Biomedical subjects

R R Allison

Publications and source records attributed to R R Allison.

7 recordsLinked to original sources

PubMed2000

Multimodality salvage for patients with persistently elevated postprostatectomy PSA.

A persistently elevated postprostatectomy prostate-specific antigen (PSA) is a therapeutic dilemma for which optimal management is undefined. We evaluated the salvage efficacy of whole-pelvis radiation with hormonal blockade in a subset of patients with persistently elevated postprostatectomy PSA. Within 180 days after surgery, 14 men with elevated postprostatectomy PSA (0.9-18 ng/ml; mean 4.8) and negative metastatic work-up began whole-pelvis radiation (4500 cGy / 25 fractions), which was directly followed by prostate-bed boost (2000 cGy / 10 fractions). Concomitant with radiation, 6 months of LHRH agonist was prescribed. No patients have been lost to follow-up. Chronic morbidity from radiation and hormone treatment was not noted and all 10 patients whose salvage was initiated when PSA was <5.0 ng/ml remain with undetectable PSA at follow-up (36-56 months; median 44 months). Of the four patients with PSA levels >5.0 ng/ml at salvage initiation, none remain with undetectable follow-up PSA. Postprostatectomy salvage initiated at PSA levels < or =5.0 ng/ml with the combination of whole-pelvis external-beam radiation and hormone blockade offers excellent diminishment of PSA for prolonged follow-up periods. Patients with postprostatectomy PSA of >5 ng/ml likely require salvage regimens with greater emphasis on systemic treatment. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 331-335 (2000).

Aged↗

PubMed1999

Stereotactic neurosurgical biopsy is an underutilized modality.

The objective of this study was to ascertain if stereotactic neurosurgical biopsy (SNB) optimizes the therapy of undefined CNS masses. The design was of retrospective treatment and outcome analysis and the setting was a large general hospital. We studied a total of 141 patients with undefined, space-occupying CNS lesions detected between 1991-1997, with whom we used SNB to define the lesions. We sought to correlate empiric and histological diagnostics and their impact on medical management. The stereotactic biopsy produced a diagnostic yield for each patient. Management was altered in 57 cases (40%) due to histology and, of these, malignancy was found in 39. Morbidity was ten asymptomatic hemorrhages on post-biopsy CT scans and two cases of clinical deterioration. Our conclusions were that SNB produces high yield with low morbidity. In the community setting, a wide variety of diagnoses can be made with improvements in medical management. SNB should be employed to guide therapy of CNS lesions where complete excision is not possible or when diagnostic questions arise.

Adolescent↗

PubMed1998

Photodynamic therapy for the treatment of nonmelanomatous cutaneous malignancies.

Photodynamic therapy (PDT) is a modality whose concept is not new to dermatologists. PDT has gained regulatory approval in the United States for the treatment of esophageal and lung malignancies. The field has grown over the last decade, and now phase II/III clinical trials using second generation drugs for the treatment of nonmelanoma skin cancers, palliation of metastases to the skin, and Kaposi's sarcomas have been introduced. These new sensitizers tend to reduce the one side effect of PDT, namely persistent generalized cutaneous photosensitivity. PDT has shown efficacy in (1) patients who have failed conventional therapies, and for whom local treatment options are limited (2) patients in whom surgery would result in cosmetic disfigurement, and (3) patients prone to developing multiple lesions as in Gorlins syndrome. Dosimetry is based on well-understood treatment matrices that have optimized light delivery with known photosensitizer administrations. The advantages of PDT for cutaneous malignancies include the ability to treat numerous lesions in one setting, in a noninvasive manner without any apparent concern for the development of carcinogenicity.

Bowen's Disease↗

PubMed1997

If you 'watch and wait,' prostate cancer may progress dramatically.

PURPOSE: Observation has been proposed as an option for localized prostate cancer. However, most series reporting on 'watch and wait' include patients treated by TUR or hormones that may affect results. We retrospectively reviewed the natural history of truly untreated prostate cancer and report the outcome for these patients. METHODS AND MATERIALS: From 1976 to 1992, 34 patients of median age 70 years (range 56-88) with biopsy proven localized adenocarcinoma of the prostate refused therapy. All had negative bone scan and none underwent TUR or hormone treatment. No patient was lost to follow-up (median 76 months). Failure patterns and survival were analyzed. RESULTS: At diagnosis 27 patients had palpable nodules (T2), of which 13 were well differentiated and 14 moderately differentiated. Seven had moderately differentiated T3 lesions. Mild prostatitis including nocturia, hesistancy, and urgency were reported in 16 T2 and 6 T3 patients. Within 36 months, local progression requiring therapy occurred in all T3, all T2 moderate and 5 of 13 T2 well-differentiated patients. Systemic progression occurred in 6 of 7 T3, 9 of 14 T2 (mod), and 2 of 13 T2 (well) patients. Overall 59% are alive, 26% succumbed to prostate carcinoma and 15% to other causes. CONCLUSION: Observation results in a high rate of local progression requiring intervention (77%) and excessive systemic disease development (50%) for patients with clinically palpable disease. Perhaps this strategy is viable for earlier stage lesions detected by PSA but it must be tested in a rigorous fashion before accepted.

