Clinical value of [18-F]] fluorodeoxyglucose positron emission tomography imaging in soft tissue sarcomas

OBJECTIVE: To evaluate positron emission tomography (PET) using 2-fluoro-2-deoxy-D-glucose (FDG) for clinical application in soft tissue sarcomas. SUMMARY AND BACKGROUND DATA: FDG PET is a promising noninvasive method for the preoperative assessment of soft tissue sarcomas and may complement radiologic tomography. METHODS: Data from 50 consecutive patients with 59 masses, either suspicious for primary or locally recurrent soft tissue sarcoma, were prospectively gathered. The semiquantitative FDG uptake (standardized uptake values [SUVs]) was calculated in tumor and normal tissue (muscle). Histopathology of surgical specimens and follow-up data were used as control criteria. RESULTS: In primary soft tissue sarcomas, PET displayed a sensitivity of 91% and a specificity of 88%. Local recurrence was detected with a sensitivity of 88% and a specificity of 92%. All intermediate-grade and high-grade soft tissue sarcomas (primary and locally recurrent) were visualized with a precise differentiation from muscle. Fifty percent of the low-grade sarcomas showed an FDG uptake equivalent to muscle (false-negative results in one primary and three recurrent soft tissue sarcomas). Benign soft tissue tumors (e.g., lipoma, leiomyoma, ganglion) did not accumulate FDG. Inflammation resulted in an increased FDG uptake. The semiquantitative FDG uptake (SUVs) correlated with tumor grade but not with size and histologic type. CONCLUSION: High-grade and intermediate-grade soft tissue sarcomas are amenable to PET imaging, whereas low-grade lesions may not be depicted. SUVs for FDG correlate with tumor grade in soft tissue sarcomas. Benign soft tissue tumors are differentiated from higher-grade soft tissue sarcomas. These data show that FDG-PET can complement preoperative radiologic assessment for soft tissue sarcomas and that FDG-PET is a powerful diagnostic tool for detecting high-grade and intermediate-grade local recurrence.     

F-18-fluoro-deoxy-glucose positron-emission tomography scanning in detection of local recurrence after radiotherapy for laryngeal/ pharyngeal cancer.

BACKGROUND: The objective of this investigation was to determine whether F18-fluoro-deoxy-glucose (FDG) positron-emission tomography (PET) could differentiate between local recurrence and late radiation effects after radiotherapy for laryngeal/pharyngeal cancer. METHODS: In a prospective study of 75 patients (67 larynx, eight oro/hypopharynx), 160 laryngoscopies and 109 FDG PET scans were performed on the head and neck region. The mean follow-up time after the first FDG PET scan was 23 months (minimum 1 year). RESULTS: Local recurrence was diagnosed in 37 patients: 19 after the first biopsy and 18 after follow-up biopsies. For all of the negative initial FDG scans (27), the biopsies that were taken at the same time were negative and no recurrence was seen for at least 1 year. The first FDG scan was a true positive in 34 of 48 patients. In 12 of the 14 patients with false-positive results, FDG scans were repeated; a decreased FDG uptake was found in 9 of the 12. The sensitivity and specificity of the first scan were respectively 92% and 63%; including subsequent FDG scans, the rates were 97% and 82%, respectively. CONCLUSIONS: When a local recurrence is suspected after radiotherapy for cancer of the larynx/pharynx, an FDG PET scan should be the first diagnostic step. No biopsy is needed if the scan is negative. If the scan is positive and the biopsy negative, a decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely.     

