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Rodney J Hicks

Publications and source records attributed to Rodney J Hicks.

At least 19 recordsLinked to original sources
PubMed2026

Tumor-Intrinsic Blood and Imaging Correlatives in Advanced Prostate Cancer Treated with Combination Radiopharmaceutical Therapy and Immunotherapy.

The PRINCE trial showed the clinical activity for 177Lu-PSMA-617 in combination with pembrolizumab for metastatic castration-resistant prostate cancer. To refine patient selection and improve response monitoring strategies to this combination, we investigated candidate tumor-intrinsic biomarkers of treatment response and resistance. Methods: We performed circulating tumor DNA (ctDNA), circulating tumor cell (CTC), and PET imaging analyses at baseline, 12 wk on-treatment, and disease progression in participants enrolled in PRINCE (n = 37). We performed targeted sequencing for ctDNA quantification and genomic analysis of more than 70 prostate cancer genes. CTC enumeration was performed on the EpicSciences platform and was combined with selective single-cell whole-genome sequencing. PET imaging included serial PSMA PET as well as 18F-FDG PET imaging at baseline. Results: A low baseline ctDNA fraction and high PSMA avidity in metastatic lesions were linked to superior treatment responses and may have composite biomarker value. Genomic alterations in tumor suppressor genes TP53, RB1, or PTEN were associated with higher 18F-FDG avidity and metabolic tumor volume on 18F-FDG PET imaging and worse prognosis. At 12-wk on-treatment, both ctDNA detection and PSMA PET imaging were strong indicators of response depth and durability. At disease progression, PSMA expression on PET imaging was lower compared with baseline and supported by subclonal remodeling of ctDNA and CTC copy number profiles and by clonal expansions of tumor suppressor gene mutations. Conclusion: We provide the first integrated molecular and imaging insights into determinants of response and resistance to combined radiopharmaceutical therapy and immunotherapy in prostate cancer and propose biomarker strategies to inform future clinical development.

177Lu-PSMA-617↗
PubMed2026

Whole genome and exome sequencing of pancreatic neuroendocrine tumour to investigate PRRT response.

Patients with pancreatic neuroendocrine tumours (PNETs) often have similar baseline clinical characteristics, including grade and molecular imaging phenotype, yet have highly variable responses to peptide receptor radionuclide therapy (PRRT). To identify genomic alterations and mutational patterns associated with PRRT treatment response and acquired somatic changes following PRRT exposure, whole genome or exome sequencing was applied to 40 PNET samples from 32 patients, including eight paired pre- or post-PRRT samples. The genomic profile of tumours reflected the known mutational landscape of PNET with MEN1 (34%), ATRX/DAXX (47%) alterations and a recurrent pattern of aneuploidy (38%) detected. A recurrent PSIP1::TBL1X fusion of unknown function was also identified in four tumours. The disease control rate following PRRT using RECIST1.1 and molecular imaging criteria was 88% (28/32). No mutational features were found to be statistically associated with progression-free survival. There was no significant increase in tumour mutational burden in the post-PRRT tumours, nor recurrent emergent mutational changes in cancer driver genes to explain progression to higher-grade disease, when observed. However, a small indel signature (ID8) previously associated with DNA damage repair by non-homologous end joining (NHEJ) was higher in PRRT-exposed compared with PRRT-naive samples (23.8 vs 4.8%, respectively; P < 0.001). Thus, comprehensive DNA analysis of pancreatic NETs did not identify biomarkers predictive of PRRT response nor evidence for high-level PRRT-induced genomic instability or hypermutation, yet mutation signature analysis supports NHEJ as being important for DNA repair and survival of neuroendocrine cells following exposure to beta-particle radiation.

Humans↗
PubMed2007

How do oncologists deal with incidental abnormalities on whole-body fluorine-18 fluorodeoxyglucose PET/CT?

