Renal injury management in an urban trauma centre and implications for urological training.

INTRODUCTION: The aim of this study was to analyse the treatment and management of renal injury patients presenting to our major trauma unit to determine the likelihood of patients needing immediate nephrectomy. METHODS: The Trauma Audit and Research Network (TARN) database was used to review trauma cases presenting to our department between February 2009 and September 2013. Demographic data, mechanism and severity of injury, grade of renal trauma, management and 30-day outcome were determined from TARN data, electronic patient records and imaging. RESULTS: There were a total of 1,856 trauma cases, of which 36 patients (1.9%) had a renal injury. In this group, the median age was 28 years (range: 16-92 years), with 28 patients (78%) having blunt renal trauma and 8 (22%) penetrating renal trauma. The most common cause for blunt renal trauma was road traffic accidents. Renal trauma cases were stratified into American Association for the Surgery of Trauma (AAST) grades (grade I: 19%, grade II: 22%, grade III: 28%, grade IV: 28%, grade V: 0%). All patients with grade I and II injuries were treated conservatively. There were three patients (1 with grade III and 2 with grade IV renal injuries) who underwent radiological embolisation. One of these patients went on to have a delayed nephrectomy owing to unsuccessful embolisation. CONCLUSIONS: Trauma patients rarely require emergency nephrectomy. Radiological selective embolisation provides a good interventional option in cases of active bleeding from renal injury in haemodynamically stable patients. This has implications for trauma care and how surgical cover is provided for the rare event of nephrectomy.

Synthesis, DNA cleavage, and cytotoxicity of a series of bis(propargylic) sulfone crown ethers.

Compounds that couple molecular recognition of specific alkali metal ions with DNA damage may display selective cleavage of DNA under conditions of elevated alkali metal ion levels reported to exist in certain cancer cells. We have prepared a homologous series of compounds in which a DNA reactive moiety, a bis(propargylic) sulfone, is incorporated into an alkali metal ion binding crown ether ring. Using the alkali metal ion pricrate extraction assay, the ability of these crown ethers to bind Li(+), Na(+), and K(+) ions was determined. For the series of crown ethers, the association constants for Li(+) ions are generally low (< 2 x 10(4)M(-1)). Only two of the bis(propargylic) sulfone crown ethers associate with Na(+) or K(+) ions (K(a) 4-8 x 10(4)M(-1)), with little discrimination between Na(+) or K(+) ions. The ability of these compounds to cleave supercoiled DNA at pH 7.4 in the presence of Li(+), Na(+), and K(+) ions was determined. The two crown ethers that bind Na(+) and K(+) display a modest increase in DNA cleavage efficiency in the presence of Na(+) or K(+) ions as compared to Li(+) ions. These two bis(propargylic) sulfone crown ethers are also more cytotoxic against a panel of human cancer cell lines when compared to a non-crown ether macrocyclic bis(propargylic) sulfone.

Soft tissue sarcoma of the hand.

A retrospective review of our institute's tumor registry from January 1972 to January 1996 revealed 24 patients with a diagnosis of primary soft tissue sarcoma of the hand, from a total of 570 extremity soft tissue sarcomas (4%). The most frequent histologic type was malignant fibrous histiocytoma, which occurred in 9 (38%) of the 24 patients. The second most common histologic type was epithelioid sarcoma, which occurred in 6 (25%) patients. There was a statistically significant difference in the rate of local recurrence based on the type of treatment in which amputation was superior to the other forms of treatment. There was no statistically significant difference in the rate of distant failures between treatment groups. The estimated cumulative 5- and 10-year overall survival rates for all patients were 59% and 53%, respectively. Stage II patients had estimated cumulative 5- and 10-year survival rates of 68% and 59%, respectively. Stage III patients had a cumulative 5-year survival rate of 20%. Factors that were statistically significant in predicting survival were the size of the primary tumor, with tumors smaller than 5 cm having a better prognosis, and stage of the tumor at presentation, with stage I and II tumors having the highest survival rate. In selected patients with a primary hand sarcoma, aggressive limb-sparing surgery with adjuvant therapy offered equivalent survival compared with amputation.

Sarcoma of the breast: implications of the extent of local therapy.

Although the majority of breast neoplasms will be of epithelial origin, tumors of the stromal elements of the breast may occur. A retrospective review of the medical records and tumor registry data of 25 patients with breast sarcoma treated at Roswell Park Cancer Institute from 1964 to 1995 was performed. There were 24 females and 1 male, with a median age of 55 years. Delay in seeking medical attention was common. Angiosarcoma was the most common histologic type of breast sarcoma (n = 10). Mastectomy was the predominant form of local therapy (21 patients). Overall survival was 61 per cent at 5 years and 36 per cent at 10 years. There was no difference in survival or local control rates for those patients treated with local excision when compared with patients treated with mastectomy. Sarcoma is an unusual form of breast tumor. Survival and local control are similar when comparing local excision and mastectomy. When local excision is performed, attention must be directed to achieving clear margins of resection. The benefit of adjuvant therapy remains undefined.

