- Email: [email protected]
Prostate brachytherapy seed migration to the left testicular vein
Brachytherapy 9 (2010) 224e226
Case Report
Prostate brachytherapy seed migration to the left testicular vein Ba D. Nguyen*, Genevieve L. Egnatios Department of Radiology, Mayo Clinic, Scottsdale, AZ
ABSTRACT
PURPOSE: Prostate brachytherapy seeds may detach from their initial insertion sites and migrate to lungs, heart, coronary artery, liver, kidney, and vertebral venous plexus. The authors present the left testicular vein as additional site of seed embolization. METHODS AND MATERIALS: The authors report a 68-year-old man with seed migration to the left testicular vein shortly after brachytherapeutic procedure. All imaging procedures obtained after the transperineal seed implant insertion are retrospectively analyzed in correlation with the patient’s clinical course. RESULTS: The retrospective imaging review shows a left lower abdominal seed anterior to the left psoas muscle. CT re-evaluation localizes the seed in the left testicular vein. This embolized seed was not initially identified on any imaging modality. Although there is no solid causeeeffect proof in this case, the fully potent embolized seed may be contributory to the patient’s testicular symptomatology. CONCLUSION: The uncommon seed relocation to the left testicular vein is probably because of periprostaticepampiniform venous communication. Ó 2010 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Keywords:
Brachytherapy; Prostate; Iodine-125 seed; Left testicular vein; CT
Introduction Migration and embolization of prostate brachytherapy seeds have been reported in lungs, right and left cardiac cavities, vertebral venous plexus, liver, and kidney. These seed relocations are related to multiple facilitating factors: the small size and loose characteristics of seeds, their insertion close to prominent periprostatic venous circulation, the presence of right-to-left shunts, and the communication of periprostatic veins to other pelvic venous plexuses. This latest factor is the plausible explanation for a rare case of seed embolization to the left testicular vein via the pampiniform venous plexus.
Case report A 68-year-old man presented with clinical T1cN0M0, Gleason score 6 adenocarcinoma of the prostate. The Received 27 July 2009; received in revised form 22 October 2009; accepted 29 October 2009. * Corresponding author. Department of Radiology, Mayo Clinic, 13400 E Shea Boulevard, Scottsdale, AZ 85259. Tel.: þ1-480-301-4707; fax: þ1-480-301-4303. E-mail address: [email protected] (B.D. Nguyen).
malignancy was diagnosed by ultrasound-guided biopsy involving 50% of a single core taken from the right horn of the gland. His prostate-specific antigen value was 2.6 ng/mL. He opted for brachytherapy consisting of 145 iodine-125 seeds (model 6711, Oncura, Arlington Heights, IL) containing 0.297 mCi per seed. The immediate postimplantation course was remarkable only for urination discomfort and perineal tenderness. Routine pelvic CT obtained 1 day after the procedure showed on the topogram an unreported seed migration projecting over the left sacroiliac joint (Fig. 1). The patient complained of multiple episodes of left testicular swelling exacerbating in standing and walking positions beginning at 41 days after the seed insertion event with one of these onsets diagnosed clinically as acute epididymitis. The prostate-specific antigen level was 0.1 ng/mL 3 years after prostate brachytherapy. Subsequent lumbar spine radiographs confirmed the detached seed overlying the left sacroiliac joint on the anterior image (similar to Fig. 1) and 5.5 cm ventral to L5 on the lateral view (Fig. 2). A corresponding CT showed the seed anterior to the left psoas muscle within a vascular structure joining the left renal vein (Fig. 3). All radiographic and cross-sectional findings previously described were not recognized at initial radiologic interpretation. The diagnosis of seed embolization to the left testicular vein was made retrospectively based on the CT findings.
1538-4721/$ - see front matter Ó 2010 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.brachy.2009.10.002
B.D. Nguyen, G.L. Egnatios / Brachytherapy 9 (2010) 224e226
225
Fig. 3. Axial CT image of the upper pelvis showing the seed anterior to the left psoas muscle embedded in the left testicular vein (arrow).
Fig. 1. Topographic CT image of the abdomen and pelvis 1 day after implantation showing seeds in the prostatic fossa (grid) and a detached seed projected over the left sacroiliac joint (arrow).
