SORAMIC: NM Procedures

Transcription

1 : NM Procedures J. Ruf Klinik für Radiologie und Nuklearmedizin

2 : NM Procedures Evaluation - 99m Tc MAA Scintigraphy Lung shunt assessment Treatment activity determination Therapy - 90 Y-SIR-Spheres Procedure Estimation of residual vial activity 2

3 99m Tc MAA Scintigraphy 3

4 99m Tc MAA Scintigraphy Essential pre-treatment evaluation before SIRT All Patients scheduled to receive SIR spheres therapy (palliative group) must undergo a scintigraphy aftercoiling Lung shunt assessment Extrahepatic activity elsewhere 4

5 99m Tc MAA Scintigraphy - Procedure 1. Check for informed consent 2. Na-I-Symporter blocking 3. 99m Tc MAA Preparation 4. 99m Tc MAA Handling & Application 5. 99m Tc-MAA Imaging 6. 99m Tc-MAA Semiquantification & Dosimetry 5

6 Na-I-Symporter Blocking 300mg sodium perchlorate (20-30gtt per os) min. 2 4 hours prior 99m Tc MAA application * Aim: Na-I-symporter-Inhibition in the gastric mucosa Safer discrimination of specific gastric extrahepatic MAA (i.e. due to collaterals) from gastric accumulation of free pertechnetate * Rendl J., et al: Schilddrüse und Röntgenkontrastmittel; Dt Ärztebl 2001; 98: A

7 99m Tc MAA - Preparation Any commercialy available 99m Tc MAA kit usable Preparation according to manufacturer instructions Activity to be injected: MBq No. of particles to be injected: 100, ,000 Shelf life of 99m Tc MAA: preparation should be done shortly before administration (max. 2 h) 7

8 99m Tc MAA Handling & Application Handling guidance: Avoid contact of MAA-suspension with air Shortly before administration the vial must be carefully shaken to guarantee a homogeneous suspension Pulsatile application to avoid backflow Application: Single right lobe treatment right hepatic artery* Single left lobe treatment left hepatic artery* Bi-lobar treatment right & left common hepatic artery* *or variants therof 8

9 99m Tc MAA Planar Scintigraphy Double head gamma camera Anterior and posterior projection Whole body scanning or Separate acquisition of the thorax and abdomen (700 K 1000 K-cts for abdomen and same time for thorax) Timely image acquisition after tracer application to avoid tracer degradation 9

10 99m Tc MAA Abdominal SPECT Comparison of SPECT and contemp. CT/MRI Preferably image fusion (SPECT/CT or retrospective with software) Aim: Exclusion of extrahepatic accumulation! SPECT/CT vs. Planar imaging * accuracy: 96% vs. 72% sensitivity: 100% vs. 25% specificity: 94% vs. 87% * Hamami M. E., et al: SPECT/CT with 99m Tc-MAA in Radioembolization with 90 Y Microspheres in Patients with Hepatocellular Cancer; J Nucl Med 2009; 50:

11 99m Tc MAA Extrahepatic Activity In case of extrahepatic accumulation an angiographic re-evaluation (incl. coiling) and subsequent 99m Tc MAA shunt study is necessary 11

12 99m Tc MAA Semiquantification anterior and posterior views on planar scans Regions of Interests (ROI) Lungs Liver Murthy R et al. Yttrium-90 microsphere therapy for hepatic malignancy: devices, indications, technical considerations, and potential complications. Radiographics. 2005;25 Suppl 1:S

13 99m Tc MAA Semiquantification Geometric mean of counts within the ROIs Calculation of the percentage lung shunting (PLS) 13

14 SIRT Dosimetry 14

15 90 Y-SIRT - Activity Calculation Determination of the prescribed activity (PA) Required information Percentage lung shunt (PLS) Body surface area (BSA) Volume of the right and the left liver lobe Tumor volume of the right and the left liver lobe 15

