18F-FDG PET/CT and sentinel lymph node biopsy in the staging of patients with cervical and endometrial cancer. Role of dual-time-point imaging

OBJECTIVE

Definitive staging for cervical (CC) and endometrial cancer (EC) takes place once surgery is performed. The aim of this study was to evaluate the role of PET/CT in detecting lymphatic metastasis in patients with CC and EC using dual-time-point imaging (DPI), taking the histopathological results of sentinel lymph node (SLN) and lymphadenectomy as the reference.

MATERIAL AND METHODS

A prospective study was conducted on 17 patients with early CC, and 13 patients with high-risk EC. The patients had a pre-operative PET/CT, MRI, SLN detection, and lymphadenectomy, when indicated. PET/CT findings were compared with histopathological results.

RESULTS

In the pathology study, 4 patients with CC and 4 patients with EC had lymphatic metastasis. PET/CT showed hypermetabolic nodes in 1 patient with CC, and 5 with EC. Four of these had metastasis, one detected in the SLN biopsy. Four patients who had negative PET/CT had micrometastasis in the SLN biopsy, 1 patient with additional lymph nodes involvement. The overall patient-based sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT to detect lymphatic metastasis was 20.0%, 100.0%, 100.0%, 87.9%, and 88.2%, respectively, in CC, and 57.1%, 88.9%, 66.7%, 84.2% and 80.0%, respectively, in EC. DPI showed higher retention index in malignant than in inflammatory nodes, although no statistically significant differences were found.

CONCLUSIONS

PET/CT has low sensitivity in lymph node staging of CC and EC, owing to the lack of detection of micrometastasis. Thus, PET/CT cannot replace SLN biopsy. Although no statistically significant differences were found, DPI may help to differentiate between inflammatory and malignant nodes.

Dual time-point (18)F-FDG PET/CT to assess response to radiofrequency ablation of lung metastases

AIM

To establish the usefulness of dual time-point PET/CT imaging in determining the response to radiofrequency ablation (RFA) of solitary lung metastases from gastrointestinal cancer.

MATERIALS AND METHODS

This prospective study included 18 cases (3 female, 15 male, mean age 71±15 yrs) with solitary lung metastases from malignant digestive tract tumors candidates for RFA. PET/CT images 1h after injection of 4.07MBq/kg of (18)F-FDG (standard images) were performed at baseline, 1 month, and 3 months after RFA. PET/CT images 2h after injection centered in the thorax at 1 month after RFA were also performed (delayed images). A retention index (RI) of dual time-point images was calculated as follows: RI=(SUVmax delayed image-SUVmax standard image/SUVmax standard image)*100. Pathological confirmation of residual tumor by histology of the treated lesion was considered as local recurrence. A negative imaging follow-up was considered as complete response.

RESULTS

Local recurrence was found in 6/18 lesions, and complete response in the remaining 12. The mean percentage change in SUVmax at 1 month and at 3 months showed a sensitivity and specificity for PET/CT of 50% and 33%, and 67% and 92%, respectively. The RI at 1 month after RFA showed a sensitivity and specificity of 83% and 92%, respectively.

CONCLUSIONS

Dual time point PET/CT can predict the outcome at one month after RFA in lung metastases from digestive tract cancers. The RI can be used to indicate the need for further procedures to rule out persistent tumor due to incomplete RFA.

Prognostic value of (18)F-FDG PET/CT volumetric parameters in recurrent epithelial ovarian cancer

OBJECTIVE

Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various solid neoplasms. These volumetric parameters and the SUVmax have shown to be useful criteria for disease prognostication in preoperative and post-treatment epithelial ovarian cancer (EOC) patients. The purpose of this study was to evaluate the utility of (18)F-FDG PET/CT measurements to predict survival in patients with recurrent EOC.

MATERIAL AND METHODS

Twenty-six patients with EOC who underwent a total of 31 (18)F-FDG PET/CT studies for suspected recurrence were retrospectively included. SUVmax and volumetric parameters whole-body MTV (wbMTV) and whole-body TLG (wbTLG) with a threshold of 40% and 50% of the SUVmax were obtained. Correlation between PET parameters and progression-free survival (PFS) and the survival analysis of prognostic factors were calculated.

