- The doses of radiation emitted by these seeds serve as a guide during the in-tervention, since they can be captured during surgery with a radiation detec-tor
- MD Anderson Cancer Center Madrid is one of the few private centers per-forming the technique in these lesions, as it requires a multidisciplinary team of highly specialized professionals with extensive experience
- The technique is also used in breast, lung and some muscle lesions, also with very satisfactory results
Nowadays, advances in imaging techniques such as computerized axial tomography (CAT) or positron emission tomography (PET) allow professionals to detect lesions at increasingly smaller sizes. The problem is that, often, the small lesions detected with these imaging techniques are not accessible by touch or sight, making it difficult to locate them during the surgery necessary for their removal for therapeutic or diagnostic purposes. A difficulty that MD Anderson Cancer Center Madrid solves by marking these lesions with radioactive iodine seeds capable of guiding the intervention thanks to the doses of radiation they emit.
"The seeds give off very small doses of radiation, which are not harmful to patients, but which professionals can follow during surgery thanks to a special detector," explains Dr. Oscar Alonso, specialist in gastrointestinal surgical oncology at MD Anderson Madrid. "The detector emits an acoustic signal as we get closer to the lesion, which increases in intensity the closer we get," he continues.
In most cases, the seeds are implanted a few days before the surgery because they do not move once in place and, in the operating room, the radiation they emit allows the professionals to position the laparoscopic instruments much more accurately. "Being able to prepare the intervention with the lesion perfectly localized and the patient already lying in the position in which we are going to work improves accuracy," says Dr. Alonso.
The technique can be used for the localization and extraction of both primary tumors and metastases, although it is usually more useful in metastases located in the peritoneum or lymph nodes, since primary tumors are often located in a specific organ and, for these cases, other techniques, like endoscopy, are used. The most important thing in opting for this technique is, above all, the nature of the injury. "Radio-guided surgery is indicated in small intra-abdominal lesions that are difficult to localize intra-operatively," says the specialist.
Seed marking in breast cancer
At MD Anderson Madrid, not only is this radio-guided surgical technique used for small abdominal lesions, but also in lesions of difficult to access by sight and touch in the breast, lung and some muscles. Specifically in breast, this therapeutic and diagnostic technique has been successful in "reducing the time needed for surgery by 15% to 20% in comparison with the traditional technique, harpoon marking, and has allowed volumes of up to 30 cubic centimeters of healthy tissue in the breast to be saved", explained Dr. Maria Eugenia Rioja, responsible for the implantation of the sentinel lymph node technique and radio-guided surgery techniques in the Department of Nuclear Medicine at MD Anderson Madrid.
Of course, the most important factor in the success of this intervention is a multidisciplinary team of professionals, one of the reasons MD Anderson Madrid is one of the few private centers performing this technique in the country. As Dr. Alonso explains, specialists in nuclear medicine and radiology are in charge of starting the process, since they mark the lesion with the seeds. Subsequently, to carry out the intervention, are anesthetists, surgical oncologists and a multidisciplinary team of highly specialized professionals with experience in the field, not available at all hospitals.