Treatment Response Imaging in Prostate Cancer

Objective criteria for measuring treatment response in prostate cancer are critical to clinical research and practice. The Prostate Cancer Working Group 3 criteria are widely accepted relying only on conventional imaging for radiographic treatment response. Prostate-specific membrane antigen PET/computed tomography was proven to be superior to conventional imaging in initial diagnosis and biochemical recurrence of prostate cancer. Moreover, there is growing evidence of its role in treatment response assessment in prostate cancer. This study will review the different criteria for imaging treatment response on conventional and advanced molecular imaging for different therapies, and the future perspective in posttherapy imaging.

Development of a Visually Calculated SUVmean (HIT Score) on Screening PSMA PET/CT to Predict Treatment Response to 177Lu-PSMA Therapy: Comparison with Quantitative SUVmean and Patient Outcomes

177Lu-PSMA therapy is an effective treatment in patients with metastatic castration-resistant prostate cancer. SUVmean is a valuable screening biomarker to assess the suitability for 177Lu-PSMA therapy but requires quantitative software. This study aims to develop a simple, clinically applicable prostate-specific membrane antigen PET/CT score that encompasses the elements of SUVmean without requiring additional quantification. Methods: Datasets from ethics-approved trials of patients with metastatic castration-resistant prostate cancer after androgen receptor signaling inhibition and taxane chemotherapy (or unfit for taxane), who were treated with 177Lu-PSMA-617 and 177Lu-PSMA I&T with a pretreatment screening with 68Ga-PSMA-11 PET/CT, and clinical outcome data, including a prostate-specific antigen (PSA) 50% response rate (PSA50), PSA progression-free survival (PSA-PFS), and overall survival (OS), were included. The screening 68Ga-PSMA-11 PET/CT of all participants was analyzed both semiquantitatively and visually. Semiquantitative analysis was used to derive the SUVmean Visual analysis of the 68Ga-PSMA-11 PET/CT images involved a binary visual heterogeneity assessment (homogeneous or heterogeneous), allocating a tumor SUVmax range (<15, 15-29, 30-49, 50-79, or ≥80). A 4-category score incorporating both heterogeneity and intensity of tumors (HIT) was then developed as a combination of heterogeneity and intensity (SUVmax range). The SUVmax was less than 15 for score 1, 15-79 with heterogeneous intensity for score 2, 15-79 with homogeneous intensity for score 3, and 80 or greater for score 4. This score was evaluated according to clinical outcomes (PSA50, PSA-PFS, and OS) and compared with SUVmean Results: Data from 139 participants were analyzed. In total, 75 (54%) patients achieved a PSA50 with a median PSA-PFS of 5.5 mo (95% CI, 4.1-6.0 mo) and an OS of 13.5 mo (95% CI, 11.1-17.9 mo). SUVmean was associated with PSA50 and survival outcomes when analyzed as a continuous variable or as quartiles. The PSA50 for HIT scores 1-4 was 0%, 39%, 65%, and 76%, respectively. The HIT score was strongly related to PSA-PFS and OS (log-rank test, P < 0.001 and P = 0.002). The median PSA-PFS for HIT scores 1-4 was 1.0, 4.1, 6.0, and 8.5, respectively, and the median OS was 7.6, 12.0, 18.5, and 16.9 mo, respectively. Cohen κ between readers for the HIT score was 0.71. Conclusion: A prostate-specific membrane antigen PET/CT score incorporating HIT derived from tools on a standard PET workstation is comparable with quantitative SUVmean as a prognostic tool following 177Lu-PSMA therapy.

How to Report PSMA PET

Prostate cancer (PCa) is the most common cancer diagnosed in men in most developed countries and a leading cause of cancer-related morbidity and mortality. Prostate-specific membrane antigen positron emission tomography (PSMA-PET) has become a valuable tool in the staging and assessment of disease recurrence in PCa, and more recently for assessment for treatment eligibility to PSMA radioligand therapy (RLT). Harmonization of PSMA-PET interpretation and synoptic reports are needed to communicate concisely and reproducibly PSMA-PET/CT to referring physicians and to support clinician therapeutic management decisions in various stages of the disease. Uniform image interpretation is also important to provide comparable data between clinical trials and to translate such data from research to daily practice. This review provides an overview of the value of PSMA-PET across the different clinical stages of PCa, discusses published reporting criteria for PSMA-PET, identifies pitfalls in reporting PSMA, and provides recommendations for synoptic reports.

