Clinical outcomes of melanoma brain metastases treated with stereotactic radiation and anti-PD-1 therapy.

BACKGROUND: The anti-programmed death-1 (anti-PD-1) therapy nivolumab has significant clinical activity in patients with metastatic melanoma. However, little is known about the safety and outcomes in patients receiving anti-PD-1 therapy and stereotactic radiation for the treatment of brain metastases (BMs). PATIENTS AND METHODS: Data were analyzed retrospectively from two prospective nivolumab protocols enrolling 160 patients with advanced resected and unresectable melanoma at a single institution. Patients were included if BMs were diagnosed and treated with stereotactic radiation within 6 months of receiving nivolumab. The primary end point of this study was neurotoxicity; secondary end points included BM control and survival. RESULTS: Twenty-six patients with a total of 73 BMs treated over 30 sessions were identified. Radiation was administered before, during and after nivolumab in 33 lesions (45%), 5 lesions (7%), and 35 lesions (48%), respectively. All BMs were treated with stereotactic radiosurgery (SRS) in a single session except 12 BMs treated with fractionated stereotactic radiation therapy, nine of which were in the postoperative setting. One patient experienced grade 2 headaches following SRS with symptomatic relief with steroid treatment. No other treatment-related neurologic toxicities or scalp reactions were reported. Eight (11%) local BM failures with a ≥20% increase in volume were noted. Of these lesions, hemorrhage was noted in 4, and edema was noted in 7. Kaplan-Meier estimates for local BM control following radiation at 6 and 12 months were 91% and 85%, respectively. Median overall survival (OS) from the date of stereotactic radiation and nivolumab initiation was 11.8 and 12.0 months, respectively, in patients receiving nivolumab for unresected disease (median OS was not reached in patients treated in the resected setting). CONCLUSIONS: In our series, stereotactic radiation to melanoma BMs is well tolerated in patients who received nivolumab. BM control and OS appear prolonged compared with standard current treatment. Prospective evaluation is warranted.

Clinical outcomes of melanoma brain metastases treated with stereotactic radiosurgery and anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors, BRAF inhibitor, or conventional chemotherapy.

BACKGROUND: The effect of immunologic and targeted agents on intracranial response rates in patients with melanoma brain metastases (MBMs) is not yet clearly understood. This report analyzes outcomes of intact MBMs treated with single-session stereotactic radiosurgery (SRS) and anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors(i), BRAFi, or conventional chemotherapy. PATIENTS AND METHODS: Patients were included if MBMs were treated with single-session SRS within 3 months of receiving systemic therapy. The primary end point of this study was distant MBM control. Secondary end points were local MBM control defined as a >20% volume increase on follow-up MRI, systemic progression-free survival, overall survival (OS) from both SRS and cranial metastases diagnosis, and neurotoxicity. Images were reviewed alongside two neuro-radiologists at our institution. RESULTS: Ninety-six patients were treated to 314 MBMs over 119 SRS treatment sessions between January 2007 and August 2015. No significant differences were noted in age (P = 0.27), gender (P = 0.85), treated gross tumor volume (P = 0.26), or the diagnosis-specific graded prognostic assessment (P = 0.51) between the treatment cohorts. Twelve-month Kaplan-Meier (KM) distant MBM control rates were 38%, 21%, 20%, 8%, and 5% (P = 0.008) for SRS with anti-PD-1 therapies, anti-CTLA-4 therapy, BRAF/MEKi, BRAFi, and conventional chemotherapy, respectively. No significant differences were noted in the KM local MBM control rates among treatment groups (P = 0.25). Treatment with anti-PD-1 therapy, anti-CTLA-4 therapy, or BRAF/MEKi significantly improved OS on both univariate and multivariate analyses when compared with conventional chemotherapy. CONCLUSION: In our institutional analysis of patients treated with SRS and various systemic immunologic and targeted melanoma agents, significant differences in distant MBM control and OS are noted. Prospective evaluation of the potential synergistic effect between these agents and SRS is warranted.

