Complete metabolic response with [18 F]fluorodeoxyglucose-positron emission tomography/computed tomography predicts survival following induction chemotherapy and radical cystectomy in clinically lymph node positive bladder cancer.

OBJECTIVE: To determine whether repeated [18 F]fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET-CT) scans can predict increased cancer-specific survival (CSS) after induction chemotherapy followed by radical cystectomy (RC). PATIENTS AND METHODS: Between 2007 and 2018, 86 patients with clinically lymph node (LN)-positive bladder cancer (T1-T4, N1-N3, M0-M1a) were included and underwent a repeated FDG-PET-CT during cisplatin-based induction chemotherapy. The 71 patients that had a response to chemotherapy underwent RC. Response to chemotherapy was evaluated in LNs through repeated FDG-PET-CT and stratified as partial response or complete response using three different methods: maximum standardised uptake value (SUVmax ), adapted Deauville criteria, and total lesion glycolysis (TLG). Progression-free survival (PFS) and CSS were analysed for all three methods by Cox regression analysis. RESULTS: After a median follow-up of 40 months, 15 of the 71 patients who underwent RC had died from bladder cancer. Using SUVmax and the adapted Deauville criteria, multivariable Cox regression analyses adjusting for age, clinical tumour stage and LN stage showed that complete response was associated with increased PFS (hazard ratio [HR] 3.42, 95% confidence interval [CI] 1.20-9.77) and CSS (HR 3.30, 95% CI 1.02-10.65). Using TLG, a complete response was also associated with increased PFS (HR 5.17, 95% CI 1.90-14.04) and CSS (HR 6.32, 95% CI 2.06-19.41). CONCLUSIONS: Complete metabolic response with FDG-PET-CT predicts survival after induction chemotherapy followed by RC in patients with LN-positive bladder cancer and comprises a novel tool in evaluating response to chemotherapy before surgery. This strategy has the potential to tailor treatment in individual patients by identifying significant response to chemotherapy, which motivates the administration of a full course of induction chemotherapy with a higher threshold for suspending treatment due to toxicity and side-effects.

Pre-treatment 18F-choline PET/CT is prognostic for biochemical recurrence, development of bone metastasis, and cancer specific mortality following radical local therapy of high-risk prostate cancer.

BACKGROUND: The aim of this study was to determine whether lymph node metastasis on pre-treatment 18F-choline PET/CT is an independent prognostic factor for biochemical recurrence (BCR), skeletal metastasis, and cancer specific mortality (CSM), after radical local treatment (radical prostatectomy and/or radiotherapy) in men with high-risk prostate cancer. Medical records were reviewed for men with newly diagnosed high-risk prostate cancer who had pre-treatment 18F-choline positron emission tomography fused with computed tomography (PET/CT) scan for primary metastasis staging. RESULTS: Of 174 eligible men, 124 met the criteria for inclusion. The PET/CT scan was negative for metastasis in 97 (78%) men, inconclusive in 15 (12%), and positive in 12 (10%). The men with a positive PET/CT scan had significantly shorter time to BCR (p = 0.02), time to skeletal metastasis (p = 0.002), and time to prostate cancer specific death (p < 0.001). On multivariable Cox regression analysis, including also tumour stage, Gleason score, and PSA, a non-negative PET/CT scan was the only significant covariate for time to BCR (HR 2.6, 95% CI 1.3-5.5) and time to skeletal metastasis (HR 2.7, 95% CI 1.3-5.9). CONCLUSIONS: In men with a newly diagnosed high-risk prostate cancer and a negative or inconclusive bone scan, 18F-choline uptake on PET/CT suggestive metastasis was associated with recurrence, progression to distant metastasis, and prostate cancer death. This strongly indicates that the choline uptakes represented metastasis and not false positive findings.

[18F]Fluorodeoxyglucose-positron emission tomography/computed tomography response evaluation can predict histological response at surgery after induction chemotherapy for oligometastatic bladder cancer.

OBJECTIVE: Patients with limited metastatic and locally advanced bladder cancer have a poor prognosis, and no definite treatment recommendations exist. However, long-term survival is possible for selected patients if surgery is combined with multiple courses of chemotherapy (i.e. induction chemotherapy). Patients with tumours that are insensitive to chemotherapy probably have little to gain from subsequent extensive surgery. The aim of this study was to evaluate sequential FDG-PET/CT examinations as an indicator of chemotherapy response. MATERIALS AND METHODS: Between 2007 and 2015, 50 patients with oligometastatic invasive bladder cancer selected for induction chemotherapy underwent two FDG-PET/CT examinations: the first before the start of chemotherapy and the second after three courses of cisplatinum-based combination chemotherapy. Responders were given up to six courses of chemotherapy. FDG-PET/CT response was correlated with histological response in excised lymph-node metastases. RESULTS: Three patients showed progression to incurable disease during chemotherapy and another two patients did not undergo surgery, for medical reasons. Lymphadenectomy was performed in the remaining 45 patients, of whom 43 had lymph-node metastasis. FDG-PET/CT prediction of the histological nodal chemotherapy response was correct in 37 (86%) of those 43. The second FDG-PET/CT examination identified four out of nine non-responders. For response, the sensitivity, specificity, and positive and negative predictive values for FDG-PET/CT accuracy were 37 out of 37 (100%), one out of six (17%), 37 out of 42 (88%) and one out of one (100%), respectively. CONCLUSIONS: Repeated FDG-PET/CT seems to predict histological response. However, with the histological response criteria used in this study, five non-responders were not identified by the second FDG-PET/CT investigation.

