Prostate image-guided radiotherapy by megavolt cone-beam CT.

PURPOSE: To test megavolt cone-beam CT (MV-CBCT) in order to evaluate setup errors in prostate radiotherapy. PATIENTS AND METHODS: The setup of 9 patients was verified weekly by electronic portal imaging (EPI) and MV-CBCT, both per-formed in the same treatment session. EPI were compared with digitally reconstructed radiographies (DRRs). MV-CBCTs were matched to simulation CTs by manual registration based on bone markers (BMR), by manual registration based on soft tissues (STR) - rectum, bladder, and seminal vesicles - and by automatic registration (AR) performed by a mutual information algorithm. Shifts were evaluated along the three main axes: anteroposterior (AP), craniocaudal (CC), and laterolateral (LL). Finally, in 4 additional patients showing intraprostatic calcifications, the calcification mismatch error was used to evaluate the three MV-CBCT matching methods. RESULTS: A total of 50 pairs of orthogonal EPIs and 50 MV-CBCTs were analyzed. Assuming an overall tolerance of 2 mm, no significant differences were observed comparing EPI vs BMR in any axis. A significant difference (p < 0.001) was observed along the AP axis comparing EPI vs AR and EPI vs STR. On the calcification data set (22 measures), the calcification mismatch along the AP direction was significantly lower (p < 0.05) after STR than after BMR or AR. CONCLUSION: Bone markers were not an effective surrogate of the target position and significant differences were observed comparing EPI or BMR vs STR, supporting the assessment of soft tissue position by MVCBs to verify and correct patient setup in prostate radiotherapy.

The impact of radiotherapy on survival in resectable gastric carcinoma: a meta-analysis of literature data.

BACKGROUND: The benefit of external radiotherapy for gastric carcinoma has been extensively studied, but data on survival are still equivocal. OBJECTIVE: To assess the effectiveness of surgery combined with preoperative radiotherapy or postoperative chemoradiotherapy in the reduction of all-cause mortality in patients with resectable gastric carcinoma. METHODS: Computerised bibliographic searches of MEDLINE and CANCERLIT (1970-2006) were supplemented with hand searches of reference lists. STUDY SELECTION: Studies were included if they were randomised controlled trials (RCTs) comparing mortality of surgery combined with preoperative radiotherapy or postoperative chemoradiotherapy to surgery alone, and if they included patients with histologically-proven gastric adenocarcinoma without metastases. Nine eligible RCTs, 4 of preoperative radiotherapy (832 patients) and 5 of postoperative chemoradiotherapy (869 patients), were identified and included in the meta-analysis. DATA EXTRACTION: Data on study populations, interventions, and outcomes were extracted from each RCT according to the intention to treat method by three independent observers and combined using the DerSimonian and Laird method. RESULTS: Surgery combined with preoperative radiotherapy compared to surgery alone significantly reduced the 3-year (OR 0.57; 95% CI 0.43-0.76: p=0.0001) and 5-year (OR 0.62; 95% CI 0.46-0.84; p=0.002) mortality rate. A significant reduction of the 5-year (OR 0.45; 95% CI 0.32-0.64; p<0.00001) mortality rate was observed when surgery followed by chemoradiotherapy was compared to surgery alone. CONCLUSIONS: In patients with resectable gastric carcinoma, adjuvant radiotherapy significantly reduces 3-year and 5-year all-cause mortality, but the magnitude of the benefit is relatively small. Available evidence is inadequate to determine whether postoperative chemoradiotherapy is superior to preoperative radiotherapy.

Comparative evaluation of two hypofractionated radiotherapy regimens for painful bone metastases.

AIMS AND BACKGROUND: In 75% of the patients with bone metastases (BM) pain is the dominant symptom. Radiotherapy (XRT) plays a major role in the palliation of pain in patients with BM. Several schedules of short and long fractionation XRT are used in clinical practice, with hypofractionated treatments being even more attractive for practical reasons. A considerable body of evidence supports the clinical use of short schedules and single-dose XRT. We retrospectively evaluated the efficacy of two short fractionated schedules of 8 Gy as a single dose and 20 Gy in 5 fractions in relieving pain in patients with multiple uncomplicated BM. METHOD: From January to December 2001, 130 patients with 146 painful BM were treated with palliative localized XRT. There were 42 males and 88 females with a median age of 58 years (range 28-84). The commonest sites of treatment were the spine (59.6%) and pelvis (14.4%). The primary endpoint was clinically significant pain relief in the first six months of follow-up evaluated with the IAEA (International Atomic Energy Agency) pain measurement score measuring pain severity and pain frequency. Analgesic use was also recorded before and after treatment as drug frequency and drug severity. Patients with painful BM from any primary tumor site were irradiated. Treatment schedules consisted of a course of XRT with 4 Gy/fraction/day (total dose: 20 Gy/5 fractions) (group A, 59 lesions) or with a single dose of 8 Gy (group B, 87 lesions). RESULTS: There was no significant difference in complete response (CR) rates between treatment schedules: complete pain relief was achieved in 17/59 lesions (29%) in the fractionated group and in 29/87 lesions (33%) in the single-dose group. Also the overall response (complete + partial) was similar: 35/59 lesions (60%) in group A and 60/87 (69%) in group B. The minimum, maximum and median follow-up was 3, 23, and 9 months, respectively, for group A and 3, 20, and 11 months for group B. The actuarial median duration of pain relief was similar: 4.5 months in group A and 4 months in group B. No particular side effects were recorded in either group. CONCLUSIONS: There were no differences between the two fractionation schedules used in our study with regard to pain relief and use of analgesics. Palliation of pain was obtained in approximately two thirds of patients with both schedules, providing further evidence of the similar efficacy between single and multiple fractions. With regard to pain response these data justify a recommendation for the use of a more simple and convenient 8 Gy single fraction for the palliation of uncomplicated BM.