SEVERE HYPERCALCEMIA SECONDARY TO PARAFFIN OIL INJECTIONS IN A BODYBUILDER WITH SIGNIFICANT FINDINGS ON SCINTIGRAPHY

Objective

Non-parathyroid hormone (PTH) mediated hypercalcemia in young patients is rare. It encompasses a broad differential including malignancy, granulomatous diseases, Addison disease, and toxicity of vitamin A and D. We present an unusual case of non-PTH mediated hyper-calcemia in a previously healthy bodybuilder, secondary to multifocal granulomatous disease from paraffin oil injections.

Methods

The patient was evaluated with laboratory tests including serum calcium, 25-hydroxyvitamin D, 1,25-hydroxyvitamin D, parathyroid hormone, and parathyroid hormone-related peptide. Imaging studies such as thorax computed tomography and bone scans were also performed.

Results

A 31-year-old male bodybuilder presented with severe hypercalcemia (corrected calcium 3.1 mmol/L) and renal failure (creatinine 840 μmol/L), with suppressed PTH 1.0 pmol/L (normal, 1.6 to 6.9 pmol/L), and 1,25-vitamin D 205 pmol/L (normal, 60 to 208 pmol/L). He had used anabolic steroids for bodybuilding purposes for 8 years, with the possibility that he may also have used paraffin oil injections. Computed tomography imaging along with patient history suggested multiple paraffinomas in the pectoralis muscles causing granulomatous foreign body reaction as a potential cause for his hypercalcemia. He was prescribed a trial of prednisone, but he discontinued it due to symptoms of acne. Unfortunately, due to poor adherence with medical direction, management of his hypercalcemia remains challenging with inconsistent use of steroids and pamidronate infusions.

Conclusion

Granulomatous foreign-body reactions are a rare side effect of paraffin oil injections used for muscle augmentation. These can lead to serious long-term side effects of severe hypercalcemia and renal failure, as seen in our patient. Prognosis is generally poor, with long term steroids as the preferred treatment.

Effect of sorafenib starting dose and dose intensity on survival in patients with hepatocellular carcinoma: Results from a Canadian Multicenter Database

Background

Sorafenib has been shown to improve survival in patients with advanced hepatocellular carcinoma (HCC), however, full dose can be difficult to tolerate. The aim of this study was to determine whether sorafenib starting dose and mean dose intensity affect survival.

Methods

Patients treated with sorafenib for HCC from January 2008 to July 2016 in several Canadian provinces were included and retrospectively analyzed. The primary end point was overall survival (OS) of patients starting on sorafenib full dose compared to reduced dose. Secondary analysis compared OS with different mean dose‐intensity groups. Survival outcomes were assessed with Kaplan‐Meier curves and Cox proportional hazards models. A propensity score analysis was performed to account for treatment bias and confounding.

Results

Of 681 patients included, sorafenib was started at full dose in 289 patients (42%). Median survival for starting full and reduced dose was 9.4 months and 8.9 months (P = .15) respectively. After propensity score matching and adjusting for potential confounders there was still no difference in survival (HR 0.8, 95% CI, 0.61‐1.06, P = .12). Almost half of the patients (45%) received a dose intensity < 50%. Median survival for mean dose intensity > 75%, 50%‐75%, and < 50% were 9.5 months, 12.9 months, and 7.1 months (P = .005) respectively. In multivariable models, starting dose(HR 1.16, 95% CI 0.93‐1.44, P = .180) and mean dose intensity were not associated with survival.

Conclusions

Starting HCC patients on a reduced dose of sorafenib compared to full dose may not compromise survival. Mean dose‐intensity of sorafenib may also not affect survival.