(18)F-choline PET/CT for early detection of metastases in biochemical recurrence following radical prostatectomy.

PURPOSE: Salvage radiotherapy (SRT) for biochemical recurrence (BCR) following radical prostatectomy (RP) should if possible be added at a prostate-specific antigen (PSA) level of <1-2 ng/mL. The value of positron emission tomography combined with computed tomography (PET/CT) at such low PSA values is not defined. The purpose was to determine what proportion of a well-defined cohort of hormone-naïve patients who were candidates for early salvage radiotherapy had (18)F-choline PET/CT findings suggesting metastases. MATERIALS AND METHODS: Patients with untreated BCR following RP, PSA <2 ng/mL, and Gleason score ≥7 or PSA doubling time ≤6 months underwent (18)F-choline PET/CT. Focal choline uptake in lymph nodes or skeletal sites was recorded. RESULTS: PET/CT indicated metastases in 16 (28 %) of 58 patients. In five (9 %) patients, the scans suggested bone metastases, and in 11 (19 %) patients, the scans suggested regional lymph node metastases only. For patients with PSA levels <1.0 ng/mL, the PET/CT scans indicated metastatic recurrence in 25 %. CONCLUSIONS: (18)F-choline PET/CT may be valuable for selecting patients with BCR following RP for SRT or experimental treatment of oligometastases, even at low PSA values.

[(18)F]Fluorodeoxyglucose - positron emission tomography/computed tomography improves staging in patients with high-risk muscle-invasive bladder cancer scheduled for radical cystectomy.

OBJECTIVE: The aim of this study was to evaluate the clinical use of [(18)F]fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in addition to conventional preoperative radiological investigations in a defined group of patients with high-risk muscle-invasive bladder cancer. MATERIALS AND METHODS: In total, 103 patients with high-risk muscle-invasive bladder cancer defined as stage T3/T4 disease or as stage T2 with hydronephrosis or high-risk histological features, who were provisionally scheduled to undergo cystectomy, were prospectively recruited to the study. The patients were referred to FDG-PET/CT in addition to standard preoperative investigation with computed tomography (CT). The final treatment decision was reached at a multidisciplinary conference based on all available information including the FDG-PET/CT findings. RESULTS: Compared to CT alone, FDG-PET/CT provided more supplemental findings suggesting malignant manifestations in 48 (47%) of the 103 patients. The additional FDG-PET/CT findings led to an altered provisional treatment plan in 28 out of 103 patients (27%), detection of disseminated bladder cancer and subsequent cancellation of the initially intended cystectomy in 16 patients, and identification of disseminated disease and treatment with induction chemotherapy before radical cystectomy in 12 patients. CONCLUSIONS: Preoperative FDG-PET/CT changed the treatment plan for a considerable proportion (27%) of the present patients. Accordingly, such examination can potentially improve the preoperative staging of cystectomy patients with high-risk features, and may also reduce the number of futile operations in patients with advanced disease who are beyond cure.

Combined 18F-fluorocholine and 18F-fluoride positron emission tomography/computed tomography imaging for staging of high-risk prostate cancer.

OBJECTIVE: To investigate how often positron emission tomography/computed tomography (PET/CT) scans, with both (18)F-fluorocholine and (18)F-fluoride as markers, add clinically relevant information for patients with prostate cancer who have high-risk tumours and a normal or inconclusive planar bone scan. PATIENTS AND METHODS: Patients with prostate cancer with prostate specific antigen (PSA) levels between 20 and 99 ng/mL and/or Gleason score 8-10 tumours, planned for treatment with curative intent based on routine staging with a negative or inconclusive bone scan, were further investigated with a (18)F-fluorocholine and a (18)F-fluoride PET/CT. None of the patients received hormonal therapy before the staging procedures were completed. RESULTS: For 50 of the 90 included patients (56%) one or both PET/CT scans indicated metastases. (18)F-fluorocholine PET/CT indicated lymph node metastases and/or bone metastases in 35 patients (39%). (18)F-fluoride PET/CT was suggestive for bone metastases in 37 patients (41%). In 18 patients (20%) the PET/CT scans indicated widespread metastases, leading to a change in therapy intent from curative to non-curative. Of the patients with positive scans, 74% had Gleason score 8-10 tumours. Of the patients with Gleason score 8-10 tumours, 64% had positive scans. CONCLUSIONS: PET/CT scans with (18)F-fluorocholine and (18)F-fluoride commonly detect metastases in patients with high-risk prostate cancer and a negative or inconclusive bone scan. For 20% of the patients the results of the PET/CT scans changed the treatment plan.