Impact of definitive radiotherapy on metabolic response measured with 68Ga-PSMA-PET/CT in patients with intermediate-risk prostate cancer.

PURPOSE: To assess the early metabolic response of the primary tumor using Gallium-68 (68Ga)-labeled-prostate-specific membrane antigen positron emission tomography (68Ga-PSMA-PET/CT), as well as the relationship between PSMA change in the primary tumor and PSA response after definitive radiotherapy (RT), either alone or in combination with androgen deprivation therapy (ADT) in intermediate risk prostate cancer (IR-PCa) patients. METHODS: The clinical data of 71 IR-PCa patients treated with RT alone (36 patients, 50.7%) or RT and ADT (35 patients, 49.3%) were retrospectively analyzed. The difference between pre- and Posttreatment primary tumor PSMA expression and serum PSA values measured 4 months after completion of treatment were compared between treatment arms. Correlation between primary tumor metabolic response and serum PSA changes was analyzed. RESULTS: The median duration between pre- and Posttreatment 68Ga-PSMA-PET/CT for the entire patient population was 6.9 months (range, 5.6-8.4 months), and it was similar in both treatment arms. A decrease in primary tumor maximum standardized uptake value (SUVmax) was seen in 66 patients (93.0%), with a median value of 61.2%, which is significantly lower in patients undergoing RT alone than those undergoing RT and ADT (45.1 ± 30.6% vs. 59.1 ± 24.7%; p = 0.004). The complete metabolic response rate was significantly higher in patients undergoing RT and ADT than those treated with RT alone (40% vs. 0%; p < 0.001). Although moderate and positive correlation between pretreatment SUVmax and oosttreatment SUVmax was observed, there was no significant correlation between SUV change and PSA change. For patients treated with RT and ADT, posttreatment SUVmax was significantly lower and SUV change was significantly higher in patients with PSA nadir than in those without. CONCLUSIONS: Our preliminary results show that RT, with or without ADT, significantly reduces primary tumor SUVmax and serum PSA levels. Nonetheless, our findings indicate that early treatment response using 68Ga-PSMA-PET/CT is not feasible for those treated with RT alone, and it may only be useful in better distinguishing patients with and without PSA nadir for those who received both RT and ADT.

Multi-institutional analysis of extracranial oligometastatic colorectal cancer patients treated with stereotactic body radiation therapy: TROD 02-008 study.

PURPOSE: To investigate the treatment outcomes of extracranial oligometastatic colorectal cancer (CRC) patients treated with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS: The clinical data of 388 extra-cranial oligometastatic CRC (≤ 5 lesions) patients and 463 lesions treated with SBRT at 19 cancer institutions were retrospectively analyzed. The prognostic factors predicting overall survival (OS), progression-free survival (PFS), and local control (LC) were assessed in uni- and multivariable analyses. RESULTS: The median age was 62 years (range, 29-92 years). The majority of the patients (90.5%) received surgery and systemic treatment for their primary tumor, had ≤ 2 metastasis (83.3%), had single organ involvement (90.3%), and staged using flouro-deoxyglucose positron emission tomography (FDG-PET/CT) (76%). The median fraction and total radiation doses were 10 Gy (range: 6-34 Gy) and 50 Gy (range: 8-64 Gy), respectively, delivered in a median of 4 fractions (range: 1-8). The median follow-up time for the entire cohort was 30.7 months (interquartile range: 27.0-34.3 months). The 3­year OS, PFS, and LC rates were 64.0%, 42.3%, and 72.7%, respectively. The 3­year LC rate was significantly higher in patients receiving BED10 ≥ 100 Gy than those receiving BED10 < 100 Gy (76.0% vs. 67.3%; p = 0.04). The 3­year PFS and OS rates were higher in patients receiving BED10 ≥ 100 Gy than those receiving BED10 < 100 Gy (33.2% vs. 25.2%; p = 0.03; 53.7% vs.  44.8%; p = 0.02). Single metastasis and complete response after SBRT were independent prognostic factors for survival in multivariable analysis. CONCLUSIONS: In this multi-center study, we demonstrated that SBRT is an effective treatment option of metastatic lesions in oligometastatic CRC patients by providing promising LC rates. Higher SBRT doses beyond BED10 ≥ 100 Gy were associated with improved LC and survival. LC of treated lesion and lower tumor burden after SBRT were associated with better outcomes.

