Preoperative chemoradiotherapy and radical surgery for locally advanced distal rectal adenocarcinoma: pathologic findings and clinical implications.

PURPOSE: Preoperative chemoradiotherapy followed by radical surgical resection has been the preferred treatment for patients presenting with locally advanced distal rectal carcinoma at our institutions. We postulated that chemoradiotherapy-induced pathologic response of the primary tumor would identify which patients would be candidates for local excision as definitive surgical therapy. METHODS: A retrospective analysis of 60 patients with palpable, locally advanced, distal rectal adenocarcinomas treated from 1995 to 2000 was performed. All patients received preoperative chemoradiotherapy consisting of 5-fluorouracil (325 mg/m(2)) and leucovorin (20 mg/m(2)) by bolus infusion on Days 1 through 5 and 29 through 33 delivered concurrently with at least 45.0 to 50.4 Gy of pelvic radiation, followed six to eight weeks later by radical surgery and then adjuvant chemotherapy. RESULTS: Among 60 patients (20 females) there was a mean age of 58.7 (28-84) years. Clinical staging was as follows: Stage II, 14 patients (23 percent); Stage III, 35 patients (58 percent); and Stage IV, 11 patients (18 percent). Pathologic examination revealed that negative margins were obtained in 58 patients (97 percent). Downstaging to T0-2N0 was achieved in 17 patients (28 percent), with five (8 percent) achieving a pathologically complete response. Lymph nodes were positive in 24 patients (40 percent) despite chemoradiotherapy. Pathologic node positivity was found in 0 of 5 pT0 patients, 9 (41 percent) of 22 pT1 or pT2, and 15 (45 percent) of 33 pT3. Clinical stage, tumor size, pathologic stage, and adverse histologic features could not reliably predict pN0 status, except pT0 (5 patients only). CONCLUSIONS: Preoperative chemoradiotherapy often downsizes and downstages locally advanced rectal carcinoma. Neither pretreatment clinical characteristics, response to preoperative chemoradiotherapy, or pathologic features reliably predict pN0 status. Therefore, local excision is not recommended as an alternative to radical surgery for locally advanced adenocarcinoma of the distal rectum regardless of the response of the primary tumor to preoperative chemoradiotherapy.

Management of neurocytomas: case report and review of the literature.

The purpose of this report is to review the available literature on the presentation, pathology, and treatment of central nervous system (CNS) neurocytomas. A case report of an extraventricular neurocytoma is presented along with a comprehensive literature search of patients with a diagnosis of CNS neurocytoma. CNS neurocytomas are rare neoplasms, with fewer than 240 cases reported in the literature. The majority of neurocytomas are found in the ventricular system of the brain. Immunohistochemistry is frequently used to help distinguish this tumor from other CNS neoplasms. MIB-1 proliferation index is commonly used in an attempt to predict biologic behavior. Little is known about the management of patients with this tumor, because most reports are from the pathologic literature and contain sparse information regarding clinical management. Neurocytomas are rare CNS tumors with varied biologic behavior. MIB-1 index may help direct adjuvant therapy. An excellent prognosis can be expected if a gross total resection is achieved. Postoperative radiation therapy (RT) may be considered after subtotal resection. Otherwise, RT is an option for medically inoperable or recurrent disease.

Urinary morbidity with a modified peripheral loading technique of transperineal (125)i prostate implantation.

PURPOSE: Analysis of urinary morbidity within the first 12 months following a modified peripheral loading technique for permanent transperineal transrectal ultrasound (TRUS) guided (125)I prostate implantation and comparison of urinary morbidity with various clinical and implant parameters. MATERIALS AND METHODS: Between October 1, 1996, and March 11, 1998, 87 patients with favorable, early stage prostate cancer were treated with permanent transperineal TRUS guided (125)I prostate implantation. A peripheral loading technique was utilized for source placement with 75-80% source distribution in the periphery and 20-25% source distribution centrally. A mean total activity of 38 mCi of (125)I was implanted (range, 19-66 mCi). The mean source activity was 0.43 mCi/source (range, 0.26-0.61 mCi/source) and the mean number of sources implanted was 88 (range, 56-134). The minimum prescribed dose to the prostate was 145 Gy. The median D(90), V(100), and V(150) were 152 Gy (range, 104-211 Gy), 92% (range, 71-99%), and 61% (range, 11-89%), respectively. The median follow-up time was 19 months (range, 12-29 months). Urinary morbidity was scored at 3 weeks and then at 3-month intervals for the first 2 years using a modified Radiation Therapy Oncology Group (RTOG) grading system (scale 0-5). RESULTS: Most patients developed at least minor urinary symptoms with frequency or nocturia being the most common. Overall, 79% (69/87) of patients experienced urinary morbidity with 21% (18/87) reporting no symptoms. The incidence of overall Grade 1 urinary morbidity was 37% (32/87); Grade 2 morbidity was 37% (32/87); and Grade 3 morbidity was 6% (5/87). There was no Grade 4 or 5 morbidity. The incidence of Grade 0 frequency/nocturia was 36% (31/87); Grade 1 was 33% (29/87); Grade 2 was 30% (26/87); and Grade 3 was 1% (1/87). Grade 0 dysuria was seen in 56% (49/87) of patients; 32% (28/87) had Grade 1; 10% (9/87) Grade 2; and 1% (1/87) Grade 3 dysuria. Most urinary symptoms started a few weeks after implantation and began to subside by 6 months. At 12 months, 22% (19/87) of patients had persistent urinary symptoms (78% Grade 0, 15% Grade 1, 3% Grade 2, and 3% Grade 3). The mean urethral point dose was 174 Gy (range, 99-315 Gy). The mean number of sources implanted correlated significantly with the likelihood of developing acute urinary morbidity (p = 0.03). The total activity implanted also correlated with the morbidity outcome dysuria (p = 0.01) with a threshold seen at 37 mCi. Urethral point dose, source activity, intraoperative TRUS prostate volume, D(90), V(100), V(150), patient age, pretreatment PSA, Gleason score, and T stage did not correlate with morbidity. CONCLUSIONS: Permanent transperineal TRUS guided (125)I prostate implantation using a modified peripheral loading technique is associated with mild urinary morbidity that resolves in 78% of patients by 12 months. Grade 3 urinary morbidity was encountered in only 6% (5/87) of patients. Urinary morbidity may be related to the total number of sources implanted and/or the total activity implanted. Overall urinary morbidity was not correlated with urethral point dose, source activity, intraoperative TRUS prostate volume, D(90), V(100), V(150), patient age, pretreatment PSA, Gleason score, and T stage. The low incidence of urinary morbidity may be a consequence of our modified peripheral loading technique and/or the selection of patients with good-to-excellent preimplant urological parameters. Longer follow-up is necessary to assess biochemical control rates and long-term morbidity.