Prolonged survival after episiotomy recurrence of cervical cancer complicating pregnancy.

BACKGROUND: We report a case of recurrent cervical cancer in an episiotomy scar and the late treatment-related sequelae. CASE: Cervical cancer was diagnosed following a vaginal delivery, and was treated with surgery and radiotherapy. The patient developed a recurrence in her episiotomy scar, and was treated with chemoradiation. She remains without evidence of disease ten years later. CONCLUSION: Successful treatment of recurrent cervical cancer with chemoradiation is possible, but may be associated with significant normal tissue toxicity.

'Insignificant' prostate cancer on biopsy: pathologic results from subsequent radical prostatectomy.

'Insignificant' prostate cancer is defined as disease of virulence insufficient to threaten survival. In this review, which describes nine articles and two abstracts discussing almost 800 cases, we discuss the correlation of such 'insignificant' biopsy findings in the context of subsequent radical prostatectomy data. From our review, minimal disease on biopsy does not reliably predict minimal disease in the subsequent prostatectomy specimen, in terms of the size and grade of tumor, extracapsular extension or positive margins. Thus, reasoned accounting should be made of other data before undertaking a course of radiation therapy as monotherapy, particularly prostate-specific antigen kinetics and potential molecular markers.

Lack of survival benefit of post-operative radiation therapy in prostate cancer patients with positive lymph nodes.

Randomized data from SWOG 8794 and EORTC 22911 confirm the benefit of post-operative radiation therapy (RT) for selected patients with pT3 prostate cancer (CaP) after radical prostatectomy (RP). However, data regarding the potential benefit of RT for patients post-RP with positive lymph node (+LN) involvement are limited. We analyzed the Surveillance Epidemiology End Results (SEER) registry for population-based data on efficacy of post-operative RT for +LN patients after RP. As LN data have only been captured by SEER since 1988, we analyzed data for 1988-1992, with specific attention to 10-year relative survival (defined as observed survival divided by the survival of a gender-, age- and race-matched population cohort without disease). Specifically analyzed were data for 1921 patients with nonmetastatic prostate cancer who underwent surgery alone, or surgery followed by RT, and who had +LNs documented. SEER does not code the interval between surgery and RT, so the ratio of patients receiving salvage versus adjuvant therapy is unknown. Using follow-up data through 2002, post-diagnosis survival was examined by number of +LNs. There was no significant relative survival benefit for +LN patients receiving post-operative RT (chi(2)P=0.270). These data do not support routine use of post-operative RT for patients with +LNs in the surgical specimen.

Port site recurrences after laparoscopic and thoracoscopic procedures in malignancy.

PURPOSE AND METHODS: A review of the literature was performed to determine the number of cases of port site recurrences (PSR) after laparoscopy or thoracoscopy. CANCERLINE and MEDLINE were searched, as were citings from retrieved and related papers. RESULTS: There have been 35 reported cases of PSR after laparoscopic colectomy for colorectal carcinoma, and 23 cases after thoracoscopic procedures for lung neoplasms. All of these have been reported since 1993. Since 1991, 12 cases have been described after laparoscopic cholecystectomy of unsuspected gallbladder carcinoma, and another case after biopsy of a known gallbladder carcinoma. Ten cases of PSR have been reported after laparoscopic procedures for ovarian lesions, often in the presence of peritoneal seeding at diagnosis. Other rare PSRs have been documented after several procedures in various malignancies. CONCLUSION: Enrollment of patients onto the ongoing intergroup study evaluating open versus laparoscopic resection of colon cancer should be encouraged. Until valid prospective data on PSR frequency are available, laparoscopic or thoracoscopic resection of malignancy off-protocol should be undertaken with circumspection.

Patterns of disease recurrence following definitive therapy of adenocarcinoma of the pancreas using surgery and adjuvant radiotherapy:correlations of a clinical trial.

