Hypofractionated Boost to the Dominant Tumor Region With Intensity Modulated Stereotactic Radiotherapy for Prostate Cancer: A Sequential Dose Escalation Pilot Study

Histopathological correlation of 11C-choline PET scans for target volume definition in radical prostate radiotherapy

“…Previous studies have examined the use of dose painting in prostate cancer using various imaging modalities including 18 F-fluorocholine PET (7), 11 C-acetate PET (8), dynamic contrast enhanced (DCE) MRI (9), magnetic resonance spectroscopy (MRS) (9,10), and endorectal coil MRI (11).…”

Quantification of the margin required for treating intraprostatic lesions

“…Onal et al (7) and Pinkawa et al (9) used a 3‐4 mm margin to account for intrafraction motion. Housri et al (3) and Miralbell et al (6) used an isotropic 3 mm margin, although the Miralbell study treated with a rectal balloon (limited central mass displacement to less than 3 mm), while Housri and colleagues used cine‐MRI, ultrasound, and fiducial marker tracking to determine that the intrafraction displacement was less than 3 mm. Singh et al (11) used a 3 mm margin due to limitations in image guidance.…”

“…One disease site in radiation oncology that has seen an increase in MRI is the prostate, where the high‐risk intraprostatic lesion (IPL) can be identified 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . Since dose escalation can improve cure rates, delivering an escalated dose to the IPL while treating the remainder of the prostate to the normal prescription dose can reduce toxicity while increasing tumor control 12 , 13 , 14 .…”

“…Due to these competing interests, there is no consensus for the IPL margin to ensure adequate dose is delivered. In some recent studies the IPL is treated with no additional margin, (5,8,22 ) while in others margins of up to 8 mm are added 2 , 3 , 4 , 6 , 7 , 9 , 10 , 11 …”

Technological Advances in Radiation Therapy for Prostate Cancer

“…To address the concern that hypofractionated radiation schedules potentially can increase toxicity to normal organs situated close to the prostate, multiple studies have looked at toxicity profiles of hypofractionated regimens using both 3D-CRT and IMRT to doses of 50 to 70 Gy and have reported that toxicities are comparable to conventional radiation schedules [45••, 47-49]. Studies looking at standard fractionation IMRT with hypofractionated sequential or simultaneous integrated boost for localized prostate cancer also have reported preliminary results that hypofractionated boost is well tolerated [50,51].…”