title: Evaluation of patient effective dose from sentinel lymph node lymphoscintigraphy in breast cancer: a phantom study with SPECT/CT and ICRP-103 recommendations.
abstract: OBJECTIVE
  To evaluate the effective dose delivered to patients undergoing sentinel lymph node (SLN) lymphoscintigraphy by taking into account both the transmission dose using the CT component of a SPECT/CT system and the (99m)Tc internal emission dose.
  
  
  METHODS
  An adult female humanoid phantom and a set of thermoluminescent dosimeters were used in dose measurement from the CT transmission irradiation. The choice of measurement organs in the humanoid was guided by the recommendations described in the International Commission on Radiological Protection report number 103 (ICRP-103). The effective doses due to (99m)Tc internal emission source were re-calculated from measurement data reported in our previous study on the same subject with the use of tissue weighting factors of ICRP-103.
  
  
  RESULTS
  CT transmission dose is the main contribution to the patient total effective dose for both 1-day and 2-day lymphoscintigraphy protocols and for different surgical procedures. Patients undergoing SLN lymphoscintigraphy receive about the same amount of total effective dose of about 3mSv for both 1-day and 2-day protocol, regardless of whether the tissues containing radioactivity would be excised at surgery or not.
  
  
  CONCLUSIONS
  Although the total effective dose from using SPECT/CT is equivalent to the annual natural background radiation of about 3mSv, nuclear medicine physicians should be aware of the increase in effective dose for SLN lymphoscintigraphy using hybrid imaging technique of SPECT/CT when compared to conventional planar (57)Co flood source for transmission scan. Results from the current study provide update information in radiation exposure to patients undergoing SLN lymphoscintigraphy with the use of SPECT/CT.
authors.affiliation: Department of Clinical Oncology, 102, Pokfulam Road, Queen Mary Hospital, Hong Kong. lawwm@ha.org.hk
authors.forename: Martin
authors.initials: M
authors.lastname: Law
authors.forename: Wai-Han
authors.initials: WH
authors.lastname: Ma
authors.forename: Raymond
authors.initials: R
authors.lastname: Leung
authors.forename: Steve
authors.initials: S
authors.lastname: Li
authors.forename: Kwong-Kuen
authors.initials: KK
authors.lastname: Wong
authors.forename: Wai-Yin
authors.initials: WY
authors.lastname: Ho
authors.forename: Ava
authors.initials: A
authors.lastname: Kwong
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D038622:Internationality; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D017410:Practice Guidelines as Topic; D011829:Radiation Dosage; D011874:Radiometry; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods