Limits...
Bone marrow dosimetry in peptide receptor radionuclide therapy with [177Lu-DOTA(0),Tyr(3)]octreotate.

Forrer F, Krenning EP, Kooij PP, Bernard BF, Konijnenberg M, Bakker WH, Teunissen JJ, de Jong M, van Lom K, de Herder WW, Kwekkeboom DJ - Eur. J. Nucl. Med. Mol. Imaging (2009)

Bottom Line: Radioactivity in the bone marrow was compared with radioactivity in the blood drawn simultaneously.A strong linear correlation and high agreement between the measured radioactivities in the bone marrow aspirates and in the blood was found (r=0.914, p<0.001).No correlation between the calculated absorbed dose in the bone marrow and the change in platelets was found.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, Erasmus MC Rotterdam, Dr. Molewaterplein 40, NL-3015 GD, Rotterdam, The Netherlands. fforrer@uhbs.ch

ABSTRACT

Purpose: Adequate dosimetry is mandatory for effective and safe peptide receptor radionuclide therapy (PRRT). Besides the kidneys, the bone marrow is a potentially dose-limiting organ. The radiation dose to the bone marrow is usually calculated according to the MIRD scheme, where the accumulated activity in the bone marrow is calculated from the accumulated radioactivity of the radiopharmaceutical in the blood. This may underestimate the absorbed dose since stem cells express somatostatin receptors. We verified the blood-based method by comparing the activity in the blood with the radioactivity in bone marrow aspirates. Also, we evaluated the absorbed cross-dose from the source organs (liver, spleen, kidneys and blood), tumours and the so-called "remainder of the body" to the bone marrow.

Methods: Bone marrow aspirates were drawn in 15 patients after treatment with [(177)Lu-DOTA(0),Tyr(3)]octreotate. Radioactivity in the bone marrow was compared with radioactivity in the blood drawn simultaneously. The nucleated cell fraction was isolated from the bone marrow aspirate and radioactivity was measured. The absorbed dose to the bone marrow was calculated. The results were correlated to the change in platelet counts 6 weeks after treatment.

Results: A strong linear correlation and high agreement between the measured radioactivities in the bone marrow aspirates and in the blood was found (r=0.914, p<0.001). No correlation between the calculated absorbed dose in the bone marrow and the change in platelets was found. There was a considerable contribution from other organs and the remainder of the body to the bone marrow absorbed dose.

Conclusion: (1) After PRRT with [(177)Lu-DOTA(0),Tyr(3)]octreotate, the radioactivity concentration in the bone marrow is identical to that in the blood; (2) There is no significant binding of the radiopharmaceutical to bone marrow precursor stem cells; (3) The contribution of the cross dose from source organs and tumours to the bone marrow dose is significant; and (4) There is considerable variation in bone marrow absorbed dose between patients. These findings imply that for individual dose optimization, individual calculation of the bone marrow absorbed dose is necessary.

Show MeSH

Related in: MedlinePlus

Typical example of transverse SPECT slices through the thorax obtained 24 h after treatment with 7.4 GBq [177Lu-DOTA0,Tyr3]octreotate. Note that there is no clear uptake over the spine area
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2691529&req=5

Fig3: Typical example of transverse SPECT slices through the thorax obtained 24 h after treatment with 7.4 GBq [177Lu-DOTA0,Tyr3]octreotate. Note that there is no clear uptake over the spine area

Mentions: No or only very faint uptake in the bone marrow could be seen on the SPECT scans of the thorax. The bone marrow to background (ROI placed into the lungs) ratios were between 1 and 1.8. Therefore it was not possible to place a ROI reliably, and consequently no absorbed dose to the bone marrow was calculated from SPECT scans. An example of transaxial SPECT slices in one patient is shown in Fig. 3.Fig. 3


Bone marrow dosimetry in peptide receptor radionuclide therapy with [177Lu-DOTA(0),Tyr(3)]octreotate.

Forrer F, Krenning EP, Kooij PP, Bernard BF, Konijnenberg M, Bakker WH, Teunissen JJ, de Jong M, van Lom K, de Herder WW, Kwekkeboom DJ - Eur. J. Nucl. Med. Mol. Imaging (2009)

Typical example of transverse SPECT slices through the thorax obtained 24 h after treatment with 7.4 GBq [177Lu-DOTA0,Tyr3]octreotate. Note that there is no clear uptake over the spine area
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2691529&req=5

Fig3: Typical example of transverse SPECT slices through the thorax obtained 24 h after treatment with 7.4 GBq [177Lu-DOTA0,Tyr3]octreotate. Note that there is no clear uptake over the spine area
Mentions: No or only very faint uptake in the bone marrow could be seen on the SPECT scans of the thorax. The bone marrow to background (ROI placed into the lungs) ratios were between 1 and 1.8. Therefore it was not possible to place a ROI reliably, and consequently no absorbed dose to the bone marrow was calculated from SPECT scans. An example of transaxial SPECT slices in one patient is shown in Fig. 3.Fig. 3

Bottom Line: Radioactivity in the bone marrow was compared with radioactivity in the blood drawn simultaneously.A strong linear correlation and high agreement between the measured radioactivities in the bone marrow aspirates and in the blood was found (r=0.914, p<0.001).No correlation between the calculated absorbed dose in the bone marrow and the change in platelets was found.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, Erasmus MC Rotterdam, Dr. Molewaterplein 40, NL-3015 GD, Rotterdam, The Netherlands. fforrer@uhbs.ch

ABSTRACT

Purpose: Adequate dosimetry is mandatory for effective and safe peptide receptor radionuclide therapy (PRRT). Besides the kidneys, the bone marrow is a potentially dose-limiting organ. The radiation dose to the bone marrow is usually calculated according to the MIRD scheme, where the accumulated activity in the bone marrow is calculated from the accumulated radioactivity of the radiopharmaceutical in the blood. This may underestimate the absorbed dose since stem cells express somatostatin receptors. We verified the blood-based method by comparing the activity in the blood with the radioactivity in bone marrow aspirates. Also, we evaluated the absorbed cross-dose from the source organs (liver, spleen, kidneys and blood), tumours and the so-called "remainder of the body" to the bone marrow.

Methods: Bone marrow aspirates were drawn in 15 patients after treatment with [(177)Lu-DOTA(0),Tyr(3)]octreotate. Radioactivity in the bone marrow was compared with radioactivity in the blood drawn simultaneously. The nucleated cell fraction was isolated from the bone marrow aspirate and radioactivity was measured. The absorbed dose to the bone marrow was calculated. The results were correlated to the change in platelet counts 6 weeks after treatment.

Results: A strong linear correlation and high agreement between the measured radioactivities in the bone marrow aspirates and in the blood was found (r=0.914, p<0.001). No correlation between the calculated absorbed dose in the bone marrow and the change in platelets was found. There was a considerable contribution from other organs and the remainder of the body to the bone marrow absorbed dose.

Conclusion: (1) After PRRT with [(177)Lu-DOTA(0),Tyr(3)]octreotate, the radioactivity concentration in the bone marrow is identical to that in the blood; (2) There is no significant binding of the radiopharmaceutical to bone marrow precursor stem cells; (3) The contribution of the cross dose from source organs and tumours to the bone marrow dose is significant; and (4) There is considerable variation in bone marrow absorbed dose between patients. These findings imply that for individual dose optimization, individual calculation of the bone marrow absorbed dose is necessary.

Show MeSH
Related in: MedlinePlus