PURPOSE: Between 1980 and 1984, 26 patients with resectable adenocarcinoma of the pancreatic head were enrolled in a National Cancer Institute protocol evaluating intraoperative radiotherapy vs. standard therapy. METHODS AND MATERIALS: After complete excision of their lesions, patients were observed (Stage I), or randomized to intraoperative radiotherapy vs. external beam radiotherapy (Stages II-IV). The intraoperative dose was 20 Gy in a single fraction using 9-20 MeV electrons. The external beam radiotherapy schema involved daily 150-180 cGy fractions to 45-55 Gy in 5-6 weeks. Chemotherapy was not used for primary disease but was administered off protocol for recurrent disease. Median potential followup for the trial was > 9 years, with a median patient survival of 18 months. Perioperative mortality was 27% (7 patients). Of the remaining 19 patients, one remains alive and without evidence of disease 9 years post-therapy. Twelve patients underwent autopsy and 2 required antemortem laparotomy; histopathologic evidence of disease recurrence was analyzed. RESULTS: Of 15 patients evaluable for intra-abdominal control, 7 (47%) suffered local recurrences and 7 (47%) failed regionally, with 5 patients (35%) failing in both areas. Five patients (35%) developed peritoneal seeding. Of 13 patients evaluable for systemic disease, 8 (62%) suffered distant failure. There were no differences in outcome between intraoperative or external beam radiotherapy or observation in this subset of patients. CONCLUSION: This report is among the most rigorous descriptions of patterns of failure after resection of pancreatic cancer. It appears clear that advances in local control of this disease are unlikely to translate into increased survival in the absence of improved systemic therapy.

Quality of life in T1-3N0 prostate cancer patients treated with radiation therapy with minimum 10-year follow-up.

PURPOSE: To describe patient-reported quality of life using a validated survey in a cohort of patients who are long-term survivors of definitive radiotherapy for T1-3N0 prostate cancer. METHODS AND MATERIALS: Survivors of a previously reported cohort of prostate cancer patients treated with staging pelvic lymphadenectomy and definitive radiotherapy between November 1974 and August 1988 were queried using a questionnaire incorporating the RAND 36-Item Health Survey and the University of California, Los Angeles Prostate Cancer Index. Responses were reviewed and analyzed. Of the 146 N0 patients, 88 have survived for 10 years postdiagnosis. Fifty-six (64%) of these patients were still alive with valid addresses and were mailed copies of the questionnaires, of which 46 (82%) responded. Median potential follow-up from date of diagnosis was 13.9 years, with a median age of responders of 80 years. RESULTS: The mean sexual function score was 15.4, with a bother score of 42. The mean urinary function score was 65, with a bother score of 61. The mean bowel function score was 72.6, with a bother score of 64.8. The amount of patient bother reported in the sexual category is similar to that previously reported for cohorts of prostate cancer patients undergoing radiotherapy or observation. This is despite the fact that sexual function was similar to that previously reported for patients postprostatectomy. Patient-reported function and bother scores in urinary and bowel categories were somewhat more severe than a previously reported radiotherapy cohort with shorter follow-up. CONCLUSIONS: With long follow-up, most patients who underwent radiotherapy for prostate cancer in the era described exhibit somewhat worse bladder, bowel, and erectile function than recently published controls without prostate cancer. In this cohort of older men with long follow-up, erectile function is similar to reported prostatectomy series. However, patient bother related to erectile function is similar to that of controls in earlier published radiotherapy series. Worse urinary and bowel function may be due to progressive symptoms with aging and longer follow-up, or to the radiotherapy techniques performed during the era in question.

Grading inaccuracies in diagnostic biopsies revealing prostatic adenocarcinoma: implications for definitive radiation therapy.

