in patients with a solitary kidney, bulky tumors, or tumor thrombus. The Radiosurgery Society endorses this case-based guide to provide a practical framework for delivering SBRT to primary RCC, exemplified by 3 cases. This article explores topics of tumor size and dose fractionation, impact on renal function and treatment in the setting of a solitary kidney, and radiation's role in the management of inferior vena cava tumor thrombus. Additionally, we review existing evidence and expert opinion on target delineation, advanced techniques such as magnetic resonance imaging guided SBRT, and SBRT response assessment.

Purpose: To provide a comprehensive review of the means by which to optimize target volume definition for the purposes of treatment planning for patients with intact prostate cancer with a specific emphasis on focal boost volume definition.

Methods: Here we conduct a narrative review of the available literature summarizing the current state of knowledge on optimizing target volume definition for the treatment of localized prostate cancer.

Results: Historically, the treatment of prostate cancer included a uniform prescription dose administered to the entire prostate with or without coverage of all or part of the seminal vesicles. The development of prostate magnetic resonance imaging (MRI) and positron emission tomography (PET) using prostate-specific radiotracers has ushered in an era in which radiation oncologists are able to localize and focally dose-escalate high-risk volumes in the prostate gland. Recent phase 3 data has demonstrated that incorporating focal dose escalation to high-risk subvolumes of the prostate improves biochemical control without significantly increasing toxicity. Still, several fundamental questions remain regarding the optimal target volume definition and prescription strategy to implement this technique. Given the remaining uncertainty, a knowledge of the pathological correlates of radiographic findings and the anatomic patterns of tumor spread may help inform clinical judgement for the definition of clinical target volumes.

Conclusion: Advanced imaging has the ability to improve outcomes for patients with prostate cancer in multiple ways, including by enabling focal dose escalation to high-risk subvolumes. However, many questions remain regarding the optimal target volume definition and prescription strategy to implement this practice, and key knowledge gaps remain. A detailed understanding of the pathological correlates of radiographic findings and the patterns of local tumor spread may help inform clinical judgement for target volume definition given the current state of uncertainty.

The International Federation of Gynecology and Obstetrics (FIGO) 2023 staging system for endometrial cancer has marked changes from the previous staging system instituted 14 years prior in 2009. The new staging system includes nonanatomic factors for the first time (lymphovascular space invasion and histology) and molecular classification, which impacts the stage in early-stage disease (IAm_POLEmut and IICm_p53abn). The purpose of these changes was to provide (1) high accuracy in the predictive prognosis for patients and (2) identification of distinct treatment-relevant subgroups. Our understanding of the biology and natural history of endometrial cancer has undergone a radical transformation since the Cancer Genome Atlas results in 2013. The 2023 FIGO staging system harmonizes and integrates old and new knowledge on anatomic, histopathologic, and molecular features. Moreover, FIGO 2023 has distinct substages that improve adjuvant treatment decision making. Although the practicality of the new staging system has been debated, we postulate that FIGO 2023 is more useful for radiation oncologists aiming to provide personalized care recommendations. FIGO 2023 requires a change in our perception of a staging system, from a traditional anatomic borders-based system to a staging system integrating anatomy and tumor biology as pivotal prognostic factors for patients while providing important information for treatment decision making.

Purpose: Concurrent chemoradiotherapy is the current non-surgical standard of care for locally advanced non-small cell lung cancer (NSCLC). However, this is a difficult regimen to tolerate especially for those who are elderly, have multiple comorbidities or poor performance status. Alternative treatment regimens are needed for this vulnerable population. We report initial results of concurrent durvalumab, an immune checkpoint inhibitor, and hypofractionated, dose-escalating, proton external beam radiotherapy (EBRT).

Patients and methods: This phase I, pilot dose-escalation trial enrolled seven patients with newly diagnosed stage IIIA-IIIC NSCLC who were unable or unwilling to undergo concurrent chemoradiotherapy. Patients previously treated with immunotherapy were excluded. Five patients in the initial phase of this 3+3 study design received a fixed dose of durvalumab each 28-day cycle plus hypofractionated proton EBRT 60 Gy in 20 fractions while two patients received the escalation dose of 69 Gy in 23 fractions. The primary objective assessed safety while secondary objectives assessed feasibility and adverse events.

Results: All patients experienced treatment-related adverse events, primarily grades 1-2. Pneumonitis and anemia were the most common. Only one dose limiting toxicity occurred, in arm one, which was a grade 3 pneumonitis leading to grade 5 pneumonia. Additionally, two delayed-onset grade 5 tracheal necrosis events occurred > 13 months after treatment initiation.