Local recurrence and survival in soft-tissue sarcomas

Background: There is a continuous interest in the literature concerning the management and survival after treatment of local recurrence in sarcomas because it is one of the most common types of recurrence. Design: We retrospectively reviewed 93 patients treated for local recurrence from soft-tissue sarcoma. Methods: We evaluated prognostic parameters (grade, tumor size, location) and the effect of treatment on survival. Results: Resection of all the gross tumor at first visit to our Institute for local recurrence was accomplished in 88 patients (95%). Of the 59 patients with extremity tumors, six (10%) required an amputation. At a mean follow-up of 66 months, further local recurrence was noted in 27%. The estimated 5-year survival rate was 100% for patients with grade I tumors (n=16), 77% for grade II (n=31), and 45% for grade III tumors (n=46) (p=0.0002). This value was 78% for tumors ≤5 cm and 57% for those >5 cm (p=0.03). Conclusions: Local recurrence is resectable and limb preservation is possible in the majority of patients. The overall 5-year survival rate was 65%. Survival after treatment of local recurrence is determined mainly by the grade and secondarily by the size of the tumor as for primary sarcomas.     

Fluorine-18-fluorodeoxyglucose positron emission tomography is useless for the detection of local recurrence after radical prostatectomy.

OBJECTIVE: After radical retropubic prostatectomy a rise of the prostate-specific antigen (PSA) indicates a local recurrent or metastatic disease. If the bone scan shows no apparent bone metastasis, morphological imaging methods like x-ray computed tomography, magnetic resonance imaging or transrectal ultrasound often cannot distinguish between postoperative scar and local recurrence. Therefore we investigated the feasibility of fluorine-18-fluorodeoxyglucose positron emission tomography (F-18 FDG PET) for metabolic characterization of prostatic cancer, especially for differentiation of scar or recurrent prostate cancer after radical prostatectomy. METHODS: Dynamic PET with 370 MBq F-18 deoxyglucose (F-18 FDG) up to 60 min p.i. was performed in 2 patients with biopsy-proven benign prostatic hyperplasia, in 11 patients with a histologically proven prostate cancer prior to radical retropubic prostatectomy (RRP) and 7 patients with suspected local recurrence (with negative bone scan) after RRP prior to biopsy of anastomosis (3 local recurrence, 4 postoperative scar). RESULTS: Prostate cancer showed a very low F-18 FDG uptake. The placement of regions of interest was only possible by the use of other imaging methods. There was not difference between the F-18 FDG uptake of benign prostate hyperplasia, prostate carcinoma, postoperative scar or local recurrence after radical prostatectomy. CONCLUSION: F-18 FDG seems not to be useful to distinguish between postoperative scar and local recurrence after radical prostatectomy.     

Utilidad de la tomografía de emisión de positrones / tomografía computarizada con 18F-colina en el manejo terapéutico de pacientes con recidiva bioquímica de adenocarcinoma de próstata tratados con braquiterapia

ObjectiveThe objective of the study was to evaluate the usefulness of 18F-choline PET/CT in biochemically recurrent prostate cancer patients treated with brachytherapy, as well as to assess the changes in therapeutic management derived from its outcome.Material and methodsRetrospective study of 20 patients between 51 and 78 years old, with a history of prostate adenocarcinoma that had been treated with brachytherapy and presented biochemical recurrence (PSA 3.1-12  ng/ml) and staging tests (CT and bone scan) without alterations, were included. The findings visualized in the PET/CT scan with ¹⁸F-choline were correlated with the histopathology and/or the evolution of the PSA after therapy.Results¹⁸F-choline PET/CT scan only detected local recurrence in 15 patients. Local and regional recurrences were seen in 4 patients, and 1 patient presented local and bone recurrence. Local recurrence detected in PET was confirmed by anatomopathological studies in 85% of the cases. In one patient, these findings (PET scan) turned out to be prostatitis, and it could not be confirmed in another patient. Of the cases with local and regional recurrence, local recurrence was histologically confirmed in 3 out of 4 patients. ¹⁸F-choline PET/CT changed the therapeutic management in 25% of the patients, discarding the initially planned salvage surgery in 3 cases, 1 radiotherapy and 1 brachytherapy.Conclusion¹⁸F-choline PET/CT could be a useful technique in the group of patients with biochemical recurrence after brachytherapy, providing locoregional and distant involvement findings which had not been detected with conventional imaging tests, thus determining a more adequate therapeutic management.     

