Imaging as a surveillance tool in rectal cancer

Despite advances in diagnosis and treatment, half of patients with treated rectal cancer will die owing to recurrent disease. There is no evidence of benefit on survival from an intensive surveillance program, even if presymptomatic recurrent disease is detected. The aim of this article is to review the results described for the different imaging techniques in diagnosing rectal cancer recurrence in different sites and to discuss their relative clinical impact. The sensitivity of imaging techniques is related to the performance of the machines and the site being examined. Computed tomography is the most used technique owing to its availability, speed, panoramic images and ease of use, while MRI of the pelvis and the liver produces the highest resolution, sensitivity and specificity in these anatomical areas. Owing to its high cost, [(18)F] fluorodeoxyglucose-PET should be used as a third-level examination, a 'problem-solving' method when the site of recurrence is unknown or to rule out other possible sites of recurrence before a second surgery, and, finally, because it offers the possibility to investigate the whole body. The follow-up must be designed for individual patients, taking into account a number of factors. In the near future, whole-body imaging, probably by MRI, that is free from radiation will become the method of choice for screening for recurrent diseas

Peritoneal carcinomatosis from ovarian cancer: the role of CT and [18F]FDG-PET/CT

PURPOSE: The diagnosis of peritoneal carcinomatosis secondary to ovarian cancer is a real challenge in the cancer imaging field. In this retrospective study, we evaluate the accuracy of Single Detector Computed Tomography (SDCT), Multi Detector Computed Tomography (MDCT), and Positron Emission Tomography-Computed Tomography with F18-fluorodeoxyglucose ([\ub9\u2078F]FDG-PET/CT) in the diagnosis of peritoneal seeding and we evaluate the possible applications of MDCT to predict the complete surgical removal of the peritoneal deposits. METHODS AND MATERIALS: A total of 228 scans (91 SDCT, 89 MDCT, and 48 [\ub9\u2078F]FDG-PET/CT) of patients with peritoneal carcinomatosis secondary to ovarian cancer proved at laparoscopy and confirmed by histopathology were retrospectively reviewed by two independent groups of Radiologists and Nuclear Medicine Physicians for the evaluation of ascites, peritoneal nodules, and omental cake signs. RESULTS: MDCT showed 81% of true positives, SDCT 72.5%, and [\ub9\u2078F]FDG-PET/CT 77%. False negatives were 19% for MDCT, 27.5% for SDCT, and 23% for [\ub9\u2078F]FDG-PET/CT. CONCLUSION: From our results, we concluded that MDCT is the technique of choice in the diagnosis of peritoneal seeding, while [\ub9\u2078F]FDG-PET/CT, though showing similar accuracy, remains the most accurate technique for monitoring therapeutic response and disease recurrence. MDCT could play an important role due to its ability to predict the possibility of complete surgical removal of disease thus influencing the treatment plan aimed to improve quality of life

Lymph node involvement in T1 non-small-cell lung cancer : could glucose uptake and maximal diameter be predictive criteria?

Objective: The introduction of modern staging systems such as computed tomography (CT) and positron emission tomography/CT (PET/CT) with fluorodeoxyglucose ([18F]FDG) has increased the detection of small peripheral lung cancers at an early stage. We analyzed the behavior of pathological T1 non-small-cell lung cancer (NSCLC) to identify criteria predictive of nodal involvement, and the role of cancer size in lymph node metastases. Methods: We retrospectively analyzed 219 patients with pathological T1 NSCLC. All patients were staged by high-resolution CT and PET as stage I, and underwent anatomical resection and radical lymphadenectomy. Our data were collected based on pathological nodule size (0-10mm; 11-20mm; and 21-30mm); morphological features of lung nodule and FDG uptake of the tumor measured by standardized uptake value (SUV). Results: A total of 190 patients (87%) were pN0, 14 (6%) pN1, and 15 (7%) pN2. No nodal involvement was observed in any of the 62 patients with nodule size less than 10mm, in 20 out of 120 patients (17%) with nodule size 11-20mm, and in nine out of 37 tumors (28%) 21-30mm in size (p=0.0007). All 55 patients with nodule SUV<2.0 and all 26 non-solid lesions were pN0 (respectively, p=0.0001 and p=0.03). All nodal metastases occurred among the group of 132 patients with size larger than 10mm and SUV higher than 2.0 with a 22% rate of nodal involvement of (29 patients) (p<0.0001). Conclusions: The low probability of lymph node involvement in NSCLC <1cm or showing glucose uptake <2 suggests lymphadenectomy could be avoided. A randomized trial should be performed to validate our data