Long-term analysis of hematological parameters as predictors of recurrence patterns and treatment outcomes in cervical cancer patients undergoing definitive chemoradiotherapy.

PURPOSE: This study sought to determine the predictive and prognostic value of clinicopathological parameters and neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and hemoglobin (Hgb) level in predicting recurrence patterns and locoregional relapse-free survival (LRFS) and distant metastasis-free survival (DMFS) in cervical cancer patients receiving definitive chemoradiotherapy (ChRT). METHODS: This study included 261 cervical cancer patients treated with ChRT. The primary endpoints were the predictors of local recurrence (LR) and distant metastasis (DM), whereas the secondary endpoints were LRFS and DMFS. The association of survival with potential prognostic factors was analyzed using Cox regression analysis, and the predictors of LR and DM were identified using logistic regression analysis. RESULTS: The median follow-up time was 10.9 years. Recurrences occurred in 132 patients (50.6%) within a median of 11.2 months after definitive ChRT. NLR and PLR values were significantly higher in patients with LR and DM than in those without, with no significant differences in Hgb levels in patients with or without LR and DM. In the multivariable logistic regression analysis, lymph node metastasis, elevated NLR, and low Hgb level were significantly correlated with LR and DM. In the multivariable analysis, large tumor size, presence of lymph node metastasis, and elevated NLR were the independent predictors for poor LRFS and DMFS, and Hgb level was an additional prognostic factor for DMFS. CONCLUSION: Hematological markers, particularly NLR and Hgb, may serve as cost-effective and readily accessible indicators for predicting recurrence and survival in cervical cancer patients, contributing to their practical use in routine assessments.

Dosimetric evaluation of ultrafractionated dose escalation with simultaneous integrated boost to intraprostatic lesion using 1.5-Tesla MR-Linac in localized prostate cancer.

Background: We analyzed a dose escalation of 36.25 Gy to the entire prostate and a dose increment up to 40 Gy with 1.25 Gy increments to intraprostatic lesion (IPL) using simultaneous integrated boost (SIB) in five fractions. Materials and methods: Eighteen low- and intermediate-risk prostate cancer patients treated with 1.5T MR-Linac were retrospectively evaluated. The same planning computed tomography (CT) images generated four plans: no SIB, 37.5 Gy SIB, 38.75 Gy SIB, and 40 Gy SIB. In four plans, planning target volume (PTV) doses, organ at risk (OAR) doses, and PTV-SIB homogeneity index (HI), gradient index (GI) and conformity index (CI) were compared. Results: All plans met the criteria for PTV and PTV-SIB coverage. PTV 40 Gy plan has higher maximum PTV and PTV-SIB doses than other plans. The PTV HI was significantly higher in the SIB 40 Gy plan (0.135 ± 0.007) compared to SIB 38.75 Gy plan (0.099 ± 0.007; p = 0.001), SIB 37.5 Gy (0.067 ± 0.008; p < 0.001), and no SIB plan (0.049 ± 0.010; p < 0.001), while there were no significant differences in HI, GI and CI for PTV-SIB between three plans. Four rectum and bladder plans had similar dosimetric parameters. The urethra D5 was significantly higher in SIB 40 Gy plan compared to no SIB plan (37.7 ± 1.1 Gy vs. 37.0 ± 0.7 Gy; p = 0.009) and SIB 37.5 Gy plan (36.9 ± 0.8 Gy; p = 0.008). There was no significant difference in monitor units between the four consecutive plans. Conclusions: Ultra-hypofractionated dose escalation to IPL up to 40 Gy in 5 fractions with a 1.5-T MR-linac is dosimetrically feasible, potentially paving the way for clinical trials.

Machine learning predicts conventional imaging metastasis-free survival (MFS) for oligometastatic castration-sensitive prostate cancer (omCSPC) using prostate-specific membrane antigen (PSMA) PET radiomics.

