title: The effect of concurrent androgen deprivation and 3D conformal radiotherapy on prostate volume and clinical organ doses during treatment for prostate cancer.
abstract: In this study, we investigated the shrinking effect of concurrent three-dimensional conformal radiotherapy (3D-CRT) and androgen deprivation (AD) on prostate volume, and its possible impact on the dose received by the rectum and bladder during the course of 3D-CRT. The difference between the prostatic volumes determined on pre-treatment planning CT (PL-CT) and post-treatment CT (PT-CT) following a 3D-CRT course was assessed in 52 patients with localised prostate carcinoma. The changes in mean prostate volume when compared with PL-CT and PT-CT-based measurements were assessed. The pre- and post-treatment mean prostate volumes for the whole study population were 49.7 cm(3) and 41.0 cm(3) (p _ 0.02), respectively. The study cohort was divided into two groups depending on the duration of neoadjuvant androgen deprivation (NAD): 23 patients (44.7%) were designated as "short NAD" (< or =3 months; SNAD) and the remaining 29 (55.3%) as "long NAD" (>3 months; LNAD). Patients on SNAD experienced a significantly greater reduction in prostate volume compared with those on LNAD (14.1% vs 5.1%; p _ 0.03). A significant increase in rectum V(40-60) values in PT-CT compared with PL-CT was demonstrated. LNAD patients had significantly higher rectal V(50-70) values at PT-CT compared with the SNAD group. There was a significant decline in V(30)-V(75) bladder values in PT-CT compared with PL-CT in the SNAD group. In conclusion, a higher prostate volume reduction during 3D-CRT was demonstrated when RT planning was performed within 3 months of NAD. However, this reduction and daily organ motion may lead to an unpredictable increase in rectal doses.
authors: Department of Radiation Oncology, Baskent University, Adana, Turkey. hcemonal@hotmail.com
authors: C
authors: C
authors: Onal
authors: E
authors: E
authors: Topkan
authors: E
authors: E
authors: Efe
authors: M
authors: M
authors: Yavuz
authors: G
authors: G
authors: Arslan
authors: A
authors: A
authors: Yavuz
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D000726:Androgen Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000813:Anilides / Q000008:administration & dosage; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D004334:Drug Administration Schedule; D017273:Goserelin / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D009570:Nitriles / Q000008:administration & dosage; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods; D012007:Rectum / Q000528:radiation effects; D014057:Tomography, X-Ray Computed; D014105:Tosyl Compounds / Q000008:administration & dosage; D016896:Treatment Outcome; D001743:Urinary Bladder / Q000528:radiation effects
chemical_list: D000726:Androgen Antagonists; D000813:Anilides; D018931:Antineoplastic Agents, Hormonal; D009570:Nitriles; D014105:Tosyl Compounds; D017273:Goserelin; C053541:bicalutamide