Interactive-plan technique conquers the disadvantages of volume-reducing hormone therapy in 125I permanent implantation for localized prostate cancer.
BACKGROUND
The purpose of this study was to assess the impact of hormone therapy on post-implant dosimetry in patients in whom pre-plan and interactive-plan techniques were used for transperineal brachytherapy against prostatic cancer.


METHODS
The subjects comprised 244 patients treated using (125)I seed implantation as monotherapy. The prescribed dose to the periphery of the prostate was 145 Gy. The pre-plan technique was used for 116 patients, and the interactive-plan technique for 128 patients. Hormone therapy was used in 71 patients (29.1%). The D90 (dose to 90% of prostate volume) of post-implant computed tomography (CT) analysis was assessed in both groups. In addition, the ratio of post-implant CT volume to preoperative ultrasonography (US) volume was assessed.


RESULTS
In the pre-plan group, D90 was significantly lower for patients who received hormone therapy than for those who did not (P = 0.035). However, in the interactive-plan group, D90 did not differ between patients with and without hormone therapy (P = 0.467). The CT-to-US prostate volume ratio was 1.022 for patients who received hormone therapy and 0.960 for patients who did not (P = 0.021).


CONCLUSIONS
Post-traumatic swelling following implantation is increased by cessation of hormone therapy and may reduce D90. However, the present results suggest that the interactive-plan technique overcomes this disadvantage of hormone therapy.
Ishiyama
Hiromichi
H
Department of Radiology, Kitasato University School of Medicine, Sagamihara, Japan. hishiyam@kitasato-u.ac.jp
Satoh
Takefumi
T
Kitano
Masashi
M
Kotani
Shouko
S
Uemae
Mineko
M
Baba
Shiro
S
Hayakawa
Kazushige
K
D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage*; D001918:Brachytherapy; D017024:Chemotherapy, Adjuvant; D004334:Drug Administration Schedule; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009929:Organ Size; D011467:Prostate / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography
D018931:Antineoplastic Agents, Hormonal; D007457:Iodine Radioisotopes