Discussion Prostate brachytherapy consists of placing radioactive sources in the form of iodine-125 or palladium-103 seeds in the prostate and periprostatic regions with ultrasound guidance. This type of treatment is a well-accepted option for localized adenocarcinoma of the gland in addition to the surgical and radiotherapeutic choices. The objectives of
Fig. 2. Lateral lumbar spine radiograph showing the seed 5.5 cm anterior to L5 vertebra (arrow).
brachytherapy are to achieve adequate prostatic radiation volume coverage with an average dose of 145 Gy and to induce minimal side effects on the adjacent rectum and urethra (1). Potential complications of this procedure include incontinence, impairment of the urinary function, proctitis, erectile dysfunction, passage of seeds through urination or ejaculation, and seed migration. The loose periprostatic seeds have a high propensity of embolization in up to 55% of all brachytherapy patients with an average of 2.2 seeds per patient (2). Fortunately, the detachment involves only 1% of the total number of seeds inserted with negligible impact on the radiation planning for the prostate. Seeds preferentially migrate to lungs and to a lesser extent to right cardiac cavities through the pathway of periprostatic veins and inferior vena cava (3, 4). With existing right-to-left shunts from pulmonary arteriovenous malformations or patent foramen ovale, seeds can relocate to the left cardiac cavities, coronary arteries, and systemic organs, such as kidneys (5e7). The connections between the periprostatic veins and hemorrhoidal venous plexus allow the seed migration to the liver via mesenteric vessels (4). The periprostatic venous communication with Batson’s plexus directs seed embolization to vertebral veins (8). In this case presentation, the seed embolization to the left testicular vein may be explained by periprostatic venous connection with the pampiniform plexus. This circulatory relationship has been described in the clinical pathologic settings of varicocele and pelvic venous flow impairment of various etiologies (9, 10). The testicular swelling episodes experienced by the patient may be totally coincidental and independent from the testicular venous seed relocation. It is difficult to prove that the migration of a fully potent radioactive seed 1 day after implantation could induce radiation changes to the testicular vein. Most of the seed embolization events are asymptomatic except for a few anecdotal instances of cardiac arrhythmia, myocardial infarction, radiation pneumonitis, massive seed detachment responsible for recurrent prostate cancer, and repeat seed
226
B.D. Nguyen, G.L. Egnatios / Brachytherapy 9 (2010) 224e226
implantation (3, 6, 11e13). The absence or low rate of seed migration radiologic reporting is because of the lack of physician awareness of this frequent event, the most clinically silent pattern of seed embolization, and the small size of the seed often overlooked by imagers. The identification of embolized seed rests on its radiologic metallic attenuation characteristics or scintigraphic photopeak energy before total decay (14, 15). Seed radiographic detection is relatively easy in the peripheral aspect of lungs. Imaging diagnosis is difficult when there is seed superimposition with bones, dense mediastinal or abdominal soft tissue, and cardiac motion artifact. The use of seeds linked with an absorbable suture material has been reported with a decreased rate of seed embolization with however a potentially higher risk of radiotoxicity to the urethra and rectum (16e18).
Conclusions Prostatic brachytherapy seed migration to the left testicular vein is rare. This event may be explained by venous connections between the periprostatic and pampiniform plexuses. Awareness of silent seed embolization and all the potential sites of seed relocation in the body along with keen radiologic interpretation are helpful to correctly identify the detached foreign body. References [1] Langley SE, Laing RW. Iodine seed prostate brachytherapy: An alternative first-line choice for early prostate cancer. Prostate Cancer Prostatic Dis 2004;7:201e207. [2] Eshleman JS, Davis BJ, Pisansky TM, et al. Radioactive seed migration to the chest after transperineal interstitial prostate brachytherapy: Extraprostatic seed placement correlates with migration. Int J Radiat Oncol Biol Phys 2004;59:419e425. [3] Davis BJ, Pfeifer EA, Wilson TM, et al. Prostate brachytherapy seed migration to the right ventricle found at autopsy following acute cardiac dysrhythmia. J Urol 2000;164:1661.
