Sentinel lymph node biopsy in N+ breast cancer with conversion into N0 after neoadjuvant chemotherapy. / Biopsia selectiva de ganglio centinela en carcinomas de mama N+ convertidos a N0 después de quimioterapia neoadyuvante.

OBJECTIVE: Sentinel lymph node biopsy (SLNB) usefulness in breast carcinoma N+ converted to N0 after neoadjuvant chemotherapy (NC). MATERIAL AND METHODS: Descriptive study including 16 females with infiltrating carcinoma with lymphatic metastasis confirmed by biopsy, leaving a metallic marker (MM) in pathological lymph nodes (LN). All patients underwent NC reaching a complete radiological response in LN. Lymphoscintigraphy was performed after 99mTc nanocoloid injection, obtaining planar images and SPECT/CT. Lymphatic drainage and concordance of sentinel node (SN) with MM was analyzed. RESULTS: SN was visualized in lymphoscintigraphy in 93.7% of cases. The SN coincided with the MM in 12/15 cases on SPECT/CT. The SLNB technique was completed on 14/16 patients, intraoperatively locating the GC in all of them. The SN was negative in 10 cases, 3 cases presented macrometastases and 1 micrometastases. Axillary lymphadenectomy (AL) was performed in a case of macrometastasis with>15,000cp/µARNm CK-19, absence of drainage and in one case that showed no coincidence with the MM due different Berg's level location. These last two cases presented lymph node metastasis. In the other two cases with not coincidence between the SN and the MM, a total of 4 lymph nodes were removed, showing no evidence of metastasis. Patients without AL were followed up for an average of 10 months (range 6-17), with no evidence of lymph node involvement. CONCLUSION: SLNB in breast cancer with conversion into N0 after neoadjuvant treatment is a technique with good results and a low false negative rate.

Utilidad de la 18F-FDG PET/TC en un caso de sospecha de infección de injerto vascular / Usefulness of 18F-FDG PET/CT in a case of suspected vascular graft infection

La infección del injerto vascular protésico (VPGI) se asocia a una gran morbimortalidad. Es esencial un diagnóstico precoz y preciso para llevar a cabo el tratamiento más adecuado. Presentamos el caso de un varón de 74 años intervenido de by-pass aorto-bifemoral con sospecha clínica de infección de la prótesis vascular y pruebas complementarias no concluyentes, en el que se realiza un estudio PET/TC con 18F-FDG que muestra una captación patológica a nivel periprotésico sugestiva de infección, así como lesión incidental pulmonar sugestiva de neoplasia primaria. Una 18F-FDG PET/TC de control tras tratamiento antibiótico prolongado demostró una mejoría significativa en la captación en el injerto vascular. La 18F-FDG es un trazador prometedor para detectar VPGI, ya que los leucocitos activados tienen una gran demanda de la 18F-FDG y se acumulan en el lugar de la infección, y podría ayudar a definir la respuesta al tratamiento antibiótico (AU)

Vascular prosthetic graft infection (VPGI) is associated with high mortality and morbidity. An early and accurate diagnosis is essential in order to give the most appropriate treatment. The case is presented of a 74 year old male subjected to an aortobifemoral bypass graft, with clinical suspicion of VPGI with inconclusive tests. Later on an 18F-FDG PET/CT study showed a pathological uptake, suggestive of periprosthetic infection, as well as an incidental pulmonary lesion, suggestive of a primary neoplasm. A new 18F-FDG PET/CT showed a significant improvement in the uptake by the vascular graft after prolonged antibiotic treatment. 18F-FDG is a promising tracer for detecting VPGI as the accumulated activated white cells at the infection site have a high demand for 18F-FDG, and could help define the response to antibiotic treatment (AU)

Role of 18F-FDG PET/CT in primary brain lymphoma. / Utilidad de la 18F-FDG PET/TC en el linfoma cerebral primario.

