Impact of fluorine-18 fluorodeoxyglucose positron emission tomography on patient management: first year's experience in a clinical center.

PURPOSE: To measure the impact of whole-body fluorodeoxyglucose (FDG) positron emission tomography (PET) on patient management during its first year of use in a community hospital. MATERIALS AND METHODS: First-year FDG-PET impact was determined from 463 referring physicians' evaluations of their patients' PET imaging results using two surveys. Survey 1 was given to all physicians referring patients to PET to discover whether PET changed patient management or had decision-making value in the patient's clinical algorithm. Survey 2 was given to one surgeon and one pulmonologist after therapy to determine how PET affected the surgical, chemotherapeutic, and/or radiotherapeutic treatment for the 53 cancer patients they referred. RESULTS: The 463 responses to survey 1 described 23 different PET indications. Lung (40%), head and neck (18%), and colorectal cancers (11%) were the three leading causes of referral. PET changed patient management/therapy in 45% of all patients referred and had inferential/decision-making value in another 44%. Overall, PET had some type of positive influence in 412 (89%) of the patients. Survey 2 provided a more detailed assessment of 53 referrals from two specialists. PET positively affected surgery in 31 patients (58%), prompted the addition of chemotherapy or radiation therapy in nine patients (17%), and eliminated chemotherapy or radiation therapy in four cases (8%). Overall, PET affected patient management/therapy in 70% of the cases and had some decision-making value in another 26%, for a combined PET impact on patient management of 96%. CONCLUSION: FDG-PET can be valuable for physicians in clinical practice. Its sensitivity and specificity in metabolic imaging, when combined with complementary anatomic imaging techniques, contribute significantly to the clinical treatment of cancer patients. In addition, the high accuracy of FDG-PET makes it a cost-effective radiologic procedure in the work-up of all suspected and/or recurrent cancer patients. Further research is needed to link this demonstrated impact on patient management to cost-effectiveness.     

The impact of positron emission tomography (PET) on expected management during cancer treatment

BACKGROUND:

Positron emission tomography (PET) performed during cancer therapy (treatment monitoring) has shown promise for predicting treatment outcome. However, when used for this purpose, PET generally is not considered standard care. Under the Medicare ‘coverage with evidence development’ policy, PET (and integrated PET/computed tomography) became a covered service for treatment monitoring if prospective registry data were collected.

METHODS:

The National Oncologic PET Registry collected questionnaire data on intended patient management before and after PET. Data were available from 8240 patients who had 10,497 treatment‐monitoring PET scans at 946 centers; these studies were used to monitor chemotherapy alone (82%), radiation therapy alone (6%), or combined‐modality treatment (12%). Ovarian, pancreatic, and lung cancers accounted for 37% of the cohort. In 54% of scans, the pre‐PET summary stage was metastatic disease.

RESULTS:

If PET had not been available, then the pre‐PET plan would have been other imaging (53%), ongoing treatment (41%), or biopsy or watching (6%). Change in the post‐PET intended management was similar in the imaging and treatment groups: 26% to 28% of scans to switching to another therapy, and 16% to 19% scans led to adjustment of the dose or duration of therapy. Changes in management were more frequent if the referring physician judged that the post‐PET prognosis was worse rather than improved or unchanged (78% vs 40%). The physicians indicated that PET enabled 91% of their patients to avoid future tests.

CONCLUSIONS:

Physicians often report plans to modify their therapeutic plans in elderly cancer patients when PET is used for treatment monitoring. Cancer 2009. © 2009 American Cancer Society.     

Clinical impact of (18)F fluorodeoxyglucose positron emission tomography in patients with non-small-cell lung cancer: a prospective study.

