. 2014 Jul 23;87(1041):20140206. doi: 10.1259/bjr.20140206

Table 2.

Error detection capacities (detectability) of real-time in vivo dosimetry (IVD) and real-time imaging, uncertainty levels of each error scenario (quality item), and the probabilities and effects of the error scenarios

Quality item	Detectability		Uncertainty level^5,40	Error probability and effect (authors' opinion)
Quality item	Real-time IVD	Real-time imaging	Uncertainty level^5,40	Probability of error	Effect^a
Source calibration	✔^b		2%	Low	Low–high
Afterloader source positioning and dwell time (non-patient specific)^c	✔^d		4%	–	–
Afterloader malfunction	✔^d		–	Low	Low–high
Patient identification		✔^e	–	Low	High
Correct treatment plan	✔^f		–	Low	High
Intra- and interfraction organ/applicator movement^c	✔^d^,^g	✔	10–25% for organs at risk; >10–25% for target if high-dose-rate needle movements uncorrected	–	–
Applicator reconstruction and fusion errors	✔^d^,^h	✔	4%	Intermediate	Low–intermediate
Applicator length/source indexer length	✔^d^,ⁱ		–	Intermediate	Low–high
Source step size (patient specific)	✔^d^,ⁱ		–	Low	High
Interchanged guide tubes	✔^d		–	Intermediate	Low–high
Recording of dose^c	✔^j		3–5%	–	–

The table is a complement to Table 1 by Tanderup et al.¹¹ The uncertainty levels are taken from Tanderup et al⁵ and Kirisits et al.⁴⁰ The probabilities and effects were estimated by the authors.

^{^a}

Refers to the potential effect on dose administration.

^{^b}

If the dosemeter calibration is independent from the actual source.

^{^c}

Quality item that corresponds to an uncertainty in the treatment, which is always present and therefore does not have an occurrence likelihood, rather than an error.

^{^d}

Quality items for which detectability strongly would benefit from two or more point detectors, as stated or indicated in Andersen et al,¹⁴ Therriault-Proulx et al,^17,18 Cartwright et al,²⁰ Kertzscher et al,²¹ Reniers et al,²² Kertzscher et al,²⁵ Cherpak et al⁴⁶ and Nakano et al.⁹⁹

^{^e}

Wrong patient identification could be detected, for example, by comparing the patient's anatomy acquired during the treatment with the anatomy from the treatment plan.

^{^f}

If digital imaging and communications in medicine (DICOM) was exported independently to the afterloader and the IVD data acquisition system (see second paragraph in the Automation section.).

^{^g}

If IVD dosemeter probe is not attached to source applicator (see last paragraph in the Dosemeter placement tools section).

^{^h}

May be detected with source localization and applicator reconstruction (see Source localization and real-time applicator reconstruction section), dedicated algorithms for real-time IVD (see fourth paragraph in the Knowledge of dosemeter position section) and positioning technology (see third paragraph in the Knowledge of dosemeter position section).

^ⁱ

May be detected by means of comparisons between measured and expected dose rates or source positions.

^{^j}

Relevant if treatment planning system dose calculations are inaccurate, for example, if significant tissue heterogeneity and/or dose field perturbation effects are insufficiently accounted for by TPS (see seventh paragraph in Dosimeter placement tools section).