Conclusions: Concurrent durvalumab plus hypofractionated proton EBRT was well tolerated in the short term. However, three treatment-related deaths, including two delayed-onset grade 5 tracheal necroses negatively impacted overall safety. A dose de-escalation protocol of proton-based radiotherapy plus durvalumab is warranted.

Purpose: New technologies are continuously emerging in radiation oncology. Inherent technological limitations can result in health care disparities in vulnerable patient populations. These limitations must be considered for existing and new technologies in the clinic to provide equitable care.

Materials and methods: We created a health disparity risk assessment metric inspired by failure mode and effects analysis. We provide sample patient populations and their potential associated disparities, guidelines for clinics and vendors, and example applications of the methodology.

Results: A disparity risk priority number can be calculated from the product of 3 quantifiable metrics: the percentage of patients impacted, the severity of the impact of dosimetric uncertainty or quality of the radiation plan, and the clinical dependence on the evaluated technology. The disparity risk priority number can be used to rank the risk of suboptimal care due to technical limitations when comparing technologies and to plan interventions when technology is shown to have inequitable performance in the patient population of a clinic.

Conclusions: The proposed methodology may simplify the evaluation of how new technology impacts vulnerable populations, help clinics quantify the limitations of their technological resources, and plan appropriate interventions to improve equity in radiation treatments.

Purpose: The occurrence of genitourinary (GU) toxicity is a common adverse event observed after external beam radiation therapy (EBRT) for prostate cancer (PCa). Recent findings suggest that the dose delivered to specific urinary organs at risk (OARs) such as the ureters, bladder trigone, and urethra is involved in the development of GU toxicity.

Methods and materials: A multidisciplinary task force including 3 radiation oncologists, a uroradiologist, and a urologist was created in 2022. First, OARs potentially involved in GU toxicity were identified and discussed. A literature review was performed, addressing several questions relative to urinary OARs: anatomic and radiological definition, radiation-induced injury, and dose-volume parameters. Second, results were presented and discussed with a panel of radiation oncologists and members of the "Francophone Group of Urological Radiation Therapy." Thereafter, the "Francophone Group of Urological Radiation Therapy" experts were asked to answer a dedicated questionnaire, including 35 questions on the controversial issues related to the delineation of urinary OARs.

Results: The following structures were identified as critical for PCa EBRT: ureters, bladder, bladder neck, bladder trigone, urethra (intraprostatic, membranous, and spongious), striated sphincter, and postenucleation or posttransurethral resection of the prostate cavity. A consensus was obtained for 32 out of 35 items.

Conclusions: This consensus highlights contemporary urinary structures in both the upper and lower urinary tract to be considered for EBRT treatment planning of PCa. The current recommendations also propose a standardized definition of urinary OARs for both daily practice and future clinical trials.

Purpose: Meningiomas represent the most common primary tumor of the central nervous system. Current treatment options include surgical resection with or without adjuvant radiation therapy (RT), definitive RT, and observation. However, the radiation dose, fractionation, and margins used to treat patients with WHO grade 2 meningiomas, which account for approximately 20% of all meningiomas, are not clearly defined, and deciding on the optimal treatment modality can be challenging owing to the lack of randomized data.

Methods and materials: In this manuscript, 3 cases of patients with WHO grade 2 meningiomas are presented with descriptions of treatment options after gross total resection, subtotal resection, and previous irradiation. Treatment recommendations were compiled from 9 central nervous system radiation oncology and neurosurgery experts from The Radiosurgery Society, and the consensus of treatment recommendations is reported.

Results: Both conventional and stereotactic RT are treatment options for WHO grade 2 meningiomas. The majority of prospective data in the setting of WHO grade 2 meningiomas involve larger margins. Stereotactic radiosurgery/hypofractionated stereotactic RT are less appropriate in this setting. Conventionally fractionated RT to at least 59.4 Gy is considered standard of care with utilization of preoperative and postoperative imaging to evaluate the extent of disease and possible osseous involvement. After careful discussion, stereotactic radiosurgery/hypofractionated stereotactic RT may play a role for the subset of patients who are unable to tolerate the standard lengthy conventionally fractionated treatment course, for those with prior RT, or for small residual tumors. However, more studies are needed to determine the optimal approach.

