Procurement buyer’s guide

Radiation Therapy Dosimetry & QA Equipment: The Multi-Vendor Buyer’s Guide

By Michael Diab, Founder, OncoSource · Updated June 16, 2026· Educational & price-free · Directory-linked

A radiation oncology physics program does not buy “dosimetry equipment.” It buys an IMRT/VMAT plan-QA array, a daily beam-constancy device, a water-phantom scanning system for commissioning, an ADCL-traceable reference chamber and electrometer, and a QA management software platform to tie the workflow together — five different purchases, in five categories, with a different manufacturer short-list in each. This guide maps the four specialist manufacturers across those five categories, names each verified product family, and lists the questions that most often invalidate a naive quote-to-quote comparison.

The guide is educational, price-free, and vendor-neutral. Four manufacturers dominate the US radiation therapy dosimetry and QA category — Sun Nuclear, PTW, IBA Dosimetry, and Standard Imaging — and they are described here at equal weight. Every product family named was verified against the manufacturer’s own public catalog; where a family name could not be verified, it was left out rather than guessed. Of the four, only Sun Nuclear’s catalog is currently indexed in the OncoSource manufacturer directory, so it is the only one that links there — a directory-coverage fact, not a recommendation. Sun Nuclear is part of Mirion Technologies.

The dosimetry and QA landscape at a glance

A physics-equipment purchase is a category decision before it is a brand decision. A program standing up patient-specific QA for SRS is shopping one category; a program commissioning a new linac is shopping another; a program replacing an aging electrometer is shopping a third — and the manufacturer short-list, the acceptance criteria, and the service implications are different in each. The matrix below maps the four manufacturers to the five categories this guide covers, with the comparison watch-items that most often make two quotes non-comparable as written.

Among these four, only Sun Nuclear is currently listed in the OncoSource manufacturer directory, so it is the only manufacturer name in this guide that links there. PTW, IBA Dosimetry, and Standard Imaging are named factually and at equal weight in prose. Sun Nuclear is part of Mirion Technologies, named here once for accuracy; the directory indexes the Sun Nuclear catalog, not a Mirion corporate listing.

Citable rule: a dosimetry or QA quote is a system-and-service quote, not a hardware quote. A QA array is inseparable from the analysis software that reads it, a scanning tank is inseparable from its scanning detectors and its TPS-export format, and a reference chamber is inseparable from its calibration traceability and its electrometer. Two manufacturers’ lines in the same category are alternatives only when the whole chain — hardware, software, calibration, and service — survives the switch.

Patient-specific QA arrays (IMRT, VMAT, and SRS plan QA)

Patient-specific QA verifies that the dose a treatment-planning system computed for a specific plan is actually delivered by the machine, before the patient is treated. It is the highest-visibility dosimetry purchase in most departments and the category where detector geometry and software lock-in matter most. The two structural choices are cylindrical-versus-planar detector geometry and spatial resolution against your smallest fields.

Sun Nuclear builds ArcCHECK, a cylindrical (helical-diode) array sized for rotational VMAT and arc delivery; MapCHECK 3, a planar diode array for 2D IMRT QA; and SRS MapCHECK, a high-resolution planar array purpose-built for the small fields of stereotactic radiosurgery and SBRT. PTW takes the phantom-plus-array approach with OCTAVIUS 4D, a rotating phantom that pairs with detector arrays for true 4D (time-resolved) measurement, and the 2D-ARRAY seven29, a 729-element ionization-chamber array. IBA Dosimetry fields the MatriXX ionization-chamber array family for patient QA. The diode-versus-ion-chamber and cylindrical-versus-planar distinctions are not interchangeable details: they change the resolution, the angular dependence, and the analysis assumptions, which is why a department comparing two patient-QA arrays is comparing two measurement philosophies, not two prices.