BACKGROUND: Combined positron emission tomography (PET)/computed tomography (CT) using fluorine-18 fluorodeoxyglucose (FDG) is an exciting technique for cancer evaluation, but false-positive results are a recognized limitation. The aim of the study was to evaluate how oncologists deal with focal extrathyroidal FDG abnormalities considered by imaging specialists to be unrelated to the referral indication. METHODS: PET scan reports from a 12-month period from August 2002 to July 2003 in 1727 consecutive patients (mean age, 63 years) were reviewed. Incidental, nonphysiologic FDG abnormalities were classified based on the report conclusion. The frequency with which such abnormalities were investigated by oncologists and the final diagnosis were compared with the imaging diagnosis with a minimum potential follow-up of 2 years (mean, 27.5 months). RESULTS: Incidental FDG abnormalities were reported in 199 (12%) of 1727 patients, including 181 with adequate follow-up. Of 59 cases with a suspected second malignancy, 34 (58%) were actively investigated, with 14 confirmed, 7 unexpected metastatic sites, and 10 other active pathologies. Only 1 further cancer was subsequently detected in the 25 (42%) patients not actively investigated. Conversely, of 122 sites presumed to be benign, only 10 (8%) were actively investigated. Only 2 were proven to relate to malignancy. CONCLUSIONS: Although incidental abnormalities were common, most were benign and appropriately categorized by experienced readers. For actively investigated extrathyroidal abnormalities, a neoplastic basis was confirmed in over 60% of cases. Conversely, for cases deemed most likely benign by the PET/CT report or after review of readily available clinical information by the referring oncologist, the rate of malignancy was less than 2%.

Adult↗
PubMed2006

PET/CT: will it change the way that we use CT in cancer imaging?

Accurate staging of cancer is of fundamental importance to treatment selection and planning. Current staging paradigms focus, first, on a detailed delineation of the primary tumour in order to determine its suitability for resection, and, thereafter, on assessment of the presence of metastatic spread that would alter the surgical approach, or mandate non-surgical therapies. This approach has, at its core, the assumption that the best, and sometimes the only, way to cure a patient of cancer is by surgical resection. Unfortunately, all non-invasive techniques in current use have imperfect ability to identify those primary tumours that are able to be completely excised, and even worse ability to define the extent of metastatic spread. Nevertheless, because of relatively low cost and widespread availability, computed tomography (CT) scanning is the preferred methodology for tumour, nodal and systemic metastasis (TNM) staging. This is often supplemented by other tests that have improved performance in particular staging domains. For example, magnetic resonance imaging (MRI), mammography, or endoscopic ultrasound may be used as complementary tests for T-staging; surgical nodal sampling for N-staging; and bone scanning, MRI or ultrasound for M-staging. Accordingly, many patients undergo a battery of investigations but, even then, are found to have been incorrectly staged based on subsequent outcomes. Even for those staged surgically, pathology can only identify metastases within the resection specimens and has no capability for detecting remote disease. As a result of this, many patients undergo futile operations for disease that could never have been cured by surgery. In the case of restaging, the situation is even worse. The sequelae of prior treatment can be difficult to differentiate from residual cancer and the likelihood of successful salvage therapy is even less than at presentation. More deleteriously, patients may be subjected to additional morbid treatments when cure has already been achieved. Thus, in post-treatment follow-up, the presence and extent of disease is equally critical to treatment selection and patient outcome as it is in primary staging. One of the major strengths of positron emission tomography (PET)/CT as a cancer staging modality is its ability to identify systemic metastases. At any phase of cancer evaluation, demonstration of systemic metastasis has profound therapeutic and prognostic implications. Only in the absence of systemic metastasis does nodal status become important, and only when unresectable nodal metastasis has been excluded does T-stage become important. There are now accumulating data that PET/CT could be used as the first, rather than the last test to assess M- and N-stage for evaluating cancers with an intermediate to high pre-test likelihood of metastatic disease based on poor long-term survival. In this scenario, there is great opportunity for subsequently selecting and tailoring the performance of anatomically based imaging modalities to define the structural relations of abnormalities identified by PET, when this information would be of relevance to management planning. Primary staging of oesophageal cancer and restaging of colorectal cancer are illustrative examples of a new paradigm for cancer imaging.