Adenocarcinoma↗

PubMed1997

Radiation and chemotherapy improve outcome in oligodendroglioma.

PURPOSE: Oligodendroglioma is a rare central nervous system tumor which may occur in pure or mixed histology. This scarcity results in difficulty in defining optimal management, mainly due to a lack of outcome analysis. Results are further complicated because the reported series include patients treated before megavoltage radiation or computed tomographic (CT) scan development. This makes extrapolation of outcome difficult to apply to modern-era patients. We report results obtained by current treatment and evaluation. METHODS AND MATERIALS: Outcome of all 38 patients (age 5-70 years) pathologically diagnosed between 1975 and 1993 were reviewed. Pure lesions were seen in 14 cases, of which three were anaplastic. The remainder had mixed tumors, of which six contained anaplastic astrocytic elements. Each patient had undergone maximal debulking surgery, but all remained with residual disease on postoperative CT. RESULTS: For nonanaplastic lesions, no local failure was seen in any patient receiving postoperative radiation (60 Gy) and chemotherapy (vincristine, procarbazine, and carmustine). Follow-up ranged from 28 to 240 months (median 125; N = 6). No postoperative therapy or chemotherapy alone resulted in local failure in all nine patients at risk [time to failure (TTF): 2-40 months; median 25]. Radiation alone in doses of 50 Gy at 2 Gy per day resulted in all six patients failing (TTF: 12-52 months; median 36). Achieving 60 Gy at 2 Gy a day allowed five of eight patients to remain disease free (disease-free survival: 24-160 months; median 66), with three failing at 26, 40, and 60 months. All lesions containing anaplastic elements underwent postoperative radiation therapy (60 Gy) and chemotherapy, with five of nine patients alive and well (median disease-free survival: 48 months; range 28-120). CONCLUSION: The combination of radiation and chemotherapy increases local control of oligodendroglioma whether they contain pure, mixed, or anaplastic histology. Radiation alone may offer good local control as long as 60 Gy is delivered. Chemotherapy alone appears to delay TTF and may be useful for pediatric patients.

Adolescent↗

PubMed1995

Symptomatic acute mucositis can be minimized or prophylaxed by the combination of sucralfate and fluconazole.

Mucositis is a common and often serious acute morbidity when radiation is delivered to portals encompassing the oral cavity, pharynx, or esophagus. In an effort to minimize this side effect, the combination of sucralfate and fluconazole was prescribed to 40 patients. Half were given sucralfate, 1 g in suspension q.i.d. from the first week to the completion of radiation with fluconazole 100 mg., q.d. for 14 days initiated during the fourth week. The remaining individuals were placed on the same dosages of the two drugs dispensed simultaneously after symptoms appeared. For both cohorts the combination of sucralfate and fluconazole was effective in diminishing oral discomfort and pain associated with radiation and chemotherapy. When medication was delivered from the first week of therapy, all patients could achieve the prescribed radiation dose without treatment interruption and be maintained on a regular diet. The combination of drugs was also effective in minimizing symptoms once they appeared.

Drug Therapy, Combination↗

PubMed1993

Response of primary colon cancer cells in hybrid spheroids to 5-fluorouracil.

We have measured the clonogenic survival of cells isolated directly from colon cancer surgical specimens and treated with 5-fluorouracil (5-FU). Enzymatically disassociated cells were incorporated into hybrid spheroids, consisting predominantly of nonproliferating HeLa feeder cells. Aliquots were exposed for 1.5 hr to a range of concentrations of 5-FU. From the decrease in clonogenic survival, as deduced from the frequency of colony formers among hybrid spheroids after chemical treatment, we were able to construct survival curves in 50% of the surgical specimens tested. A striking revelation was the presence of a resistant plateau in the survival curves, reminiscent of the solid tumor response to treatment with 5-FU. This resistance was absent in monolayer cultures. Evidence is presented that this resistance is due to the absence of, or delay in, cell cycle progression of cells residing in hybrid spheroids.

Cell Survival↗