OBJECTIVE: To study the usefulness of 18F-FDG PET/CT in the initial evaluation and in the response assessment in primary brain lymphoma. MATERIAL AND METHODS: A retrospective analysis was carried out on 18 patients diagnosed with primary brain lymphoma, a histological subtype of diffuse large B-cell lymphoma, on whom an initial 18F-FDG PET/CT and MRI was performed, with 7 of the cases being analysed after the completion of treatment in order to assess response and clinical follow up. RESULTS: Initial 18F-FDG PET/CT showed 26 hypermetabolic foci, whereas 46 lesions were detected by MRI. The average SUV maximum of the lesions was 17.56 with T/N 3.55. The concordance of both tests for identifying the same number of lesions was moderate, obtaining a kappa index of 0.395 (P<.001). In the evaluation of treatment, MRI identified 16 lesions compared to 7 pathological accumulations observed by 18F-FDG PET/CT. The concordance of both tests to assess type of response to treatment was moderate (kappa index 0.41) (P=.04). In both the initial evaluation and the assessment of the response to treatment, PET/CT led to a change strategy in 22% of patients who had lesions outside the cerebral parenchyma. CONCLUSIONS: MRI appears to be the method of choice for detecting brain disease in patients with primary brain lymphoma, whereas 18F-FDG PET/CT seems to play a relevant role in the assessment of extra-cerebral disease.

Usefulness of 18F-FDG PET/CT in a case of suspected vascular graft infection. / Utilidad de la 18F-FDG PET/TC en un caso de sospecha de infección de injerto vascular.

Vascular prosthetic graft infection (VPGI) is associated with high mortality and morbidity. An early and accurate diagnosis is essential in order to give the most appropriate treatment. The case is presented of a 74 year old male subjected to an aortobifemoral bypass graft, with clinical suspicion of VPGI with inconclusive tests. Later on an 18F-FDG PET/CT study showed a pathological uptake, suggestive of periprosthetic infection, as well as an incidental pulmonary lesion, suggestive of a primary neoplasm. A new 18F-FDG PET/CT showed a significant improvement in the uptake by the vascular graft after prolonged antibiotic treatment. 18F-FDG is a promising tracer for detecting VPGI as the accumulated activated white cells at the infection site have a high demand for 18F-FDG, and could help define the response to antibiotic treatment.

Lymphatic drainage in prostate carcinoma assessed by lymphoscintigraphy and SPECT/CT: its importance for the sentinel node procedure.

PURPOSE: The goal was to evaluate the sentinel node procedure in relation to different pathways of lymphatic drainage and the areas of pelvic lymphadenectomy in patients with prostate cancer assessed by lymphoscintigraphy and SPECT/CT study. METHODS: Eighteen patients with prostate cancer of intermediate prognosis were injected with 240 MBq of (99m)Tc-nanocolloid in the peripheral zone of each quadrant of the prostate, guided by transrectal ultrasonography. Tracer administration was also controlled with a portable gamma camera to assure that there was no diffusion outside the prostate. The injection was followed by planar imaging at 15 min. and 2 h, performing a SPECT/CT study at 2 h. with 2 mm slices. On the same day, a laparoscopic sentinel node lymphadenectomy assisted by a gamma probe and a portable gamma camera was performed. RESULTS: A total of 55 sentinel lymph nodes (SLNs) were visualized. In 17/18 of patients (94%) SLNs were observed outside the obturator region. Twenty SLNs (36%) were observed along the external iliac artery, 14 in the obturator fossa (25.4%), 6 in internal iliac area (11%) and 4 in common iliac region (7.2%). Three SLNs were visualized in presacral (5.4%), paraaortic (5.4%), and pararectal areas (5.4%) and two in paravesical region (3.6%). SLN metastases were found in 6 patients (33%), and in one of them, a SLN located along the common iliac artery, was the only one with metastases. CONCLUSION: Lymphatic drainage from the prostate has high individual variability, and direct drainage outside the pelvic area is observed frequently. With the SLN procedure, SLNs outside the routine area of lymphadenectomy can also be sampled to stage the patient more accurately.

[Detection by SPECT-CT scan with (99m)Tc-(V) DMSA of bone metastases in patient with medullary thyroid cancer]. / Detección mediante SPECT-TAC con (99m)Tc-(V) DMSA de metástasis óseas en paciente con cáncer medular de tiroides.

Multiple endocrine neoplasia syndrome, type 2B (MEN 2B), is a rare entity characterized by the presence of medullary thyroid cancer in 100% of the cases. The phenotype of this syndrome consists in the presence of marfanoid features and mucocutaneous neuromas. We describe the case of a male patient with MEN 2B syndrome who was diagnosed with medullary thyroid cancer after lung metastases was found. We analyze the role of DMSA-V and the new hybrid SPECT-CT scan systems in the extension study and monitoring of medullary thyroid cancer.