PET-guided dose escalation tomotherapy in malignant pleural mesothelioma.
OBJECTIVE
To test the feasibility of salvage radiotherapy using PET-guided helical tomotherapy in patients with progressive malignant pleural mesothelioma (MPM).


METHODS
A group of 12 consecutive MPM patients was treated with 56 Gy/25 fractions to the planning target volume (PTV); FDG-PET/CT simulation was always performed to include all positive lymph nodes and MPM infiltrations. Subsequently, a second group of 12 consecutive patients was treated with the same dose to the whole pleura adding a simultaneous integrated boost of 62.5 Gy to the FDG-PET/CT positive areas (BTV).


RESULTS
Good dosimetric results were obtained in both groups. No grade 3 (RTOG/EORTC) acute or late toxicities were reported in the first group, while 3 cases of grade 3 late pneumonitis were registered in the second group: the duration of symptoms was 2-10 weeks. Median overall survival was 8 months (1.2-50.5 months) and 20 months (4.3-33.8 months) from the beginning of radiotherapy, for groups I and II, respectively (p=0.19). A significant impact on local relapse from radiotherapy was seen (median time to local relapse: 8 vs 17 months; 1-year local relapse-free rate: 16% vs 81%, p=0.003).


CONCLUSIONS
The results of this pilot study support the planning of a phase III study of combined sequential chemoradiotherapy with dose escalation to BTV in patients not able to undergo resection.
Department of Radiotherapy, San Raffaele Scientific Institute, Milan, Italy. fodor.andrei@hsr.it
Andrei
A
Fodor
Claudio
C
Fiorino
Italo
I
Dell'Oca
Sara
S
Broggi
Marcella
M
Pasetti
Giovanni Mauro
GM
Cattaneo
Luigi
L
Gianolli
Riccardo
R
Calandrino
Nadia Gisella
NG
Di Muzio
D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D003131:Combined Modality Therapy; D018450:Disease Progression; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005227:Fatty Acids; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008654:Mesothelioma / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging; D010166:Palliative Care; D010865:Pilot Projects; D010997:Pleural Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D049268:Positron-Emission Tomography; D011832:Radiation Injuries / Q000209:etiology; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D016879:Salvage Therapy / Q000379:methods*; D036542:Tomography, Spiral Computed / Q000379:methods*; D014057:Tomography, X-Ray Computed
D005227:Fatty Acids; C476671:simumeramide; D019788:Fluorodeoxyglucose F18