PURPOSE: To prospectively study the impact of (18)F fluorodeoxyglucose (FDG) positron emission tomography (PET) on clinical management of patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: One hundred five consecutive patients with NSCLC undergoing (18)F FDG PET were analyzed. Before PET, referring physicians recorded scan indication, conventional clinical stage, and proposed treatment plan. PET scan results were reported in conjunction with available clinical and imaging data, including results of computed tomography (CT). Subsequent management and appropriateness of PET-induced changes were assessed by follow-up for at least 6 months or until the patient's death. RESULTS: Indications for PET were primary staging (n = 59), restaging (n = 34), and suspected malignancy subsequently proven to be NSCLC (n = 12). In 27 (26%) of 105 of cases, PET results led to a change from curative to palliative therapy by upstaging disease extent. Validity of the PET result was established in all but one case. PET appropriately downstaged 10 of 16 patients initially planned for palliative therapy, allowing either potentially curative treatment (four patients) or no treatment (six patients). PET influenced the radiation delivery in 22 (65%) of 34 patients who subsequently received radical radiotherapy. Twelve patients considered probably inoperable on conventional imaging studies were downstaged by PET and underwent potentially curative surgery. PET missed only one primary tumor (5-mm scar carcinoma). CT and PET understaged three of 20 surgical patients (two with N1 lesions < 5 mm and one with unrecognized atrial involvement), and PET missed one small intrapulmonary metastasis apparent on CT. No pathological N2 disease was missed on PET. CONCLUSION: FDG PET scanning changed or influenced management decisions in 70 patients (67%) with NSCLC. Patients were frequently spared unnecessary treatment, and management was more appropriately targeted.     

Impact of whole-body 18F-FDG PET on diagnostic and therapeutic management of Medical Oncology patients

AimMost studies evaluating positron-emission tomography (PET) impact on decision making are based on questionnaires sent to referring physicians, with low response rates and potential bias. Studies directly evaluating influence of PET on routine management of Medical Oncology patients are scarce.Patients and methodsWe retrospectively studied all patients evaluated by whole-body ¹⁸F-FDG PET during 1 year in a Haematology/Oncology Department. We collected information regarding indication, PET results, modification of diagnostic and therapeutic management and adequacy of therapeutic changes.ResultsOne hundred consecutive patients having PET were evaluated. Diagnostic strategy was modified in 63% of patients (30% avoiding biopsy). Therapeutic management was modified by PET in 34% of cases: changes were classified as adequate in 30% and as inadequate in 4% of patients.ConclusionsOur study shows a major impact of PET in the diagnostic and therapeutic management of cancer patients and supports its introduction as a routine diagnostic tool in Medical Oncology.     

Clinical utility of gene-expression profiling for tumor-site origin in patients with metastatic or poorly differentiated cancer: impact on diagnosis, treatment, and survival

PURPOSE

The primary tissue-site origin in over 4% of cancers remains uncertain despite thorough clinicopathological evaluation. This study assessed the effect of a Food and Drug Administration-cleared 2,000-gene–expression-profiling (GEP) test on primary tissue-site working diagnoses and management for metastatic and poorly differentiated cancers.

METHODS

Clinical information was collected from physicians ordering the GEP test for patients with difficult to diagnose cancers. Endpoints included diagnostic procedures, physicians’ working diagnoses and treatment recommendations before and after GEP result availability, and physician reports of the test''s usefulness for clinical decision making. Patient date of death was obtained, with a minimum of one year follow-up from date of biopsy.

RESULTS

Sixty-five physicians participated in the study (n=107 patients). Before GEP, patients underwent 3.2 investigations on average (e.g., radiology, endoscopy). Ten immunohistochemistry tests were used per biopsy (SD 5.2). After GEP testing, physicians changed the primary working diagnosis for 50% of patients (95% CI: 43%,58%) and management for 65% of patients (95% CI: 58%,73%). With GEP results, the recommendation for guideline-consistent chemotherapy increased from 42% to 65% of patients, and the recommendation for non-guideline-consistent regimens declined from 28% to 13%. At last follow-up, 69 patients had died, and median survival was 14.0 months (95% CI: 10.2,18.6). Thirty-three percent of patients were alive at 2 years.

CONCLUSION

In patients with difficult-to-diagnose cancers, GEP changed the working diagnosis and management for the majority of patients. Patients for whom the GEP test was ordered had longer median survival than that historically reported for patients enrolled in treatment trials for cancer of unknown primary.     

