Forrer, F.

Maecke, H.

Mueller-Brand, J.

RERO DOC Digital Library

Eur J Nucl Med Mol Imaging (2005) 32:511–512DOI 10.1007/s00259-004-1726-3Published online: 2 February 2005© Springer-Verlag 2005Pre-therapeutic dosimetry withradiolabelled somatostatin analogues inpatients with advanced neuroendocrinetumoursDear Sir,Helisch and co-workers have reported important data onpre-therapeutic dosimetry with radiolabelled somatostatinanalogues in patients with advanced neuroendocrine tu-mours (Eur J Nucl MedMol Imaging 2004;31:1386–1392).They compared the dosimetry and biodistribution of [86Y-DOTA-D-Phe1-Tyr3]-octreotide (DOTA-TOC) with thoseof 111In-pentetreotide. They concluded that adequatedosimetry prior to 90Y-DOTA-TOC therapy is mandatoryand that dosimetry with both compounds is possible, al-though dosimetry with 86Y-DOTA-TOC is more adequate.The latter finding is not surprising since 86Y is the almostperfect surrogate for 90Y and since dosimetry with 86Y-DOTA-TOC was defined as the gold standard by theauthors.The authors point out that dosimetry with 86Y-DOTA-TOC is not widely available owing to the limited access tothe radionuclide and the elaborate correction algorithmrequired. Therefore in our opinion the aim should be to finda more widely feasible method for pre-therapeutic or, aswe suggest, peri-therapeutic dosimetry. Since the aim is aneffective treatment with 90Y-DOTA-TOC, we think that do-simetry on planar scintigraphic images should be per-formed with DOTA-TOC. It is known that the two peptidespentetreotide and DOTA-TOC have different affinity pro-files on somatostatin receptors [1, 2]. If pre-therapeuticdosimetry is demanded by an ethical committee or byauthorities, we suggest the use of 111In-DOTA-TOC if 86Y-DOTA-D-Phe1-Tyr3-octreotide is not available.The treatment protocol presented by the authors foreseesthree treatment cycles with a fixed injected activity of4.4 GBq during each session. This seems surprising sincemost trials using 90Y-DOTA-TOC base the dose on bodysurface area or use a kidney absorbed dose adapted schemewith dosimetric calculations during the first therapy cycle[3–7]. It is also known that the kidney volume plays acrucial role in the absorbed dose to the organ [8]. Thereforean individually adapted dose scheme, based on bodysurface area or individual dosimetry, should be chosen. Ifindividual dosimetry is performed in every patient and ifseveral treatment cycles are planned, dosimetry would bemost adequate when performed during the first treatmentcycle by adding 111In-DOTA-TOC. Pre-therapeutic dosim-etry would then be unnecessary.A careful reading of this article conveys the impressionthat the main message is to exclude from treatment thosepatients who would receive an absorbed dose to the kidneyhigher than 27 Gy. This would deprive them of a palliativetreatment that also can potentially prolong life and improveits quality [3, 9]. The fact that these cancer patients usuallyhave no other treatment options makes their exclusion fromtreatment ethically unacceptable. Knowing the absorbeddose to the kidney (mGy/MBq), it is obvious that thesepatients can also be treated safely by a reduction in theinjected activity.The authors state correctly that no clear data exist on therelation between absorbed dose and irreversible renal tox-icity in internal radiotherapy. For us this seems to be an-other argument as to why 27 Gy can only be a guideline andshould not serve as a justification to exclude a patient fromtreatment with an injected activity adjusted to give a kidneydose of <27 Gy. For instance, 23 Gy was taken as the max-imum allowed dose in another study [10].Moreover, the pre-therapeutic kidney function of the patient has to be taken intoconsideration. Of the patients we see, some have already hadtreatments with potentially nephrotoxic agents such as cis-platin or 131I-MIBG. An additional effect of toxicity is mostlikely.It has been shown that the distribution of radiolabelledsomatostatin analogues in the kidney is inhomogeneous[11]. The kidney damage observed after internal radio-therapy is located in glomeruli showing thrombotic micro-angiopathy [12]. These facts indicate that kidney dosimetryis much more complex than the way in which it is handledby the MIRDOSE concept.To conclude, the