Adenocarcinoma↗
PubMed2006

PET tracer development--a tale of mice and men.

PET scanning is an emerging technology for the clinical evaluation of many disease processes in man. The vast majority of clinical positron emission tomography (PET) studies are performed using a single tracer, fluorodeoxyglucose. Despite the excellent diagnostic performance of this tracer, it has recognised limitations. New tracers offer the potential to both address these limitations, and to establish new applications for PET. Small animal PET is a logical technique for validating new tracers relevant to human diseases. However, interspecies differences in the handling of chemicals may significantly influence the handling of novel tracers. This requires caution in extrapolating findings in animals to expectations of performance in man. Already there are several examples where biodistribution studies in mice would not have predicted the clinical utility of existing PET tracers. Nevertheless, application of a systematic approach to tracer development is likely to speed transition of new tracers from animals into man.

Animals↗
PubMed2006

The extent of resection of FDG-PET hypometabolism relates to outcome of temporal lobectomy.

A significant minority of patients undergoing surgery for medically refractory non-lesional temporal lobe epilepsy (TLE) continue to have seizures, but the reasons for this are uncertain. Fluorodeoxyglucose (FDG) PET shows hypometabolism in a majority of patients with non-lesional TLE, even in the absence of hippocampal atrophy. We examined whether the extent of resection of the area of FDG-PET hypometabolism influenced outcome following surgery for non-lesional TLE. Twenty-six patients who underwent temporal lobectomy for medically refractory TLE with at least 12 months follow-up were studied. The preoperative FDG-PET was compared with 20 non-epileptic controls using SPM99 to identify regions of significant hypometabolism (P < 0.0005, cluster > 200). This image was then co-registered to the postoperative MRI scan. The volume of the FDG-PET hypometabolism that lay within the area of the resected temporal lobe was calculated. The volume of temporal lobe resected was also calculated. Patients with a good outcome had a greater proportion of the total FDG-PET hypometabolism volume resected than those with a poor outcome (24.1% versus 11.8%, P = 0.02). There was no significant difference between the groups in the volume of temporal lobe resected (P = 0.86). Multivariate regression demonstrated that the extent of resection of the hypometabolism significantly correlated with outcome (P = 0.03), independent of the presence of hippocampal sclerosis (P = 0.03) and total brain volume of hypometabolism (P = 0.45). The extent of resection of the region of hypometabolism on the preoperative FDG-PET is predictive of outcome following surgery for non-lesional TLE. Strategies that tailor resection extent to regional hypometabolism may warrant further evaluation.

Adult↗
PubMed2006

Multicenter phase II clinical study of iodine-131-rituximab radioimmunotherapy in relapsed or refractory indolent non-Hodgkin's lymphoma.

PURPOSE: To evaluate efficacy and safety of iodine-131 (131I) -rituximab chimeric anti-CD20 antibody radioimmunotherapy in patients with relapsed or refractory indolent non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: After a standard loading dose of rituximab 375 mg/m2, individualized dosimetry was performed by whole-body gamma imaging of a tracer activity of 131I-rituximab followed by administration of a therapeutic activity of 131I-rituximab to deliver an estimated whole-body radiation absorbed dose of 0.75 Gy. RESULTS: Ninety-one patients were entered onto the trial: 78 patients (86%) had follicular lymphoma, six patients (7%) had mucosa-associated lymphoid tissue/marginal zone lymphoma, and seven patients (8%) had small lymphocytic lymphoma. The objective overall response rate (ORR) was 76%, with 53% attaining a complete response (CR) or CR unconfirmed (CRu). Median duration of response for patients achieving CR/CRu was 20 v 7 months for those with a partial response (P = .0121). Median progression-free survival for the entire cohort was 13 months, with 14% remaining relapse free beyond 4 years. Median follow-up was 23 months, with a 4-year actuarial survival rate of 59% +/- 10%. Toxicity was principally hematologic; grade 4 thrombocytopenia occurred in 4% and neutropenia occurred in 16% of patients, with nadirs at 6 to 7 weeks after treatment. CONCLUSION: 131I-rituximab radioimmunotherapy of relapsed or refractory indolent NHL achieves high ORR and CR rates with minimal toxicity.