Utility of PET/CT imaging performed early after surgical resection in the adjuvant treatment planning for head and neck cancer

PURPOSE: To evaluate the utility of positron emission tomography (PET)/computed tomography (CT) early after surgical resection and before postoperative adjuvant radiation therapy. METHODS AND MATERIALS: We studied a prospective cohort of 91 consecutive patients referred for postoperative adjuvant radiation therapy after complete surgical resection. Tumor histologies included 62 squamous cell and 29 non-squamous cell cancers. Median time between surgery and postoperative PET/CT was 28 days (range, 13-75 days). Findings suspicious for persistent/recurrent cancer or distant metastasis were biopsied. Correlation was made with changes in patient care. RESULTS: Based on PET/CT findings, 24 patients (26.4%) underwent biopsy of suspicious sites. Three patients with suspicious findings did not undergo biopsy because the abnormalities were not easily accessible. Eleven (45.8%) biopsies were positive for cancer. Treatment was changed for 14 (15.4%) patients (11 positive biopsy and 3 nonbiopsied patients) as a result. Treatment changes included abandonment of radiation therapy and switching to palliative chemotherapy or hospice care (4), increasing the radiation therapy dose (6), extending the radiation therapy treatment volume and increasing the dose (1), additional surgery (2), and adding palliative chemotherapy to palliative radiation therapy (1). Treatment for recurrent cancer and primary skin cancer were significant predictors of having a biopsy-proven, treatment-changing positive PET/CT (p < 0.03). CONCLUSIONS: Even with an expectedly high rate of false positive PET/CT scans in this early postoperative period, PET/CT changed patient management in a relatively large proportion of patients. PET/CT can be recommended in the postoperative, preradiation therapy setting with the understanding that treatment-altering PET/CT findings should be biopsied for confirmation.     

PET imaging for suspected residual tumour or thoracic recurrence of non-small cell lung cancer after pneumonectomy

F-18 fluorodeoxyglucose-positron emission tomography (PET) was investigated in patients with suspected residual disease or intrathoracic recurrence after pneumonectomy. Patients were identified from a prospective database. Impact of PET on staging and patient management was assessed. Clinical outcome was used to assess appropriateness of management. PET was performed in 17 cases, either post-operatively (n = 8), or later for suspected recurrence (n = 9) in patients with good performance status and without extensive disease on conventional imaging. PET changed treatment in 10 cases (59%). In five patients (29%), PET changed treatment intent (curative versus non-curative) from radical radiotherapy (RT) to palliative RT (n = 1), or observation or supportive care (n = 3), or from palliative to radical RT (n = 1). In a further patient with unexplained pain, PET appropriately showed no evidence of disease. In additional five cases (29%), PET influenced choice of RT dose and the use of concurrent chemotherapy (n = 3) or target volume (n = 2). Patients without tumour or with limited disease on PET had favourable outcomes whereas those with extensive disease suffered early tumour progression. PET was discordant with conventional assessment in >50% of cases. PET may be valuable after pneumonectomy if the patient is being considered for adjuvant or salvage radiotherapy although specificity may be reduced due to post-operative inflammatory changes.     

Impact of [18f] fluorodeoxyglucose positron emission tomography on staging and management of early-stage follicular non-hodgkin lymphoma

PURPOSE: Accurate staging is critical to select patients with early-stage (I-II) follicular lymphoma (ESFL) suitable for involved-field radiotherapy (IFRT) and to define the radiotherapy portal. We evaluated the impact of fluorodeoxyglucose (FDG) PET on staging, treatment, and outcome for patients with ESFL on conventional staging. METHODS AND MATERIALS: Forty-two patients with untreated ESFL (World Health Organization Grade I-IIIa, or "low grade") following a minimum of physical examination, computerized tomography, and bone marrow examination (conventional assessment) and who had staging PET from June 1997 to June 2006 were studied retrospectively. Stage allocation was based on routine imaging reports. Disease sites, stage, and management plan were recorded based on conventional assessment or conventional assessment plus PET. RESULTS: FDG avidity was demonstrated in 97% of patients in whom disease was evident on conventional assessment after biopsy. PET findings suggested a change of stage or management in 19 patients: 13 (31%) who were upstaged to Stage III-IV, altering ideal management from IFRT to systemic therapy, and 6 (14%) who had the involved field enlarged, including 4 upstaged from Stage I to II. Of these 19 cases, PET findings were considered true positive in 8 patients, indeterminate in 10, and false positive in only 1 patient. CONCLUSIONS: Our data confirm that ESFL is usually FDG-avid. In routine practice, PET has the potential to upstage and thereby alter management in a high proportion of patients with apparent ESFL.     

