Kidney-sparing radiotherapy by multiple-field three-dimensional technique in the postoperative management of patients with gastric cancer: comparison with standard two-field conformal technique.

AIMS AND BACKGROUND: The opposed two-field technique is the standard approach for delivering adjuvant radiotherapy to patients with resected gastric cancer. Since a considerable radiation dose may reach both kidneys with this beam arrangement, with a potential risk of late effects, we investigated whether the CT-based multiple-field (M-F) approach was superior in terms of sparing critical organs at risk. METHODS: From March 2001 to March 2004, 19 patients with radically resected gastric cancer entered the study. They were treated with adjuvant chemoradiotherapy according to the INT 0116 protocol. For each patient dose-volume histograms were calculated and the volume values of both kidneys and liver receiving 25 Gy (V25), 30 Gy (V30) and 40 Gy (V40) individually estimated with the M-F and two-field techniques were compared in detail. RESULTS: Right kidney median V25, V30 and V40 values for the two-field and M-F techniques were 1.50%, 0%, 0% and 0%, 0% and 0%, respectively (P < 0.005, P < 0.01, P < 0.05). Left kidney median V25, V30 and V40 values for the M-F and two-field technique were 16%, 9.80%, 0.90% and 33.20%, 30.20%, 21.40% (P < 0.001, P < 0.0005, P < 0.0005). Liver median V25, V30 and V40 values for the M-F and two-field techniques were 51.30%, 22.30%, 8.90% and 13.30%, 11.60%, 8.10%, respectively (P < 0.0001, P < 0.0005 and P = 0.18). CONCLUSIONS: Our comparison revealed that with the multiple-field technique the right kidney may be largely spared from irradiation; with respect to the two-field technique, the left kidney may receive a significantly reduced dose; however, the liver receives an increased dose that warrants careful long-term monitoring of hepatic function.

Role of (64)CuCl 2 PET/CT in staging of prostate cancer.

AIM: The presence of an elevated copper concentration in cancer cells may be potentially used to differentiate healthy from transformed cells. In this study, we aimed to look at the possible role of (64)CuCl2 PET/CT in staging of patients with prostate cancer (PC). METHODS: Seven patients affected by histologically confirmed PC have been prospectively enrolled. Three patients underwent adrenal deprivation therapy (ADT) at time of imaging. The remaining four patients had no ADT, surgery, or external beam radiation therapy (EBRT). In all patients, up to three (64)CuCl2 PET/CT scans 10 min, 1 h and 3 h (and an additional scan 24 h in 2 patients) after administration of mean 339 MBq (64)CuCl2 were performed and analyzed for presence of disease. Additionally, dosimetric calculations were performed. All patients underwent a multiparametric magnetic resonance imaging (mMRI) for confirmation of disease. RESULTS: Lesions specifically in the pelvic area could be easily delineated, which was due to the absence of urinary excretion of the tracer. (64)CuCl2 uptake was higher in primary tumors of patients without ADT than in patients under bicalutamide therapy. In two patients with suspected lymphadenopathy at MRI (>10 mm diameter), there was no enhanced (64)CuCl2 uptake. In other two patients, there was focal enhanced uptake in involved pelvic lymph nodes, one of which with a normal size of <10 mm. CONCLUSIONS: The preliminary results of this study show a high uptake of (64)CuCl2 in PC and involved regional lymph nodes indicating to a great potential of (64)CuCl2 PET/CT for primary staging of patients with prostate cancer.

Planning hybrid intensity modulated radiation therapy for whole-breast irradiation.

PURPOSE: To test tangential and not-tangential hybrid intensity modulated radiation therapy (IMRT) for whole-breast irradiation. METHODS AND MATERIALS: Seventy-eight (36 right-, 42 left-) breast patients were randomly selected. Hybrid IMRT was performed by direct aperture optimization. A semiautomated method for planning hybrid IMRT was implemented using Pinnacle scripts. A plan optimization volume (POV), defined as the portion of the planning target volume covered by the open beams, was used as the target objective during inverse planning. Treatment goals were to prescribe a minimum dose of 47.5 Gy to greater than 90% of the POV and to minimize the POV and/or normal tissue receiving a dose greater than 107%. When treatment goals were not achieved by using a 4-field technique (2 conventional open plus 2 IMRT tangents), a 6-field technique was applied, adding 2 non tangential (anterior-oblique) IMRT beams. RESULTS: Using scripts, manual procedures were minimized (choice of optimal beam angle, setting monitor units for open tangentials, and POV definition). Treatment goals were achieved by using the 4-field technique in 61 of 78 (78%) patients. The 6-field technique was applied in the remaining 17 of 78 (22%) patients, allowing for significantly better achievement of goals, at the expense of an increase of low-dose (∼5 Gy) distribution in the contralateral tissue, heart, and lungs but with no significant increase of higher doses (∼20 Gy) in heart and lungs. The mean monitor unit contribution to IMRT beams was significantly greater (18.7% vs 9.9%) in the group of patients who required 6-field procedure. CONCLUSIONS: Because hybrid IMRT can be performed semiautomatically, it can be planned for a large number of patients with little impact on human or departmental resources, promoting it as the standard practice for whole-breast irradiation.