Adult↗
PubMed2006

Powerful prognostic stratification by [18F]fluorodeoxyglucose positron emission tomography in patients with metastatic breast cancer treated with high-dose chemotherapy.

PURPOSE: This study examines the use of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) for the evaluation of the therapeutic response for patients treated with high-dose chemotherapy (HDC) with autologous stem cell transplantation for metastatic breast cancer (MBC) focusing on prognostic stratification. PATIENTS AND METHODS: Forty-seven patients with MBC were treated with a maximum of three cycles of HDC. Therapeutic response was assessed with conventional imaging (CImg; including a computed tomography in all cases and ultrasound, mammography, and bone scanning as clinically indicated) and by FDG-PET study performed after the last cycle of HDC. Parameters analyzed for predicting survival were FDG-PET and CImg results, pattern of disease, prior treatment, and HDC regimen. RESULTS: Complete responses were observed in 16 patients (37%) with CImg and 34 patients (72%) with FDG-PET. The FDG-PET result was the most powerful and independent predictor of survival; patients with a negative post-treatment FDG-PET had a longer median survival than patients with a positive FDG-PET (24 months v 10 months; P < .001). By multivariate analysis the relative risk (RR) of death was higher in patients with FDG-PET-positive disease (RR, 5.3), prior anthracycline treatment (RR, 3.3), or with visceral metastasis (RR, 2.4). CONCLUSION: A single FDG-PET study performed after completion of HDC for MBC can powerfully stratify for survival. This may have implications for how we should assess outcome after conventional-dose therapy for MBC and warrants additional study.

Adult↗
PubMed2006

Prognostic significance of [18F]-misonidazole positron emission tomography-detected tumor hypoxia in patients with advanced head and neck cancer randomly assigned to chemoradiation with or without tirapazamine: a substudy of Trans-Tasman Radiation Oncology Group Study 98.02.

PURPOSE: To determine the association between tumor hypoxia, treatment regimen, and locoregional failure (LRF) in patients with stage III or IV squamous cell carcinoma of the head and neck randomly assigned to radiotherapy (70 Gy in 35 fractions over 7 weeks) plus either tirapazamine and cisplatin in weeks 1, 4, and 7 and tirapazamine alone in weeks 2 and 3 (TPZ/CIS) or cisplatin and infusional fluorouracil during weeks 6 and 7 (chemoboost). PATIENTS AND METHODS: Forty-five patients were enrolled onto a hypoxic imaging substudy of a larger randomized trial. Pretreatment and midtreatment [18F]-fluoromisonidazole positron emission tomography scans (FMISO-PET) were performed 2 hours after tracer administration, with qualitative scoring of uptake in both primary tumors and nodes. RESULTS: Thirty-two patients (71%) had detectable hypoxia in either or both primary and nodal disease. In patients who received chemoboost, one of 10 patients without hypoxia had LRF compared with eight of 13 patients with hypoxia; the risk of LRF was significantly higher in hypoxic patients (exact log-rank, P = .038; hazard ratio [HR] = 7.1). By contrast, in patients who received the TPZ/CIS regimen, only one of 19 patients with hypoxic tumors had LRF; risk of LRF was significantly higher in chemoboost patients (P = .001; HR = 15). Similarly, looking at the primary site alone, in patients with hypoxic primaries, zero of eight patients treated with TPZ/CIS experienced failure locally compared with six of nine patients treated with chemoboost (P = .011; HR = 0). CONCLUSION: Hypoxia on FMISO-PET imaging, in patients receiving a nontirapazamine-containing chemoradiotherapy regimen, is associated with a high risk of LRF. Our data provide the first clinical evidence to support the experimental observation that tirapazamine acts by specifically targeting hypoxic tumor cells.