Value of FDG PET/Contrast-Enhanced CT in Initial Staging of Colorectal Cancer - Comparison with Contrast-Enhanced CT

Background FDG PET/CT is at an equivocal stage to recommend for staging of colorectal cancer as compared to contrast-enhanced CT (ceCT). This study was intended to evaluate the value of FDG PET/ceCT in colorectal cancer staging as compared to ceCT alone. Materials and Methods PET/ceCT was performed for 61 colorectal cancer patients who were prospectively enrolled in the study. Three patients were excluded due to loss to follow-up. PET/ceCT ndings and ceCT results alone were read seperately. The treatment planning was then determined by tumor board consensus. The criteria for T staging were determined by the ndings of ceCT. Nodal positive by PET/ceCT imaging was determined by visual analysis of FDG uptake greater than regional background blood pool activity. The diagnostic accuracy of T and N staging was determined only in patients who received surgery without any neoadjuvant treatment. Results Of 58 patients, there were 40 with colon cancers including sigmoid cancers and 18 with rectal cancers. PET/ceCT in pre-operative staging detected bone metastasis and metastatic inguinal lymph nodes (M1a) that were undepicted on CT in 2 patients (3%), clearly de ned 19 equivocal lesions on ceCT in 18 patients (31%) and excluded 6 metastatic lesions diagnosed by ceCT in 6 patients (10%). These resulted in alteration of management plan in 15 out of the 58 cases (26%) i.e. changing from chemotherapy to surgery (4), changing extent of surgery (9) and avoidance of futile surgery (2). Forty four patients underwent surgery within 45 days after PET/CT. The diagnostic accuracy for N staging with PET/ceCT and ceCT alone was 66% and 48% with false positive rates of 24% (6/25) and 76% (19/25) and false negative rates of 47% (9/19) and 21% (4/19), respectively. All of the false negative lymph nodes from PET/ceCT were less than a centimeter in size and located in peri-lesional regions. The diagnostic accuracy for T staging was 82%. The sensitivity of the peri-lesional fat stranding sign in determining T3 stage was 94% and the speci city was 54%. Conclusions Our study suggested promising roles of PET/ceCT in initial staging of colorectal cancer with better diagnostic accuracy facilitating management planning.     

Therapeutic impact of 2-[fluorine-18]fluoro-2-deoxy-D-glucose positron emission tomography in the pre- and postoperative staging of patients with clinically intermediate or high-risk breast cancer.

BACKGROUND: Positron emission tomography with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG-PET) is an accurate imaging modality for the staging of breast cancer. The aim of this study was to determine the potential therapeutic impact of pre- and postoperative FDG-PET in patients with clinically intermediate or high-risk breast cancer. PATIENTS AND METHODS: One hundred and fourteen patients with newly diagnosed breast cancer were examined before (73) or after (41) surgery. Patient data were translated into three scoring sheets corresponding to information available before positron emission tomography (PET), after PET and after further diagnostic tests. Three medical oncologists independently reviewed the retrospectively acquired patient data and prospectively made decisions on the theoretically planed treatment for each time point, according to the recommendations of St Gallen Consensus Guidelines 2005. RESULTS: FDG-PET changed the planed treatment in 32% of 114 patients. In 20% of cases, therapeutic intention (curative versus palliative) was modified. Radiation treatment planning was changed in 27%, surgical planning in 9%, chemotherapy in 11% and intended therapy with bisphosphonates in 13% of all patients. CONCLUSION: Based on current treatment guidelines, FDG-PET, as a staging procedure in patients with newly diagnosed clinically intermediate or high-risk breast cancer examined pre- and postoperatively, may have a substantial therapeutic impact on treatment planning.     

18F FDG PET/CT对恶性肿瘤放射治疗方法的影响

目的：探讨^18F FDG PET／CT对恶性肿瘤放射治疗的影响方法：对148例恶性肿瘤治疗前行PET／CT扫描，对扫描前后检出病灶进行定性分析，重新确定期别和治疗方法结果：PET／CT扫描发现恶性或可疑病灶79个，25个病灶排除或修正诊断52例检出病灶与检查前不符，28例重新分期，12例修正诊断，57例治疗方法发生改变。结论：放射治疗前PET／CT检查，提高诊断准确性和定位的精确性，减少病灶的遗漏，对制定合理有效的治疗方案具有指导价值。     

