[FDG-PET-CT based imaging of retropharyngeal lymph nodes with its impact on radiotherapy]. / Die Darstellung retropharyngealer Lymphknoten in der FDG-PET/CT und ihre Bedeutung für die Radiotherapie.

BACKGROUND: In about 20% there is an involvement of the retropharyngeal lymph nodes in patients with locally advanced carcinoma of the hypopharynx and cervical esophagus. A case report should demonstrate the diagnostic and therapeutic impact of FDG-PET/CT in the radiotherapeutic management of a locally advanced carcinoma of the hypopharynx in special consideration of the RPLN. PATIENT AND METHOD: A pretherapeutic FDG-PET/CT was performed with the patient fixed in the radiotherapy mask in order to integrate the anatomic and metabolic information into the radiotherapy planning system by an exact matching of the data. RESULTS: Only the FDG-PET could detect a retropharyngeal lymph node involvement (RPLN) by an intensive glucose utilisation with a consecutive modification of the target volume and dose increase in this region. CONCLUSION: This case report demonstrates that FDG-PET/CT facilitates the imaging of metabolic active and otherwise hardly detectable lymph nodes in locally advanced head and neck cancer with consequences on target volume definition and dose application in radiotherapy.

[Survival with distant metastatic disease in head and neck cancer. A retrospective analysis]. / Uberleben mit hämatogen metastasierten HNO-Tumoren: Eine retrospektive monozentrische Analyse.

QUESTIONS: The objective of this retrospective analysis was to investigate parameters with a potential impact on survival in a collective of 114 patients with distant metastatic disease after head and neck cancer. PATIENTS AND METHODS: The primary endpoint was the survival with distant metastatic disease, the secondary endpoint was overall survival. Primary therapy, local recurrence, second neoplasms, palliative chemotherapy (CHT) and radiotherapy (RT), as well as Karnofsky performance status (KPS) at the time of diagnosis of the metastases were analyzed as potential impact parameters using the log-rank test with subsequent Cox regression analysis. RESULTS: Palliative CHT (P=0.0020) and KPS (P=0.0011) had a significant positive impact on the median survival probability with metastases (8.2 months) using the log-rank test, KPS at the time of diagnosis of metastases remained as an independent prognostic parameter in the Cox regression (P=0.0013). Primary therapy, local tumor control and KPS had a significant positive influence on the median overall survival probability (18.5 months) univariately (P=0.0139, P=0.0106, P= 0.0096) and multivariately (P=0.0123, and P=0.0063, P=0.0197, respectively). CONCLUSIONS: KPS at the time of diagnosis of metastases is an independent prognostic parameter for both endpoints. Lacking evidence for life prolongation, palliative therapies should therefore first and foremost focus on the stabilization of the KPS.

Improving the use of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PPIX) for the gastrointestinal tract by esterification--an in vitro study.

Possible approaches to improve the diagnostic and therapeutic effects of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PPIX) are the esterification of ALA for enhanced uptake and the choice of wavelength for irradiation. The human colonic cell lines HT29 [G2] and CCD18 (fibroblasts) were incubated with 0.6 mM ALA, ALA-hexylester or -benzylester respectively, and for further assays with hypotaurine, in addition. PPIX-accumulation was analyzed by flow cytometry and fluorescence spectroscopy. PPIX formation kinetics were continuously recorded. Incubated cells were irradiated with an incoherent light source lambda = 400-700 nm or lambda = 590-700 nm, respectively. After PDT treatment, clonogenicity assays were performed to determine cell viability. Esterification leads to increased PPIX-accumulation, decreased time for production of detectable amounts of PPIX as well as increased response to PDT. Tumor specificity is always maintained or exceeds values for ALA alone. ALA enters the cells via beta transporter whereas esters by passive diffusion. Altering irradiation wavelengths showed the independence of wavelength rather than light dose. Results emphasize the role of heme metabolism for generating tumor specificity rather than the process of ALA-uptake, an important detail for future clinical application.