[4] Nguyen BD. Cardiac and hepatic seed implant embolization after prostate brachytherapy. Urology 2006;68:673.e17e673.e19. [5] Davis BJ, Bresnahan JF, Stafford SL, et al. Prostate brachytherapy seed migration to a coronary artery found during angiography. J Urol 2002;168:1103. [6] Zhu AX, Wallner KE, Frivold GP, et al. Prostate brachytherapy seed migration to the right coronary artery associated with an acute myocardial infarction. Brachytherapy 2006;5:262e265. [7] Nguyen BD, Schild SE, Wong WW, et al. Prostate brachytherapy seed embolization to the right renal artery. Brachytherapy 2009;8: 309e312. [8] Nakano M, Uno H, Gotoh T, et al. Migration of prostate brachytherapy seeds to the vertebral venous plexus. Brachytherapy 2006;5:127e130. [9] Umeoka S, Koyama T, Togashi K, et al. Vascular dilatation in the pelvis: Identification with CT and MR imaging. Radiographics 2004;24:193e208. [10] Sakamoto H, Ogawa Y. Is varicocele associated with underlying venous abnormalities? Varicocele and the prostatic venous plexus. J Urol 2008;180:1427e1431. [11] Miura N, Kusuhara Y, Numata K, et al. Radiation pneumonitis caused by a migrated brachytherapy seed lodged in the lung. Jpn J Clin Oncol 2008;38:623e625. [12] Gacci M, Serni S, Lapini A, et al. PSA recurrence after brachytherapy for seed misplacement: A double-blind radiologic and pathologic work-up after salvage prostatectomy. Prostate Cancer Prostatic Dis 2008;11:99e101. [13] Di Muzio N, Longobardi B, Losa A, et al. Seed migration in prostate brachytherapy: A re-implant case report. Br J Radiol 2003;76: 913e915. [14] Blair HF, Porter A, Chen QS. In vivo detection of an 125I seed located in the intracardiac region after prostate permanent brachytherapy. Int J Radiat Oncol Biol Phys 2004;58:888e891. [15] Kono Y, Kubota K, Mitsumoto T, et al. Scintigraphic detection of 125I seeds after permanent brachytherapy for prostate cancer. J Nucl Med 2008;49:541e545. [16] Al-Qaisieh B, Carey B, Ash D, et al. The use of linked seeds eliminates lung embolization following permanent seed implantation for prostate cancer. Int J Radiat Oncol Biol Phys 2004;59:397e399. [17] Reed DR, Wallner KE, Merrick GS, et al. A prospective randomized comparison of stranded vs. loose 125I seeds for prostate brachytherapy. Brachytherapy 2007;6:129e134. [18] Saibishkumar EP, Borg J, Yeung I, et al. Loose seeds vs. stranded seeds: A comparison of critical organ dosimetry and acute toxicity in (125)I permanent implant for low-risk prostate cancer. Brachytherapy 2008; 7:200e205.
Case Report
Prostate brachytherapy seed migration to the left testicular vein Ba D. Nguyen*, Genevieve L. Egnatios Department of Radiology, Mayo Clinic, Scottsdale, AZ
ABSTRACT
PURPOSE: Prostate brachytherapy seeds may detach from their initial insertion sites and migrate to lungs, heart, coronary artery, liver, kidney, and vertebral venous plexus. The authors present the left testicular vein as additional site of seed embolization. METHODS AND MATERIALS: The authors report a 68-year-old man with seed migration to the left testicular vein shortly after brachytherapeutic procedure. All imaging procedures obtained after the transperineal seed implant insertion are retrospectively analyzed in correlation with the patient’s clinical course. RESULTS: The retrospective imaging review shows a left lower abdominal seed anterior to the left psoas muscle. CT re-evaluation localizes the seed in the left testicular vein. This embolized seed was not initially identified on any imaging modality. Although there is no solid causeeeffect proof in this case, the fully potent embolized seed may be contributory to the patient’s testicular symptomatology. CONCLUSION: The uncommon seed relocation to the left testicular vein is probably because of periprostaticepampiniform venous communication. Ó 2010 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Keywords:
Brachytherapy; Prostate; Iodine-125 seed; Left testicular vein; CT
Introduction Migration and embolization of prostate brachytherapy seeds have been reported in lungs, right and left cardiac cavities, vertebral venous plexus, liver, and kidney. These seed relocations are related to multiple facilitating factors: the small size and loose characteristics of seeds, their insertion close to prominent periprostatic venous circulation, the presence of right-to-left shunts, and the communication of periprostatic veins to other pelvic venous plexuses. This latest factor is the plausible explanation for a rare case of seed embolization to the left testicular vein via the pampiniform venous plexus.