Cell Hypoxia↗
PubMed2006

The impact of PET/CT in the management of recurrent ovarian cancer.

OBJECTIVES: To evaluate the impact of PET/CT on the restaging and management of recurrent ovarian cancer. METHODS: From January 2002 to July 2003, all women undergoing either surveillance or investigation of possible recurrent ovarian cancer at the Centre for Molecular Imaging, The Peter MacCallum Cancer Centre, were invited to take part in a prospective evaluation of the clinical impact of PET/CT. RESULTS: Fifty-six women having 66 scans were available for analysis. All patients had at least 12months follow-up after the PET/CT unless they died before that time. Apart from one equivocal scan, all scans performed in women with a CA125 higher than 35IU/ml had a positive PET/CT. PET/CT altered the known disease distribution in 40 scans (64%). Overall, PET/CT showed less disease in six scans (9%) and more disease in 34 scans (52%). Regardless of the value of CA125, PET/CT identified a sub group of women with apparently localized disease or no definite evidence of disease. This group showed improved survival compared with women shown to have systemic disease. PET/CT resulted in a major change of management plan in 34 patients (58%). CONCLUSION: PET/CT modifies the assessment of the distribution of recurrent ovarian cancer and alters patient management in a substantial proportion of patients. PET/CT appears to offer prognostic information.

CA-125 Antigen↗
PubMed2006

FDG-PET status following chemoradiotherapy provides high management impact and powerful prognostic stratification in oesophageal cancer.

PURPOSE: The purpose of this study was to evaluate the impact of FDG-PET following chemoradiotherapy (CRT) on treatment planning and survival in patients with oesophageal cancer (OC). METHODS: Fifty-three consecutive OC patients had a post-treatment PET scan to evaluate tumour response to CRT prior to possible surgery. Baseline pre-CRT PET was performed in 33 patients. Prospectively recorded post-CRT management plans were compared with post-PET treatment. High impact was defined as a change in treatment intent or modality. Survival was analysed using the Kaplan-Meier product limit method and Cox proportional hazards regression model. RESULTS: After completion of CRT, 23/53 patients (43%) achieved complete metabolic response (CMR), as compared with only four (8%) with complete response on computed tomography. High PET impact was observed in 19 patients (36%). CMR was strongly predictive of survival (p<0.008) on multivariate analysis. CMR patients in whom resection was not performed had comparable survival to those (CMR and non-CMR) who underwent resection. CONCLUSION: The use of post-treatment FDG-PET for assessment of tumour response after CRT changed the clinical management of more than one-third of OC patients. CMR status as assessed by PET powerfully stratified prognosis. Even in the absence of a baseline study, normalisation of uptake at all sites of known tumoral involvement carries a good medium-term prognosis.

Adult↗
PubMed2006

A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer.

