Reirradiation of paraaortic lymph node metastasis by brachytherapy with hyaluronate injection via paravertebral approach: With DVH comparison to IMRT.
PURPOSE/INTRODUCTION: To safely irradiate retroperitoneal targets as paraaortic lymph node by separating abdominal at-risk organs from the target during irradiation, we created a percutaneous paravertebral approach of high-dose-rate brachytherapy with hyaluronate gel injection (HGI). We report a case treated with this technique.


METHODS
We encountered a patient with symptomatic regrowth of paraaortic lymph node metastasis from prostatic cancer. He had previously received 58.4Gy of radiotherapy to the same region 12 months prior. Brachytherapy needles and a HGI needle were deployed via the paravertebral approach under local anesthesia at our outpatient clinic.


RESULTS
A single dose of 22.5Gy (equivalent to 60.94Gy in 2Gy per fraction schedule calculated at α/β=10) was delivered to the target, with preservation of the surrounding small intestine by HGI with D(2cc) (minimum dose to the most irradiated volume of 2mL) of 5.05Gy. Therapeutic ratio was 3.64 times higher for this brachytherapy plan compared with an intensity-modulated radiation therapy plan. At followup at 1 year after brachytherapy, the symptoms had disappeared, tumor size had reduced with no fluorodeoxyglucose accumulation, and prostate-specific antigen level had decreased.


CONCLUSIONS
We consider that high-dose-rate brachytherapy with the HGI procedure offers effective treatment even in this type of reirradiation situation.
Department of Radiology, Wakayama Medical University, Wakayama City, Wakayama, Japan. kazushi.kishi@gmail.com
Kazushi
K
Kishi
Tetsuo
T
Sonomura
Shintaro
S
Shirai
Yasutaka
Y
Noda
Morio
M
Sato
Hitoshi
H
Ikushima
Ryoong-Jin
RJ
Oh
D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D008207:Lymphatic Metastasis; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D011471:Prostatic Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control; D011835:Radiation Protection / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome
D006820:Hyaluronic Acid