The Krenning Score on Your — DOTA PET Report

Most centres, following ENETS criteria, require a score of 3 or 4 on all target lesions before recommending PRRT. A score of 1 or 2 indicates that the tumour is not absorbing enough of the tracer for the treatment to deliver meaningful radiation to it. If even one lesion scores lower than the others, your oncologist will factor that into the eligibility decision. This threshold exists to protect you from the side effects of a treatment that is unlikely to work at lower expression levels.

Yes, it can. Receptor expression is not always fixed — it can vary between scans, between different lesions in the same patient, and sometimes after treatment. Some patients are rescanned after a period on somatostatin analogues, and a follow-up DOTA PET may show a different picture. A low score at one scan does not permanently close the door to PRRT. The reverse is also possible: a high score at one point does not guarantee the same result on a later scan.

In most published guidance, including ENETS criteria, a score of 2 is not sufficient. There are individual circumstances in which a multidisciplinary team may consider it differently — for example, when disease is very limited and the score-2 lesion is the only site of active disease. That is a case-by-case clinical judgement, not a standard threshold. If your score is 2, ask your oncologist whether there is a specific clinical reason to revisit the decision for your situation, rather than treating the score as an absolute answer.

The liver has a predictable, moderate level of somatostatin receptor expression that is relatively consistent between patients. That consistency makes it a reliable baseline for comparison. The spleen is used as the upper reference point because its receptor expression is reliably high. By comparing tumour uptake to both organs, the score captures where on a spectrum from low to high your tumour sits — without relying on absolute numbers that vary between scanners and centres.

No. The Krenning score measures somatostatin receptor expression, which is a structural feature of how the tumour is built, not a measure of how quickly it is growing. A tumour with a high Krenning score simply has more of the receptors that PRRT targets — that is a favourable treatment-selection finding, not a sign of worse disease. Tumour grade and aggressiveness are assessed separately, usually through the Ki-67 proliferation index, and your oncologist will consider both alongside the Krenning score.

It should, but practice varies between radiologists and reporting centres. Some reports state the grade explicitly as a number from 1 to 4; others describe uptake in comparative terms without using the numerical scale. If your report does not state a Krenning score and you need to discuss PRRT eligibility, ask your oncologist or the reporting radiologist to confirm what the uptake level corresponds to on the Krenning scale. At CION partner imaging centres, where DOTATATE and DOTANOC PET-CT is available at ₹23,999 with tracer supply confirmed at the time of booking, the Krenning score is part of the standard reported read.