Resectability and survival in retroperitoneal sarcomas

Background: Retroperitoneal sarcomas historically have presented difficulties in their management due to a high rate of unresectability, which affects the survival of these patients. Methods: We retrospectively reviewed the charts of 87 consecutive patients with retroperitoneal sarcomas treated in the period 1977–1994. Results: The resectability rate was 100% for the primary tumors (n=55) and 87% for the locally recurrent tumors (n=32). The 5-year survival rate was 63% (66% for the primary tumors and 57% for those with local recurrence). The 10-year survival rate was 46% (57% for primary tumors and 26% for those referred with locally recurrent tumor). The overall local recurrence rate was 31% (25% for the primary tumors and 41% for those referred with local recurrence); it was 56% after local excision and 15% after wide resection (p=0.0003). The 10-year disease-free survival of patients with local excision (n=25) was 7%, and that of patients with wide resection (n=54) 59% (p=0.0001). Conclusions: The overall resectability rate of retroperitoneal sarcomas was 95%. Wide resection produced a significantly higher survival rate compared with that of local excision. The survival rate for the primary tumors, varying significantly with the histologic grade, approached the rate reported for primary soft-tissue sarcomas of the extremity.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.     

Diagnosis of renal and hepatic cyst infections by 18-F-fluorodeoxyglucose positron emission tomography in autosomal dominant polycystic kidney disease

Background:Infection of a renal or hepatic cyst is a serious complication of autosomal dominant polycystic kidney disease (ADPKD). Although crucial for successful management, early diagnosis is difficult, largely because of nonspecific symptoms and limitations of conventional imaging techniques. Because of an increased metabolic rate, inflammatory cells take up large amounts of glucose. 18-F-fluorodeoxyglucose (FDG), therefore, represents a promising agent for detection of cyst infections using positron emission tomography (PET).Methods:The authors studied the results of 7 FDG PET scans in 3 ADPKD patients suspected of renal or hepatic cyst infection. Two PET scans were performed in patient A (PET 1 and 2), one PET scan was performed in patient B (PET 3), and 4 PET scans were performed in patient C (PET 4, 5, 6 and 7).Results:FDG PET identified the infected cysts in 2 episodes of renal cyst infection (PET 2 and 3), 2 episodes of hepatic cyst infection (PET 6 and 7), and 1 episode of both renal and hepatic cyst infection (PET 1). In patient C, FDG PET was normal after 6 weeks of antibiotic treatment for hepatic cyst infection (PET 4) and again at a time when hepatic cyst infection was suspected, but eventually colchicine intoxication was diagnosed (PET 5).Conclusion:In these patients, FDG PET proved very helpful in diagnosing and in excluding renal and hepatic cyst infections. It is concluded that FDG PET is a promising new imaging technique enabling early identification of renal and hepatic cyst infections in ADPKD patients.     

Wound complications after resection and immediate postoperative brachytherapy in the management of soft-tissue sarcomas

Background: When used as the sole source of postoperative radiotherapy, brachyradiation therapy (BRT) (4,500–6,000 cGy) should be delayed beyond the fourth postoperative day to minimize wound complications. However, when 1,000–2,000 cGy BRT are given as a “boost” to the tumor bed, it is unclear if a similar treatment delay is necessary. The purpose of this review was to determine the incidence of wound complications when BRT (1,000–2,000 cGy) is administered ⩽48 h after soft-tissue sarcoma resection. Methods: The results of treatment in 21 patients with soft-tissue sarcomas of the extremity and superficial trunk treated with resection, immediate postoperative brachytherapy, and external beam radiation were reviewed. All patients were followed through the completion of radiation (median follow-up 30 months). A median of seven (range 3–24) after-loading catheters were placed at the time of resection and were loaded with iridium-192 a median of 2 days postoperatively to deliver 1,000–2,000 cGy radiation. Results: Eight patients (38%) experienced minor wound complications (seromas, wound separation, and flap edge necrosis) within 30 days of operation. There were no early complications that required reoperation or delayed further therapy. Conclusions: Brachytherapy (1,000–2,000 cGy) can be administered ⩽48 h postoperatively with a low risk of major wound complications. Minor wound complications are common but do not delay further treatment.     