Citable rule: in patient-specific QA, the brand decision is downstream of three device decisions — cylindrical versus planar detector geometry against your delivery technique, spatial resolution against your smallest treated field (SRS cones expose resolution limits a routine IMRT array never sees), and the analysis-software workflow you will live in daily. An array that cannot resolve your smallest field is not a candidate at any price.

Daily and machine QA / beam constancy

Daily QA is the morning beam-constancy check: output, flatness, symmetry, and energy stability verified before the first patient. It is a high-frequency, low-ceremony measurement, and the procurement watch-items are detector count, supported energies, and how cleanly the device trends results over time. Daily QA also bleeds into broader machine QA — the periodic, more comprehensive checks a physics program runs monthly and annually.

Standard Imaging builds the Daily QA 3, a multi-chamber daily beam-constancy device with built-in ion chambers measuring output, flatness, and symmetry in a single setup. Sun Nuclear approaches beam constancy through IC PROFILER, a tankless ionization-chamber profiler for fast beam-profile and constancy checks, with its broader machine-QA workflow managed in SunCHECK Machine. IBA Dosimetry covers the same ground through its myQA Daily and myQA Machines modules. The watch-item that most often makes two daily-QA quotes non-comparable is the software: the hardware captures the measurement, but the trending, baseline management, and tolerance alerting live in a platform, and that platform is where the workflow lock-in sits.

Citable rule: a daily-QA device is bought once and lived with every morning for a decade. The comparison that matters is not the sensor price but the daily-workflow cost: how fast the setup is, how many energies it checks in one acquisition, and how the trending software fits the physics program’s existing QA records. A cheaper sensor attached to a workflow your physicists will fight every morning is not a saving.

Water-phantom beam scanning and commissioning

A scanning water phantom is the instrument a physics program uses to commission a new linac and to verify beam data periodically thereafter: a motorized detector scans depth-dose curves and beam profiles through a water tank, and the data feeds the treatment-planning system’s beam model. It is an infrequent but high-stakes capital purchase, and the structural choices are tank geometry, scanning-detector compatibility, and how cleanly the data exports to the TPS.

Sun Nuclear builds SunSCAN 3D, a cylindrical water-scanning system, and the 1D SCANNER for depth-dose and single-axis measurements. PTW builds BEAMSCAN, a motorized water phantom for commissioning and routine beam scanning. IBA Dosimetry builds the Blue Phantom family of motorized scanning water tanks. The cylindrical-versus-Cartesian tank distinction changes setup, leveling, and the scan geometry; and every scanning system is only as useful as the scanning detectors it accepts and the format in which it hands data to the planning system. Commissioning data that does not import cleanly into your TPS is a multi-week problem, not a line-item difference.

Citable rule: a water-phantom purchase is a commissioning-workflow purchase. The comparable unit is the full chain — tank geometry, the compatible scanning detectors, the leveling and alignment system, and the TPS data-export format — not the tank alone. A tank that cannot drive your commissioning detectors, or cannot export to your planning system without manual reformatting, is a different project with a different timeline.

Reference dosimetry — ion chambers and electrometers

Reference dosimetry is the foundation the rest of the program stands on: an ADCL-calibrated ion chamber and electrometer establish the absolute dose against which everything else is measured. This is the category where calibration traceability and cadence dominate the purchase, because a chamber is only as trustworthy as its last accredited calibration.

PTW builds the Farmer chamber family (the workhorse 0.6 cm³ reference chambers, e.g. the 30010/30013) and the Semiflex family (smaller-volume chambers such as the 31010/31013/31021 for scanning and small-field work), read out by its UNIDOS reference-class electrometer line. Standard Imaging builds the Exradin ion-chamber family across a range of volumes and geometries, read out by the MAX 4000 electrometer. IBA Dosimetry reads its chambers with the DOSE-X reference-class electrometer. Chamber volume is the clinical choice — larger Farmer-type volumes for stable reference dosimetry, smaller Semiflex/micro volumes for small-field and scanning work — and any chamber-and-electrometer pairing is only meaningful with current ADCL traceability. A chamber quote that does not specify the calibration laboratory and the calibration cadence is incomplete as written.