RESULTS

Serous cancer was the most common histological subtype (76.9%). The median PFS was 12.5 months (range 10.7-20.6 months). Volumetric parameters showed moderate inverse correlation with PFS but there was no significant correlation in the case of SUVmax. The correlation was stronger for first recurrences. By Kaplan-Meier analysis and log-rank test, wbMTV 40%, wbMTV 50% and wbTLG 50% correlated with PFS. However, SUVmax and wbTLG 40% were not statistically significant predictors for PFS.

CONCLUSION

Volumetric parameters wbMTV and wbTLG 50% measured by (18)F-FDG PET/CT appear to be useful prognostic predictors of outcome and may provide valuable information to individualize treatment strategies in patients with recurrent EOC.

[Presence of intramammary lymph nodes in the preoperative lymphoscintigraphy to locate the sentinel lymph node. Clinical significance]

OBJECTIVE

The routes of lymphatic drainage from a breast cancer are the axilla (the most frequent) and the extra axillary regions. Among the latter, there are the so-called intrammamary lymph nodes (IMLN). This study has aimed to assess the incidence of IMLNs in our patients and study the evolution of these cases with IMLN in the lymphoscintigraphy.

MATERIAL AND METHODS

Thirty-eight patients (out of 1725) with IMLN in the pre-operative lymphoscintigraphy were assessed. During the surgical procedure, using a gamma probe, IMLNs were located and excised. After their harvesting, a meticulous surgical field scan was performed. When the axillary sentinel node was positive for metastasis, a complete axillary lymphadenectomy was performed. In those where the axillary sentinel node was negative and IMLN was positive (IMLN+), axillary lymphadenectomy was also performed, except for one case.

RESULTS

Thirty-four out of the 38 IMLNs were obtained (89.5%), because no lymphatic tissue was found in pathology analysis in three cases (8%) and in one patient (3%) IMLN was not found during surgery. Ten (26%) metastatic IMLNs were located and the remaining 24 IMLNs cases (63%) were metastasis-free. During the clinical follow-up, one patient with IMLN+ developed hepatic metastases. The remaining 33 patients did not present any recurrence. No follow-up data were available for three patients.

CONCLUSIONS

IMLN and axillary sentinel node biopsy are recommended when both are depicted in preoperative lymphoscintigraphy. The axilla treatment will only depend on the axillary sentinel node status. Based on the data from other authors and our own experience, avoiding the axillary lymphadenectomy when a metastatic IMLN without axillary involvement seems reasonable.

Sea urchin (Paracentrotus lividus) cryopreserved embryos survival and growth: effects of cryopreservation parameters and reproductive seasonality

The cryopreservation of embryos can be a powerful biotechnological tool to supply all year-round biological material for sea urchin aquaculture production. This study investigates different methodological and biological factors that may affect the result of the cryopreservation process of sea urchin (Paracentrotus lividus) embryos. Our data indicate that neither embryo density nor the use of different cryopreservation containers presented effect on the cryopreservation outcome. Contrary to other marine invertebrates, for sea urchin embryo cryopreservation ultrapure water cannot be used as CPA solvent, yielding zero survival. After studying the reproductive parameters along the reproductive season, we found a positive correlation between both male and female Condition Index (C.I.), and between the oocyte weight and C.I. Both the histology study of female gonads and the C.I. variation, suggest that the sea urchin natural spawning period in the Ría de Vigo occurs between June and July. We found no correlation between any of the reproductive parameters monitored and the cryopreservation outcome.

Contribution of perioperative imaging to radioguided surgery

Radioguided surgery has been investigated and applied to almost any neoplastic disease that is surgically treated. The impact of radioguided surgery on the surgical management of cancer patients includes relevant and real-time information to the surgeon regarding the location and extent of the disease, as well as regarding the assessment of surgical resection margins. Despite the fact that sentinel lymph node biopsy has been worldwide accepted as a highly accurate staging method for various solid cancers (among which breast cancer and cutaneous melanoma), some potential intraoperative drawbacks still remain. This article provides an update on currently available perioperative techniques regarding the use of radiotracers for radioguided surgery and sentinel lymph node mapping and biopsy, in particular in combination with vital dyes or other agents. The integration of computer technology and data processing makes it possible to integrate anatomic and functional images together with 3D rendering systems. This facilitates the targeted-tissue perioperative localization, especially in anatomically complex areas. Furthermore, we provide an update on advances in the integration of intraoperative imaging devices as well as optical tracers for the surgical management of patients. Evidence is emerging that these devices, together with new potential tracers, may improve intraoperative identification of sentinel nodes and/or tumors. A detailed presentation on a portable gamma camera in breast cancer patients, and the application of perioperative imaging devices in gynaecological cancers are included. Other important procedures, such as ROLL and RSL for occult lesion excision in the breast and other organs, are extensively discussed.

