ABSTRACT
Following the publication of this article [1], the authors noticed that figures 2, 3, 4 and 5 were in the incorrect order and thus had incorrect captions.
ABSTRACT
BACKGROUND: To assess the effect of radiochemotherapy (RCT) on proposed tumour hypoxia marker transverse relaxation time (T2*) and to analyse the relation between T2* and 18F-misonidazole PET/CT (FMISO-PET) and 18F-fluorodeoxyglucose PET/CT (FDG-PET). METHODS: Ten patients undergoing definitive RCT for squamous cell head-and-neck cancer (HNSCC) received repeat FMISO- and 3 Tesla T2*-weighted MRI at weeks 0, 2 and 5 during treatment and FDG-PET at baseline. Gross tumour volumes (GTV) of tumour (T), lymph nodes (LN) and hypoxic subvolumes (HSV, based on FMISO-PET) and complementary non-hypoxic subvolumes (nonHSV) were generated. Mean values for T2* and SUVmean FDG were determined. RESULTS: During RCT, marked reduction of tumour hypoxia on FMISO-PET was observed (T, LN), while mean T2* did not change significantly. At baseline, mean T2* values within HSV-T (15 ± 5 ms) were smaller compared to nonHSV-T (18 ± 3 ms; p = 0.051), whereas FDG SUVmean (12 ± 6) was significantly higher for HSV-T (12 ± 6) than for nonHSV-T (6 ± 3; p = 0.026) and higher for HSV-LN (10 ± 4) than for nonHSV-LN (5 ± 2; p ≤ 0.011). Correlation between FMISO PET and FDG PET was higher than between FMSIO PET and T2* (R2 for GTV-T (FMISO/FDG) = 0.81, R2 for GTV-T (FMISO/T2*) = 0.32). CONCLUSIONS: Marked reduction of tumour hypoxia between week 0, 2 and 5 found on FMISO PET was not accompanied by a significant T2*change within GTVs over time. These results suggest a relation between tumour oxygenation status and T2* at baseline, but no simple correlation over time. Therefore, caution is warranted when using T2* as a substitute for FMISO-PET to monitor tumour hypoxia during RCT in HNSCC patients. TRIAL REGISTRATION: DRKS, DRKS00003830 . Registered 23.04.2012.
Subject(s)
Chemoradiotherapy , Head and Neck Neoplasms/diagnostic imaging , Head and Neck Neoplasms/therapy , Positron Emission Tomography Computed Tomography/methods , Squamous Cell Carcinoma of Head and Neck/diagnostic imaging , Squamous Cell Carcinoma of Head and Neck/therapy , Tumor Hypoxia , Dose Fractionation, Radiation , Fluorodeoxyglucose F18 , Head and Neck Neoplasms/metabolism , Humans , Magnetic Resonance Imaging/methods , Misonidazole/analogs & derivatives , Oxygen Consumption , Prospective Studies , Radiation-Sensitizing Agents , Radiopharmaceuticals , Squamous Cell Carcinoma of Head and Neck/metabolism , Time Factors , Tumor Burden , Tumor Hypoxia/drug effects , Tumor Hypoxia/radiation effectsABSTRACT
BACKGROUND: Accurate tumour bed localisation is a key requirement for adjuvant radiotherapy. A new procedure is described for head and neck cancer treatment that improves tumour bed localisation using titanium clips. MATERIALS AND METHODS: Following complete local excision of the primary tumour, the tumour bed was marked with titanium clips. Preoperative gross target volume (GTV) and postoperative tumour bed were examined and the distances between the centres of gravity were evaluated. RESULTS: 49 patients with squamous cell carcinoma of the oral cavity were prospectively enrolled in this study. All patients underwent tumour resection, neck lymph node dissection and defect reconstruction in one stage. During surgery, 7-49 clips were placed in the resection cavity. Surgical clip insertion was successful in 88% (n=43). Clip identification and tumour bed delineation was successful in all 43 patients. The overall distance between the centres of gravity of the preoperative tumour extension to the tumour bed was 0.9cm. A significant relationship between the preoperative tumour extension and the postoperative tumour bed volume could be demonstrated. CONCLUSION: We demonstrate a precise delineation of the former tumour cavity. Improvements in tumour bed delineation allow an increase of accuracy for adjuvant treatment.