Dose-response relationship in patients with newly diagnosed atypical meningioma treated with adjuvant radiotherapy

Radiation Therapy for Meningiomas - Where Do We Stand and What's on the Horizon?

Radiation therapy, including conventionally fractionated external beam radiation therapy, stereotactic radiosurgery, and fractionated stereotactic radiation therapy, is a cornerstone in the interdisciplinary management of meningiomas. Recent advances in radiation oncology and also in other fields, such as neuropathology and imaging, have various implications for meningioma radiation therapy. This review aims to summarize current and anticipated developments, as well as active clinical trials related to the use of radiation therapy for meningiomas. In imaging, positron emission tomography has proven valuable for assessing the spatial extension of meningiomas and may enhance target delineation, treatment response monitoring, and recurrence assessment after radiation therapy. Particle therapy, including protons and carbon ions, as well as stereotactic radiosurgery and fractionated stereotactic radiation therapy, allow for conformal treatments that permit dose escalation in selected patients with high-grade meningiomas. Additionally, emerging integrated molecular and genetic classifications offer superior risk stratification and may refine patient selection for radiation therapy. However, there is a paucity of active meningioma trials directly investigating or refining the use of radiation therapy. In summary, significant advances in functional imaging, molecular and genetic diagnostics, and radiation treatment techniques hold the potential to improve patient outcomes and to avoid over- and undertreatment. Collaborative efforts and further clinical trials are essential to optimize meningioma radiation therapy.

Overall Survival of Primary Single Intracranial Atypical Meningioma with Different Surgical and Postoperative Treatment Options: Evidence from the SEER Database

Objective

The aim of this study is to evaluate the impact of different surgical and postoperative treatment options on the long-term overall survival (OS) in patients with primary single intracranial atypical meningioma.

Methods

In this retrospective study, participants were drawn from the Surveillance, Epidemiology, and End Results (SEER) database. Inclusion criteria comprised patients who underwent either gross total resection (GTR) or subtotal resection (STR). The inverse probability weighting (IPW) method using generalized boosted models was used to achieve balance in variables across various treatment groups. Subsequent to IPW, multivariate Cox analysis and Kaplan-Meier analysis were conducted, with OS as the endpoint.

Results

GTR was conducted on 1650 patients, while STR was conducted on 1109 patients. Among these, 432 patients who underwent GTR and 401 patients who underwent STR received postoperative radiotherapy (PORT). In the case of patients who were under 60 years old, PORT emerged as a significant protective factor for OS in those who underwent STR (HR 0.44; 95% CI 0.23-0.84; p = 0.013). Survival curves demonstrated that patients who underwent STR with PORT exhibited comparable OS to those who underwent GTR without PORT (p = 0.546). Conversely, for patients aged 60 years or older, PORT emerged as an independent risk factor for both GTR (HR 1.42; 95% CI 1.00-2.00; p = 0.048) and STR (HR 1.81; 95% CI 1.26-2.60; p = 0.001).

Conclusion

PORT may contribute to improving OS in primary single atypical meningioma patients under 60 years old who receive STR. However, in older patients who underwent either GTR or STR, the administration of PORT may be associated with a potential risk of OS. Therefore, age should be taken into account in applying PORT therapy, and the optimal treatment strategy for PORT in patients with atypical meningiomas needs to be further explored and validated.

Predictive Dosimetry and Outcomes of Hepatocellular Carcinoma Treated by Yttrium-90 Resin Microsphere Radioembolization: A Retrospective Analysis Using Technetium-99m Macroaggregated Albumin Single Photon Emission CT/CT and Planning Software

PURPOSE

To characterize estimated mean absorbed tumor dose (ADT), objective response (OR), and estimated target dose of hepatocellular carcinoma (HCC) after resin microsphere yttrium-90 (90Y) radioembolization using partition dosimetry.

MATERIALS AND METHODS

In this retrospective, single-center study, multicompartment dosimetry of index tumors receiving 90Y radioembolization between October 2015 and June 2022 was performed using a commercial software package and pretreatment technetium-99m macroaggregated albumin single photon emission computed tomography (SPECT)/computed tomography (CT). In total, 101 patients with HCC underwent 102 treatments of 127 index tumors. Patients underwent imaging every 2-3 months after treatment to determine best response per modified Response Evaluation Criteria in Solid Tumors (mRECIST). Best response was defined as the greatest response category per mRECIST and categorized as OR or nonresponse (NR). A Cox proportional hazards model evaluated the probability of tumor OR and progression-free survival using ADT.

RESULTS

The median follow-up period was 148 days (interquartile range [IQR], 92-273 days). The median ADT of OR was 141.9 Gy (IQR, 89.4-215.8 Gy) compared with the median ADT of NR treatments of 70.8 Gy (IQR, 42.0-135.3 Gy; P < .001). Only ADT was predictive of response (hazard ratio = 2.79 [95% confidence interval {CI}: 1.44-5.40]; P = .003). At 6 months, an ADT of 157 Gy predicted 90.0% (95% CI: 41.3%-98.3%) probability of OR. At 1 year, an ADT of 157 Gy predicted 91.6% (95% CI: 78.3%-100%) probability of progression-free survival. Partition modeling and delivered activity were predictive of progression (P = .021 and P = .003, respectively).

CONCLUSIONS

For HCC treated with resin microspheres, tumors receiving higher ADT exhibited higher rates of OR. An ADT of 157 Gy predicted 90.0% OR at 6 months.