PURPOSE: This study investigated imaging biomarkers derived from PSMA-PET acquired pre- and post-metastasis-directed therapy (MDT) to predict 2-year metastasis-free survival (MFS), which provides valuable early response assessment to improve patient outcomes. MATERIALS/METHODS: An international cohort of 117 oligometastatic castration-sensitive prostate cancer (omCSPC) patients, comprising 34 from John Hopkins Hospital (JHH) and 83 from Baskent University (BU), were treated with stereotactic ablative radiation therapy (SABR) MDT with both pre- and post-MDT PSMA-PET/CT scans acquired. PET radiomic features were analyzed from a CT-PET fusion defined gross tumor volume ((GTV) or zone 1), and a 5 mm expansion ring area outside the GTV (zone 2). A total of 1748 PET radiomic features were extracted from these zones. The six most significant features selected using the Chi2 method, along with five clinical parameters (age, Gleason score, number of total lesions, untreated lesions, and pre-MDT prostate-specific antigen (PSA)) were extracted as inputs to the models. Various machine learning models, including Random Forest, Decision Tree, Support Vector Machine, and Naïve Bayesian, were employed for 2-year MFS prediction and tested using leave-one-out and cross-institution validation. RESULTS: Six radiomic features, including Total Energy, Entropy, and Standard Deviation from pre-PSMA-PET zone 1, Total Energy and Contrast from post-PSMA-PET zone 1, and Entropy from pre-PSMA-PET zone 2, along with five clinical parameters were selected for predicting 2-year MFS. In a leave-one-out test with all the patients, random forest achieved an accuracy of 80 % and an AUC of 0.82 in predicting 2-year MFS. In cross-institution validation, the model correctly predicted 2-year MFS events with an accuracy of 75 % and an AUC of 0.77 for patients from JHH, and an accuracy of 78 % and an AUC of 0.80 for BU patients, respectively. CONCLUSION: Our study demonstrated the promise of using pre- and post-MDT PSMA-PET-based imaging biomarkers for MFS prediction for omCSPC patients.

PIK3/Akt/mTOR pathway alterations in metastatic castration-sensitive prostate cancer.

BACKGROUND: Alterations in the PIK3/Akt/mTOR pathway are commonly seen in metastatic castration-sensitive prostate cancer (mCSPC), however their role in outcomes is unknown. We aim to evaluate the prognostic significance as well as the genetic landscape of PIK3/Akt/mTOR pathway alteration in mCSPC. METHODS: Fourhundred and seventy-two patients with mCSPC were included who underwent next generation sequencing. PIK3/Akt/mTor pathway alterations were defined as mutations in Akt1, mTOR, PIK3CA, PIK3CB, PIK3R1, PTEN, TSC1, and TSC2. Endpoints of interests were radiographic progression-free survival (rPFS), time to development of castration resistant prostate cancer (tdCRPC), and overall survival (OS). Kaplan-Meier analysis was performed and Cox regression hazard ratios (HR) were calculated. RESULTS: One hundred and fifty-two (31.9%) patients harbored a PIK3/Akt/mTOR pathway alteration. Median rPFS and tdCRPC were 23.7 and 21.0 months in PIK3/Akt/mTOR altered compared to 32.8 (p = 0.08) and 32.1 months (p = 0.002) in wildtype tumors. On multivariable analysis PIK3/Akt/mTOR pathway alterations were associated with tdCRPC (HR 1.43, 95% CI, 1.05-1.94, p = 0.02), but not rPFS [Hazard ratio (HR) 1.20, 95% confidence interval (CI), 0.90-1.60, p = 0.21]. PIK3/Akt/mTOR pathway alterations were more likely to be associated with concurrent mutations in TP53 (40% vs. 28%, p = 0.01) and TMPRSS2-ERG (37% vs. 26%, p = 0.02) than tumors without PIK3/Akt/mTOR pathway alterations. Concurrent mutations were typically associated with shorter median times to rPFS and tdCRPC. DAVID analysis showed p53 signaling and angiogenesis pathways were enriched in PIK3/Akt/mTOR pathway altered tumors while beta-catenin binding and altered BRCA pathway were enriched in PIK3/Akt/mTOR pathway wildtype tumors. CONCLUSIONS: PIK3/Akt/mTOR pathway alterations were common in mCSPC and associated with poorer prognosis. The genetic landscape of PIK3/Akt/mTOR pathway altered tumors differed from wildtype tumors. Additional studies are needed to better understand and target the PIK3/Akt/mTOR pathway in mCSPC.