前列腺特异性膜抗原PET/CT对中高危前列腺癌初始TNM分期及临床治疗策略的影响

  目的  评估前列腺特异性膜抗原（prostate-specific membrane antigen,PSMA）正电子发射计算机断层显像（positron emission tomography/computed tomography,PET/CT）对中高危前列腺癌初始临床分期及治疗策略的影响。  方法  回顾性分析2019年10月至2021年11月63例于重庆大学附属肿瘤医院初诊的中高危前列腺癌患者的临床及影像资料。比较PSMA PET/CT和传统影像学对前列腺癌病灶检出率及TNM分期的差异,评估PSMA PET/CT对治疗计划的影响。  结果  PSMA PET/CT对区域外淋巴结和骨转移的检出率分别为23.81%（15/63）和52.38%（33/63）,较传统影像学的检出率3.17%（2/63）和25.40%（16/63）高,差异具有统计学意义（均P<0.001）。PSMA PET/CT检查后53.97%（34/63）患者TNM分期发生改变,N、M分期上调（均P<0.05）;22.22%（14/63）患者的治疗计划发生改变。  结论  PSMA PET/CT检查后上调中高危前列腺癌初始TNM分期中的N、M分期,导致超过20%患者临床治疗策略发生改变。PSMA PET/CT可成为精准评估中高危前列腺癌肿瘤负荷的首选影像学检查。      

18-FDG PET-CT should be included in preoperative staging of gall bladder cancer

BackgroundOnly few retrospective studies have looked into the ability of PET-CT to diagnose distant metastases in gall bladder cancer (GBC) patients with variable results. This study aims to determine the utility of PET –CT in potentially resectable GBC.MethodsAll GBC patients with resectable disease on CECT chest, abdomen & pelvis were subjected to FDG- PET-CT scan. Incidental GBC was excluded. All additional findings and change in management plan was recorded.ResultsOut of 149 patients, 99 (66.4%) were females and the mean age was 56.7 ± 11.0 years,. After PET scan, additional findings were seen in 46/149 (30.9%) patients and it lead to change in management plan in 35 (23.4%) patients due to the presence of distant metastases. Impact of PET scan in changing the stage was higher in patients having node positive disease on CECT (26/96, 27%) as compared to node negative patients (9/53, 16.9%), but this difference was not statistically significant (p = 0.233). After assessment on CECT, 76 patients were planned for NACT in view of locally advanced disease but after PET-CT in these patients, the management plan changed to palliative chemotherapy in 26 (34.2%) cases whereas it changed in only 9 out of 73 (12.3%) patients who were planned for upfront surgery (p = 0.003).ConclusionOur results show that preoperative staging workup for GBC should include PET-CT as it changed the management plan in approximately one-fourth of all resectable GBC patients and in one-third of locally advanced cases.     

The role of FDG-PET/CT in suspected recurrence of breast cancer

BACKGROUND: Early diagnosis of recurrent breast cancer is crucial to selection of the most appropriate therapy. The current study evaluated the role of FDG-PET/CT in the assessment of suspected recurrent breast cancer in patients who presented with elevated serum tumor markers. METHODS: Forty-seven consecutive FDG-PET/CT studies of 46 women (aged 32-79 years; mean, 59.9 years) with a history of breast cancer presented with elevated serum tumor markers 1-21 years (mean = 6.2 years) after their initial diagnosis and were retrospectively evaluated. PET/CT results were confirmed by pathology (n = 11), further imaging, and follow-up (mean = 17.2 months; n = 36). Changes in further management based on PET/CT were recorded. RESULTS: Thirty (65%) patients had tumor recurrence, and 16 (35%) patients showed no further evidence of disease. Thirty-one patients had 32 abnormal PET/CT studies, and 15 patients had normal studies with an overall sensitivity, specificity, and accuracy of 90%, 71%, and 83%, respectively. In 37 patients, PET/CT was compared with contrast-enhanced CT and had a higher sensitivity (85% vs 70%), specificity (76% vs 47%), and accuracy (81% vs 59%). PET/CT had an impact on the management of 24 (5l%) patients. Of these, chemotherapy or radiotherapy was started in 16 patients, treatment was modified in 2 patients, and 6 patients were referred to biopsy, followed by referral to surgery for 2 patients. CONCLUSIONS: In patients with breast cancer and rising tumor markers, FDG-PET/CT had high performance indices and was superior to CT for diagnosis of tumor recurrence, which led to changes in the subsequent clinical management of 51% of these patients.     

