Evidence map›Paper›PMID 34631232›Full record

ArticleJournal of radiosurgery and SBRT2021

Is there a volume threshold of brain metastases for Linac-based stereotactic radiotherapy?

Chieh-Wen Liu, Saeed Ahmed, Tara Gray, Tianjun Ma, Young-Bin Cho, Gennady Neyman, Samuel Chao, John Suh, Ping Xia

Open access · greenAbstract read
In one paragraph

Article in Journal of radiosurgery and SBRT, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
0.3field-weighted citation impact, top 39% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 2 citations in OpenAlex.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 1 institution in 1 country.

Chieh-Wen LiuDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Saeed AhmedDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Tara GrayDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Tianjun MaDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Young-Bin ChoDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Gennady NeymanDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Samuel ChaoDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
John SuhDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Ping XiaDepartment of Radiation Oncology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
Cleveland Clinic · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTo investigate whether there is a volume threshold in target volume of brain metastases below which a small cone size and sharp penumbra in Gamma Knife (GK) may provide improved plan quality when compared to Volumetric Modulated Arc Therapy (VMAT)-based stereotactic radiosurgery (SRS).

methodsFor patients treated on GK SRS for brain metastases in 2018-2019 in our institution, 121 patients with two and three targets were identified. Twenty-six patients with two or three brain metastases (total of 76 lesions) were selected for this study. Two VMAT plans, SmartArc (Pinnacle) and HyperArc (Eclipse), were generated retrospectively for each patient. Plan quality was evaluated based on RTOG conformity index (CI), Paddick gradient index (GI), normal tissue (NT) V12Gy and V4.5Gy. By using the receiver operating characteristic (ROC) curve for both VMAT plans (SmartArc and HyperArc) and metrics of RTOG CI and NT V12Gy, we compared GK plans to SmartArc and HyperArc plans separately to determine the threshold volume.

resultsFor SmartArc plans, both ROC curve analyses showed a threshold volume of 0.4 cc for both CI and NT V12Gy. For HyperArc plans, the threshold volumes were 0.2 cc for the CI and 0.5 cc for NT V12Gy. GK plans produced improved dose distribution compared to VMAT for targets ≤0.4 cc, but HyperArc was found to have competing results with GK in terms of CI and NT V12Gy. For targets > 0.4 cc, both SmartArc and HyperArc showed better plan quality when compared to the GK plans.

conclusionsTarget volumes ≤0.4 cc may require a small cone size and sharp penumbra in GK while for target volumes >0.4 cc, VMAT-based SRS can provide improved overall plan quality and faster treatment delivery.

Indexed as

brain metastasesGamma KnifeLinac SRSplan qualityradiosurgeryVMAT

Identifiers

PMID34631232
PMCPMC8492046
OpenAlexW3207386829

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.