Citable rule: a reference chamber is a calibration instrument, not a sensor. The comparable unit is the chamber plus its electrometer plus its ADCL-traceable calibration and the cadence of recalibration — never the chamber price alone. A cheaper chamber without documented accredited traceability is not a reference instrument; it is an uncalibrated detector.

QA management software platforms

The last category is the one that increasingly ties the other four together: the software platform that ingests measurements, manages baselines and tolerances, runs secondary independent dose checks, and produces the audit record. Hardware is bought once; the software platform is the daily surface a physics program lives in, and it is where the deepest vendor lock-in occurs.

Sun Nuclear builds the SunCHECK platform (with Patient and Machine modules) as a comprehensive QA management environment, and DoseCHECK as a secondary independent dose-calculation check that runs without re-measuring. IBA Dosimetry builds the myQA platform across machine QA, patient QA, and daily QA. The structural watch-items here are scope and openness: whether the platform is a secondary-check tool, a measurement-management tool, or both; and how much non-native hardware it will read. A platform that only ingests its own manufacturer’s detectors couples the software decision to the hardware decision permanently, which is the single biggest reason a dosimetry-equipment purchase is rarely a clean head-to-head on the sensor alone.

Citable rule: the QA software platform, not the sensor, is where a dosimetry-equipment decision compounds. A platform that reads only its own manufacturer’s hardware turns every future array, profiler, and phantom purchase into a same-brand decision. Evaluate the platform’s cross-vendor hardware support and its licensing model before the hardware, because the platform outlives the sensor.

How to compare vendors with no price list in sight

None of these manufacturers publishes US transaction prices, and published list prices — where they exist at all — say little about what facilities actually pay. The structural opacity is well documented: the JAMA Oncology chargemaster analysis and the University of Pennsylvania medical-device price-transparency working paper both describe markets where transaction prices are deliberately confidential, and the AAPM’s task-group reports — for example the patient-specific IMRT QA guidance in TG-218 and the linac QA framework in TG-142 — tie equipment selection to measurement methodology and acceptance criteria rather than to price.

OncoSource’s answer is not a price list. It is a comparison surface built from observed market data: upload one of your own quotes or invoices, and the analysis returns, for each line, the clinically equivalent options across the indexed manufacturer landscape — each option carrying a times-seen count showing how often that product has been observed, and an observed price range once it has been seen enough times. Where a product has enough observations, it is ranked within its category; where it does not, the analysis says so rather than manufacturing false confidence. You see only your own lines, and no single price point is ever published.

Citable rule: the comparable unit in dosimetry-equipment procurement is the clinically equivalent option set — every product in the same category that could serve the same measurement, each with a times-seen count and an observed price range where the observations support one — never a single quoted price. A range with its observation count attached tells you where your quote sits; a lone price point, yours or anyone else’s, tells you almost nothing.

See your own options on a real quote

The fastest way to use this landscape is to put one of your own documents through it. Upload a quote or invoice and get a free, no-signup, line-item analysis: every line read, pack and configuration quantities normalized, and the clinically equivalent options surfaced across the indexed manufacturers — each option with its times-seen count, an observed price range where the data supports one, and a rank where the observations support a ranking. Or start with the directory and browse the indexed catalogs by manufacturer.

Frequently asked questions

The questions radiation oncology physicists and buyers most often ask about the multi-vendor dosimetry and QA landscape. Each answer is self-contained and price-free.

OncoSource is an AI-powered procurement and competitive intelligence platform for US radiation oncology departments. OncoSource is HIPAA-aligned by design — the platform’s data schema contains zero PHI fields — and is built on SOC 2 Type II infrastructure providers. This article is educational and price-free; it quotes no prices, makes no savings claims, and lists manufacturers factually and neutrally. Product-family names were verified against each manufacturer’s public catalog as of the publication date.

Last updated June 16, 2026.