16 90 Y-SIRT - Activity Calculation Percentage lung shunt (PLS) Derived from 99m Tc MAA Semiquantification BSA-Calculation ( Mosteller -formula) * * Mosteller,R.D. Simplified calculation of body-surface area. N. Engl. J. Med. 1987, 317;17:

17 90 Y-SIRT - Activity Calculation Liver and tumor volumetry Based on contrast enhanced CT/MRI (preferably triple phase, dual phase allowed) Segmental classification of right and left lobe according to Couinaud s model Correction of lobar segment attribution if aberrant arteries are detected during angiography session Segmentation and corresponding volumetry can be performed according to in-house standards * Fischer L, et al. The segments of the hepatic veins is there a spatial correlation to the Couinaud liver segments? Eur J Radiol 53(2): ,

18 90 Y-SIRT - Activity Calculation Prescribed activity (PA) * - single lobe treatment TuV lobar TV lobar TV lobar TV liver TuV tumor volume, TV total volume, BSA body surface area * Murthy R et al. Yttrium-90 microsphere therapy for hepatic malignancy: devices, indications, 18 technical considerations, and potential complications. Radiographics. 2005;25 Suppl 1:S41-55

19 90 Y-SIRT - Activity Calculation Prescribed activity (PA) * - bilobar sequential treat. Right lobe TuV right TV right TV right TV liver Left lobe TuV left TV left TV left LV liver TuV tumor volume, TV total volume, BSA body surface area 19

20 90 Y-SIRT - Impact of Lung Shunt Pulmonary Radiation Dose (PRD) the limits * < 30 Gy: no correction: deliver Prescribed Activity (PA) 30 Gy: correction: Calculate the Corrected Prescribed Activity (CPA) * Ho S, et al. Clinical evaluation of the partition model for estimating radiation doses from yttrium- 90 microspheres in the treatment of hepatic cancer. Eur J Nucl Med 1997; 24:

21 90 Y-SIRT - Impact of Lung Shunt Pulmonary Radiation Dose (PRD) PRD (Gy) = 50 x PA x (PLS / 100) Corrected Prescribed Activity (CPA) CPA (GBq) = 30 x PA lobar / PRD PA prescribed activity, PLS percentage lung shunt, 21

22 90 Y-SIRT Procedure

23 90 Y-SIRT Patient Preparation Premedication Dexamethasone 20mg i.v. (e.g. Fortecortin ) Ondansetrone 8mg i.v. (e.g. Zofran )

24 Vial Activity Prior to SIR-Spheres application, the activity contained in the vial must be measured Spheres inside the vial are to be stirred up before measuring Dose calibrator with default setting for 90 Y Measurements (activity and time) must be documented in the protocol

25 90 Y-SIRT Procedure Microcatheter Patient Dead space Dead space (3-4 ml) V-vial Plexiglassshielding Radiologist Nuc.Med. 25

26 90 Y-SIRT Procedure Microcatheter at an identical position as for the MAA-application Stay below dead space volume when pushing spheres in Safe means 2 ml per cycle (pulsed flow!) Check the blood flow after each push! Very slow application: minimum 20min! Stop tx in case of stasis 26

27 Residual Vial Activity After application of SIR-Spheres, residual activity in the vial must be estimated - always Refill vial to the original liquid volume (i.e. before application) with water for injection purposes to minimize geometry effects on the dose calibrator Stir Suspension before measuring Time and activity estimation must be documented in the protocol Caution: avoid contamination

28 90 Y-SIRT - Post Treatment Medication Radiation induced liver disease (RILD) Methylprednisolone 4mg/d; for 6 weeks Ursodesoxicholic acid 250mg 3x/d; for 6 weeks Gastritis and ulceration Proton pump inhibitor (e.g. Pantoprazole 40mg/d; for 6 weeks) In case of sequential treatment continue medication in between therapy sessions

29 Thank you for your attention!