A retained plastic protective cover mimicking malignancy: Case report

INTRODUCTIONCases of retained foreign bodies during surgery are more frequently seen in developing countries. Following surgical procedures, unintentionally retained foreign bodies can cause serious complications, in addition to medico-legal issues.PRESENTATION OF CASEA 60-year-old man presented with abdominal cramps. He had previously undergone a laparoscopic radical right nephrectomy due to renal cell carcinoma. Abdominal tomography revealed a mass surrounding the main vascular structures with malignant features in the location of previously performed nephrectomy. Further evaluation of the mass was undertaken by PET/CT. Increased FDG uptake on the PET/CT scan suggested disease recurrence. Retroperitoneal lymph node dissection was performed. The dissection specimen was opened to determine the nature of the mass. Retained plastic foreign bodies were found. There were no malignant cells in the histopathological examination of the surgical specimen.DISCUSSIONA granulomatous reaction which is mainly responsible for morbidity occurs around the foreign bodies due to the inflammatory response. These granulomas may cause confusion during patient follow-up, especially in those who have undergone major abdominal surgery due to cancer.CONCLUSIONFollowing surgical resection for malignancy, unintentionally retained foreign bodies can produce a moderate increase in FDG uptake mimicking disease recurrence.     

Detection of recurrent and metastatic colorectal cancer: Comparison of positron emission tomography and computed tomography

Background: This study evaluates the clinical value of positron emission tomography (PET) with 2-[F-18] fluoro-2-deoxy-D-glucose (FDG) as compared to computed tomography (CT) in patients with suspected recurrent or metastatic colorectal cancer (CRC). Methods: A retrospective review of the records of 58 patients who had FDG-PET for evaluation of recurrent or advanced primary CRC was performed. FDG-PET results were compared with those of CT and correlated with operative and histopathologic findings, or with clinical course and autopsy reports. Results: Recurrent or advanced primary CRC was diagnosed in 40 and 11 patients, respectively. The sensitivity and specificity of FDG-PET were 91% and 100% for detecting local pelvic recurrence, and 95% and 100% for hepatic metastases. These values were superior to CT, which had sensitivity and specificity of 52% and 80% for detecting pelvic recurrence, and 74% and 85% for hepatic metastases. FDG-PET correctly identified pelvic recurrence in 19 of 21 patients; CT was negative in 6 of these patients and equivocal in 4. FDG-PET was superior to CT in detecting multiple hepatic lesions and influenced clinical management in 10 of 23 (43%) patients. Conclusion: FDG-PET is more sensitive than CT in the clinical assessment of patients with recurrent or metastatic CRC, and provides an accurate means of selecting appropriate treatment for these patients. Presented at the 50th Annual Cancer Symposium of The Society of Surgical Oncology, Chicago, Illinois, March 20–23, 1997.     

Assessing prognosis for high-grade soft-tissue sarcomas: Search for a marker

Background: Although improved staging technology, limb-sparing surgery, and adjunctive radiation and chemotherapy have improved the outlook for patients with malignant soft-tissue tumors of the trunk and extremities, it is evident that we cannot predict which patients will develop distant metastases. Although local control is now frequently achieved, most series of high-grade soft-tissue sarcomas carry a mortality rate of >50%. Methods: In a retrospective study of 93 patients with high-grade sarcomas treated between 1986 and 1992 for whom complete studies including size and volume measurements and DNA ploidy determinations as assessed by flow cytometry were available, a search for a marker for increased risk of metastasis or death was performed. Results: Grade of the lesion, sex, diagnosis, anatomical site, ploidic data (including mean DNA index and presence of an aneuploid peak), and treatment factors (including type of surgery, local recurrence, or radiation protocol) did not correlate with outcome. Age (younger patients did better), size (greatest diameter) and volume, and positive margins at surgery correlated with total survival. Conclusions: The results of the study, although negative, point out that using anatomical site, diagnosis, or ploidic analysis offers little toward anticipating outcome, whereas the size of the tumor is important.     

