Clinical experience with the first combined positron emission tomography/computed tomography scanner in Australia

Use of CT, ED presentation and hospitalisations 12 months before and after a diagnosis of cancer in Western Australia: a population-based retrospective cohort study

OBJECTIVE

To examine the use of CT, emergency department (ED)-presentation and hospitalisation and in 12 months before and after a diagnosis of cancer.

DESIGN

Population-based retrospective cohort study.

SETTING

West Australian linked administrative records at individual level.

PARTICIPANTS

104 009 adults newly diagnosed with cancer in 2004-2014.

MAIN OUTCOME MEASURES

CT use, ED presentations, hospitalisations.

RESULTS

As compared with the rates in the 12th month before diagnosis, the rate of CT scans started to increase from 2 months before diagnosis with an increase in both ED presentations and hospitalisation from 1 month before the diagnosis. These rates peaked in the month of diagnosis for CT scans (477 (95% CI 471 to 482) per 1000 patients), and for hospitalisations (910 (95% CI 902 to 919) per 1000 patients), and the month prior to diagnosis for ED (181 (95% CI 178 to 184) per 1000 patients) then rapidly reduced after diagnosis but remained high for the next 12 months. While the patterns of the health services used were similar between 2004 and 2014, the rate of the health services used during after diagnosis was higher in 2014 versus 2004 except for CT use in patients with lymphohaematopoietic cancer with a significant reduction.

CONCLUSION

Our results showed an increase in demand for health services from 2 months before diagnosis of cancer. Increasing use of health services during and post cancer diagnosis may warrant further investigation to identify factors driving this change.

Survival outcomes following aggressive treatment of oligometastatic breast cancer: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this systematic review is to assess the effectiveness of aggressive treatment of oligometastatic breast cancer (OMBC) on survival outcomes by conducting a meta-analysis of current available evidence.More specifically, the objectives are to identify the effectiveness of intensified multidisciplinary treatment with aggressive locoregional therapies on survival time, five-year survival rates and disease free survival. The population is adult women (18 years and over) with OMBC defined as single or few (five or less) metastases limited to a single organ and the comparative group is conventional palliative treatment aimed at disease control. Secondary objectives to be assessed will be adverse outcomes associated with intensified treatment regimes.

PET/CT without capacity limitations: a Danish experience from a European perspective

OBJECTIVES

We report the 3-year clinical experience of a large new Danish PET/CT centre without capacity limitations in relation to national and European developments.

METHODS

The use of PET/CT in cancer was registered from early 2006 to early 2009 to judge the impact on patient management and to compare it with national and European trends.

RESULTS

6056 PET/CT examinations were performed in 4327 patients. Activity increased by 86 examinations per month compared with the same month the year before. Referrals came primarily from oncology (23.0%), haematology (21.6%), surgery (12.6%), internal medicine (12.7%) and gynaecology (5.5%). Referral indications were diagnosis (31.3%), staging (22.3%), recurrence detection (21.2%), response evaluation (17.0%) and other (8.2%). Response from nearly 60% of users showed that PET/CT caused a change in diagnosis and/or staging and/or treatment plan in 36.0% of cases. During the study period, there was a steep increase in the national use of FDG and in the European use of PET/CT.

CONCLUSIONS

We recorded a constantly increasing use of PET/CT that caused a change in diagnosis and/or staging and/or treatment plan in 36.0% of cases. In line with national and European trends this may suggest a shift in favour of functional rather than anatomical imaging.

Functional imaging of renal cell carcinoma

The incidence of early and advanced-stage renal cell carcinoma (RCC) is increasing. Methods of diagnosing, staging and evaluating tumor burden that are more accurate and reliable than the currently available options are needed in order to identify RCC at a stage at which it is curable and to accurately determine the response to treatment. Functional imaging, particularly with combined PET-CT, might improve accuracy of detection and provide essential information that has been unavailable to date. This approach is against a background in which targeted therapies for metastatic RCC have entered clinical practice in the past few years, further highlighting the importance of accurate imaging for patient selection and for monitoring response to treatment. We outline the current clinical status of functional imaging in RCC using PET-CT, which allows simultaneous capture and co-registration of functional and anatomical data. New radiotracers and approaches-including radiolabeled monoclonal antibodies and imaging of tumor hypoxia-are touched on, and areas of future research discussed.

Automated cardiac motion compensation in PET/CT for accurate reconstruction of PET myocardial perfusion images

Error-free reconstruction of PET data with a registered CT attenuation map is essential for accurate quantification and interpretation of cardiac perfusion. Misalignment of the CT and PET data can produce an erroneous attenuation map that projects lung attenuation parameters onto the heart wall, thereby underestimating the attenuation and creating artifactual areas of hypoperfusion that can be misinterpreted as myocardial ischemia or infarction. The major causes of misregistration between CT and PET images are the respiratory motion, cardiac motion and gross physical motion of the patient. The misalignment artifact problem is overcome with automated cardiac registration software that minimizes the alignment error between the two modalities. Results show that the automated registration process works equally well for any respiratory phase in which the CT scan is acquired. Further evaluation of this procedure on 50 patients demonstrates that the automated registration software consistently aligns the two modalities, eliminating artifactual hypoperfusion in reconstructed PET images due to PET/CT misregistration. With this registration software, only one CT scan is required for PET/CT imaging, which reduces the radiation dose required for CT-based attenuation correction and improves the clinical workflow for PET/CT.

Hybrid imaging is the future of molecular imaging

Correlative imaging has long been used in clinical practice and particularly for the interpretation of nuclear medicine studies wherein detailed anatomical information is often lacking. Previously, side-by-side comparison or software co-registration techniques were applied but suffered from technical limitations related to the differing geometries of the imaging equipment, differences in the positioning of patients and displacement of mobile structures between studies. The development of the first hybrid PET and CT device struck a chord with the medical imaging community that is still ringing loudly throughout the world. So successful has been the concept of PET-CT that none of the major medical imaging manufacturers now offers stand-alone PET scanners. Following close behind this success, SPECT-CT devices have recently been adopted by the nuclear medicine community, already compelled by the benefits of hybrid imaging through their experience with PET-CT. Recent reports of adaptation of PET detectors to operate within the strong magnetic field of MRI scanners have generated further enthusiasm. Prototype PET-MRI devices are now in development. The complementary anatomical, functional and molecular information provided by these techniques can now be presented in an intuitive and aesthetically-pleasing format. This has made end-users more comfortable with the results of functional imaging techniques than when the same information is presented independently. Despite the primacy of anatomical imaging for locoregional disease definition, the molecular characterisation available from PET and SPECT offers unique complementary information for cancer evaluation. A new era of cancer imaging, when hybrid imaging will be the primary diagnostic tool, is approaching.

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.

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.