The utility of PET/CT in staging and assessment of treatment response of nasopharyngeal cancer

Introduction: The aim of this study was to evaluate the impact of positron emission tomography/computerised tomography (PET/CT) as an adjunct to conventional imaging (CI) in the management of nasopharyngeal cancer (NPC) both for initial staging and assessment of post‐treatment response. Methods: All NPC cases referred to the Peter MacCallum Centre for Metabolic Imaging between January 2002 and December 2007 were identified. In patients undergoing initial staging, any differences between the pre‐PET/CT management plan based on CI and that following performance of the PET/CT scan were noted. Clinical impact was scored using the Centre's published criteria: 'high' if PET/CT changed the primary treatment modality or intent, ‘medium’ if treatment modality was unchanged but the radiotherapy technique or dose was altered, and ‘low’ if there was no change in treatment modality or intent. Patients undergoing PET/CT following definitive treatment were scored according to whether or not they achieved a complete metabolic response. Results: Forty‐eight patients underwent a staging PET/CT. The clinical impact was high in 8%, medium in 25% and low in 66% of patients. Twenty‐one patients were scanned for post‐treatment response. PET/CT was less frequently equivocal than MRI (3 vs 8/21). A complete metabolic response on PET/CT was associated with a 93% negative predictive value for subsequent recurrence. Conclusion: PET/CT is a valuable staging tool for the detection of occult metastatic disease and defining the extent of neck nodal disease. Post‐treatment, a complete metabolic response on PET/CT has a very high negative predictive value with fewer equivocal results than MRI.     

Routine positron emission tomography and positron emission tomography/computed tomography in melanoma staging with positive sentinel node biopsy is of limited benefit

Positron emission tomography (PET) is increasingly used for the staging and management of melanoma. The aim of this study was to evaluate the role of PET or PET/ computed tomography (CT) as a routine procedure in patients with positive sentinel node biopsy (SNB). Thirty patients with melanoma of Breslow thickness greater than 1 mm who had PET or PET/CT scans performed within 100 days after a positive SNB were reviewed retrospectively. Two patients (6%) had a positive PET scan, none of which were melanoma related. The first patient had a synchronous neuroendocrine thyroid tumour and the second patient had increased uptake in the chest wall, which proved to be old trauma. Lymph node dissection was positive in five cases (16%). With a median follow-up of 24 months, 21 patients remained disease free. In none of the 30 cases did the early PET scan after a positive SNB alter subsequent melanoma management. The role of PET scanning soon after a positive sentinel node biopsy seems to be of limited benefit. It is questionable whether any imaging is beneficial at this stage. The results of this review suggest that PET scanning might not be indicated for this group of patients.     

Cancer pain management by radiotherapists: a survey of radiation therapy oncology group physicians

PURPOSE: Radiation Therapy Oncology Group (RTOG) physicians were surveyed to determine their approach to and attitudes toward cancer pain management. METHODS AND MATERIALS: Physicians completed a questionnaire assessing their estimates of the magnitude of pain as a specific problem for cancer patients, their perceptions of the adequacy of pain management, and their report of how they manage pain in their own practice setting. RESULTS: Eighty-three percent believed the majority of cancer patients with pain were undermedicated. Forty percent reported that pain relief in their own practice setting was poor or fair. Assessing a case scenario, 23% would wait until the patient's prognosis was 6 months or less before starting maximal analgesia. Adjuvants and prophylactic side effect management were underutilized in the treatment plan. Barriers to pain management included poor pain assessment (77%), patient reluctance to report pain (60%), patient reluctance to take analgesics (72%), and staff reluctance to prescribe opioids (41%). CONCLUSIONS: Physicians' perceptions of barriers to cancer pain management remain quite stable over time, and physicians continue to report inadequate pain treatment education. Future educational efforts should target radiation oncologists as an important resource for the treatment of cancer pain.     