Role of multidetector CT and FDG-PET/CT in the diagnosis of local and distant recurrence of resected rectal cancer

PURPOSE: The aim of this study was to compare the diagnostic value of multidetector computed tomography (MDCT) and F18-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) for the detection of local and distant recurrence in patients operated on for rectal cancer. MATERIALS AND METHODS: Sixty-seven patients who underwent radical surgery for rectal cancer and were followed up with FDG-PET/CT and MDCT were included in this retrospective study. The FDG-PET/CT and MDCT findings were independently compared with histological sampling or 2 years' follow-up. RESULTS: Local recurrence occurred in 15/67 patients. MDCT diagnosed local recurrence in 15/15 cases and FDG-PET/CT in 14/15. Sensitivity and specificity were 100% and 98% for MDCT and 93% and 98% for FDG-PET/CT, respectively. Hepatic lesions were found in 17/67 patients. All hepatic metastases were detected by both techniques. Pulmonary metastases occurred in 8/67 patients: they were correctly identified in all cases by MDCT and in 6/8 by FDG-PET/CT. CONCLUSIONS: MDCT and FDG-PET/CT showed high sensitivity and specificity for the detection of local recurrence of rectal cancer. Both techniques were equally accurate for the detection of hepatic metastases. MDCT showed slightly higher sensitivity and positive predictive value in detecting pulmonary metastases compared with FDG-PET/CT

Lymphatic mapping to tailor selective lymphadenectomy in cN0 tongue carcinoma: beyond the sentinel node concept

Purpose: Cervical lymph node status is the most important pathological determinant of prognosis and decision making in head and neck squamous cell carcinoma (SCC). The aim of this study was to demonstrate that lymphoscintigraphy (LS) can supply a complete map of the lymphatic drainage before surgery, allowing planning of the type of intervention and serving to guide lymphadenectomy. Methods: The study population comprised 14 patients with T2-4 SCCs of the tongue and clinically negative lymph nodes in the neck (cN0) who were scheduled to undergo tumour resection and selective level I-IV neck dissection extended to level V. LS was performed in all patients following the injection of Tc-99m-colloidal sulphide in three aliquots around the primary lesion. Dynamic, static and tomographic images of the head and neck were acquired. The operative specimens were subjected to lymphoscintigraphic evaluation. Preoperative and postoperative imaging results were compared with the pathological findings. All nodes were examined using haematoxylin-eosin staining. Results: Preoperative LS was successful in all patients. Preferential pathways of lymphatic drainage were identified: level II of the neck was the most common lymphatic drainage pattern, followed by levels IV and III. Contralateral drainage occurred in 11 patients and in two of them metastatic nodes were found on the contralateral side. Metastases were observed only in radioactive lymph nodes. Conclusion: LS is able to supply a complete map of the lymphatic drainage before surgery, making it possible to tailor selective neck dissection to each individual patient based on the results of preoperative mapping, thereby sparing healthy lymphatic tissue and reducing surgery-related morbidity

Radio-guided ultrasound lymph node localization: feasibility of a new technique for localizing and excising nonpalpable lymph nodes ultrasound suspicious for melanoma metastases

Identification of lymph nodes suspicious for metastases is crucial in melanoma patients during the follow-up. We propose a procedure called radio-guided ultrasound lymph node localization (RULL) for melanoma patients with ultrasound (US) suspicious, not palpable, lymph nodes. The aim of this study was to evaluate the feasibility of this technique, and to assess the efficacy of this new method. RULL was applied in 12 consecutive melanoma patients with non-palpable lymph nodes found suspicious for metastases during US follow-up. Macro-aggregates of human serum albumin labelled with diluted technetium-99m were injected into the suspected lymph node under US guidance and followed by a scintigraphy. The surgical treatment was carried out with the support of hand-held gamma-probe used for sentinel node biopsy. The tracer was correctly positioned in all 12 patients. Pathological examination revealed seven patients with metastatic lymph nodes, four with no metastatic lymph node, one patient with Hodgkin disease. No surgical complications were described. In conclusion, RULL may integrate the standard ultrasound-guided fine-needle aspiration to improve the diagnostic accuracy on US suspicious nodes and might replace the more logistically complicated wire identification or less accurate cutaneous marker identification of these nodes. Sensibility and specificity of this approach should be defined through a large multicentric study