Radiotherapy in the treatment of resectable rectal adenocarcinoma.

The goal of treatment is to cure whereas maintaining sphincter function and minimizing toxicity. Although the mainstay of the treatment is surgery, radiotherapy (RT) is used in a substantial proportion of patients depending on the location and extent of the tumor. The aim of this article is to discuss the role of RT in patients with resectable rectal adenocarcinoma. This article is a review of the pertinent literature. Results show that patients with T1N0 exophytic, well to moderately differentiated, mobile tumors < or = 3 cm in diameter may be treated with either transanal excision or endocavitary RT. The probability of cure with either approach is approximately 80% to 90% and depends on selection criteria. The advantages of endocavitary RT are that it is an outpatient procedure requiring, at most, local anesthesia and is suitable for elderly, infirm patients. The disadvantage is that few of these treatment units are available. Patients who experience a local-regional recurrence may be surgically salvaged. Patients who undergo transanal excision and have unfavorable pathologic findings including equivocal or close margins, poor differentiation, invasion of the muscularis propria, and/or endothelial-lined space invasion have a high risk of local-regional recurrence after surgery alone. The addition of postoperative RT improves the likelihood of cure from 85% to 90%. Patients presenting with unfavorable tumors that are borderline resectable with a transanal excision may be downstaged with preoperative RT and rendered suitable for a wide local excision. The addition of concomitant chemotherapy probably enhances downstaging and may improve the likelihood of sphincter preservation. Patients with T3 and/or N1 rectal cancers have a relatively high probability of local-regional recurrence after surgery alone. Preoperative RT and postoperative RT combined with adjuvant chemotherapy have been shown to significantly reduce the risk of local-regional recurrence and improve survival. Whether preoperative RT alone or combined with chemotherapy is more efficacious than postoperative chemoradiation remains unclear. Endocavitary RT or transanal excision is suitable for patients with T1N0 cancers. Depending on tumor location and extent, adjuvant RT may improve the probability of local-regional control and survival for patients with locally advanced rectal adenocarcinomas.

The dynamic tumor bed: volumetric changes in the lumpectomy cavity during breast-conserving therapy.

PURPOSE: To characterize the magnitude of volume change in the postoperative tumor bed before and during radiotherapy, and to identify any factors associated with large volumetric change. METHODS AND MATERIALS: Thirty-six consecutive patients with early-stage or preinvasive breast cancer underwent breast-conserving therapy at our institution between June 2006 and October 2007. Computed tomography (CT) scans of the breast were obtained shortly after surgery, before the start of radiotherapy (RT) for treatment planning, and, if applicable, before the tumor bed boost. Postoperative changes, seroma, and surgical clips were used to define the tumor bed through consensus agreement of 3 observers (B.P., D.I., and J.L.). Multiple variables were examined for correlation with volumetric change. RESULTS: Between the first and last scan obtained (median time, 7.2 weeks), the tumor bed volume decreased at least 20% in 86% of patients (n = 31) and at least 50% in 64% of patients (n = 23). From the postoperative scan to the planning scan (median time, 3 weeks), the tumor bed volume decreased by an average of 49.9%, or approximately 2.1% per postoperative day. From planning scan to boost scan (median interval, 7 weeks), the median tumor bed volume decreased by 44.6%, at an average rate of 0.95% per postoperative day. No single factor was significantly associated with a change in tumor bed volume greater than 20%. CONCLUSIONS: The average postlumpectomy cavity undergoes dramatic volumetric change after surgery and continues this change during RT. The rate of change is inversely proportional to the duration from surgery. In this study no factors studied predicted large volumetric change.

Long-term outcomes of radiotherapy for pituitary adenomas.

PURPOSE: To evaluate long-term local control and toxicity for pituitary adenomas treated with fractionated radiotherapy (RT). METHODS AND MATERIALS: The records of 100 patients with pituitary adenomas treated between 1983 and 2003 were retrospectively reviewed. Thirty-one patients had hormone-secreting tumors; 69 patients were treated with surgery and postoperative RT. Median follow-up was 6.7 years (range, 0.6-20.2 years) for all patients and 6.2 years (range, 2-20.2 years) for living patients. The mean dose delivered was 45 Gy (range, 43-50.4 Gy). RESULTS: The 10-year actuarial local control rates for nonsecreting and secreting adenomas were 98% and 73%, respectively (p = 0.0015). Actuarial 10-year cause-specific survival (CSS) rates were 95% and 88%, and overall survival rates were 66% and 79% for nonsecreting and secreting adenomas, respectively. Involvement of the sphenoid sinus was found to be significantly associated with decreased 10-year CSS (p = 0.0453). When compared with the two- or three-field techniques, stereotactic RT was associated with improved CSS (p = 0.0775). CSS was not significantly associated with hormone excretion, extent of surgery, or whether RT was administrated postoperatively or for salvage after a postsurgical recurrence. New cases of hypopituitarism occurred in 35 patients. One patient experienced vision loss, and one patient developed a post-treatment glioma. CONCLUSIONS: This is one of the most mature series in the literature that documents excellent results with fractionated RT for pituitary adenoma. We recommend 45 Gy at 1.8 Gy per fraction using stereotactic noncoplanar fields.