Background and purpose: This study aimed to summarize the clinical outcomes of patients with metastatic melanoma who received high-dose radiation prior to or during systemic therapy at a single academic institution.
Methods: We identified patients with metastatic melanoma who underwent high-dose radiation therapy (HDRT) for extracranial metastases prior to or during systemic therapy from 2010 to 2018. Treatment indications included oligometastases, oligoprogression, and local control. Using the Kaplan-Meier method, we plotted overall survival (OS), progression-free survival-1 (PFS1), and PFS2. Competing risk analysis determined the cumulative incidence of local failure (LF) and the time to start or change systemic therapy (SCST). Univariate and multivariable analyses were used to identify predictive factors.
Results: We analyzed 34 patients with 79 lesions, with a median follow-up of 17.4 months. Sixty-eight percent of patients received systemic therapy after the first HDRT. The median OS was 22 months, with brain metastases before HDRT being a significant predictor in multivariable analysis. The median PFS1 for first-line HDRT was 4.1 months, and the median PFS2 was 3.9 months. Rates of LF were 10.3% at 12 months and 11.7% at 24 months. The incidence of SCST following HDRT was 59.8% at 12 months and 76.1% at 24 months, with radiation targeted at the lung associated with a lower incidence of SCST.
Conclusion: HDRT for treating metastatic lesions in melanoma demonstrated excellent local control and may play a role in delaying SCST. Additional courses of HDRT may provide cumulative benefits.
Objective: Eye plaque radiation therapy is the treatment of choice for small- and medium-sized choroidal melanomas. This study investigated the dose distribution around eye plaques containing 125I seeds to treat ocular melanoma using Monte Carlo N-Particle eXtended (MCNPX) and Plaque Simulator (PS) software.
Methods: Dosimetry evaluation and comparison of the resulting isodose curves for 125I COMS plaques were performed using the MCNPX code. The isodose curves and dose distributions were calculated using PS treatment planning for a 125I COMS plaque.
Results: In the validation, the maximum relative difference between the results of this study and those reported in other literature was approximately 9%–10% for the COMS plaques. The dose distributions of MCNPX were lower than those of PS with a relative difference of approximately 27.7%–35.4%. The dose distribution may differ depending on the 125I source spectra and seed design used in the two methods. In addition, the dose algorithm used in PS made a major contribution to the relative differences between the results.
Conclusion: The PS did not provide accurate details of dose distribution near the surface of the plaque insert. The source parameters used in each program should be studied more carefully to determine the source of the differences in the estimated dose values.
Objective: This study aimed to analyze the effect of different gantry angles on portal imaging in terms of isocenter shifts and their dosimetric impact on dose delivery.
Methods: Thirty patients with head and neck cancers were prospectively selected for this study. The reference anterior to posterior (AP) digitally reconstructed reference radiograph image was obtained at a gantry angle of 0°. The AP portal images were acquired at angles of 0°, 0.5°, 1°, 1.5°, and 2.0°. The average deviation of the isocenter shift with respect to the zero-gantry angle was calculated. To check the dosimetric effects, the reference fluence was compared with different fluences measured at different isocenter shifts.
Results: The average isocenter shift differences in the lateral direction were 0.7 mm, 1.3 mm, 1.9 mm, and 2.5 mm. The average difference was <±0.1 mm for isocenter shift in the longitudinal direction. The results of the statistical analysis showed that the average isocenter shift and gamma pass rate with respect to the different isocenter position errors were significant in the lateral direction.
Conclusion: The results of this study showed that as the gantry angle increased, the isocenter shifted and the percentage of deviation in the lateral direction increased.
Lung oligometastases represent an intermediate state of cancer dissemination between localized and widespread metastases. Stereotactic body radiation therapy (SBRT) has emerged as an effective treatment option, with an efficacy comparable to that of surgical resection. This review aimed to provide a comprehensive summary of the latest advancements and controversial issues regarding SBRT for lung oligometastases. It focuses on four crucial perspectives: efficacy of SBRT, optimal patient selection criteria, technological innovations, and synergistic effects of SBRT combined with systemic therapy. Relevant clinical trials investigating SBRT for lung oligometastases have been conducted, with median 1- and 5-year local control rates of 90% and 79%, respectively. The origin of the primary tumor, size and number of lesions, and biomarker profiles were highlighted as pivotal considerations in patient selection. The precise dose delivery was enhanced using robotic SBRT and optimized dose fractionation schemes. Evidence suggests that dose escalation above 100 Gy biologically effective dose may improve tumor control. Combined immunotherapy and SBRT have demonstrated synergistic effects in prolonging progression-free survival and overall survival. This review provides valuable insights into the precise treatment of oligometastatic lung diseases using SBRT. Further multicenter randomized trials are warranted to develop definitive patient selection criteria and optimize the integration with systemic therapies.
Esophageal cancer is among the top causes of cancer-related mortality worldwide, and the main treatment modality for locally advanced esophageal cancer is concurrent chemoradiotherapy. The current photon-based radiotherapy modalities and procedures have increased the incidence of treatment-related cardiac and pulmonary complications. Additionally, anatomical changes in the esophagus resulting from diaphragmatic movement, weight loss, and tumor progression present challenges for radiotherapy. These challenges have spurred interest in particle therapies, such as proton beam therapy (PBT) and heavy-ion therapy, for esophageal cancer. This paper comprehensively reviews the dosimetric advantages, clinical efficacy, and limitations of PBT and heavy-ion therapy for esophageal cancer and discusses their prospects. This highlights the unique dosimetric benefits of these therapies, particularly their ability to deliver high-dose radiation precisely to the tumor while sparing the surrounding normal organs and tissues. Although PBT and heavy-ion therapy demonstrate superior clinical efficacy compared to photon therapy, they are not without limitations. Multiple studies are needed to further validate and supplement the existing clinical and preclinical data to better exploit the benefits of PBT and thereby provide improved survival advantages to these patients
Temporal bone squamous cell carcinoma (TBSCC) is a rare and invasive malignant tumor. The common predisposing factors include a history of local radiotherapy and chronic suppurative otitis media. The current treatment approach for TBSCC primarily involves surgery, followed by adjuvant radiotherapy and chemotherapy, based on T staging and high-risk factors. Although patients with early-stage TBSCC have a high survival rate after treatment, the majority of patients are diagnosed in the intermediate to advanced stages, with extensive tumor involvement, posing challenges for surgical intervention. Definitive chemoradiotherapy (CRT) serves as a viable alternative for unresectable tumors. Constraints in administering curative radiation doses, due to the tolerance of surrounding organs, can lead to uncontrolled tumor growth. Although programmed cell death 1 inhibitors have demonstrated efficacy in head and neck squamous cell carcinoma and cutaneous squamous cell carcinoma, their application in TBSCC remains underexplored. Herein, we report a case of a 47-year-old man diagnosed with unresectable advanced and localized TBSCC. Following inadequate tumor control with primary chemoradiotherapy, immunotherapy was initiated, resulting in disease remission within a follow-up period of > 4 years.