a procedureGamma knife radiosurgery

A high dose of radiation delivered to a target inside the skull from many directions at once, so that the beams meet at the lesion and each individual path through healthy brain carries little dose. The head is held still, by a frame pinned to the skull under local anaesthetic or by a moulded mask on newer machines, and the whole treatment is given in one session. It is used for small brain tumours, for metastases, for arteriovenous malformations and for trigeminal neuralgia. There is no incision and no general anaesthetic.

Gamma knife travels for the reason proton therapy travels: the machine is where it is. Elekta, which makes it, said on its own fiftieth-anniversary page in January 2018 that "today, 330 clinical Gamma Knife units across 54 countries treat a combined 80,000 new patients each year", and that over fifty years "1.1 million people around the world have received the therapy". That figure was eight years old when it was read for this record on 16 September 2026, and no newer installed-base count appears on the manufacturer's current product pages. Fifty-four countries out of roughly two hundred is the fact that moves patients.

Trade practice — the beams come from cobalt-60 sources arranged around a helmet; the sources decay and are reloaded on a cycle, which is one of the reasons a unit is a standing commitment rather than a purchase.

What is published about volume is published about literature rather than about treatment. A 2025 systematic review in Cancer Medicine screened 5,424 articles, included 538, and counted "120,756 patients treated with SRS for brain cancer and tumors since 2000" in them. That counts patients who appear in papers. It does not count patients.

Inference — the comparison a reader is usually making here is not between countries but between operations: a craniotomy with a ward stay and a recovery against an afternoon in a machine. The published argument over which is right for which lesion is a clinical one, and this directory reports that it is argued rather than settling it.

A single session in one day. The London Gamma Knife Centre, a private unit whose own description this record reads, puts it as: "Unlike conventional radiation therapy, which requires treatment over multiple days or weeks, Leksell Gamma Knife delivers a high dose of radiation to one or more brain tumours during a single treatment session, in one day", and, where the target is too large, "it is also possible to stage the treatment in three fractions at 2 weekly intervals." It is "a single day outpatient visit" and "does not require a general anaesthetic"; with a frame, the patient feels "some discomfort from the local anaesthetic, and pressure from the pins when tightened", and the treatment itself is painless. Most patients "return to their normal activities the following day". Newer machines offer "the option of using a standard radiotherapy mask" instead of the frame.

No published price for a gamma knife session was found on any provider page read for this record on 16 September 2026, including the UK centre quoted above, whose self-pay link redirects to a hospital page carrying no figure. That is a statement about the pages read, not about the world: units in India, Türkiye, Thailand and Japan may publish, and no figure from them has been read here. What the scarcity does produce is a referral pattern rather than a price list — the patient is sent to the machine.

This page describes a treatment. It is not advice about whether to have one, or where.