dosimetric results of this work are im-portant and we are convinced that internal radiotherapy hasto be improved by means of dosimetry. But patients shouldnot be excluded from a beneficial treatment by adherence tostrict settings which are not proven and can be overcome. Ifindividual dosimetry is performed, we suggest that thisshould be done peri-therapeutically during the first treatmentcycle with 111In-/90Y-DOTA-TOC. This is the most practicalmethod and also the most convenient method for patients.The circumstances really represent the therapeutic situation.The “commercial success” of Zevalin in countries where pre-therapeutic dosimetry is demanded might give us a hint as towhere additional examinations may lead.An authors’ reply to this letter is available athttp://dx.doi.org/10.1007/s00259-004-1727-2.Letters to the editorEuropean Journal of Nuclear Medicine and Molecular Imaging Vol. 32, No. 4, April 2005References1. Reubi JC, Schar JC, Waser B, Wenger S, Heppeler A, Schmitt JS,et al. Affinity profiles for human somatostatin receptor subtypesSST1-SST5 of somatostatin radiotracers selected for scintigraphicand radiotherapeutic use. Eur J Nucl Med 2000;27(3):273–82.2. Froidevaux S, Heppeler A, Eberle AN, Meier AM, Hausler M,Beglinger C, et al. Preclinical comparison in AR4-2J tumor-bearing mice of four radiolabeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-somatostatin analogs for tumor diagnosisand internal radiotherapy. Endocrinology 2000;141(9):3304–12.3.Waldherr C, Pless M, Maecke H, Schumacher T, Crazzolara A,Nitzsche E, et al. Tumor response and clincical benefit in neuro-endocrine tumors after 7.4 GBq 90Y-DOTATOC. J Nucl Med2002;43:610–6.4. Paganelli G, Bodei L, Handkiewicz Junak D, Rocca P, Papi S,Lopera Sierra M, et al. 90Y-DOTA-D-Phe1-Try3-octreotide in ther-apy of neuroendocrinemalignancies. Biopolymers 2002;66:393–8.5. Otte A, Herrmann R, Heppeler A, Behe M, Jermann E, Powell P,et al. Yttrium-90 DOTATOC: first clinical results. Eur J NuclMed 1999;26:1439–47.6.Waldherr C, PlessM,MaeckeHR,HaldemannA,Mueller-Brand J.The clinical value of [90Y-DOTA]-D-Phe1-Tyr3-octreotide (90Y-DOTATOC) in the treatment of neuroendocrine tumours: a clinicalphase II study. Ann Oncol 2001;12(7):941–5.7. Kwekkeboom D, Bakker W, Kam BLR, Teunissen J, Kooij P,HerderW, et al. Treatment of patientswith gastro-entero-pancreatic(GEP) tumours with the novel radiolabelled somatostatin analogue[177Lu-DOTA0, Tyr3]octreotate. Eur J Nucl Med Mol Imaging2003;30:417–22.8. Konijnenberg MW. Is the renal dosimetry for [90Y-DOTA0,Tyr3]octreotide accurate enough to predict thresholds for individualpatients? Cancer Biother Radiopharm 2003;18(4): 619–25.9. Teunissen J, Kwekkeboom D, Krenning E. Quality of life inpatients with gastro-entero- pancreatic tumors treated with[177Lu- DOTA0,Tyr3]octreotate. J Clin Oncol 2004;22:2724–9.10. Jamar F, Barone R, Mathieu I, Walrand S, Labar D, Carlier P, etal. 86Y-DOTA0-D-Phe1-Tyr3-octreotide (SMT 487)—a phase 1clinical study: pharmacokinetics, biodistribution and renal pro-tective effect of different regimens of amino acid co-infusion.Eur J Nucl Med Mol Imaging 2003;30:510–8.11. De Jong M, Valkema R, Van Gameren A, Van Boven H, Bex A,Van De Weyer EP, et al. Inhomogeneous localization of radio-activity in the human kidney after injection of [111In-DTPA]octreotide. J Nucl Med 2004;45(7):1168–71.12. Moll S, Nickeleit V, Mueller-Brand J, Brunner FP, Maecke HR,Mihatsch MJ. A new cause of renal thrombotic microangiopathy:yttrium-90-DOTATOC internal radiotherapy. Am J Kidney Dis2001;37(4):847–51.F. Forrer (*), J. Mueller-Brand.Institute of Nuclear Medicine, University Hospital Basel,Petersgraben 4, 4031 Basel, Switzerlande-mail: fforrer@uhbs.chH. MaeckeDivision of Radiological Chemistry, University Hospital Basel,Basel, Switzerland512European Journal of Nuclear Medicine and Molecular Imaging Vol. 32, No. 4, April 2005

Pre-therapeutic dosimetry with radiolabelled somatostatin analogues in patients with advanced neuroendocrine tumours

http://doc.rero.ch/record/311215/files/259_2004_Article_1726.pdf

Pre-therapeutic dosimetry with radiolabelled somatostatin analogues in patients with advanced neuroendocrine tumours

Abstract

Similar works

Full text

Available Versions

RERO DOC Digital Library