Preoperative idoxuridine and radiation for large soft tissue sarcomas: Clinical results with five-year follow-up

Background: Local control remains an important issue in the management of large soft tissue sarcomas. Radiation is the main adjuvant to surgery for local therapy of sarcomas, but it requires relatively high doses, hitherto considered prohibitive in areas such as the retroperitoneum. We developed a preoperative treatment approach to large soft tissue sarcomas that would deliver a high total dose of radiation administered in conjunction with the halogenated pyrimidine radiosensitizer idoxuridine (IdUrd). Methods: Thirty-seven patients with large sarcomas of the head and neck, mediastinum, retroperitoneum, or extremity received three or five cycles of sequential IdUrd infusion (1000–1600 mg/m²/d×5 d) alternating weekly with twice daily radiation (125–150 cGy per dose) and were then evaluated for resection. The delivered preoperative radiation dose was up to 6250 to 7500 cGy. Results: Five patients (14%) had a partial response to preoperative therapy, and 28 of 37 patients underwent successful resection. There were no intra- or postoperative deaths. Local control was achieved in 19 of 28 resected patients, but in only 1 of 6 patients who remained unresectable despite therapy. With a median follow-up of 5.8 years, 28% of patients are alive with no evidence of disease, 17% are alive with disease, and 53% have died of their disease. Conclusions: Using the dose and schedule we employed, resection of large soft tissue sarcomas was possible after high-dose radiation delivered in conjunction with IdUrd. Although local control was acceptable, the high rate of distant failure represents a limitation of any local approach to the treatment of large soft tissue sarcomas and suggests the need for integration of this approach with an effective systemic therapy. Presented at the 50th Annual Cancer Symposium of The Society of Surgical Oncology, Chicago, Illinois, March 20–23, 1997.     

Value of fluorodeoxyglucose positron emission tomography in characterizing clinically‐significant thyroid carcinomas

Background: Despite the rising incidence of thyroid incidentalomas, their clinical significance remains unclear. The present study aimed to determine whether fluorodeoxyglucose positron emission tomography (FDG‐PET) is associated with a significantly higher risk of clinically‐significant thyroid carcinoma (CSC) in incidentalomas than other non‐functional imaging modalities. Methods: Over a 2‐year period, 89 patients were identified as having a thyroid incidentaloma. All patients had either surgery or fine needle aspiration cytology (FNAC) with a 12‐month follow up to confirm the nature of the incidentaloma. Surgery was carried out for nodules with malignant or indeterminate FNAC result, or those with in a retrosternal location, with size > 4 cm or local symptoms. Results: A total of 21 (23.6%) patients had their incidentaloma detected by FDG‐PET (PET group) and 68 (76.4%) by non‐PET imaging modalities (non‐PET group). Differentiated thyroid carcinoma was confirmed in 18 (20.2%) patients. The rate of malignancy was 61.9% in the PET group and 7.4% in the non‐PET group (P = 0.001). After excluding the occult microcarcinomas, the risk of malignancy reduced to 14.6%, but the difference in malignancy rate became more marked between the PET and non‐PET group (42.9% vs 2.9%, P = 0.001). The maximum standardized uptake value on FDG‐PET was similar between benign and malignant lesions (P = 0.124). Conclusion: The overall risk of CSC in thyroid incidentalomas was 14.6%. Those detected by FDG‐PET were significantly more likely to harbour CSC than those by non‐functional modalities. Incidentalomas with focal FDG uptake should be thoroughly investigated with USG and FNAC.     