PURPOSE: A critical determinant of prognosis in prostate cancer is grade of disease. Historically, this has been determined by biopsy of the prostate using transperineal, transrectal, or transurethral approaches. Several reports in the literature reveal that these biopsies often underestimate the histologic grade of the tumor when compared with subsequent radical prostatectomy specimens. METHODS AND MATERIALS: Data from the literature were analyzed to assess the magnitude of this bias towards undergrading. Grade of biopsy specimens (well-differentiated = Gleason score 2-4; moderately differentiated = Gleason 5-7; poorly differentiated = Gleason 8-10) were correlated with the ultimate prostatectomy grade. Analysis was made of tendency to undergrade specimens using strict criteria of data inclusion for needle biopsies, and more relaxed criteria for all types of prostate biopsies. RESULTS: Grading accuracy from needle biopsies was 71%, with 23% undergraded and 6% overgraded. A chi-square test on equal chance of under- vs. overgrading yielded p = 0.022. Grading accuracy from needle, open perineal, and transurethral biopsies was 65%, with 23% undergraded and 12% overgraded. A similar chi-square test yielded p = 0.007. In both cases, there appears to exist a significant bias towards undergrading. CONCLUSIONS: In addition to other well-documented factors that confound comparisons between radiation therapy and surgical series in carcinoma of the prostate, grade migration exists as well. The equivalence of radiation therapy and surgery with respect to overall survival in this disease is accomplished despite these biases.

Acupuncture for pilocarpine-resistant xerostomia following radiotherapy for head and neck malignancies.

OBJECTIVE: Xerostomia is a frequent and potentially debilitating toxicity of radiotherapy (XRT) for cancers of the head and neck. This report describes the use of acupuncture as palliation for such patients. METHODS AND MATERIALS: Eighteen patients with xerostomia refractory to pilocarpine therapy after XRT for head and neck malignancy were offered acupuncture as palliation. All patients are without evidence of cancer recurrence at the primary site. Acupuncture was provided to three auricular points and one digital point bilaterally, with electrostimulation used variably. The Xerostomia Inventory (XI) was administered retrospectively to provide an objective measure of efficacy. RESULTS: Acupuncture contributed to relief from xerostomia to varying degrees. Palliative effect as measured by the XI varied from nil to robust (pre- minus post- therapy values of over 20 points). Nine patients had benefit of over 10 points on the XI. CONCLUSIONS: Acupuncture reduces xerostomia in some patients who are otherwise refractory to best current management.

Effects of intraoperative radiotherapy on vascular grafts in a canine model.

PURPOSE: The effects of intraoperative radiotherapy +/- external beam radiotherapy on prosthetic vascular grafts were investigated in a canine model. METHODS AND MATERIALS: In 1986 and 1987, 30 adult beagles underwent laparotomy with transection and segmental resection of the infrarenal aorta followed by immediate reconstruction with a prosthetic graft. Intraoperative radiotherapy at varying doses from 0-30 Gy was then administered to all animals. Half of the dogs received 36 Gy external beam radiotherapy in 10 fractions postoperatively. Animals were sacrificed and necropsied at predetermined intervals and as clinically indicated to assess early (< or = 6 months) and late (> 6 months) effects to the vascular graft and surrounding normal tissue. RESULTS: Histopathologic analyses of irradiated vascular structures were performed and correlations were made with the clinical outcome. The most frequent early clinical toxicity was graft thrombosis, occurring in 7 of 10 animals followed for < or = 6 months. Early graft thrombus formation appeared unrelated to radiotherapy dose and probably represented a technical surgical complication. Anastomotic stenosis of varying severity occurred in most animals followed > 6 months. Late (> 6 months) graft stenosis was correlated with intraoperative radiotherapy dose. At < or = 20 Gy of intraoperative irradiation, 3 of 14 animals developed late graft occlusion; at > 25 Gy, five of six animals developed late occlusion. On histopathologic review, increasing intraoperative dose and increasing total radiotherapy dose (intraoperative+external beam) appeared to correspond with increasing severity of graft changes seen after 6 months of follow-up. CONCLUSIONS: Thrombus formation is a frequent early complication of vascular graft placement of the infrarenal aorta in our beagle dog model. Intraoperative doses up to 20 Gy appear to contribute minimally to late graft occlusion, while doses > or = 25 Gy contribute to late occlusion with high likelihood. Both intraoperative dose and total radiotherapy dose correlated with late graft occlusion, and with histopathologic changes in the graft and anastomoses.

Sarcomas of the hand and foot: analysis of local control and functional result with combined modality therapy in extremity preservation.

