In-body radiation measurement to give clinicians confidence that doses are delivered to plan

The Technology

DOSEmapper™ is a unique high performance thermoluminescent detector (TLD) array consisting of 100+ small (lmm) micro silica glass beads packed on a thread for use in a standard catheter and inserted into a natural orifice next to the tumour. The inserted beads absorb the received radiation as stored energy over 100 points across and around the tumour. This is applicable to 70% of cancer occurrences.

After the radiotherapy session (usually the first fraction), the dose levels and spread will be measured by our fully automated high-performance TLD reader. The results will be ready, typically, after 20 minutes and sent to a local computer connected by USB.  The measurements are a unique “radiation ruler” or profile of the actual radiation doses received along or across the tumour area and beyond at a resolution of +/- lmm.

The clinical team can see the beads, their sequence and positioning on the patient imaging system and can compare the measurements provided with those expected with the patient treatment plan. The team can decide if adjustments need to be made for the next session.

Current Problems with Radiotherapy

  • Radiation inaccuracy causes damage to patient

  • Damage is not revealed for weeks

  • 10-25% of patients affected

  • Costs of treating damage from radiation inaccuracy

DOSEmapper™ enables clinicians to see and measure where radiation actually hits at and around the target tumour

Radiotherapy in Practice

Radiotherapy clinical teams carefully calculate and pre-test radiation treatment for each cancer patient. For external beam therapy the calculated radiation beams are directed at the tumour from the best and safest angles. Great care is taken to minimise hitting the surrounding healthy tissue and especially the patient’s critical organs. But, despite all the care, between 10% and 25% of radiotherapy patients worldwide suffer serious side effects or treatment failure.

One problem is how to directly measure the actual  radiation dose delivered into the patient’s body during radiotherapy. And that includes in brachytherapy when radiation sources are inserted into the patient. Today no one can see what the radiation hits or if it hits solely according to the specified patient treatment plan. No one knows the effects until the patient reports problems some weeks later.

TRUEinvivo bead array detectors are easily inserted via a catheter into a suitable natural orifice and measure the dose and spread of the radiation received at the site of the tumour.  The clinical team can use this “radiation ruler” to check for accuracy against the plan immediately after the first patient session and, if necessary, adjust for the next dose. This test and correction for accuracy gives the clinical team real confidence that the correct dose has been given and in the correct places. More confidence can lead to less sessions.

The patient and clinicians still wait a few weeks to see if the cancer is cured but the wait is with the confident knowledge that the treatment was really accurate and that side effects and harm have been minimised.

1D-Dosemappers photographed on a glpved hand.

1D DOSEmappers on a gloved hand: for direct in-body dose measurement

Read the latest DOSEmapper™ Digest

DOSEmapper™ micro silica bead array TLDs

TRUEinvivo 1D (linear), 2D(mesh) and 3D (cavity) DOSEmapper™ micro silica bead array TLDs are suitable for medical physics applications that use X, γ, β, proton and neutron radiations.  This includes external beam radiotherapy and brachytherapy treatments. For more details of the actual TLD material see the Researcher pages.

The 1D DOSEmappers shown on the glove above are typically eighty (80) dual bead measuring points with 1mm spacing between each set. This gives a very high resolution of dose measurement in any natural orifice. The DOSEmappers are typically used for the planning CT and the first fraction.  Our automated reader reads the DOSEmapper 160 TLDs in about 30 minutes. 1D DOSEmappers can be ordered to any length up to 400 beads and different spacing/resolution. We have supplied them with as few as 5 detector beads at 1mm resolution for commissioning work.

The 2D DOSEmapper shown on the left (10 x 10 taped to a phantom) has 100 double bead measuring points in a mesh that can be used in breast cancer treatment or on any other curved skin area.  The 2D DOSEmappers also come in 5 x 5 and 20 x 20 sizes. Other sizes can be made to order.

The 3D DOSEmapper (prototype also shown on the left) effectively has a 1D DOSEmapper wrapped in a spiral along the length of a central catheter and former. When used as a rectal insert the 3D DOSEmapper beads measure the received doses at the rectal wall. This is especially useful for the treatment of prostate cancer when the total number of fractions could be reduced if the doses to organs at risk could be measured giving clinicians confidence to safely increase the fractional doses.

Use Cases

Use of TRUEinvivo® DOSEmapper™ silica beads for SABR dose verification
Filmed with the medical physics team at Queen Alexandra Hospital, Portsmouth Hospitals NHS Trust.

Estimated that clinicians can save 7,000 patients from damage annually just in the UK

Who is working with us?

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TRUEinvivo can power radiotherapy improvement worldwide!

To find out more about how TrueInvivo technology is being implemented in hospitals around the country, please get in touch.
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