Local recurrence in breast cancer: Implications for systemic disease

Background: Recurrence in breast carcinoma follows a pattern of growth marked by local, regional, or widespread dissemination. Local recurrence may be the harbinger of systemic disease or failure of local control. Delineation of these processes may have implications in treatment. Methods: A retrospective review found 1,171 patients with stages I and II breast cancer from 1978 to 1990 treated at the City of Hope Medical Center. Results: Twenty-seven percent (n=313) of patients developed recurrences. These were classified as local, including chest wall and regional nodes (n=40), local and distant (n=63), and distant (n=210). Mean follow-up was 60 months. Multivariate analysis demonstrates tumor size was not different between the three groups, but the presence of positive lymph nodes was: local=51%, local and distant=78%, and distant=64%. The disease-free interval was longest in the local group (42 months) versus the local and distant group (23 months) and distant group (39 months). Median survival was calculated from the time of recurrence: local=90 months, local and distant=26 months, and distant=16 months. Conclusions: A group of patients with local recurrence have improved survival and do not develop distant disease. This group may benefit from aggressive surgical treatment to control local disease. These data suggest that a subset of breast tumors can act locally aggressive without metastatic potential. Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.     

What Are Risk Factors for Local Recurrence of Deep High-grade Soft-tissue Sarcomas?

Background  

Patients with local recurrence of soft-tissue sarcomas have a poor overall survival. High-grade, soft-tissue sarcomas in deep locations may have a poorer prognosis regarding local recurrence than low-grade sarcomas or those located superficially. Although previous reports evaluated tumors at various depths, it is unclear what factors influence recurrence of deep, high-grade sarcomas.     

Local recurrence in malignant melanoma: Long-term results of the multiinstitutional randomized surgical trial

Background: In the past, radical margins of excision were prescribed for cutaneous melanoma based on preconceived notions rather than on hard clinical evidence. Methods: In a prospective study of 742 patients with intermediate-thickness melanoma (1–4 mm), 470 patients with trunk or proximal extremity lesions were randomized into a 2-or 4-cm margin. Patients with distal extremity or head and neck lesions (n=272) received uniformly a 2-cm margin. Results: The overall rate of local recurrence was 3.8%. This rate in the randomized portion (n=470) was 2.1% for the 2-cm margin and 2.6% for the 4-cm margin (p=0.72). A progressive increase in local recurrence rates was observed with thickness: 2.3% for lesions 1.0–2.0 mm, 4.2% for those 2.01–3.0 mm, and 11.7% for those 3.01–4.0 mm thick (p=0.001). Local recurrence occurred in 1.5% of those without ulceration and in 10.6% of those with ulceration of the primary lesion (p=0.001). The local recurrence rate was not significantly affected by the margin of resection even among the thicker or ulcerated lesions. It also was not affected significantly by the method of closure of the primary site or management of the regional nodes, or the age or gender of the patients. Conclusions: A 2-cm margin is as effective as a 4-cm margin in local control and survival of intermediate-thickness melanomas. The local recurrence rate is significantly affected by the thickness of the primary lesion and the presence or not of ulceration. Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1996.     

FDG-PET for evaluating musculoskeletal tumors: a review

 Positron-emission tomography (PET) can provide an in vivo method for evaluating metabolism and physiology in normal and diseased tissues. Clinical trials with [¹⁸F]2-deoxy-2-fluoro-d-glucose (FDG), the most commonly used radiolabeled tracer for PET imaging, have demonstrated increased accumulation of FDG in several cancer tissues. In this article, we introduce the basic principles of FDG-PET and review current knowledge about FDG-PET for evaluating musculoskeletal tumors. Recent reports and our own experience suggest that FDG-PET cannot be a screening method for differential diagnosis between benign and malignant musculoskeletal lesions, including many neoplasms originating from different tissues altogether. FDG-PET might not accurately reflect the malignant potential of musculoskeletal tumors, but rather might implicate cellular components included in the lesions. A high accumulation of FDG can be observed in histiocytic, fibroblastic, and some neurogenic lesions, regardless of whether they are benign or malignant. More specific uses of FDG-PET, such as grading, staging, and monitoring of musculoskeletal sarcomas, should be considered for each tumor of a different histologic subtype. Received: October 2, 2001 RID="*"     

