Weight-Based Protocols Offer Significant Reduction in Radiation Dose Without Affecting PET-CT Image Quality.

PURPOSE: To investigate the use of weight-based protocols during full- and half-body fluorodeoxyglucose F 18 (FDG) positron emission tomography-computed tomography (PET-CT) and their effect on image quality, radiation dose, and lifetime attributable risks. METHODS: A total of 1817 patients were referred for FDG PET-CT studies. Each scanning group (4 total: full-body groups A and C and half-body groups B and D) was randomly allotted into conventional or weight-based CT. Groups A and B followed a conventional protocol of 120 kVp, 120 mA, 0.5 second rotation time, and pitch 0.8 mm/rotation for all body weights. Groups C and D were scanned using 1 of 4 weight-based CT protocols. All 4 weight-based protocols used 140 kVp, 0.75 seconds rotation time, and pitch 0.8 mm/rotation. Milliamperage varied by body weight as follows: protocol I (≤ 60kg [132.3 lb]), 35 mA; protocol II (61-80 kg [134.5-176.4 lb]), 50 mA; protocol III (81-100 kg [178.6-220.5 lb]), 65 mA; and protocol IV (> 100kg [222.7 lb]), 100 mA. All protocols (weight based and conventional) employed tube current modulation. CT quantitative image quality measurements were evaluated for each protocol, and lifetime attributable risks were calculated for each age group and sex. RESULTS: Patient demographics demonstrated no significant differences between groups. Mean effective dose was significantly lower for group C (full body, weight based) compared with A (full body, conventional) (P < .001), as were lifetime attributable risks (P < .001). Mean effective dose and lifetime attributable risks also were significantly lower (P < .001) for group D (half body, weight based) compared with B (half body, conventional). Contrast-to-noise ratios showed no difference between groups (P = .12), supporting a preference for the weigh-based protocols used for groups C and D. For half-body, weight-based protocols (group D), the lifetime attributable risks decreased for men by 91.9% and for women by 38.9%. For full-body, weight-based protocols (group C), the lifetime attributable risks decreased by 72.5% and 66.3% for men and women, respectively. DISCUSSION: Radiologists and radiologic technologists face the challenge of balancing the potential risks of radiation-induced cancer against providing diagnostic-quality images and uncompromised disease detection. Weight-based protocols address this challenge without compromising image quality or pathology detection. CONCLUSION: Significant reductions in radiation dose and lifetime attributable risks can be achieved using CT weight-based protocols during half- and whole-body FDG PET-CT without compromising CT image quality.

Management of patients with high-risk and advanced prostate cancer in the Middle East: resource-stratified consensus recommendations.

PURPOSE: Prostate cancer care in the Middle East is highly variable and access to specialist multidisciplinary management is limited. Academic tertiary referral centers offer cutting-edge diagnosis and treatment; however, in many parts of the region, patients are managed by non-specialists with limited resources. Due to many factors including lack of awareness and lack of prostate-specific antigen (PSA) screening, a high percentage of men present with locally advanced and metastatic prostate cancer at diagnosis. The aim of these recommendations is to assist clinicians in managing patients with different levels of access to diagnostic and treatment modalities. METHODS: The first Advanced Prostate Cancer Consensus Conference (APCCC) satellite meeting for the Middle East was held in Beirut, Lebanon, November 2017. During this meeting a consortium of urologists, medical oncologists, radiation oncologist and imaging specialists practicing in Lebanon, Syria, Iraq, Kuwait and Saudi Arabia voted on a selection of consensus questions. An additional workshop to formulate resource-stratified consensus recommendations was held in March 2019. RESULTS: Variations in practice based on available resources have been proposed to form resource-stratified recommendations for imaging at diagnosis, initial management of localized prostate cancer requiring therapy, treatment of castration-sensitive/naïve advanced prostate cancer and treatment of castration-resistant prostate cancer. CONCLUSION: This is the first regional consensus on prostate cancer management from the Middle East. The following recommendations will be useful to urologists and oncologists practicing in all areas with limited access to specialist multi-disciplinary teams, diagnostic modalities and treatment resources.

Randomized, Prospective, Open-label Phase III Trial Comparing Mebo Ointment With Biafine Cream for the Management of Acute Dermatitis During Radiotherapy for Breast Cancer.

PURPOSE: Acute radiation dermatitis is a common side-effect of radiotherapy in breast cancer and has a profound impact on patients' quality of life, due to pain and discomfort. The aim of this study is to compare the effect of ß-sitosterol (Mebo) ointment to trolamine (Biafine) cream for the prevention and treatment of radiation dermatitis in breast cancer patients receiving adjuvant radiation therapy. MATERIALS AND METHODS: This is a prospective open-label randomized phase III study developed to assess the efficacy of 2 topical agents used for management of acute radiation dermatitis. Female breast cancer patients who needed a course of radiation therapy in our institution were enrolled and randomized into 2 groups 1 with Mebo ointment and 1 with Biafine cream. Both medications were applied twice per day during the whole period of treatment and skin reactions and related symptoms were assessed weekly during the entire course. Grading of skin reactions was done according to the Radiation Therapy Oncology Group grading system. RESULTS: Between September 2015 and May 2017, a total of 161 patients were recruited for this trial. Mean age was similar for both groups (50.19±12.57 vs. 51.73±11.23, respectively, P=0.41). All other patients and treatment characteristics were similar in both groups, except for the use of boost (82.7% in the Biafine group vs. 36.7% in Mebo group, P=0.012). Analysis was done for reactions recorded before the beginning of the boost and for the entire course including the boost. Using univariate and multivariate analysis, there was no significant difference in grades 2 and 3 dermatitis between the 2 groups. However, the incidence of severe pruritus and severe local skin pain were both significantly reduced in the Mebo group (14.1% in Biafine vs. 2.9% in Mebo, P=0.016 for pruritus and 11.5% vs. 1.4%, respectively, P=0.02 for severe pain). CONCLUSIONS: This study showed no difference between Mebo and Biafine in the incidence and severity of breast skin dermatitis during radiation therapy. However, the use of Mebo ointment was associated with decreased severe pruritus and pain which could positively affect patient comfort and quality of life.

