Peptide receptor radionuclide therapy (PRRT) is a promising treatment for patients with neuroendocrine tumors, giving rise to improved survival. Dosimetric calculations in relation to PRRT have been concentrated to normal organ dosimetry in order to limit side effects. However, the relation between the absorbed dose to the tumor and treatment response has so far not been established. Better knowledge in this respect may improve the understanding of treatment effects, allow for improved selection of those patients who are expected to benefit from PRRT, and avoid unnecessary treatments. The aim of the present work was to evaluate the dose-response relationship for pancreatic neuroendocrine tumors treated with PRRT using 177 Lu-DOTATATE. Methods: Tumor-absorbed dose calculations were performed for 24 lesions in 24 patients with metastasized pancreatic neuroendocrine tumors treated with repeated cycles of 177 Lu-DOTATATE at 8-wk intervals. The absorbed dose calculations relied on sequential SPECT/CT imaging at 24, 96, and 168 h after infusion of 177 Lu-DOTATATE. The unit density sphere model from OLINDA was used for absorbed dose calculations. The absorbed doses were corrected for partial-volume effect based on phantom measurements. On the basis of these results, only tumors larger than 2.2 cm in diameter at any time during the treatment were included for analysis. To further decrease the effect of partial-volume effect, a subgroup of tumors (.4.0 cm) was analyzed separately. Tumor response was evaluated by CT using Response Evaluation Criteria In Solid Tumors. Results: Tumor-absorbed doses until best response ranged approximately from 10 to 340 Gy. A 2-parameter sigmoid fit was fitted to the data, and a significant correlation between the absorbed dose and tumor reduction was found, with a Pearson correlation coefficient (R 2 ) of 0.64 for tumors larger than 2.2 cm and 0.91 for the subgroup of tumors larger than 4.0 cm. The largest tumor reduction was 57% after a total absorbed dose of 170 Gy. Conclusion: The results imply a significant correlation between absorbed dose and tumor reduction. However, further studies are necessary to address the large variations in response for similar absorbed doses.

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Many management options are available to patients with newly diagnosed prostate cancer. Magnetic resonance (MR) imaging plays an important role in initial staging of prostate cancer, but it also aids in tumor detection when there is clinical or biochemical suspicion of residual or recurrent disease after treatment. The purpose of this review is to describe the normal appearances of the prostatic region after different kinds of treatment for prostate cancer and to discuss how these appearances differ from those of recurrent and residual disease. Several MR imaging techniques used in evaluating patients with prostate cancer are described, including conventional MR imaging sequences (mainly T1- and T2-weighted sequences), MR spectroscopic imaging, diffusion-weighted imaging, and dynamic contrast agent-enhanced MR imaging. Clinical considerations, together with the different approaches for interpreting serum prostate-specific antigen values in the posttreatment setting, are also presented. All forms of treatment alter the MR imaging features of the prostatic region to a greater or lesser extent, and it is important to be able to recognize expected posttreatment appearances and distinguish them from the features of recurrent or residual cancer to aid subsequent clinical management.

Summary To quantify the risk of second primary cancers among patients with cutaneous malignant melanoma, we studied 20 354 patients in the Swedish Cancer Register during 1958-88. A second primary cancer was reported in 1605 patients, compared with an expected number of 1109.5 [standardised incidence ratio (SIR) = 1.45, 95% confidence interval (CI) = 1.38-1.52]. The highest risk was found among patients younger than 60 years. The greatest risk was seen during the first year after diagnosis (SIR = 1.91, CI = 1.69-2.14), but even after long-term follow-up -15 years or more -the risk was still significantly elevated (SIR = 1.56, CI = 1.35-1.79). The strongest association was found for a second primary malignant melanoma (men, SIR = 10.0, CI = 8.26-12.00; women, SIR = 8.66, CI = 7.22-10.30) and non-melanoma skin cancer (men, SIR = 3.58, CI = 2.85-4.44; women, SIR = 2.41, CI = 1.71-3.29). The risk of second cancers associated with tissues of neuroectodermal origin was increased, especially tumours of the nervous system (men, SIR = 1.73, CI = 1.10-2.60; women, SIR = 2.03, CI = 1.45-2.78). The SIR of second cancers involving the immune system was also increased. An excess risk of endometrial cancer was seen (SIR = 1.41, CI = 1.03-1.88), but no significant associations existed for cancers of the breast, ovary, testis or other endocrine glands. Among tumours of the digestive tract, only colon cancer in men had a significantly increased SIR (1.33, CI = 1.00-1.74).

