Brachytherapy seed migration to the lung is a known complication of radioactive seed therapy. These seeds are used for localised treatment of malignancies, most commonly prostate cancer.
Regarding staging, nearly 79% of the cases are localized, 12% are regional and 5% present with distant disease 1. Currently, there are several management options for prostate cancer, including active surveillance, radical prostatectomy and radiation therapy (external beam and brachytherapy).
The most frequent site of seed migration is the lung. Sugawara et al. reported 0.36% of implanted seed migration to the chest in 20% of patient population 2.
The proposed migration route is via the periprostatic veins to the iliac veins, right heart and then the lungs 3. Migration to the heart, coronary arteries, liver, bladder, renal arteries and testicular vein has also been reported 4-11.
The majority of the cases are asymptomatic and incidentally found.
Nonetheless, several reports describe symptomatic presentation with hematuria, flank and back pain, chest pain, acute myocardial infarction, acute cardiac dysrhythmia and testicular swelling 4-9,11.
Usually, only one or two seeds migrate, and therefore it has no significant effect on postimplant dosimetry 2.
On CT the migrated seed appears as a linear hyperdense structure, with extreme beam and streak artefacts relative to their small size.
Treatment and prognosis
The latest consensus guidelines for transrectal ultrasound-guided permanent prostate brachytherapy by the American Brachytherapy Society no longer recommends the use of imaging methods for the detection of seed migration 13. The American College of Radiology appropriateness criteria follows the same recommendations as the American Brachytherapy Society 14.
-  Siegel RL, Miller KD, Jemal A. Cancer statistics, 2018. (2018) CA: a cancer journal for clinicians. 68 (1): 7-30. doi:10.3322/caac.21442 - Pubmed
-  Sugawara A, Nakashima J, Kunieda E, Nagata H, Mizuno R, Seki S, Shiraishi Y, Kouta R, Oya M, Shigematsu N. Prostate brachytherapy seed migration to a left varicocele. (2012) Brachytherapy. 11 (6): 502-6. doi:10.1016/j.brachy.2011.11.003 - Pubmed
-  Chen WC, Katcher J, Nunez C, Tirgan AM, Ellis RJ. Radioactive seed migration after transperineal interstitial prostate brachytherapy and associated development of small-cell lung cancer. (2012) Brachytherapy. 11 (5): 354-8. doi:10.1016/j.brachy.2011.12.003 - Pubmed
-  Davis BJ, Pfeifer EA, Wilson TM, King BF, Eshleman JS, Pisansky TM. Prostate brachytherapy seed migration to the right ventricle found at autopsy following acute cardiac dysrhythmia. (2000) The Journal of urology. 164 (5): 1661. Pubmed
-  Davis BJ, Bresnahan JF, Stafford SL, Karon BL, King BF, Wilson TM. Prostate brachytherapy seed migration to a coronary artery found during angiography. (2002) The Journal of urology. 168 (3): 1103. Pubmed
-  Haroun RR, Nance JW, Fishman EK. Prostate Brachytherapy seed migration to the Bladder presenting with Gross Hematuria. (2016) Journal of radiology case reports. 10 (1): 22-6. doi:10.3941/jrcr.v10i1.2657 - Pubmed
-  Sachdeva S, Udechukwu NS, Elbelasi H, Landwehr KP, St Clair WH, Winkler MA. Prostate brachytherapy seed migration to the heart seen on cardiovascular computed tomographic angiography. (2017) Radiology case reports. 12 (1): 31-33. doi:10.1016/j.radcr.2016.10.009 - Pubmed
-  Nguyen BD, Schild SE, Wong WW, Vora SA. Prostate brachytherapy seed embolization to the right renal artery. (2009) Brachytherapy. 8 (3): 309-12. doi:10.1016/j.brachy.2008.11.011 - Pubmed
-  Nguyen BD, Egnatios GL. Prostate brachytherapy seed migration to the left testicular vein. (2010) Brachytherapy. 9 (3): 224-6. doi:10.1016/j.brachy.2009.10.002 - Pubmed
-  Nguyen BD. Cardiac and hepatic seed implant embolization after prostate brachytherapy. (2006) Urology. 68 (3): 673.e17-9. doi:10.1016/j.urology.2006.03.056 - Pubmed
-  Zhu AX, Wallner KE, Frivold GP, Ferry D, Jutzy KR, Foster GP. Prostate brachytherapy seed migration to the right coronary artery associated with an acute myocardial infarction. (2006) Brachytherapy. 5 (4): 262-5. doi:10.1016/j.brachy.2006.08.004 - Pubmed
-  Miura N, Kusuhara Y, Numata K, Shirato A, Hashine K, Sumiyoshi Y, Kataoka M, Takechi S. Radiation pneumonitis caused by a migrated brachytherapy seed lodged in the lung. (2008) Japanese journal of clinical oncology. 38 (9): 623-5. doi:10.1093/jjco/hyn063 - Pubmed
-  Davis BJ, Horwitz EM, Lee WR, Crook JM, Stock RG, Merrick GS, Butler WM, Grimm PD, Stone NN, Potters L, Zietman AL, Zelefsky MJ. American Brachytherapy Society consensus guidelines for transrectal ultrasound-guided permanent prostate brachytherapy. (2012) Brachytherapy. 11 (1): 6-19. doi:10.1016/j.brachy.2011.07.005 - Pubmed
-  Davis BJ, Taira AV, Nguyen PL, Assimos DG, D'Amico AV, Gottschalk AR, Gustafson GS, Keole SR, Liauw SL, Lloyd S, McLaughlin PW, Movsas B, Prestidge BR, Showalter TN, Vapiwala N. ACR appropriateness criteria: Permanent source brachytherapy for prostate cancer. (2017) Brachytherapy. 16 (2): 266-276. doi:10.1016/j.brachy.2016.10.002 - Pubmed