The value of 18F‐FDG PET/CT in diagnosing and localising deep sternal wound infection to guide surgical debridement

Deep sternal wound infection (DSWI) is a severe complication in patients after open heart surgery (OHS). But there is a lack of appropriate imaging tool to detect the infection sites, which may lead to incomplete debridement. The present study aims to investigate the value of ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F‐FDG PET/CT) in comparison with CT scan in diagnosing and localising DSWI. A total of 102 patients with DSWI after OHS were retrospectively collected from January 2012 to December 2017 in our hospital. All the patients had surgical debridements for DSWI with pretreatment imaging of either ¹⁸F‐FDG PET/CT or CT scan. The sensitivity, specificity, and accuracy of localising infection sites were compared between PET/CT and CT groups, with surgical, microbiological, and histopathological findings as the gold standard. The length of hospital stays and the rate of recurrence were also compared. Ten patients in the PET/CT group had a follow‐up PET/CT scan after debridement, and the correlations between the changes of PET/CT findings and surgical outcomes were analysed. ¹⁸F‐FDG PET/CT is more accurate than CT in diagnosing and localising DSWI after OHS, which leads to a more successful surgical debridement with a lower rate of recurrence and a shorter length of hospital stay. In addition, follow‐up PET/CT after debridement could evaluate the treatment effect.     

Incidental focal colonic lesions found on 18Fluorodeoxyglucose positron emission tomography/computed tomography scan: further support for a national guideline on definitive management

Aim ¹⁸Fluorodeoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT) is an established part of staging in a wide variety of malignancies. Incidental abnormal uptake of ¹⁸FDG of unknown significance is frequently encountered. Therefore, we investigated patients with abnormal colonic uptake of ¹⁸FDG, determined by PET/CT images, using colonoscopy. Method The radiology reports of all patients referred to a tertiary referral centre for a PET/CT scan were reviewed retrospectively. Patients with abnormal colonic uptake of ¹⁸FDG were identified and the PET/CT findings were correlated with colonoscopic findings. Results Of 555 consecutive patients identified over a 26‐month period, 53 had abnormal colonic uptake of ¹⁸FDG, as determined by PET/CT images. Twenty‐nine were not investigated following discussion in a specialist multidisciplinary (MDT) meeting, according to local protocol. Twenty out of 24 patients investigated by endoscopy had a colonic lesion correlating to the site identified on the PET/CT image: 16 patients had tubulovillous adenomas (nine of which were > 10 mm), two had invasive adenocarcinomas, two had diverticular disease and one had collagenous colitis; no colonic lesion was detected in three. These findings were incidental and not related to the primary diagnosis for which the scan was being performed. Accordingly, a positive predictive value of 83% is associated with the finding of abnormal uptake of ¹⁸FDG on PET/CT images. Conclusion Incidental abnormal colonic uptake of ¹⁸FDG, determined by a PET/CT scan requires definitive colonic investigation in patients suitable for further treatment because significant colonic pathology is frequently identified. The benefit of this approach should be discussed in specialist MDT meetings and tailored to each patient; however, national guidelines for management are required.     

Application of whole-body positron emission tomography in the imaging of esophageal cancer: Report of a case

We describe herein a case of esophageal cancer in which both primary and metastatic lymph node foci were successfully imaged with whole-body positron emission tomography (PET) scanning. A 75-year-old woman with biopsy-proven squamous cell carcinoma of the esophagus underwent whole-body PET scanning for staging evaluation. The patient was injected with 373.7 MBq [¹⁸F]-2-fluoro-2-d-deoxyglucose (FDG), and 60 min later, scanning was performed from the neck to the pelvis. The whole-body images showed intense FDG uptake in the primary lesion and multiple focal areas of increased FDG uptake in the mediastinum and abdomen, which corresponded to the lymph node foci confirmed by computed tomography (CT) scan. To our knowledge, this is the first report of whole-body PET scanning being applied in the imaging of esophageal cancer.