PURPOSE: The records of 28 patients with sarcomas of the hand and foot treated at the National Cancer Institute (NCI) between 1977 and 1992 were reviewed to assess local control and functional results. METHODS AND MATERIALS: Histologic types included 15 cases of the Ewing's sarcoma family of tumors, 7 cases of alveolar rhabdomyosarcoma, and 6 cases of nonrhabdomyosarcoma soft tissue sarcomas. Median age of all patients was 18 years (range 4-61), with a median potential follow-up of 114 months following diagnosis. Surgery varied from incisional biopsies for Ewing's Sarcoma and rhabdomyosarcoma lesions to complete excision when possible for nonrhabdomyosarcoma soft tissue sarcoma lesions. Amputation was not primarily performed, except in two patients who underwent ray resections of hand lesions (patients 13 and 24). Radiotherapy generally consisted of 50 Gy/25 fractions (fx)/5 weeks for Ewing's Sarcoma, 54 Gy/30 fx/6 weeks for rhabdomyosarcoma, and 63 Gy/35 fx/7 weeks for nonrhabdomyosarcoma soft tissue sarcomas. Chemotherapy was administered on various NCI protocols. RESULTS: Actuarial local control for Ewing's Sarcoma was 84% at 5 and 10 years. All but one survivor are capable of hand/foot function for routine activities without orthotic requirements. Five of six patients (83%) who died of metastatic disease had functional distal extremities. Actuarial local control for rhabdomyosarcomas was 100%, with equivalent function. No patient developed a second malignancy in the treatment field. CONCLUSIONS: Although equivalent local control may be achieved in these lesions with either amputation or radiotherapy, a prudent management course would be to defer amputation for management of local recurrences. Many patients with these lesions fail in distant sites only and die without local failure. For these patients and for those who remain long-term survivors, we believe a functional hand and foot provides a better quality of life than a prosthesis.

Primary soft tissue sarcomas of the breast: local-regional control with post-operative radiotherapy.

PURPOSE: A retrospective analysis was undertaken to determine the efficacy of postoperative radiotherapy in patients with primary sarcoma of the breast. METHODS AND MATERIALS: Ten patients with high-grade nonmetastatic primary sarcoma of the breast were treated at the National Cancer Institute, NIH, between 1979 and 1989 with mastectomy and adjuvant radiotherapy. Chemotherapy was given to three patients as part of a randomized trial. RESULTS: With a median potential followup of 99 months postoperatively, seven patients remain alive and without evidence of disease 142, 119, 82, 48, 45, 28, and 19 months postoperatively. Three patients died of metastatic disease 7, 25, and 29 months, postoperatively. There were no local or regional failures. Actuarial 5-year disease free and overall survival were 68% and 66%, respectively. CONCLUSION: Sarcomas of the breast have a prognosis similar to that of extremity sarcomas. When adjuvant radiotherapy is used, excellent local control may be achieved.

Tumors in dogs exposed to experimental intraoperative radiotherapy.

PURPOSE: The frequency of radiation-induced neoplasms was determined in dogs enrolled in the National Cancer Institute canine trials of intraoperative radiotherapy (IORT). METHODS AND MATERIALS: Twelve protocols assessing normal tissue response to IORT involved 238 dogs in a 15-year trial. Eighty-one dogs were followed for > 24 months postoperatively and were assessed for tumor development; 59 of these animals received IORT. RESULTS: Twelve tumors occurred in the 59 dogs receiving IORT. Nine were in the IORT portals and were considered to be radiation induced. No tumors occurred in 13 sham animals or in 9 animals treated with external beam radiotherapy alone. The frequency of radiation-induced malignancies in dogs receiving IORT was 15%, and was 25% in animals receiving > or = 25 Gy IORT. Frequency of all tumors, including spontaneous lesions, was 20%. CONCLUSIONS: Intraoperative radiotherapy contributed to a high frequency of sarcoma induction in these dogs. Unknown to date in humans involved in clinical trials of IORT, this potential complication should be looked for as long-term survivors are followed.

