The impact of 18F-deoxyglucose positron emission tomography on tumor staging, treatment strategy and treatment planning for radiotherapy in a department of radiation oncology.
OBJECTIVE
The study analyzed the potential contribution of positron emission tomography (PET) in patient selection for radiotherapy and in radiation therapy planning.


METHODS
Eighty-seven patients with a histological cancer diagnosis were accrued for the study from December 2000 to December 2001. Demographic characteristics included a median age of 54 years and male/female ratio of 51/36. All patients staged by conventional workup who were candidates for radiotherapy had PET imaging and were allocated to a conventional "pre/post-PET stage". The treatment protocol and the shape and/or size of the portals was directly related to PET results. We examined 26 lung cancers, 15 gastrointestinal tumors, 22 genitourinary cancers and 24 hematologic malignancies.


RESULTS
In the lung cancer group, the stage was modified in 10/26 patients (38.5%) by PET, with a change in management in 13 (50%) and a change in radiotherapy planning in 6 (23.1%). In the hematological group, stage was modified by PET in 8/24 cases (33.3%), with a change in treatment strategy in 9 (37.5%) and a change in radiotherapy planning in 3 (12.5%). In the gastrointestinal group, the stage was modified by PET in 2/15 cases (13.4%), with a change inn treatment strategy in 4 (26.7%) and a change in the decision for radiotherapy in 8 (no radiotherapy in 53.3%). In the mixed group (genitourinary, breast and other), the stage was modified by PET in 6/22 cases (27.3%), with a change in treatment strategy in 11 (50%) and a very low rate of change in radiotherapy planning.


CONCLUSIONS
PET contributed to a modification of stage in 26/87 patients (30%), to a changing in treatment strategy in 37/87 (42.5%), and to a substantial change of the shape and/or size of radiotherapy portals in 13/43 (30%) who underwent radiotherapy.
Gabriele
Pietro
P
Radiation Therapy Unit, Institute for Cancer Research and Treatment (IRCC), Candiolo (TO), Italy.
Malinverni
Giuseppe
G
Moroni
Gian Luca
GL
Gatti
Marco
M
Regge
Daniele
D
Versari
Annibale
A
Serafini
Desiderio
D
Fraternali
Alessandro
A
Salvo
Diana
D
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging; D019337:Hematologic Neoplasms / Q000000981:diagnostic imaging; D006801:Humans; D007558:Italy; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant; D014565:Urogenital Neoplasms / Q000000981:diagnostic imaging
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18