Evaluation of the response to therapy of head and neck squamous cell carcinoma by using 3-[123I]iodo-L-α-methyl tyrosine and single photon emission tomography

Abstract

Early detection of residual tumour tissue offers the possibility for rapid administration of adjuvant treatment. Single photon emission tomography (SPET) with 3-[123I]iodo-L-alpha-methyl tyrosine (IMT) offers the ability to detect recurrence. The aim of this study was to carry out a prospective evaluation of sequential IMT SPET before and after primary therapy and to determine the best timing for scanning in order to establish the response to treatment. Sixteen consecutive patients with histologically proven head and neck cancer (HNC), who underwent IMT SPET before therapy, within 1 week of therapy, and 1 and 3 months after completion of primary therapy were included. Images were classified, according to clinical evaluation, as indicating a high likelihood (HL), intermediate likelihood (IL) and low likelihood (LL) that residual tumoural tissue was present. The definitive clinicopathological diagnosis and follow-up was considered as the 'gold standard'. Based on the definitive clinicopathological outcome, 10 of 16 patients were diagnosed with evidence of local tumour and six without. Nine of 10 patients with evidence of local tumour presented with an HL IMT SPET image after 3 months, seven of whom were from within the first week. In this group, 1/10 patients was considered clinically HS the first week and eventually 4/10 patients became HL, of which there were three at 3 months. Of the six patients diagnosed without local evidence of tumour, with an average follow-up of 15 months, 6/6 were clinically LL in the first week. Three of six had a consistently LL IMT SPET from within the first week. The three other patients had an HL scan the first week, of which one became IL. It is concluded that IMT SPET assessed the response to primary therapy most accurately 3 months after completion of therapy. An IMT SPET image that indicates a high likelihood of residual tumoural tissue may allow earlier stratification of the patients for secondary treatment. If negative, an IMT SPET can exclude residual tumoural tissue from within the first week after completion of therapy.

Combined SPECT/CT imaging using 123I-IMT in the detection of recurrent or persistent head and neck cancer

“…The IMT-SPECT (b) demonstrates a high tracer accumulation in the tumour. The fused SPECT/CT (c) images allow a precise localisation of the tumour mass in the surround of the left sinus piriformis ed recurrence of pre-treated head and neck carcinoma [24], and showed that this method is promising also for evaluation of the therapy response [22]. Using IMT-SPECT, Henze et al [40] found a detection rate for hypopharynx and larynx carcinoma comparable with that of FDG PET.…”

“…In this respect, PET using [ 11 C-methyl]-methionine (MET) appears promising [15][16][17][18], but would not get widely used in the clinical routine due to its of sophisticated production process, as well as the limited availability and high costs of the PET technique. SPECT imaging using a synthetic amino acid derivate L-3-[ 123 I]iodine-α-methyl tyrosine (IMT) represents an alternative to MET-PET [19][20][21] and was shown to be useful for the diagnosis of recurrent head and neck carcinoma [22][23][24]. However, the interpretation of metabolic data is sometimes difficult due to the lack of anatomical information [24,25].…”

Diagnostic Value of ¹²³I-IMT SPECT in the Follow-up of Head and Neck Cancer

“…Therefore, metabolic imaging modalities, such as positron emission tomography (PET) or single-photon emission tomography (SPECT), have been proposed as alternative techniques and are regarded to be useful especially in patients with inconclusive CT/MRI findings. Specifically, SPECT using the amino acid tracer L-3-[ 123 I]iodine-α-methyl-tyrosine (IMT) may be used to measure the proliferative activity of tumors in the head and neck area [14][15][16][17]. In the present study, we analyze the predictive value of IMT uptake for the detection of recurrent head and neck cancer, measured by a dual head gamma camera with integrated low-dose CT.…”