Comparison of the conventional 'box technique' with two different 'conformal' beam arrangements for prostate cancer treatment.
OBJECTIVE
To quantify the possible advantages arising from the use of 'conformal' radiotherapy of localized prostate cancer, and to compare the dose distributions obtained with two different 'conformal' techniques.


METHODS
Twelve patients with localized prostate cancer were enrolled in the study. For each patient, three techniques were planned: the standard 'box technique' (A), a four-fields 'conformal' technique (B), and a 6-fields conformal technique (C). For each of the 36 3D plans, dose-volume histograms (DVH) were obtained, along with the mean, maximum and minimum doses for the clinical and planning target volumes (CTV, PTV) for the rectum, the bladder, and the femoral heads. The resulting data were compared.


RESULTS
On average, the standard technique resulted in the exposure of a significantly larger bladder volume to the higher doses; a similar, but less remarkable difference has been observed for the rectal volume. The coverage of the PTV appears to be significantly more homogeneous with the two conformal techniques.


CONCLUSIONS
The results presented here add to the evidence available in the literature and suggest a possible advantage of both the conformal techniques over the standard 'box technique' for the treatment of localized prostate cancer. The 6-field conformal technique does not seem superior to the four field one.
Department of radiotherapy, Policlinico di Careggi, Florence, Italy.
S M
SM
Magrini
E
E
Cellai
F
F
Rossi
M
M
Pertici
A
A
Compagnucci
G P
GP
Biti
D000368:Aged; D005270:Femur Head; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal; D012007:Rectum; D001743:Urinary Bladder