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Positron emission tomography-computed tomography (PET-CT) has changed cancer imaging in the last decade, for better. It can be employed for radiation treatment planning of different cancers with improved accuracy and outcomes as compared to conventional imaging methods. (18)F-fluorodeoxyglucose remains the most widely used though relatively non-specific cancer imaging PET tracer. A wide array of newer PET radiopharmaceuticals has been developed for targeted imaging of different cancers. PET-CT with such new PET radiopharmaceuticals has also been used for radiotherapy planning with encouraging results. In the present review we have briefly outlined the role of PET-CT with newer radiopharmaceuticals for radiotherapy planning and briefly reviewed the available literature in this regard.

Background: Index lesion characterization is important in the evaluation of primary prostate carcinoma (PPC). The aim of this study was to analyze the contribution of (11) C-Choline PET/CT and the Apparent Diffusion Coefficient maps (ADC) in detecting the Index Lesion and clinically significant tumors in PPC., Methods: Twenty-one untreated patients with biopsy-proven PPC and candidates for radical prostatectomy (RP) were prospectively evaluated by means of Ultra-High Definition PET/CT and 3T MRI, which included T2-weighted imaging (T2WI) and ADC maps obtained from diffusion weighted imaging (DWI). Independent experts analyzed all the images separately and were unaware of the pathological data. In each case, the Index lesion was defined as the largest tumor measured on histopathology (Index H). In addition, the largest lesion observed on MRI (Index MRI) and the highest avid (11) C-Choline uptake lesion (Index PET) were obtained. The Gleason scores (GS) of the tumors were determined. PET/CT and ADC map quantitative parameters were also calculated. Measures of correlation among imaging parameters as well as the sensitivity (S), specificity (Sp), negative and positive predictive values (NPV and PPV) for tumor detection were analyzed. All data was validated with the pathological study., Results: In the morphological study, 139 foci of carcinoma were identified, 47 of which corresponded to clinically significant tumors (>0.5 cm(3)). The remaining foci presented a maximum diameter (dmax ) of 0.1 cm ± SD 0.75 and were not classified as clinically significant. Thirty-two tumors presented a GS (3 + 3), nine GS (3 + 4), and six GS (4 + 3). A total of 21 Index H (dmax = 1.37 cm SD ± 0.61) were identified. The S, Sp, NPV, and PPV for tumor detection with PET were 100%, 70%, 83%, 100%, and for MRI were 46%, 100%, 100%, 54%, respectively. Both Index PET and Index MRI were complementary and identified 95% of the Index H when quantitative criteria were used., Conclusion: In spite of the fact that PET imaging has higher tumor sensitivity than MRI, (11) C-Choline PET and ADC maps have complementary roles in the evaluation of Index Lesion in PPC. Index PET and Index MRI could be complementary targets in the therapeutic planning of PPC., (© 2015 Wiley Periodicals, Inc.)

Purpose: To demonstrate the technical feasibility of intensity modulated radiation therapy (IMRT) dose painting using 11C-choline positron emission tomography PET scans in patients with localized prostate cancer. Methods and Materials: This was an RT planning study of 8 patients with prostate cancer who had 11C-choline PET scans prior to radical prostatectomy. Two contours were semiautomatically generated on the basis of the PET scans for each patient: 60% and 70% of the maximum standardized uptake values (SUV60% and SUV70%). Three IMRT plans were generated for each patient: PLAN78, which consisted of whole-prostate radiation therapy to 78 Gy; PLAN78-90, which consisted of whole-prostate RT to 78 Gy, a boost to the SUV60% to 84 Gy, and a further boost to the SUV70% to 90 Gy; and PLAN72-90, which consisted of whole-prostate RT to 72 Gy, a boost to the SUV60% to 84 Gy, and a further boost to the SUV70% to 90 Gy. The feasibility of these plans was judged by their ability to reach prescription doses while adhering to published dose constraints. Tumor control probabilities based on PET scan-defined volumes (TCPPET) and on prostatectomy-defined volumes (TCPpath), and rectal normal tissue complication probabilities (NTCP) were compared between the plans. Results: All plans for all patients reached prescription doses while adhering to dose constraints. TCPPET values for PLAN78, PLAN78-90, and PLAN72-90 were 65%, 97%, and 96%, respectively. TCPpath values were 71%, 97%, and 89%, respectively. Both PLAN78-90 and PLAN72-90 had significantly higher TCPPET (P=.002 and .001) and TCPpath (P<.001 and .014) values than PLAN78. PLAN78-90 and PLAN72-90 were not significantly different in terms of TCPPET or TCPpath. There were no significant differences in rectal NTCPs between the 3 plans. Conclusions: IMRT dose painting for localized prostate cancer using 11C-choline PET scans is technically feasible. Dose painting results in higher TCPs without higher NTCPs. [Copyright &y& Elsevier]

Abstract: Aim: to evaluate the utility of 11C-choline PET/CT in prostate cancer (PC) patients who have demonstrated a biochemical recurrence and a negative bone scintigraphy (BS). Materials and methods: 123 consecutive PC patients (mean age 67.6 years; range 54–83) with a biochemical relapse (mean PSA value 3.3ng/mL; range 0.2–25.5) after radical prostatectomy (RP) were included in our retrospective study. Patients underwent a BS that resulted negative and a 11C-choline PET/CT within 4 months from BS (range: 1 day to 4 months; mean: 2.5 months). Validation of results was established by: (1) a positive biopsy, (2) a positive subsequent BS, CT or MR and (3) a normalization of 11C-choline uptake after systemic therapy or a progression of the disease. Results: 11C-choline PET/CT was positive in 42/123 patients (34.1%). 11C-choline PET/CT detected lesions in: bone (10 patients), lymph-nodes (20 patients), bone and lymph nodes (7 patients), bone and lung (1 patient), lymph-nodes and lung (1 patient), local relapse (3 patients). Overall, 11C-choline PET/CT showed a total of 30 unknown bone lesions in 18/123 (14.6%) patients. Conclusion: 11C-choline PET/CT showed a better sensitivity than BS in patients with biochemical relapse after RP: 11C-choline PET/CT detected unknown bone lesions in 18/123 (14.6%) patients. [Copyright &y& Elsevier]

The article presents the case of a 72-year-old male patient with monoclonal gammopathy and pain at left hip. Tests including, PSA, magnetic resonance imaging, bone scintigraphy and 11C-choline PET/CT were performed. The 11C-choline PET/CT showed pathological uptake at the left ilium and the histological evaluation revealed differentiated plasmacytoma cells. The article also presents that this confirmed the presence of solitary plasmacytoma lesion.