BACKGROUND AND PURPOSE: This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatment planning of oesophageal cancer would alter the delineation of tumour volumes compared to CT alone if PET/CT is assumed to more accurately represent true disease extent. PATIENTS AND METHODS: All patients underwent FDG-PET/CT scanning in the radiotherapy treatment position. For each patient, two separate gross tumour volumes (GTV) were defined, one based on CT images alone (GTV-CT) and another based on combined PET/CT data (GTV-PET). Corresponding planning target volumes (PTV) were generated, and separate treatment plans were then produced. For each patient, volumetric analysis of GTV-CT, PTV-CT and GTV-PET was performed to quantify the proportion of PET-avid disease that was not included in the GTV and PTV (geographic miss) if CT data alone were used for radiotherapy planning. Assessment of the cranial and caudal extent of the primary oesophageal tumour as defined by CT alone vs PET/CT was also compared. RESULTS: The addition of PET information altered the clinical stage in 8 of 21 eligible patients enrolled on the study (38%); 4 patients had distant metastatic disease and 4 had unsuspected regional nodal disease. Sixteen patients proceeded to the radiotherapy planning phase of the study and received definitive chemoradiation planned with the PET/CT data set. The GTV based on CT information alone excluded PET-avid disease in 11 patients (69%), and in five patients (31%) this would have resulted in a geographic miss of gross tumour. The discordance between CT and PET/CT was due mainly to differences in defining the longitudinal extent of disease in the oesophagus. The cranial extent of the primary tumour as defined by CT vs PET/CT differed in 75% of cases, while the caudal extent differed in 81%. CONCLUSIONS: This study demonstrates that if combined PET/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone, with the potential to avoid a geographic miss of tumour.

Esophageal Neoplasms↗
PubMed2006

Significant clinical impact and prognostic stratification provided by FDG-PET in the staging of oesophageal cancer.

PURPOSE: To evaluate the clinical impact of FDG-PET in staging oesophageal cancer and whether this information improves prognostic stratification. METHODS: Impact was based on comparison of a prospectively recorded pre-PET plan with post-PET treatment in 68 consecutive patients undergoing primary staging. Survival was analysed using the Kaplan-Meier product limit method and the Cox proportional hazards regression model. RESULTS: FDG-PET findings impacted on the management of 27/68 patients (40%): in 12 therapy was changed from curative to palliative and in three from palliative to curative, while in 12 other patients there was a change in the treatment modality or delivery but not in the treatment intent. The median survival was 21 months, with post-PET stage and treatment intent both strongly associated with survival (p<0.001). Conventional stage was not able to clearly stratify this population. CONCLUSION: The use of FDG-PET for primary staging of oesophageal cancer changed the clinical management of more than one-third of patients and provided superior prognostic stratification compared with conventional investigations.

Adult↗
PubMed2006

Multi-tracer small animal PET imaging of the tumour response to the novel pan-Erb-B inhibitor CI-1033.

PURPOSE: This study was designed as "proof of concept" for a drug development model utilising multi-tracer serial small animal PET imaging to characterise tumour responses to molecularly targeted therapy. METHODS: Mice bearing subcutaneous A431 human squamous carcinoma xenografts (n=6-8) were treated with the pan-Erb-B inhibitor CI-1033 or vehicle and imaged serially (days 0, 3 and 6 or 7) with [(18)F]fluorodeoxyglucose, [(18)F]fluoro-L: -thymidine, [(18)F]fluoro-azoazomycinarabinoside or [(18)F]fluoromisonidazole. Separate cohorts (n=3) were treated identically and tumours were assessed ex vivo for markers of glucose metabolism, proliferation and hypoxia. RESULTS: During the study period, mean uptake of all PET tracers generally increased for control tumours compared to baseline. In contrast, tracer uptake into CI-1033-treated tumours decreased by 20-60% during treatment. Expression of the glucose transporter Glut-1 and cell cycle markers was unchanged or increased in control tumours and generally decreased with CI-1033 treatment, compared to baseline. Thymidine kinase activity was reduced in all tumours compared to baseline at day 3 but was sevenfold higher in control versus CI-1033-treated tumours by day 6 of treatment. Uptake of the hypoxia marker pimonidazole was stable in control tumours but was severely reduced following 7 days of CI-1033 treatment. CONCLUSION: CI-1033 treatment significantly affects tumour metabolism, proliferation and hypoxia as determined by PET. The PET findings correlated well with ex vivo biomarkers for each of the cellular processes studied. These results confirm the utility of small animal PET for evaluation of the effectiveness of molecularly targeted therapies and simultaneously definition of specific cellular processes involved in the therapeutic response.