Tolerance of the bladder to intraoperative radiation in a canine model: a five-year follow-up.

PURPOSE: Late effects of intraoperative radiation therapy (IORT) on bladder were investigated in a canine model. METHODS AND MATERIALS: After laporatomy and cystotomy in adult female foxhounds weighing 25-35 kg, 12 MeV electrons were delivered intraoperatively to a 5 cm circular bladder field which included the trigone and both uretero-vesicle junctions. Each animal received doses of 0, 20, 25, 30, 35, or 40 Gy. All the dogs were followed 5 years postoperatively. An unoperated dog receiving no surgery or radiation treatment was followed as a control. Close clinical monitoring was performed with regular cystometrics and intravenous pyelography. Animals were killed as scheduled with complete necropsies, including histopathology, with special attention to genitourinary structures. RESULTS: There were no acute or late bladder complications detected clinically in any animal. The dog receiving 30 Gy IORT developed rhabdomyosarcoma in the treatment field at 58 months. On follow-up testing over 5 years, there was no loss of bladder contractility on cystometry, and mild changes in the ureters on intravenous pyleography when animals receiving IORT were compared with baseline pretreatment values or with control animals. Histologically, a difference was evident between irradiated and unirradiated animals, but the changes were not clearly dose-related. CONCLUSION: Intraoperative radiation therapy may by safely delivered to the canine bladder with few acute or chronic complications. It is an approach which has potential for clinical use and should continue to be explored in human clinical trials.

Clinical toxicity of peripheral nerve to intraoperative radiotherapy in a canine model.

PURPOSE: The clinical late effects of intraoperative radiotherapy (IORT) on peripheral nerve were investigated in a foxhound model. METHODS AND MATERIALS: Between 1982 and 1987, 40 animals underwent laparotomy with intraoperative radiotherapy of doses from 0-75 Gy administered to the right lumbosacral plexus. Subsequently, all animals were monitored closely and sacrificed to assess clinical effects to peripheral nerve. This analysis reports final clinical results of all animals, with follow-up to 5 years. RESULTS: All animals treated with > or = 25 Gy developed ipsilateral neuropathy. An inverse relationship was noted between intraoperative radiotherapy dose and time to neuropathy, with an effective dose for 50% paralysis (ED50) of 17.2 Gy. One of the animals treated with 15 Gy IORT developed paralysis, after a much longer latency than the other animals. CONCLUSIONS: Doses of 15 Gy delivered intraoperatively may be accompanied by peripheral neuropathy with long-term follow-up. This threshold is less than that reported with shorter follow-up. The value of ED50 determined here is in keeping with data from other animal trials, and from clinical trials in humans.

Late effects of intraoperative radiation therapy on retroperitoneal tissues, intestine, and bile duct in a large animal model.

PURPOSE: The late histopathological effects of intraoperative radiotherapy (IORT) on retroperitoneal tissues, intestine, and bile duct were investigated in dogs. METHODS AND MATERIALS: Fourteen adult foxhounds were subjected to laparotomy and varying doses (0-45 Gy) of IORT (11 MeV electrons) delivered to retroperitoneal tissues including the great vessels and ureters, to a loop of defunctionalized small bowel, or to the extrahepatic bile duct. One control animal received an aortic transection and reanastomosis at the time of laparotomy; another control received laparotomy alone. This paper describes the late effects of single-fraction IORT occurring 3-5 years following treatment. RESULTS AND CONCLUSION: Dogs receiving IORT to the retroperitoneum through a 4 x 15 cm portal showed few gross or histologic abnormalities at 20 Gy. At doses ranging from 30-45 Gy, radiation changes in normal tissues were consistently observed. Retroperitoneal fibrosis with encasement of the ureters and great vessels developed at doses > or = 30 Gy. Radiation changes were present in the aorta and vena cava at doses > or = 40 Gy. A 30 Gy dog developed an in-field malignant osteosarcoma at 3 years which invaded the vertebral column and compressed the spinal cord. A 40 Gy animal developed obstruction of the right ureter with fatal septic hydronephrosis at 4 years. Animals receiving IORT through a 5 cm IORT portal to an upper abdominal field which included a defunctionalized loop of small bowel, showed a few gross or histologic abnormalities at a dose of 20 Gy. At 30 Gy, hyaline degeneration of the intestinal muscularis layer of the bowel occurred. At a dose of 45 Gy, internal intestinal fistulae developed. One 30 Gy animal developed right ureteral obstruction and hydronephrosis at 5 years. A dog receiving 30 Gy IORT through a 5 cm portal to the extrahepatic bile duct showed diffuse fibrosis through the gastroduodenal ligament. These canine studies contribute to the area of late tissue tolerance to IORT.