PurposeTo compare the features of bone metastases at computed tomography (CT) to tracer uptake at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and fluorine 18 16b-fluoro-5-dihydrotestosterone (FDHT) PET and to determine associations between these imaging features and overall survival in men with castrationresistant prostate cancer. Materials and MethodsThis is a retrospective study of 38 patients with castration-resistant prostate cancer. Two readers independently evaluated CT, FDG PET, and FDHT PET features of bone metastases. Associations between imaging findings and overall survival were determined by using univariate Cox proportional hazards regression. ResultsIn 38 patients, reader 1 detected 881 lesions and reader 2 detected 867 lesions. Attenuation coefficients at CT correlated inversely with FDG (reader 1: r = 20.3007; P , .001; reader 2: r = 20.3147; P , .001) and FDHT (reader 1: r = 20.2680; P = .001; reader 2: r = 20.3656; P , .001) uptake. The number of lesions on CT scans was significantly associated with overall survival (reader 1: hazard ratio [HR], 1.025; P = .05; reader 2: HR, 1.021; P = .04). The numbers of lesions on FDG and FDHT PET scans were significantly associated with overall survival for reader 1 (HR, 1.051-1.109; P , .001) and reader 2 (HR, 1.026-1.082; P  .009). Patients with higher FDHT uptake (lesion with the highest maximum standardized uptake value) had significantly shorter overall survival (reader 1: HR, 1.078; P = .02; reader 2: HR, 1.092; P = .02). FDG uptake intensity was not associated with overall survival (reader 1, P = .65; reader 2, P = .38). ConclusionIn patients with castration-resistant prostate cancer, numbers of bone lesions on CT, FDG PET, and FDHT PET scans and the intensity of FDHT uptake are significantly associated with overall survival.q RSNA, 2013

Background: In our center,the combination of streptozocin (STZ) and 5-fluorouracil (5-FU) has been used as the first-line treatment in the majority of patients with pancreatic neuroendocrine tumors (pNETs) over the past few decades. The objective of the current study was to assess the efficacy, prognostic factors and safety of the combination of STZ and 5-FU. Patients and Methods: Medical records and radiological reports of 133 patients with pNETs who received the combination of STZ and 5-FU during the period 1981-2014 were retrospectively evaluated. Results: The median survival from the start of treatment was 51.9 months in the whole group. In the radiologically evaluable patients (n = 100), progression-free survival was 23 months. Complete response was reached in 3 patients (3%), partial response in 25 patients (25%), 64 patients (64%) had stable disease, and 8 patients (8%) had progressive disease. In a multivariate analysis, surgery of the primary tumor and having a G3 tumor were significant positive and negative prognostic factors of survival from the start of treatment, respectively. Having either a G3 tumor or a stage IV tumor were significant prognostic factors for a shorter progression-free survival. Chemotherapy had to be discontinued in 29 patients due to side effects, of which kidney toxicity (mainly grades 1-2) was the most frequent. Conclusion: As shown in recent reports, the combination of STZ and 5-FU is effective in the treatment of pNETs in terms of survival and radiological response and has an acceptable toxicity profile.

The incidence of squamous cell carcinoma of the skin is increasing world-wide, and in Sweden this tumour is one of the most rapidly increasing malignancies. The aim of this study was to investigate incidence trends of squamous cell carcinoma in Sweden. For the 39,805 tumours registered in the Swedish Cancer Registry 1961-1995, incidence rates were calculated according to gender, age, anatomical site and unit surface area. Multivariate analysis was performed with the age-period-cohort model. Age-standardized incidence rates increased substantially in both men (+425%) and women (+146%) during this period. The highest rates per unit surface area were seen for chronically sun-exposed head-neck sites. Age-specific incidence rates increased in ages > or =60 years during the study period. Multivariate analyses showed that age, period and cohort effects in men could best explain the incidence rates, while in women the age-period effects model was adequate. In conclusion, a rapidly increasing incidence trend for squamous cell carcinoma was found, probably explained by increased accumulated sun exposure and increasing incidence among the elderly.

OBJECTIVE The purpose of this study is to retrospectively assess the incremental value of contrast-enhanced MRI (CE-MRI) to T2-weighted MRI in the detection of postsurgical local recurrence of prostate cancer by readers of different experience levels, using biopsy as the reference standard. MATERIALS AND METHODS Fifty-two men with biochemical recurrence after prostatectomy underwent 1.5-T endorectal MRI with multiphase contrast-enhanced imaging and had biopsy within 3 months of MRI. Two radiologists (reader 1 had 1 year and reader 2 had 6 years of experience) independently reviewed each MRI study and classified the likelihood of recurrent cancer on a 5-point scale. Areas under receiver operating characteristic curves (Az) were calculated to assess readers’ diagnostic performance with T2-weighted MRI alone and combined with CE-MRI. Interobserver agreement was assessed using Cohen kappa statistics. RESULTS Thirty-three patients (63%) had biopsy-proven local recurrence of prostate cancer. With the addition of CE-MRI to T2-weighted imaging, the Az for cancer detection increased significantly for reader 1 (0.77 vs 0.85; p = 0.0435) but not for reader 2 (0.86 vs 0.88; p = 0.7294). The use of CE-MRI improved interobserver agreement from fair (κ = 0.39) to moderate (κ = 0.58). CONCLUSION CE-MRI increased interobserver agreement and offered incremental value to T2-weighted MRI in the detection of locally recurrent prostate cancer for the relatively inexperienced reader.