# GTV, CTV and PTV (target volumes)

Source: https://onco.cc/terms/planning-target-volume/  
OnCo record `planning-target-volume` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The nested outlines a radiation plan is built on: the visible tumour (GTV), the tumour plus the tissue likely to hold microscopic spread (CTV), and a further margin for daily movement and setup error (PTV).

## Summary

The gross tumour volume is what imaging and examination show; the clinical target volume adds the margin of suspected microscopic disease and, in many cancers, the lymph node regions at risk; the planning target volume adds a geometric margin so that the CTV receives the dose despite setup and organ motion. Image guidance, motion management and adaptive radiotherapy all work by allowing the PTV margin to shrink.

## Fields

- Kind: Term
- Last checked: 2026-09-17
- Tags: radiation-wave1; precision

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Radiation_treatment_planning
- Wikipedia: https://en.wikipedia.org/wiki/Radiation_treatment_planning

## Connected records

- technologies: [Adaptive radiotherapy (online replanning)](https://onco.cc/technologies/adaptive-radiotherapy/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Volumetric modulated arc therapy (VMAT)](https://onco.cc/technologies/vmat/)
- terms: [Proton range uncertainty and the range margin](https://onco.cc/terms/proton-range-uncertainty/), [Variation between clinicians in drawing the radiotherapy target](https://onco.cc/terms/target-delineation-variability/)
- key papers: [Daily versus weekly prostate cancer image guided radiation therapy: phase 3 multicenter randomized trial](https://onco.cc/key-papers/paper-de-crevoisier-daily-weekly-igrt-ijrobp-2018/), [Defining the optimal planning target volume in image-guided stereotactic radiosurgery of brain metastases: results of a randomized trial](https://onco.cc/key-papers/paper-kirkpatrick-srs-margin-trial-ijrobp-2015/), [The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy](https://onco.cc/key-papers/paper-van-herk-ptv-margin-recipe-ijrobp-2000/), [Uncertainties in volume delineation in radiation oncology: a systematic review and recommendations for future studies](https://onco.cc/key-papers/paper-vinod-delineation-uncertainty-review-radiother-oncol-2016/)
- trials: [EORTC 22922/10925](https://onco.cc/trials/eortc-22922/)

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