Adenocarcinoma↗
PubMed2006

Depression in temporal lobe epilepsy surgery patients: an FDG-PET study.

PURPOSE: Depression is common in temporal lobe epilepsy (TLE) and after temporal lobectomy, and its etiology is obscure. In nonepileptic depression (including depression associated with other neurologic disorders), a consistent PET imaging finding is frontal lobe hypometabolism. Many TLE patients have hypometabolism involving frontal regions. Thus in data available from routine clinical assessments in an epilepsy surgery unit, we tested the hypothesis that the pattern of hypometabolism, particularly in the frontal lobe, may be associated with the depression seen in patients with TLE and TLE surgery. METHODS: We studied 23 medically refractory TLE patients who underwent anterior temporal lobectomy and who had preoperative FDG-PET scanning. All patients had pre- and postoperative psychiatric assessment. By using statistical parametric mapping (SPM-99), patterns of hypometabolism were compared between patients who had a preoperative history of depression (n=9) versus those who did not (n=14) and between those in whom postoperative depression developed (n=13) versus those in whom it did not (n=10). A significant region of hypometabolism was set at p<0.001 for a cluster of >or=20 contiguous voxels. RESULTS: Patients with a history of depression at any time preoperatively showed focal hypometabolism in ipsilateral orbitofrontal cortex compared with those who did not (t=4.64; p<0.001). Patients in whom depression developed postoperatively also showed hypometabolism in the ipsilateral orbitofrontal region (t=5.10; p<0.001). CONCLUSIONS: Although this study is methodologically limited, and other explanations merit consideration, orbitofrontal cortex dysfunction, already implicated in the pathophysiology of nonepileptic depression, may also be relevant to the depression of TLE and temporal lobectomy.

Adult↗
PubMed2006

Findings on 18F-FDG PET scans after neoadjuvant chemoradiation provides prognostic stratification in patients with locally advanced rectal carcinoma subsequently treated by radical surgery.

UNLABELLED: Predicting outcome after aggressive therapy for advanced rectal cancer remains difficult. (18)F-FDG PET has emerged as a valid method for predicting patient outcomes after therapy in an increasing number of cancers. We evaluated the prognostic information obtained from the degree of change in tumor (18)F-FDG PET uptake induced by chemoradiation before radical curative surgery in patients with T3/T4 rectal cancer. METHODS: The study included 34 consecutive patients with T3/T4 Nx M0 rectal cancer on structural imaging, who underwent staging and postchemoradiation (18)F-FDG PET before planned curative surgery. Change in (18)F-FDG uptake was graded visually as complete (CMR), partial (PMR), or no (NoMR) metabolic response. Pre- and postchemoradiation (18)F-FDG PET-derived standardized uptake values (SUVs) were then obtained for PMR patients to determine whether SUV further stratified this subgroup. Operative findings were available in 30 patients (3 excluded because of (18)F-FDG PET-defined M1 disease, 1 refused surgery). Clinical status at study closeout (alive free from disease, FFD; alive with disease, AWD; or died of disease, DOD) was available for all patients. RESULTS: A pathologic complete response was found in only 6 of 30 patients (5 CMR, 1 false-positive PMR). However, after an estimated median 3.1 y of follow-up, all 17 CMR patients were FFD, 6 of 10 PMR patients were FFD, 2 of 10 had DOD, and 2 of 10 were AWD. All 3 NoMR patients DOD. PET response was highly significantly associated with overall survival duration (P < 0.0001) and time to progression (P < 0.0001). Pathologic complete response was the only other statistically significant prognostic factor (P < 0.03). The percentage of maximum SUV change after chemoradiation was not predictive of survival in PMR patients. CONCLUSION: Using a simple qualitative assessment, postchemoradiation (18)F-FDG PET scintigraphy provides good medium-term prognostic information in patients with advanced rectal cancer undergoing radical surgery with curative intent.

Adult↗