[18F]-FDG uptake dose-response correlates with radiation pneumonitis in lung cancer patients.

PURPOSE: To quantify the post-radiotherapy 2-[(18)F]-fluoro-2-deoxyglucose (FDG) pulmonary uptake dose-response in lung cancer patients and determine its relationship with radiation pneumonitis symptoms. METHODS AND MATERIALS: The data from 24 patients treated for lung cancer with thoracic radiotherapy who received restaging PET/CT imaging between 4 and 12 weeks after radiotherapy completion were evaluated. Their radiation dose distribution was registered with the post-treatment restaging PET/CT. Using histogram analysis, the voxel average FDG-PET uptake vs. radiation dose was obtained for each case and linear regression was performed. The resulting slope, the pulmonary metabolic radiation response (PMRR), was used to characterize the dose-response. The Common Toxicity Criteria version 3 was used to score clinical pulmonary toxicity symptoms. Receiver operating characteristic (ROC) curves were used to determine the level of FDG uptake vs. dose, MLD, V(5), V(10), V(20), and V(30) that can best predict symptomatic and asymptomatic patients. RESULTS: The median time between radiotherapy completion and FDG-PET imaging was 59 days (range, 26-70 days). The median of the mean SUV from lung that received 0-5 Gy was 1.00 (range, 0.37-1.48), 5-10 Gy was 1.01 (range, 0.37-1.77), 10-20 Gy was 1.04 (0.42-1.53), and >20 Gy was 1.29 (range, 0.41-8.01). Using the dose range of 0 Gy to the maximum dose minus 10 Gy, hierarchical linear regression model of the radiation dose and normalized FDG uptake per case found an adequate fit with the linear model. Pneumonitis scores were: Grade 0 for 13, Grade 1 for 5, Grade 2 for 6, and Grade 3, 4 or 5 for none. Using a PMRR threshold of 0.017 yields an associated true positive rate of 0.67 and false positive rate of 0.15 with average error of 30%. A V(5) threshold of 57.6 gives an associated true positive rate of 0.67 and false positive rate of 0.05 with a 20% average error. CONCLUSION: The metabolic radiation pneumonitis dose-response was evaluated from post-treatment FDG-PET/CT imaging. Statistical modeling found a linear relationship. The FDG uptake dose-response and V(5) correlated with symptomatic radiation pneumonitis.

Detection of (154)Eu in patients post (153)Sm-EDTMP therapy using a clinical gamma camera.

Enhancements in radiation detection equipment at border crossings and airports resulted in a report to our institution from a Sm-EDTMP therapy patient who was questioned after triggering radiation alarms. Using a clinical SPECT camera in its service mode, gamma-ray spectroscopy was performed on three patients whose Sm-EDTMP injections were given between 4 mo and 2 y prior to this study. The spectra revealed the presence of high-energy photon peaks characteristic of those from Eu. While the presence of Eu in Sm injections is documented in the literature, the implications of its presence are not widely known. The results of this study show that Eu (t1/2 = 8.5 y) remains in the bones in detectable amounts for several years and may create concerning situations for post therapy patients at some security checkpoints. Institutions performing Sm-EDTMP therapy may want to inform their patients of this situation and provide a wallet card.

The Level of Europium-154 Contaminating Samarium-153-EDTMP Activates the Radiation Alarm System at the US Homeland Security Checkpoints.

(153)Sm-EDTMP is a radiopharmaceutical composed of EDTMP (ethylenediamine-tetramethylenephosphonate) and Samarium-153 [1]. (153)Sm-EDTMP has an affinity for skeletal tissue and concentrates in areas with increased bone turnover; thus, it is successfully used in relieving pain related to diffuse bone metastases [1]. The manufacturing process of (153)Sm-EDTMP leads to contamination with (154)Eu (Europium-154) [2]. A previous study only alluded to the retention of (154)Eu in the bones after receiving treatment with (153)Sm-EDTMP [2]. Activation of the alarm at security checkpoints after (153)Sm-EDTMP therapy has not been previously reported. Two out of 15 patients who received (153)Sm-EDTMP at Roger Maris Cancer Center (Fargo, N. Dak., USA) activated the radiation activity sensors while passing through checkpoints; one at a US airport and the other while crossing the American-Canadian border. We assume that the (154)Eu which remained in the patients' bones activated the sensors. METHODS: In order to investigate this hypothesis, we obtained the consent from 3 of our 15 patients who received (153)Sm-EDTMP within the previous 4 months to 2 years, including the patient who had activated the radiation alarm at the airport. The patients were scanned with a handheld detector and a gamma camera for energies from 511 keV to 1.3 MeV. RESULTS: All three patients exhibited identical spectral images, and further analysis showed that the observed spectra are the result of (154)Eu emissions. CONCLUSION: Depending on the detection thresholds and windows used by local and federal authorities, the remaining activity of (154)Eu retained in patients who received (153)Sm-EDTMP could be sufficient enough to increase the count rates above background levels and activate the sensors. At Roger Maris Cancer Center, patients are now informed of the potential consequences of (153)Sm-EDTMP therapy prior to initiating treatment. In addition, patients treated with (153)Sm-EDTMP at Roger Maris Cancer Center receive laminated cards stating the date and the dose of treatment, as well as a statement that the holder may activate the alarm at the security checkpoints.