Genomic Determinants Associated with Modes of Progression and Patterns of Failure in Metachronous Oligometastatic Castration-sensitive Prostate Cancer.

BACKGROUND AND OBJECTIVE: Oligometastatic castration-sensitive prostate cancer (omCSPC) represents an early state in the progression of metastatic disease for which patients experience better outcomes in comparison to those with higher disease burden. Despite the generally more indolent nature, there is still much heterogeneity, with some patients experiencing a more aggressive clinical course unexplained by clinical features alone. Our aim was to investigate correlation of tumor genomics with the mode of progression (MOP) and pattern of failure (POF) following first treatment (metastasis-directed and/or systemic therapy) for omCSPC. METHODS: We performed an international multi-institutional retrospective study of men treated for metachronous omCSPC who underwent tumor next-generation sequencing with at least 1 yr of follow-up after their first treatment. Descriptive MOP and POF results are reported with respect to the presence of genomic alterations in pathways of interest. MOP was defined as class I, long-term control (LTC; no radiographic progression at last follow-up), class II, oligoprogression (1-3 lesions), or class III, polyprogression (≥4 lesions). POF included the location of lesions at first failure. Genomic pathways of interest included TP53, ATM, RB1, BRCA1/2, SPOP, and WNT (APC, CTNNB1, RNF43). Genomic associations with MOP/POF were compared using χ2 tests. Exploratory analyses revealed that the COSMIC mutational signature and differential gene expression were also correlated with MOP/POF. Overall survival (OS) was calculated via the Kaplan-Meier method from the time of first failure. KEY FINDINGS AND CLINICAL IMPLICATIONS: We included 267 patients in our analysis; the majority had either one (47%) or two (30%) metastatic lesions at oligometastasis. The 3-yr OS rate was significantly associated with MOP (71% for polyprogression vs 91% for oligoprogression; p = 0.005). TP53 mutation was associated with a significantly lower LTC rate (27.6% vs 42.3%; p = 0.04) and RB1 mutation was associated with a high rate of polyprogression (50% vs 19.9%; p = 0.022). Regarding POF, bone failure was significantly more common with tumors harboring TP53 mutations (44.8% vs25.9%; p = 0.005) and less common with SPOP mutations (7.1% vs 31.4%; p = 0.007). Visceral failure was more common with tumors harboring either WNT pathway mutations (17.2% vs 6.8%, p = 0.05) or SPOP mutations (17.9% vs 6.3%; p = 0.04). Finally, visceral and bone failures were associated with distinct gene-expression profiles. CONCLUSIONS AND CLINICAL IMPLICATIONS: Tumor genomics provides novel insight into MOP and POF following treatment for metachronous omCSPC. Patients with TP53 and RB1 mutations have a higher likelihood of progression, and TP53, SPOP, and WNT pathway mutations may have a role in metastatic organotropism. PATIENT SUMMARY: We evaluated cancer progression after a first treatment for metastatic prostate cancer with up to five metastases. We found that mutations in certain genes were associated with the location and extent of further metastasis in these patients.

Evaluation of Treatment Outcomes of Prostate Cancer Patients With Lymph Node Metastasis Treated With Definitive Radiotherapy: Comparative Analysis of PSMA PET/CT and Conventional Imaging.

PURPOSE: We investigated the impact of prostate-specific membrane antigen (PSMA) PET/CT compared with conventional imaging on treatment outcomes for node-positive prostate cancer (PCa) patients who underwent androgen deprivation therapy (ADT) and external radiotherapy (RT). PATIENTS AND METHODS: A multicentric, retrospective study recruited patients with node-positive PCa patients who underwent conventional radiological evaluation or PSMA PET/CT and received ADT and RT at 3 hospitals from 2009 to 2021 were enrolled. Patients underwent prostate and pelvis RT, accompanied by a minimum of 6 months of ADT. The primary endpoints were progression-free survival (PFS) and PCa-specific survival (PCSS). Cox regression analyzed the association of survival with potential prognostic factors, whereas logistic regression identified the predictors of bone and lymph node metastasis. RESULTS: The median follow-up time was 64.0 months. The majority of patients (64.1%) underwent PSMA PET/CT for staging. The 5-year rates of PFS and PCSS were 63.7% and 83.7%, respectively. Disease progression was observed in 90 patients (36.3%). In multivariable analysis, ADT duration of less than 24 months and post-RT prostate-specific antigen (PSA) nadir were prognostic for PFS. Early clinical T stage and PSMA PET/CT predicted better PCSS. Patients staged with PSMA PET/CT had exhibited significantly higher 5-year PCSS rates than compared with those staged with conventional imaging (95.1% vs 76.9%; P = 0.01). Shorter ADT duration and higher PSA levels after RT independently predicted bone metastasis in multivariable logistic regression. Advanced T stage, shorter ADT duration, and higher PSA levels after neoadjuvant ADT predicted nonregional lymph node recurrence. CONCLUSIONS: ADT with pelvis RT is an effective treatment option for node-positive PCa patients. The PSMA PET/CT outperformed conventional imaging in PCSS, emphasizing the importance of precise clinical staging for patients undergoing definitive RT.