Beam flatness perturbation effects of a perforated thermoplastic immobilization device on 6 and 12 MeV electron beams.

PURPOSE: Perforated thermoplastic masks are widely used in radiotherapy of head and neck malignancies. They provide for patient immobilization and increase setup reproducibility. Some oncology treatment centers cut mask portals (windows) for the beam to pass through; for those centers that do not, the mask affects beam fluence. The extent to which beam flatness is altered by such a mask is investigated. MATERIALS AND METHODS: The effects of perforated thermoplastic on 6 MeV and 12 MeV electron beams was described in terms of optical density differences in a comparative film study. RESULTS: Variations of beam flatness were documented of up to 11.8% at 5 mm depth for 6 MeV, and 8.1% for 12 MeV electrons. The depth at which this effect may be considered insignificant (mean optical density differences < 2%) is approximately 10 mm for both beam energies. CONCLUSIONS: For clinical situations where the target volume is superficial, some consideration should be given to beam inhomogeneity caused by the mask.

Lymph node involvement and pancreatic resection: correlation with prognosis and local disease control in a clinical trial.

In a prospectively randomized trial evaluating pancreatic resection with adjuvant radiotherapy (intraoperative radiotherapy [IORT] vs. external beam radiotherapy [EBRT]), lymph nodal involvement was examined and correlated with outcome. Twenty-six patients underwent pancreatic resection and received either IORT or EBRT (Stages II-IV). Patients who were stage I received surgery alone. Regional nodal metastases were present in 15 of 26 (57%) patients. Seven patients suffered treatment-related mortality. Survival, mortality, and morbidity were unaffected by the type of radiotherapy. The survival of patients with negative nodes (median survival 24 months, range 10 to > 109) appeared superior to the survival of patients with nodal involvement (median survival 11.5 months; range 4-39). Even in patients with locally advanced disease extending into extrapancreatic tissues, two node-negative patients appeared to survive longer (12 and 53 months) than 10 node-positive patients with similarly extensive local disease (median survival 11.5 months; range 4-39). Local disease control, however, appeared to be independent of nodal involvement, with eventual local recurrences in 6 of 8 node-negative patients and in 4 of 7 node-positive patients who were evaluable for local disease control by autopsy or by antemortem laparotomy.

Yield of imaging and scintigraphy assessing biochemical failure in prostate cancer patients.

A retrospective study was undertaken to determine the diagnostic yield of computed tomography (CT) and bone scan in patients with biochemical failure after definitive therapy for prostate cancer. The records of the Radiation Oncology Division were screened for patients presenting with prostate cancer between January 1, 1993, and December 31, 1996. Of 198 patients, 44 developed biochemical failure postoperatively (n = 24) or postradiotherapy (n = 20), and were not treated with hormones prior to restaging. Review was made of restaging studies performed at the time of biochemical failure. Postoperatively, 5% (1 of 20) of bone scans and 11% (2 of 18) of CT scans were positive. Postradiotherapy, 30% (6 of 20) of bone scans and 30% (3 of 10) of CT scans were positive. Our study showed that imaging studies are of low utility in the evaluation of patients with biochemical failure after definitive therapy of prostate cancer given that most patients begin hormonal therapy irrespective of the results of restaging studies. If salvage therapy is considered, imaging results may have a role in the decision-making process.