PET/CT with [18F] fluorodeoxyglucose in the assessment of metabolic response to neoadjuvant chemotherapy in locally advanced breast cancer

AIM

The aim of this paper was to prospectively evaluate FDG PET/CT in the assessment of metabolic response to neoadjuvant chemotherapy and correlation with tumor cellularity in locally advanced breast cancer.

METHODS

Images were acquired with a PET/CT scanner in 50 patients at baseline and after completion of treatment, just before surgery. All findings were confirmed by histopathological analysis. PET/CT quantification (SUVmax) at baseline and after finishing neoadjuvant chemotherapy (4 cycles of epirubicin + cyclophosphamide +/- taxanes) were compared using RECIST criteria and Miller & Payne (M&P) scale.

RESULTS

Baseline mean tumor size was 4.4±1.6 cm. Thirty eight patients were considered responders and 12 nonresponders. According to M&P scale, 10 patients had good prognosis (grades 4-5) and 40 patients had bad prognosis (grades 1-3). All patients with grade 5 M&P had no significant postchemotherapy FDG uptake. Patients with bad prognosis had lower SUVmax variation (∆SUVmax) than patients with good prognosis (60.7% vs. 80.5%, P=0.0016). ∆SUVmax was lower in nonresponders than in partial responders according to RECIST criteria (38.9% vs. 67.6%, p<0.001), and was also lower in partial responders than complete responders (67.6% vs. 85.4%, P=0.005). A cut-off ∆SUVmax value of 52% differentiates responders from nonresponders with a sensitivity of 86% and a specificity of 90%. Probability densities of the ∆SUVmax (%) for stable disease (<45), partial (>45 to <82) and complete response (>82) showed an overall accuracy of 78% (Weighted Kappa=0.74).

CONCLUSION

PET/CT is useful to monitor response to neoadjuvant chemotherapy in locally advanced breast cancer. ∆SUVmax on PET/CT correlates with tumor cellularity after completion of neoadjuvant chemotherapy.

[Dual-time point images of the liver with (18)F-FDG PET/CT in suspected recurrence from colorectal cancer]

AIM

To analyze the potential improvement of (18)F-fluorodeoxyglucose (FDG) PET/CT using additional delayed images of the liver in operated colorectal cancer.

MATERIAL AND METHODS

The study prospectively included 71 patients (22 women, 49 men) with mean age of 65 ± 11 years with clinical, analytic or radiological suspicion of current disease. A whole body PET/CT scan was performed at 60 min. (standard images) and after 2 hr (delayed images) post-injection of 4.07 MBq/Kg of (18)F-FDG. Visual and quantitative SUV analysis of PET/CT findings was done. All findings were confirmed by histopathology and/or at least 6 months follow-up.

RESULTS

Thirty-seven out of 71 patients were diagnosed of liver metastases (79 metastases). In 38/71 cases there was extra-hepatic disease in the form of local recurrence (10), abdominopelvic (3) or mediastinal (3) lymph nodes, bone (1) or lung metastases (16) and carcinomatosis (10). Sensitivity and specificity in the diagnosis of liver metastases in a patient-by-patient basis in standard (81% and 91%) and in delayed images (95% y 97%) was calculated. The number of lesions detected in delayed images was significantly higher (66/79) than in standard images (57/79). Sensitivity and specificity for PET/CT in the diagnosis of extra-hepatic disease was 84% and 70%, contributing to the detection of synchronous tumors in 5 patients.

CONCLUSIONS

PET/CT may be useful in the diagnosis of extra-hepatic disease in suspected recurrence of colorectal cancer. Delayed images on PET/CT may increase the sensitivity to identify liver metastases.

[The utility of interictal SPECT in temporal lobe epilepsy]

INTRODUCTION

Interictal brain single photon emission computed tomography (SPECT) is used in the presurgical evaluation of patients with complex partial epilepsy. The aim of the present study was to compare interictal SPECT, MRI and video-electroencephalography (EEG) for seizure focus localization in patients with temporal lobe epilepsy, one year after temporal lobectomy, in order to determine the utility of interictal brain SPECT.