Case report A 68-year-old man presented with clinical T1cN0M0, Gleason score 6 adenocarcinoma of the prostate. The Received 27 July 2009; received in revised form 22 October 2009; accepted 29 October 2009. * Corresponding author. Department of Radiology, Mayo Clinic, 13400 E Shea Boulevard, Scottsdale, AZ 85259. Tel.: þ1-480-301-4707; fax: þ1-480-301-4303. E-mail address: [email protected] (B.D. Nguyen).
malignancy was diagnosed by ultrasound-guided biopsy involving 50% of a single core taken from the right horn of the gland. His prostate-specific antigen value was 2.6 ng/mL. He opted for brachytherapy consisting of 145 iodine-125 seeds (model 6711, Oncura, Arlington Heights, IL) containing 0.297 mCi per seed. The immediate postimplantation course was remarkable only for urination discomfort and perineal tenderness. Routine pelvic CT obtained 1 day after the procedure showed on the topogram an unreported seed migration projecting over the left sacroiliac joint (Fig. 1). The patient complained of multiple episodes of left testicular swelling exacerbating in standing and walking positions beginning at 41 days after the seed insertion event with one of these onsets diagnosed clinically as acute epididymitis. The prostate-specific antigen level was 0.1 ng/mL 3 years after prostate brachytherapy. Subsequent lumbar spine radiographs confirmed the detached seed overlying the left sacroiliac joint on the anterior image (similar to Fig. 1) and 5.5 cm ventral to L5 on the lateral view (Fig. 2). A corresponding CT showed the seed anterior to the left psoas muscle within a vascular structure joining the left renal vein (Fig. 3). All radiographic and cross-sectional findings previously described were not recognized at initial radiologic interpretation. The diagnosis of seed embolization to the left testicular vein was made retrospectively based on the CT findings.
1538-4721/$ - see front matter Ó 2010 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.brachy.2009.10.002
B.D. Nguyen, G.L. Egnatios / Brachytherapy 9 (2010) 224e226
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Fig. 3. Axial CT image of the upper pelvis showing the seed anterior to the left psoas muscle embedded in the left testicular vein (arrow).
Fig. 1. Topographic CT image of the abdomen and pelvis 1 day after implantation showing seeds in the prostatic fossa (grid) and a detached seed projected over the left sacroiliac joint (arrow).
Discussion Prostate brachytherapy consists of placing radioactive sources in the form of iodine-125 or palladium-103 seeds in the prostate and periprostatic regions with ultrasound guidance. This type of treatment is a well-accepted option for localized adenocarcinoma of the gland in addition to the surgical and radiotherapeutic choices. The objectives of
Fig. 2. Lateral lumbar spine radiograph showing the seed 5.5 cm anterior to L5 vertebra (arrow).
brachytherapy are to achieve adequate prostatic radiation volume coverage with an average dose of 145 Gy and to induce minimal side effects on the adjacent rectum and urethra (1). Potential complications of this procedure include incontinence, impairment of the urinary function, proctitis, erectile dysfunction, passage of seeds through urination or ejaculation, and seed migration. The loose periprostatic seeds have a high propensity of embolization in up to 55% of all brachytherapy patients with an average of 2.2 seeds per patient (2). Fortunately, the detachment involves only 1% of the total number of seeds inserted with negligible impact on the radiation planning for the prostate. Seeds preferentially migrate to lungs and to a lesser extent to right cardiac cavities through the pathway of periprostatic veins and inferior vena cava (3, 4). With existing right-to-left shunts from pulmonary arteriovenous malformations or patent foramen ovale, seeds can relocate to the left cardiac cavities, coronary arteries, and systemic organs, such as kidneys (5e7). The connections between the periprostatic veins and hemorrhoidal venous plexus allow the seed migration to the liver via mesenteric vessels (4). The periprostatic venous communication with Batson’s plexus directs seed embolization to vertebral veins (8). In this case presentation, the seed embolization to the left testicular vein may be explained by periprostatic venous connection with the pampiniform plexus. This circulatory relationship has been described in the clinical pathologic settings of varicocele and pelvic venous flow impairment of various etiologies (9, 10). The testicular swelling episodes experienced by the patient may be totally coincidental and independent from the testicular venous seed relocation. It is difficult to prove that the migration of a fully potent radioactive seed 1 day after implantation could induce radiation changes to the testicular vein. Most of the seed embolization events are asymptomatic except for a few anecdotal instances of cardiac arrhythmia, myocardial infarction, radiation pneumonitis, massive seed detachment responsible for recurrent prostate cancer, and repeat seed
226
B.D. Nguyen, G.L. Egnatios / Brachytherapy 9 (2010) 224e226
implantation (3, 6, 11e13). The absence or low rate of seed migration radiologic reporting is because of the lack of physician awareness of this frequent event, the most clinically silent pattern of seed embolization, and the small size of the seed often overlooked by imagers. The identification of embolized seed rests on its radiologic metallic attenuation characteristics or scintigraphic photopeak energy before total decay (14, 15). Seed radiographic detection is relatively easy in the peripheral aspect of lungs. Imaging diagnosis is difficult when there is seed superimposition with bones, dense mediastinal or abdominal soft tissue, and cardiac motion artifact. The use of seeds linked with an absorbable suture material has been reported with a decreased rate of seed embolization with however a potentially higher risk of radiotoxicity to the urethra and rectum (16e18).