Intraoperative 125I brachytherapy for high-risk stage I non-small cell lung carcinoma.

PURPOSE: Preliminary assessment of feasibility, efficacy, acute and chronic side effects associated with permanent intraoperative placement of 125I vicryl mesh brachytherapy in a select group of high-risk Stage I NSCLC who have undergone video-assisted thoracoscopic resection (VATR). METHODS AND MATERIALS: From January 8, 1997 to March 16, 1998, 23 patients with Stage I NSCLC at high risk for conventional surgery due to cardiopulmonary compromise underwent combined VATR and intraoperative placement of 125I seeds embedded in vicryl mesh. Seeds embedded in vicryl suture were attached with surgical clips to a sheet of vicryl mesh, and thoracoscopically inserted over the target area (tumor bed and staple line) with nonabsorbable suture or surgical clips. A total dose of 100-120 Gy prescribed to the periphery of the target area (defined as the staple line and tumor bed with a 1-cm margin) was delivered. RESULTS: The mean target area covered was 48 cm2 (range 40-72) and mean total activity was 22 mCi (range 17.2-28.2). The median length of postoperative stay was 7 days. The median follow-up was 11 months (range 2-20). Postoperative CT scans of the chest revealed no dislodgement of the seeds and no local recurrence in any patient. Three patients developed distant metastasis (1 died 6 months postoperatively; the other 2 are currently alive with disease). One patient developed an ipsilateral recurrence in the right lower lobe after having had a right upper lobe resection. There were 3 postoperative deaths due to medical comorbid conditions or surgical complications (1 in the immediate postoperative period). Pulmonary function testing performed 3 months after implantation revealed no significant difference between preoperative and postoperative values: mean preoperative FVC was 2.3 L (range 1.31-3.0) and postoperative FVC was 2.2 L (range 1.1-3.9), p = 0.42; mean preoperative FEV1 was 1.2 L (range 0.71-2.2), and postoperative FEV1 was 1.5 L (range 0.8-2.9), p = 0.28. CONCLUSION: Review of early data suggests that intraoperative 125I vicryl mesh brachytherapy in high-risk Stage I NSCLC is potentially effective and well tolerated, with no significant decline in measurable pulmonary function studies and no increase in postoperative complications. Longer follow-up is needed to determine ultimate local control and survival.

Use of cytochrome-P450 mono-oxygenase 2 E1 isozyme inhibitors to delay seizures caused by central nervous system oxygen toxicity.

BACKGROUND: The neuronal origins and mechanisms of central nervous system oxygen toxicity are only partly understood. Oxygen free radicals are felt to play a major role in the production of CNS oxygen toxicity because of the interactions of free radicals with plasma membranes producing lipid peroxidation. The cytochrome P-450 monooxygenase system IIE1 isozyme is important in the brain. This led to trials of P450 monooxygense inhibitors for prevention of oxygen toxicity. Diethyldithiocarbonate (DDC) proved to be the most promising agent in this class; 21-aminosteroid lazeroid compounds have been successful in experimentally limiting pulmonary oxygen toxicity. This led to our trying to prevent neuronal oxygen toxicity by the use of 21-aminosteroid and six other drugs during hyperoxia. METHODS: In our experiments, mice were placed in an oxygen-filled hyperbaric chamber in paired experiments. One pre-treated mouse and one control mouse were exposed simultaneously to assess the efficacy of drugs in preventing seizures caused by hyperbaric oxygen at 5.1 atmospheres absolute. Time to seizure was observed through a port hole in the hull of the hyperbaric chamber. RESULTS: DDC, 21-aminosteroid and propranolol produced significant delays in the onset of seizures (p < 0.001) with no observable side effects; 1-aminobenzotriazole and disulfiram produced much shorter delays in the onset of seizures caused by hyperbaric oxygen and also had unacceptable side effects.