Radiotherapy treatment planning and long-term follow-up with [(11)C]methionine PET in patients with low-grade astrocytoma

PURPOSE: To evaluate the feasibility of [(11)C]-methionine positron emission tomography (MET PET) in radiotherapy (RT) treatment planning and long-term follow-up in patients with low-grade glioma. PATIENTS: Thirteen patients with low-grade astrocytoma and 1 with anaplastic astrocytoma underwent sequential MET PET and magnetic resonance imaging (MRI) before and 3, 6, 12, and 21-39 months after RT, respectively. Ten patients were studied after initial debulking surgery or biopsy and 4 in the recurrence phase. METHODS: A total of 58 PET scans were performed. After transmission scanning, a median dose of 425 MBq of MET was injected intravenously and emission data was acquired 20 min after injection for 20 min. The uptake of MET in tumor area was measured as standardized uptake value (SUV) and tumor-to-contralateral brain SUV ratios were generated to assess irradiation effects on tumor metabolism. Functional imaging with PET was compared with concurrent MRI in designing the RT planning volumes and in assessment of response to RT during a median follow-up time of 33 months. RESULTS: In 12 patients (86%), tumor area was clearly discernible in the baseline PET study. In the remaining 2 patients with a suspected residual tumor in MRI, PET showed only a diffuse uptake of MET interpreted as negative in the original tumor area. In the dose planning of RT, MET PET was helpful in outlining the gross tumor volume in 3 of 11 cases (27%), whereas PET findings either coincided with MRI (46%) or were less distinctive (27%) in other cases. In quantitative evaluation, patients with a low tumor SUV initially had significantly better prognosis than those with a high SUV. Tumor-to-contralateral brain uptake ratios of MET discriminated well patients remaining clinically stable from those who have since relapsed or died of disease. CONCLUSION: Quantitative MET PET has prognostic value at the time of initial treatment planning of low-grade glioma. Some patients may benefit of RT volume definition with MET PET, which seems to disclose residual tumor better than MRI in selected cases. Stable or decreasing uptake of MET in tumor area after RT during follow-up seems to be a favorable sign.     

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging in patients with carcinoma of the nasopharynx: diagnostic accuracy and impact on clinical management

PURPOSE: To assess the value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma as compared with PET and conventional imaging (CI) alone, and to assess the impact of PET/CT on further clinical management. METHODS AND MATERIALS: Thirty-three patients with nasopharyngeal carcinoma had 45 PET/CT examinations. The study was a retrospective analysis. Changes in patient care resulting from the PET/CT studies were recorded. RESULTS: Positron emission tomography/computed tomography had sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 92%, 90%, 90%, 90%, and 91%, respectively, as compared with 92%, 65%, 76%, 86%, and 80% for PET and 92%, 15%, 60%, 60%, and 60% for CI. Imaging with PET/CT altered further management of 19 patients (57%). Imaging with PET/CT eliminated the need for previously planned diagnostic procedures in 11 patients, induced a change in the planned therapeutic approach in 5 patients, and guided biopsy to a specific metabolically active area inside an edematous region in 3 patients, thus decreasing the chances for tissue sampling errors and avoiding damage to nonmalignant tissue. CONCLUSIONS: In cancer of the nasopharynx, the diagnostic performance of PET/CT is better than that of stand-alone PET or CI. Positron emission tomography/computed tomography had a major impact on further clinical management in 57% of patients.     

Sentinel node biopsy in non-palpable breast cancer and in patients with a previous diagnostic excision.

AIM: As a means of staging the axilla with minimal surgical trauma, sentinel lymph node biopsy (SNB) has dramatically altered the management of early-stage breast cancer. The aim of this prospective multicentre study was to assess the safety of the method in cases of non-palpable tumours and in cases with an open biopsy prior to SNB. METHOD: In the period 1999-2001, 57 non-palpable breast cancers and 75 patients with diagnostic biopsy were collected prospectively to the first part of the study. In the second part, 745 patients with non-palpable breast cancers and 86 cases with prior open surgery diagnosed between 2000 and 2005 were followed up till the end of 2005. All patients in the first part of the study had an axillary clearance irrespective of sentinel node status, whereas in the second part axillary clearance was done only if the sentinel node was metastatic. RESULTS: The detection rate was 95% in the group of non-palpable breast cancers, with a false negative rate of 5.6% (1/18), and the corresponding figures for the group with prior intervention were 96% and 10% (2/20). Two axillary recurrences, after a negative SNB at primary surgery, were found in the non-palpable group after 16 and 17 months, respectively. No axillary recurrence has been observed in the group of cancers with a prior open biopsy. Four women in the non-palpable group and two women with a diagnostic operation experienced distant metastases. CONCLUSION: We conclude that SNB is a safe procedure for women with non-palpable breast cancer, as well as after previous open diagnostic excision.