Conclusions Prostatic brachytherapy seed migration to the left testicular vein is rare. This event may be explained by venous connections between the periprostatic and pampiniform plexuses. Awareness of silent seed embolization and all the potential sites of seed relocation in the body along with keen radiologic interpretation are helpful to correctly identify the detached foreign body. References [1] Langley SE, Laing RW. Iodine seed prostate brachytherapy: An alternative first-line choice for early prostate cancer. Prostate Cancer Prostatic Dis 2004;7:201e207. [2] Eshleman JS, Davis BJ, Pisansky TM, et al. Radioactive seed migration to the chest after transperineal interstitial prostate brachytherapy: Extraprostatic seed placement correlates with migration. Int J Radiat Oncol Biol Phys 2004;59:419e425. [3] Davis BJ, Pfeifer EA, Wilson TM, et al. Prostate brachytherapy seed migration to the right ventricle found at autopsy following acute cardiac dysrhythmia. J Urol 2000;164:1661.
[4] Nguyen BD. Cardiac and hepatic seed implant embolization after prostate brachytherapy. Urology 2006;68:673.e17e673.e19. [5] Davis BJ, Bresnahan JF, Stafford SL, et al. Prostate brachytherapy seed migration to a coronary artery found during angiography. J Urol 2002;168:1103. [6] Zhu AX, Wallner KE, Frivold GP, et al. Prostate brachytherapy seed migration to the right coronary artery associated with an acute myocardial infarction. Brachytherapy 2006;5:262e265. [7] Nguyen BD, Schild SE, Wong WW, et al. Prostate brachytherapy seed embolization to the right renal artery. Brachytherapy 2009;8: 309e312. [8] Nakano M, Uno H, Gotoh T, et al. Migration of prostate brachytherapy seeds to the vertebral venous plexus. Brachytherapy 2006;5:127e130. [9] Umeoka S, Koyama T, Togashi K, et al. Vascular dilatation in the pelvis: Identification with CT and MR imaging. Radiographics 2004;24:193e208. [10] Sakamoto H, Ogawa Y. Is varicocele associated with underlying venous abnormalities? Varicocele and the prostatic venous plexus. J Urol 2008;180:1427e1431. [11] Miura N, Kusuhara Y, Numata K, et al. Radiation pneumonitis caused by a migrated brachytherapy seed lodged in the lung. Jpn J Clin Oncol 2008;38:623e625. [12] Gacci M, Serni S, Lapini A, et al. PSA recurrence after brachytherapy for seed misplacement: A double-blind radiologic and pathologic work-up after salvage prostatectomy. Prostate Cancer Prostatic Dis 2008;11:99e101. [13] Di Muzio N, Longobardi B, Losa A, et al. Seed migration in prostate brachytherapy: A re-implant case report. Br J Radiol 2003;76: 913e915. [14] Blair HF, Porter A, Chen QS. In vivo detection of an 125I seed located in the intracardiac region after prostate permanent brachytherapy. Int J Radiat Oncol Biol Phys 2004;58:888e891. [15] Kono Y, Kubota K, Mitsumoto T, et al. Scintigraphic detection of 125I seeds after permanent brachytherapy for prostate cancer. J Nucl Med 2008;49:541e545. [16] Al-Qaisieh B, Carey B, Ash D, et al. The use of linked seeds eliminates lung embolization following permanent seed implantation for prostate cancer. Int J Radiat Oncol Biol Phys 2004;59:397e399. [17] Reed DR, Wallner KE, Merrick GS, et al. A prospective randomized comparison of stranded vs. loose 125I seeds for prostate brachytherapy. Brachytherapy 2007;6:129e134. [18] Saibishkumar EP, Borg J, Yeung I, et al. Loose seeds vs. stranded seeds: A comparison of critical organ dosimetry and acute toxicity in (125)I permanent implant for low-risk prostate cancer. Brachytherapy 2008; 7:200e205.