Prostate-Specific Membrane Antigen PET Response Associates with Metastasis-Free Survival After Stereotactic Ablative Radiation in Oligometastatic Prostate Cancer.

Purpose: Emerging data suggest that metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) can detect occult metastatic disease, and PSMA response has been proposed as a biomarker for treatment response. Herein, we identify and validate a PSMA-PET biomarker for metastasis-free survival (MFS) following MDT in omCSPC. Methods and Materials: We performed an international multi-institutional retrospective study of patients with omCSPC, defined as ≤3 lesions, treated with metastasis-directed stereotactic ablative radiation who underwent PSMA-PET/computed tomography (CT) before and after (median, 6.2 months; range, 2.4-10.9 months) treatment. Pre- and post-MDT PSMA-PET/CT maximum standardized uptake value (SUVmax) was measured for all lesions, and PSMA response was defined as the percent change in SUVmax of the least responsive lesion. PSMA response was both evaluated as a continuous variable and dichotomized into PSMA responders, with a complete/partial response (at least a 30% reduction in SUVmax), and PSMA nonresponders, with stable/progressive disease (less than a 30% reduction in SUVmax). PSMA response was correlated with conventional imaging-defined metastasis-free survival (MFS) via Kaplan-Meier and Cox regression analysis. Results: A total of 131 patients with 261 treated metastases were included in the analysis, with a median follow-up of 29 months (IQR, 18.5-41.3 months). After stereotactic ablative radiation, 70.2% of patients were classified as PSMA responders. Multivariable analysis demonstrated that PSMA response as a continuous variable was associated with a significantly worse MFS (hazard ratio = 1.003; 95% CI, 1.001-1.006; P = .016). Patients classified as PSMA responders were found to have a significantly improved median MFS of 39.9 versus 12 months (P = .001) compared with PSMA nonresponders. Our study is limited as it is a retrospective review of a heterogenous population. Conclusions: After stereotactic ablative radiation, PSMA-PET response appears to be a radiographic biomarker that correlates with MFS in omCSPC. This approach holds promise for guiding clinical management of omCSPC and should be validated in a prospective setting.

A Comparative Analysis of Implant-sparing Plan Versus Conventional Plans Utilizing Helical Tomotherapy in Breast Cancer Patients Undergoing Breast Reconstruction.

BACKGROUND/AIM: To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR). PATIENTS AND METHODS: The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fractions were analyzed. Three plans were created: H plan using conventional planning target volume (PTV) that included the chest wall, skin, and implant; TD plan using conventional PTV; and Hs plan using implant-sparing PTV. The H, TD, and Hs plans were compared for PTV doses, organ-at-risk (OAR) doses, and treatment times. RESULTS: Dose distribution in the Hs plan was less homogeneous and uniform than that in the H and TD plans. The TD plan had lower lung, heart, contralateral breast, spinal cord, liver, and esophagus doses than the Hs plan. Compared to the Hs plan, the H plan had lower lung volume receiving 5Gy (V5) (39.1±3.9 vs. 41.2±3.9 Gy; p<0.001), higher V20 (12.3±1.3 vs. 11.5±2.6 Gy; p=0.02), and higher V30 (7.5±1.6 vs. 4.4±1.7 Gy; p<0.001). H plan outperformed Hs plan in heart dosimetric parameters except V20. The Hs plan had significantly lower mean implant doses (43.4±2.1 Gy) than the H plan (51.4±0.5 Gy; p<0.001) and the TD plan (51.9±0.6 Gy; p<0.001). Implementing an implant sparing technique for silicone dose reduction decreases lung doses. CONCLUSION: Conventional H and TD plans outperform the implant sparing helical plan dosimetrically. Because capsular contracture during RT is unpredictable, long-term clinical outcomes are required to determine whether silicon should be spared.