Conclusions: This case-based evaluation of the current literature seeks to provide examples for the management of grade 2 meningiomas and give examples of both conventional and stereotactic RT.

The use of radiation therapy (RT) for pancreatic cancer continues to be controversial, despite recent technical advances. Improvements in systemic control have created an evolving role for RT and the need for improved local tumor control, but currently, no standardized approach exists. Advances in stereotactic body RT, motion management, real-time image guidance, and adaptive therapy have renewed hopes of improved outcomes in this devastating disease with one of the lowest survival rates. This case-based guide provides a practical framework for delivering stereotactic body RT for locally advanced pancreatic cancer. In conjunction with multidisciplinary care, an intradisciplinary approach should guide treatment of the high-risk cases outlined within these guidelines for prospective peer review and treatment safety discussions.

Purpose: Recent randomized trials have compared the efficacy and safety of stereotactic body radiation therapy (SBRT) with those of standard conventional external beam radiation therapy (cEBRT) for the treatment of painful spinal metastases. We conducted a composite analysis of these trials in order to inform current practice using pooled outcomes.

Methods and materials: Data from each randomized trial were abstracted from the final publications with biologically effective doses (BEDs) recalculated for SBRT and cEBRT. Primary outcome measures were overall pain response (OR) and complete pain response (CR) rates at 1, 3, and 6 months and rates of vertebral compression fracture. Random effects models were used to estimate primary outcome measures, and meta-regression assessed the effect of BED.

Results: Four prospective randomized clinical trials published between 2018 and 2024 were included, with a total of 686 patients (383 and 303 in the SBRT and cEBRT groups, respectively). Dose and fraction (fx) number ranged from 24 Gy/1 fx to 48.5 Gy/10 fx for the SBRT group (median BED using an α-to-β ratio of 10, 50 Gy) and from 8 Gy/1 fx to 30 Gy/10 fx for the cEBRT group (median BED using an α-to-β ratio of 10, 28 Gy). The 1-, 3-, and 6-month OR rates for SBRT and cEBRT were similar: 53.6%, 52.4%, and 58.8% versus 48.4%, 47.9%, and 43.8%, respectively (p > .05). The 3-month CR rate was significantly higher for SBRT than for cEBRT (31.9% vs 14.8%; risk ratio, 2.26; 95% CI, 1.48-3.45; p < .001), but not the 6-month rate (34.4% vs 16.3%; risk ratio, 1.83; 95% CI, 0.74-4.53; p = .194). Vertebral compression fracture rates were similar at 17.3% and 18.4% for SBRT and cEBRT, respectively. No significant dose-dependent effect was observed with increasing BED for any efficacy or safety outcomes.

Conclusions: OR rates are similar, but CR rates appear higher with SBRT than with cEBRT, yet no dose-dependent effects were identified despite approximately 1.8 × BED dose with SBRT.

Purpose: Patients undergoing radiation therapy may terminate treatment for any number of reasons. The incidence of treatment termination (TT) during radiation therapy has not been studied. Herein, we present a cohort of TT at a large multicenter radiation oncology department over 10 years.

Methods and materials: TTs between January 2013 and January 2023 were prospectively analyzed as part of an ongoing departmental quality and safety program. TT was defined as any premature discontinuation of therapy after initiating radiation planning. The rate of TT was calculated as a percentage of all patients starting radiation planning. All cases were presented at monthly morbidity and mortality conferences with a root cause reviewed.

Results: A total of 1448 TTs were identified out of 31,199 planned courses of care (4.6%). Six hundred eighty-six (47.4%) involved patients treated with curative intent, whereas 753 (52.0%) were treated with palliative intent, and 9 (0.6%) were treated for benign disease. The rate of TT decreased from 8.49% in 2013 to 3.02% in 2022, with rates decreasing yearly. The most common disease sites for TT were central nervous system (21.7%), head and neck (19.3%), thorax (17.5%), and bone (14.2%). The most common causes of TT were hospice and/or patient expiration (35.9%), patient choice unrelated to toxicity (35.2%), and clinician choice unrelated to toxicity (11.5%).

Conclusions: This 10-year prospective review of TTs identified a year-over-year decrease in TTs as a percentage of planned patients. This decrease may be associated with the addition of root cause reviews for TTs and discussions monthly at morbidity and mortality rounds, coupled with departmental upstream quality initiatives implemented over time. Understanding the reasons behind TTs may help decrease preventable TTs. Although some TTs may be unavoidable, open discourse and quality improvement changes effectively reduce TT incidents over time.