Iodine seed (I-125) as a marker in lung-lesions

In some lung lesions it may be necessary to obtain a histological biopsy. When
transthoracal punction and EUS (endoscopic ultrasound)/EBUS (endobronchial
ultrasound) fail to obtain a diagnose a surgical biopsy is the next step. Often
a VATS (video assisted thoracoscopic surgery) is used for biopsy. When the lung
lesion is localized intraparenchymale and thus not visible during VATS, there
is a need to localize the lesion. Mostly the localisation is performed using a
guide-wire. Short before surgery this guide-wire is placed by the pulmonologist
and/or radiologist. This procedure has some disadvantages of which the most
important one is dislocation of the guide-wire due to desoufflation of the
lung. In some cases there is a need to convert to thoracotomy to localize the
lesion. Even then, localisation can be difficult. Other problems which can
occur are punction pneumothorax and logistic problems.

An alternative for guide-wire localisation might be the use of radio-active
seed (I-125) implantation. This marker can easily be identified by means of a
gamma-probe. This radio-active seeds are cilindric capsules (approximately 4 mm
with a diameter of 0.8 mm), which exists of a titaniumcapsule with radio-active
Jodium-125 (I-125).
I-125 is used in breast cancer surgery for several years. Main indications are
localisation of non-palpable lesions, lesions treated with neo-adjuvant
chemotherapy (NAC) with a possibility for pCR (complete pathological respons)
and in large breast lesions (treated by breast-conserving-therapy) with a need
for landmarking.
The main advantage of the use of I-125 markers is the fact that implnated seeds
do not migrate or dislocate. Thereby providing a reliable localisation.
Further, the radio-active seeds can be implanted some time before surgery, to
overcome logistical problems.
The disadvantage of localisation, as with guide-wire placement, is the risk for
punction pneumothorax.

Patients in whom the pulmonologist indicated the need for surgical biopsy by
means of VATS.
In stead of guide-wire placement and localisation a I-125 marker is placed:

- The pulmonologist decides the indication.
- The pulmonologist and radiologist do implant teh I-125 marker with a punction
needle (under auspicien of the nucleair medicine specialist).
- The surgeon localises the I-125 marker by means of a probe during VATS and
takes a biopsy.
- The pathologist removes the I-125 marker (conform the local protocol, under
auspicien of the nucleair medicine specialist) and analyses the lesion.

Implant of a I-125 marker (radio-active seed).

No increase of burden and risk compared to the common implant technique
(guide-wire)