Effect of sorafenib (S) starting dose and dose intensity on survival in patients with hepatocellular carcinoma (HCC): Results from a Canadian multicenter HCC database

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Background: The SHARP trial showed that S improves survival in advanced HCC. Full dose (FD) S at 400mg bid can be difficult to tolerate, so some clinicians begin with a reduced dose (RD) & escalate as tolerated to maximum dose. The purpose of this study was to determine whether starting dose or dose intensity of S affects survival. Methods: All patients treated with S for HCC from 01/2008 to 06/2016 in British Columbia, Alberta, Ontario (Princess Margaret Cancer Centre & Sunnybrook Odette Cancer Centre), were included. Patient demographics, clinical, tumor characteristics, S starting dose & mean dose intensity were collected & analyzed. Patients were dichotomized into starting FD or RD of S. Mean dose intensity was categorized into > 75%, 50-75% & < 50%. Survival outcomes were assessed with Kaplan-Meier curves & compared with the log-rank test. A Cox-proportional hazard model was constructed with starting dose, dose intensity & relevant clinical & pathologic factors to assess their impact on survival. Results: We included 681 patients. Median age 64 years, 80% men, 37% East Asian, & most frequent causes of liver disease were hepatitis B (33%) & C (29%). ECOG performance status prior to starting S was 0 in 30% & 1 in 60%. Most patients were Childs-Pugh A (86%) at start of S. Overall median survival was 9.1 months (m). S was started at FD in 42% of patients & 31% had a dose intensity > 75%. The median survival for starting FD & RD was 9.4 m & 8.9 m, respectively (p = 0.15). The median survival for a dose intensity > 75% was 9.5 m, 50-75% was 12.9 m & < 50% was 7.1 m (p = 0.005). In multivariate models that adjusted for demographic, stage, performance status, AFP, prior treatment, toxicity & liver function, starting dose (HR 1.1, 95%CI 0.86-1.3, p = 0.51) & dose intensity (50-75% HR 0.93, 95% CI 0.73-1.2; < 50% HR 0.89, 95% CI 0.69-1.1, p = 0.65) were not predictors of survival. Conclusions: Based on our multi-center database, starting HCC patients on a RD of S may be a reasonable since it does not appear to compromise survival. Patients receiving a dose intensity of S at 50-75% appear to have a superior median survival, though this is not significant after controlling for baseline characteristics.

The effect of sorafenib (S) starting dose and dose intensity on survival in patients with advanced hepatocellular carcinoma (HCC)

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Background: The SHARP trial showed that S improves survival in advanced HCC. In clinical practice full dose (FD) of S at 400mg bid can be difficult to tolerate and so a reduced dose (RD) is often required. The purpose of this study was to determine whether starting dose or dose intensity of S affects survival in patients with HCC. Methods: All patients treated with S for HCC in Alberta, Canada from January 2008 to July 2016 were included in this study. Patient demographics, clinical, tumor characteristics, S starting dose and dose intensity were collected and analyzed. Patients were dichotomized into starting FD or RD of S. A mean dose intensity of > 75% and < / = 75% were considered normal and reduced, respectively. Survival outcomes were assessed with Kaplan-Meier curves and compared with the log-rank test. A Cox-proportional hazard model was constructed with starting dose, dose intensity and relevant clinical and pathologic factors to assess their impact on survival. Results: A total of 156 patients were included. Median age was 63, 78% were men, 34% were East Asian, 77% were Childs-Pugh A, and the most common causes of liver disease were hepatitis B (30%) and C (30%). Most patients had EGOG performance status of 0 and 1 prior to starting S (29% and 62%, respectively). S was started at FD in 58% of patients and 50% had a dose intensity > 75%. The median survival for both starting FD and RD was 10.3 months, and not significantly different (p = 0.14).The median survival for a dose intensity > 75% vs < / = 75% was 10.7 vs 9.5 months, respectively (p = 0.76). In multivariable models that adjusted for demographic, stage, performance status and liver function, starting dose (HR 0.8 95%CI 0.5-1.2) and dose intensity (HR0.9 95% CI 0.6-1.4) were not associated with survival. Conclusions: Starting S with a RD may be a reasonable strategy for HCC, since it does not appear to impact survival. Also, dose intensity did not impact survival, suggesting that additional dose modifications may not compromise effectiveness. Though limited by small numbers, we are planning to confirm these findings in a larger, pan-Canadian dataset.