The Pattern of Use of PET/CT Scans in the Clinical Management of Chronic Lymphocytic Leukemia.

BACKGROUND: The study aimed to evaluate the utilization patterns of positron emission tomography/computed tomography (PET/CT) in chronic lymphocytic leukemia (CLL) patients and to investigate whether the results of these scans influenced treatment decisions. PATIENTS: and Methods: In this observational study, we analyzed patients with CLL or small lymphocytic leukemia (SLL) who underwent at least one PET/CT scan from 2007 to 2018. Patients were divided into two groups: (1) patients who had at least one fluorodeoxyglucose-avid PET/CT scan, and (2) patients who had all negative scans. PET/CT results were retrieved from patients' medical files and were revised by an expert radiologist according to visual score scale, SUVmax/SUVliver mean ratio, and the SUVmax. RESULTS: Of the 524 patients, 160 patients (30.5%) had PET/CT scans, and 120 patients met the inclusion criteria. A total of 219 eligible scans were analyzed; 62 of these scans (28.3%) were reported as positive, and 167 of these scans (76.3%) were performed for staging. There was a significant association between PET/CT results and change of therapy (P < .001); however, 62.9% of the positive PET/CT scans were not followed by a change of treatment. Survival time was not different between the two groups. The SUVmax/SUVliver mean ratio was negatively significantly associated with lymphocytes percent (r = -0.237, P = .042) and positively associated with lactate dehydrogenase levels (r = 0.338, P = .008) among CLL patients. CONCLUSION: Despite the fact that the use of surveillance PET/CT for patients with CLL/SLL is not in the guidelines and that it is not useful for disease management, in practice the test is in frequent use in Israel.

Real-time Online Matching in High Dose-per-Fraction Treatments: Do Radiation Therapists Perform as Well as Physicians?

PURPOSE: In our department, for high dose-per-fraction treatments such as stereotactic body radiation therapy, we require a physician to perform the pretreatment on-board imaging match. The purpose of this study was to determine whether patient-matching positioning performed by radiation therapists (RTTs) is as accurate as that performed by physicians. METHODS AND MATERIALS: Sixteen RTTs and 5 physicians participated in this study. Data were collected from 113 patients, totaling 324 measurements. A total of 60 patients were treated for bone lesions and 53 for soft-tissue lesions, such as lung and liver. Matching was performed using kV-kV imaging for bones and cone beam computed tomography for soft tissue. All treatments were delivered on Varian linear accelerators. The initial match was performed by the RTTs, and the shifts were noted. Subsequently, the match was reset, and the physician performed an independent match blinded to the RTT match. Physician shifts were applied for treatment. We used the Wilcoxon rank sum test to determine the statistical significance between RTT and physician shifts. RESULTS: The differences in patient shifts between physicians and RTTs were calculated in 3 translational 1 one rotational axis. The average vector shift was 0.88 ± 0.57 cm versus 0.91 ± 0.57 cm for RTTs versus physicians, respectively. Neither the average vector nor the individual axis shifts were statistically significantly different (P > .2). There was no significant difference when testing for bony or soft lesion matches separately. CONCLUSIONS: RTT on-board imaging matching is as accurate as physician matching for both bone and soft tissue lesions. On the basis of these results, RTTs are as qualified as physicians to perform a pretreatment match. Thus, it may be feasible for the RTTs to perform the match and the physician to review it offline after treatment without being present at the machine during treatment. Our results show that this approach does not compromise patient safety.