Table 2.
Potential Heterogeneity Factors of Studies.
| Author (year) | CTV-to-PTV margins | Radiation range | Radiation Dose (Gy) | IGRT technology | Adjuvant | ||
|---|---|---|---|---|---|---|---|
| Intervention | Comparator | Intervention | Comparator | ||||
| Becker-Schiebe 2016 [49] | 10 mm circumferentially, except for 6 mm posteriorly; For boost contouring, 5 mm in all directions | Same margins | PORT or WPRT according to the risk | Prostate: 77.4 (1.8 per fraction) Pelvic: 50.4 (1.8 per fraction) |
Prostate: 72 or 73.8 (1.8 per fraction) Pelvic: 50.4 (1.8 per fraction) |
FMs + KV/MV or CBCT | ADT |
| Chung 2009 [50] | 2–3 mm circumferentially | 10 mm circumferentially, except for 5 mm posteriorly | WPRT | Prostate: 73.8 (1.8 per fraction) Pelvic: 48.6 (1.8 per fraction) |
Same dose | FMs + OI | NR |
| de Crevoisier 2018 [23] | 10 mm circumferentially, except for 5 mm posteriorly | Same margins | PORT | 70–80 (2 per fraction) | Same dose | FMs + EPID/KV, CBCT or Ultrasounds | ADT |
| Ghanem 2021 [45] | 10 mm circumferentially, except for 5 mm posteriorly | Same margins | PORT or WPRT according to the risk | 79.2 (1.8–2 per fraction) for prostate | 74 (1.8–2 per fraction) for prostate | CBCT | ADT |
| Gill 2011 [46] | 10 mm circumferentially, except for 7 mm posteriorly | Same margins | PORT | 78 (2 per fraction) | 74 (2 per fraction) | FMs + OI | ADT |
| Jereczek-fossa 2018 [47] | 7 mm and 3 mm, for all but posterior margins | 10 and 5 mm, for all but posterior margins | PORT | 70.2 (2.7 per fraction) | 80 (2 per fraction) | BAT, ExacTrac® or CBCT | ADT |
| Kok 2013 [21] | 10 mm circumferentially, except for 7 mm posteriorly | Same margins | PORT | 78 (2 per fraction) | 74 (2 per fraction) | FMs + KV OI | ADT |
| Kuo 2021 [51] | NR | NR | NR | 72–81 (1.8–2 per fraction) | Same dose | NR | ADT |
| Murray 2020 [44] | In the IGRT and IGRT-S arms, standard CTV to PTV posterior margins of 6 mm/3 mm/0 mm were used. In the IGRT-R arm, posterior margins were 10 mm/5 mm/0 mm | Posterior margins were 10 mm/5 mm/0 mm | PORT | Conventional: 74 (2 per fraction) hypo-fractionated: 60 (3 per fraction) or 57 (3per fraction) |
Same dose | FMs or MVCT | NR |
| Singh 2013 [18] | 7–12 mm circumferentially, except for 5–7 mm posteriorly; For boost contouring, 6–10 mm circumferentially, except for 5–7 mm posteriorly | 10–15 mm circumferentially, except for 7–10 mm posteriorly; For boost contouring, 10 mm circumferentially, except for 7–10 mm posteriorly | PORT | 70–76 (2 per fraction) | Same dose | FMs + MRI | ADT |
| Stuk 2021 [52] | 6–8 mm | 10 mm isotropic margins | PORT | 70–74 (2 per fraction) | Same dose | CBCT or KV-KV | ADT |
| Sveistrup 2014 [22] | 5 mm in the right-left and anterior-posterior planes and 7 mm in the superior-inferior plane | Fourth and fifth fractions were delivered with a margin to the PTV of 1 cm and the remaining 33 fractions with a margin of 2 cm | PORT | 78 (2 per fraction) | 76 (2 per fraction) | FMs + KV OI (ExacTrac®) | ADT |
| Tøndel 2018 [19] | 7 mm in all direction; for boost contouring, 3 mm in all direction | 15 mm in all direction; for boost contouring, 3 mm in all direction | PORT | 78 (2 per fraction) | Same dose | FMs + 2D MV OI or FMs + KV CBCT | ADT |
| Valeriani 2013 [53] | 5 mm expansion in all direction | 8 mm circumferentially, except for 6 mm posteriorly | PORT | 54.75 (3.65 per fraction) | Same dose | KV CBCT | ADT |
| Wortel 2016 [48] | 5–8 mm; for boost contouring, 3–5 mm | 10 mm; for boost contouring, 5 mm | PORT | 78 (2 per fraction) | Same dose | FMs + CBCT | ADT |
| Zapatero 2017 [54] | 1 cm circumferentially and 7 mm at the prostate-rectal interface |
Same margins | PORT | 76–80 (2 per fraction) | Same dose | FMs | ADT |
| Zelefsky 2012 [55] | 1 cm circumferentially and 6 mm at the prostate-rectal interface |
Same margins | PORT | 86.4 (1.8 per fraction) | Same dose | FMs + KV OI | ADT |
| Zhong 2014 [56] | 8–10 cm circumferentially and 6 mm at the prostate-rectal interface; for boost contouring, 3–4 mm circumferentially | Same margins | PORT or WPRT according to the risk | 76–80 (2 per fraction) for prostate | Same dose | CBCT | ADT |
Abbreviations: CTV = clinical target volume; PTV = planning target volume; WPRT = whole-pelvic radiotherapy; PORT = prostate-only radiotherapy; IGRT = image-guided radiotherapy; FMs = fiducial markers; KV = kilovoltage; MV = megavoltage; CBCT = cone beam computer tomography; OI = orthogonal imaging; EPID = electronic portal imaging device; MRI = magnetic resonance imaging; ADT = androgen deprivation therapy; NR = not reported.