Evidence map›Paper›PMID 34021698›Full record

ArticleJournal of applied clinical medical physics2021

Dosimetric comparison of multiple vs single isocenter technique for linear accelerator-based stereotactic radiosurgery: The Importance of the six degree couch.

Dania Amaya, Ashwin Shinde, Christopher Wohlers, Ka Chun Carson Wong, Jennifer Novak, John Neylon, Chunhui Han, An Liu, Savita Dandapani, Scott Glaser

Open access · goldAbstract read
In one paragraph

Article in Journal of applied clinical medical physics, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed, 1 pooled it
0.7field-weighted citation impact, top 28% 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

5 citing papers in PubMed, 1 synthesis or guideline pooled it, 9 citations in OpenAlex.

  1. Pooled it
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  5. 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

10 authors at 1 institution in 1 country.

Dania AmayaDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Ashwin ShindeDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Christopher WohlersDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Ka Chun Carson WongDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Jennifer NovakDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
John NeylonDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Chunhui HanDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
An LiuDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Savita DandapaniDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
Scott GlaserDepartment of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA.
City Of Hope National Medical Center · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeSingle isocenter technique (SIT) for linear accelerator-based stereotactic radiosurgery (SRS) is feasible. However, SIT introduces the potential for rotational error which can lead to geographical miss. Additional planning treatment volume (PTV) margin is required when using SIT. With the six degrees of freedom (6DoF) couch, rotational error can be minimized. We sought to evaluate the effect of the 6DoF couch on the dosimetry of patients with multiple brain metastases treated with SIT. MATERIALS AND

methodsTen consecutive patients treated with SRS to ≥3 metastases were identified. Original treatments had MIT plans (MITP). The lesions were replanned using SIT. Lesions 5-10 cm from isocenter had an additional 1mm of margin. Patients were replanned with these additional margins to account for inability to correct rotational error (SITPM). Multiple dosimetric variables and time metrics were evaluated. Dosimetry planning time (DPT) and patient treatment time (PTT) were evaluated. Statistics were calculated using the Wilcoxon signed-rank test.

resultsA total of 73 brain metastases receiving SRS, to a median of 6 lesions per patient, were identified. MITPs treated 73 lesions with 63 isocenters. On average, MITPs had a 19.2% higher brain V12 than SITPs (P = 0.017). For creation of SITPM, 30 lesions required 1 mm of additional margin, while none required 2 mm of margin. This increased V12 by 47.8% on average per patient (P = 0.008) from SITP to SITPM. DPT was 5.5 hours for SITP, while median for MITP was 12.5 hours (P = 0.005) PTT was 30 minutes for SITP, while median for MITP was 144 minutes (P = 0.005).

conclusionsSITPs are comparable to MITPs if rotational error can be corrected with the use of a 6DoF couch. Increasing margin to account for rotational error leads to a nearly 50% increase in V12, which could result in higher rates of radiation necrosis. Time savings are significant using SIT.

Indexed as

Brain NeoplasmsRadiosurgeryHumansParticle AcceleratorsRadiotherapy DosageRadiotherapy Planning, Computer-Assistedcouchisocenterradiosurgeryrotational errorsix degree

Identifiers

PMID34021698
PMCPMC8200442
OpenAlexW3163871783

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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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.