PATIENTS AND METHODS

Thirty four consecutive patients with refractory temporal epilepsy were evaluated with video-EEG, MRI and interictal SPECT for seizure focus localization before surgery. Seizure focus was confirmed with the clinical follow-up one year after temporal lobectomy in all patients. MRI and SPECT analysis was performed visually.

RESULTS

31/34 patients were seizure free one year after surgery and the remaining 3 patients remain with seizures occasionally. Video-EEG results coincided with postsurgical seizure focus localization in 31 (91%) patients. MRI localized seizure focus correctly in 30 (88%) patients and was normal in 3 cases. Interictal brain SPECT was normal in 10 patients and showed temporal hypoperfusion consistent with postsurgical seizure focus in 23 (68%) patients. In all patients with abnormalities in the interictal SPECT, seizure focus was identified with video-EEG or MRI.

CONCLUSIONS

When MRI and video-EEG localize seizure focus in the same temporal lobe, interictal brain SPECT does not offer any additional information for surgical decision making.

Recurrencia ovárica y paraaórtica de un carcinoma de cuello uterino detectada mediante PET/TC

We present the case of a 34-year-old woman diagnosed of an adenosquamous carcinoma of the uterine cervix, stage IIB of the FIGO classification (International Federation of Gynecology and Obstetrics), treated with quimiotherapy, radiotheraphy and brachytheraphy with posterior hysterectomy. A recurrence of the disease was suspected due to the progressive rise of CEA levels. A PET/CT revealed abnormal foci in both ovaries, that had been transposed to avoid lesions due to radiation, and in a left para-aortic adenopathy. The diagnosis of recurrence in these sites was confirmed by biopsy. PET with FDG (F18-fluorodeoxyglucose) is useful in the staging of primary tumour and in the detection of recurrence in uterine cervical carcinoma, with better sensitivity and specificity than CT and MRI. PET/CT improves anatomic resolution and helps to resolve the origin of unclear foci like in the case presented in which ovaries were not in their normal situation due to transposition.

[Psoas abscess as cause of lumbar spine pain detected by scintigraphy with gallium in a patient with suspicion of spondylodiscitis]

A 56 year old man with fever and lumbar pain who underwent an abdominal CT scan that showed lumbar arthrosic changes, although it was not possible to rule out infectious disease in L5/S1. Bone scintigraphy was requested. It showed heterogeneous hyperuptake that did not make it possible to exclude a spondylodiscitis in this site. Scintigraphy with 67Ga-citrate excluded infectious diseases in the lumbar spine column. However, a pathological uptake was observed in the left iliac fossa suggestive of psoas abscess, which was confirmed by ultrasonography, isolating streptococcus viridans.

Utilidad de la detección del ganglio centinela en el tratamiento y la estadificación del carcinoma de cérvix uterino inicial

OBJECTIVE

The aim of this study was to evaluate the usefulness of intraoperative sentinel node (SN) detection in patients with initial cervix cancer.

PATIENTS AND METHODS

Lymphoscintigraphy and intraoperative SN detection was performed in 17 patients with initial cervix cancer who we going to have a radical laparoscopic hysterectomy and pelvic lymphadenectomy. Conization was performed in 4/17. The day before surgery, an injection of 111 MBq 99mtechnetium nanocolloid around the primary tumour and a subsequent lymphoscintigraphy were carried out. Blue dye was injected at the same location intraoperatively. A laparoscopic gamma probe was used to identify SNs.

RESULTS

SNs were successfully localized using a combination of radiocolloid and blue dye in 16/17 patients (detection rate 94 %). The detection rate only using blue dye technique decreases to 71 % (12/17) and it reaches an 82 % (14/17) if we avoid the blue dye injection. In 3 cases, there was no migration in lymphoscintigraphy and in one of the three SN could not be detected. Thirty-three SNs were identified (1.9 nodes/patient). The most frequent location was left external iliac nodal group (13 nodes: 39 %). SNs were identified in regions that are not included in usual lymphadenectomy: right parametrium (2 sentinel nodes, one of them in the retrouterine region), and interiliac (2 SNs). In all four patients with previous conization SNs were identified (detection rate 100 %).

CONCLUSIONS

The rate of SN detection combining lymphoscintigraphy with gamma probe and blue dye is 82 %. The use of blue dye allows increasing this rate to 94 % in those cases which migration was not seen or when the SN is placed near the injection site. The SN technique offers the possibility to find SNs in regions not included in usual lymphadenectomy.