MRI is being increasingly used in oncology for staging, assessing tumour response and also for treatment planning in radiotherapy. Both conformal and intensity-modulated radiotherapy requires improved means of defining target volumes for treatment planning in order to achieve its intended benefits. MRI can add to the radiotherapy treatment planning (RTP) process by providing excellent and improved characterization of soft tissues compared with CT. Together with its multiplanar capability and increased imaging functionality, these advantages for target volume delineation outweigh its drawbacks of lacking electron density information and potential image distortion. Efficient MR distortion assessment and correction algorithms together with image co-registration and fusion programs can overcome these limitations and permit its use for RTP. MRI developments using new contrast media, such as ultrasmall superparamagnetic iron oxide particles for abnormal lymph node identification, techniques such as dynamic contrast enhanced MRI and diffusion MRI to better characterize tissue and tumour regions as well as ultrafast volumetric or cine MR sequences to define temporal patterns of target and organ at risk deformity and variations in spatial location have all increased the scope and utility of MRI for RTP. Information from these MR developments may permit treatment individualization, strategies of dose escalation and image-guided radiotherapy. These developments will be reviewed to assess their current and potential use for RTP and precision high dose radiotherapy.

Androgen deprivation therapy (ADT) in men with prostate cancer increases the risk of osteoporotic fractures, type 2 diabetes and, possibly, cardiovascular events. There is considerable uncertainty about the risk–benefit ratio of ADT in non‐palliative treatment; the benefits of ADT in treating non‐metastatic prostate cancer need to be carefully weighed against the risks of ADT‐induced adverse events. Baseline assessment of bone health at the initiation of ADT should include measurement of bone mineral density (BMD) by dual energy x‐ray absorptiometry and, in men with osteopaenia, a thoracolumbar spine x‐ray. General measures to prevent bone loss, including regular physical activity, as well as ensuring calcium and vitamin D sufficiency, should be instituted routinely. All men with a previous minimal trauma fracture should receive pharmacological therapy unless contraindicated; for those who have not sustained a minimal trauma fracture, treatment is advised if the BMD T score is ≤ − 2.0, or if the 10‐year risk of a major osteoporotic fracture exceeds 20%. Men with prostate cancer who are receiving ADT should be closely monitored for weight gain and diabetes; intensive lifestyle intervention is recommended to prevent ADT‐induced weight gain and insulin resistance. Management of the metabolic sequelae of ADT includes optimal reduction of cardiovascular risk factors, with particular attention to weight, blood pressure, lipid profile, smoking cessation, and glycaemic control.

Objective: While androgen deprivation therapy (ADT) has been associated with insulin resistance and frailty, controlled prospective studies are lacking. We aimed to examine the relationships between insulin resistance and frailty with body composition and testosterone. Design: Case-control prospective study. Methods: Sixty three men with non-metastatic prostate cancer newly commencing ADT (n = 34) and age-matched prostate cancer controls (n = 29) were recruited. The main outcomes were insulin resistance (HOMA2-IR), Fried's frailty score, body composition by dual x-ray absorptiometry and short physical performance battery (SPPB) measured at 0, 6 and 12 months. A generalised linear model determined the mean adjusted difference (95% CI) between groups. Results: Compared with controls over 12 months, men receiving ADT had reductions in mean total testosterone level (14.1-0.4 nmol/L, P < 0.001), mean adjusted gain in fat mass of 3530 g (2012, 5047), P < 0.02 and loss of lean mass of 1491 g (181, 2801), P < 0.02. Visceral fat was unchanged. HOMA2-IR in the ADT group increased 0.59 (0.24, 0.94), P = 0.02, which was most related to the increase in fat mass (P = 0.003), less to lean mass (P = 0.09) or total testosterone (P = 0.088). Frailty increased with ADT (P < 0.0001), which was related to decreased testosterone (P = 0.028), and less to fat mass (P = 0.056) or lean mass (P = 0.79). SPPB was unchanged. Conclusions: ADT is associated with increased insulin resistance and frailty within 12 months of commencement, independently of confounding effects of cancer or radiotherapy. Insulin resistance appears to be mediated by subcutaneous or peripheral sites of fat deposition. Prevention of fat gain is an important strategy to prevent adverse ADT-associated cardiometabolic risks.

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ConclusionOur results showed that PSMA-PET/CT could have an important role in identifying men with true oligometastatic PCa who would benefit the most from metastases-directed therapy with SABR.