The effect of dose-escalation radiotherapy with simultaneous-integrated-boost on the use of short-term androgen deprivation therapy in patients with intermediate risk prostate cancer.

PURPOSE: To compare the biochemical failure (FFBF) and prostate cancer specific survival (PCSS) rates of patients with intermediate-risk prostate cancer (IR-PC) who were treated with 6 months of androgen deprivation therapy (ADT) with 78 Gy to the prostate, those treated with ADT and focal boost (FB) of 86 Gy to intraprostatic lesion (IPL) using the simultaneous-integrated boost (SIB) technique, and those treated with SIB alone. MATERIALS AND METHODS: A retrospective analysis of 320 IR-PC patients treated between January 2012 and April 2021 was performed. Patients were divided into three groups based on their treatment arm: 78 + ADT (109 patients, 34.1%), 78/86 (102 patients, 31.8%), and 78/86 + ADT. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PCSS. RESULTS: Median follow-up was 8.8 years. The 8-year FFBF and PCSS rates were 88.6% and 99.0%. Patients who received ADT had significantly higher pretreatment PSA levels and clinical tumor stage. Disease progression occurred in 45 patients (7.3%) at a median of 41.9 months after definitive radiotherapy (RT). Younger age, positive core biopsy (PCB) ≥ 50%, and the absence of ADT were all independent predictors of poor FFBF in multivariate analysis, whereas patients with PCB < 50% who were also given ADT had better PCSS. Patients treated with 78/86 Gy alone had worse FFBF than those treated with 78 Gy and ADT (Hazard ratio [HR] = 3.39 [95% CI = 1.46-7.88]; p = 0.005), as well as than those treated with 78/86 Gy and ADT (HR = 3.21 [95% CI = 1.23-6.46]; p = 0.009). However, FB to IPL has no effect on PCSS in multivariable analysis. There was no significant difference between treatment groups in terms of acute and late Grade ≥2 genitourinary or gastrointestinal toxicity. CONCLUSIONS: Our findings demonstrated that patients who received 78/86 alone did worse than patients who received ADT with either 78 or 78/86 Gy. However, because IR-PC patients are so diverse, additional prospective trials are needed to validate our findings.

Long-term assessment of clinical parameters and positron emission tomography parameters in predicting recurrence in uterine cervical cancer patients receiving definitive chemoradiotherapy.

OBJECTIVE: The objective of this study was to assess the prognostic value of clinical factors and metabolic parameters measured using fluorodeoxyglucose PET (FDG-PET/CT) in predicting disease recurrence, as well as distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and overall survival (OS) in patients with uterine cervical cancer who received definitive chemoradiotherapy. METHODS: The clinical data and FDG-PET parameters, including standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of 194 patients with biopsy-confirmed squamous cell carcinoma of cervical cancer were retrospectively analyzed. Univariate and multivariate analyses were used to ascertain prognostic factors associated with DMFS, LRFS, and OS. RESULTS: With a median follow-up of 12.5 years, 96 patients (49.5%) presented with disease recurrence, at a median of 9.9 months after chemoradiotherapy. Patients who experienced recurrence had significantly higher values for all FDG-PET parameters compared to patients who did not. In multivariate regression analysis, lymph node metastasis, MTV, and SUV mean were significantly correlated with distant metastasis, while local recurrence was only predicted by SUV max . Lymph node metastasis, high MTV, SUV mean , and TLG predicted shorter DMFS, while only the primary tumor SUV max predicted LRFS. Age, regional nodal metastasis, and higher MTV independently predicted shorter OS in multivariate analysis. CONCLUSION: We found that metabolic parameters derived from FDG-PET/CT could serve as surrogates for disease recurrence in patients with cervical cancer who were treated with definitive chemoradiotherapy. Patients at high risk of distant metastasis could be defined using SUV mean and MTV, and for local recurrence, by using SUV max .