Use of the exercise treadmill to measure baseline functional status and surgical outcome in patients with severe lumbar spinal stenosis.

STUDY DESIGN: A prospective study of exercise tolerance on the treadmill before and after decompressive laminectomy in patients with severe lumbar spinal stenosis. OBJECTIVES: To determine whether treadmill testing provides useful information about baseline functional status and surgical outcome. SUMMARY OF BACKGROUND DATA: Historically, criteria for selecting patients for surgery and assessing postoperative outcome have been variable. Functional testing has not been used in a systematic fashion. METHODS: Fifty patients with severe lumbar spinal stenosis underwent decompressive laminectomy. Preoperatively and 3 months postoperatively, functional capacity was assessed on an exercise treadmill. Time to first symptoms and total ambulation time were recorded. The examination was stopped at the onset of severe symptoms or after 15 minutes. RESULTS: In the preoperative trial, mean time to first symptoms (+/- standard deviation) was 1.82 minutes (median, 0.58), and mean total ambulation time was 6.91 minutes (median, 5.22). In the postoperative trial, mean time to first symptoms increased to 11.93 minutes (median, 15) and mean total ambulation time increased to 13.26 minutes (median, 15). There was significant improvement after surgery in both time to first symptoms (P < 0.001) and total ambulation time (P < 0.001). CONCLUSION: Exercise stress testing on a treadmill is a safe, easily administered, and quantifiable means of assessing baseline functional status and surgical outcome in patients with neurogenic claudication due to lumbar spinal stenosis. Treadmill testing provides objective evidence that surgery is beneficial in most cases and is helpful in guiding subsequent management of patients with residual symptoms.

In vivo light transmission spectra in EMT6/Ed murine tumors and Dunning R3327 rat prostate tumors during photodynamic therapy.

BACKGROUND AND OBJECTIVE: Variations in the optical coefficients in tissue and the photosensitizer during photodynamic therapy (PDT) will require adjustment of the light dose during the course of therapy. We have studied the dynamics using light transmission spectra for two different tumor models when tetrasulfonated aluminum phthalocyanine (AlPcS4) was used as photosensitizer. STUDY DESIGN/MATERIALS AND METHODS: Spectra were measured noninvasively in the EMT6/Ed murine tumor model, and with interstitially implanted source and probe fibers in the Dunning R3327-AT rat tumor model. Measurements were performed in the range 600-840 nm, using a tunable dye laser, a diode laser, and a Ti:Sapphire laser. AlPcS4 has absorption in the range 600-700 nm with an absorption peak at 670 nm in saline. RESULTS: The in vivo spectrum of AlPcS4 both in the EMT6/Ed tumor model and the Dunning R3327-AT tumor model differs from the spectrum of AlPcS4 in saline. The absorption at 670 nm was reduced, whereas the absorption at 640 nm increased. Exposure of phototherapeutic levels of light caused reduced light absorption by the photosensitizer and further spectral shift. CONCLUSION: We found that the AIPcS4 absorption spectrum changes in a biological environment, and we also observed increased light transmission at the treatment wavelength during PDT in both tumor models. Instability in the absorption spectrum of the photosensitizer may influence the effectiveness of PDT.

Hypocrellins as photosensitizers for photodynamic therapy: a screening evaluation and pharmacokinetic study.

Hypocrellin compounds were selected as potential photosensitizers for photodynamic therapy (PDT) owing to their high quantum yields of singlet oxygen (1O2), and facility for site-directed chemical modification to enhance phototoxicity, pharmacokinetics, solubility, and light absorption in the red spectral region, among other properties. Parent hypocrellins A and B share an absorption peak at 658 nm. These molecules may therefore be considered useful progenitors of derivatives which absorb more strongly in the red, considering that the ideal sensitizer should absorb in the 650-800 nm range, beyond the absorption range of hemoglobin and melanin, and where light penetration in tissues is maximized through reduced scattering. A series of pure, monomeric hypocrellin derivatives was tested for properties of dark cytotoxicity and photosensitizing potential by clonogenic assay in monolayer cultures of EMT6/Ed murine tumor cells. Their respective toxicities are reported on a molar basis. The in vitro screening assay has, to date, resulted in the selection of four hypocrellin derivatives for further development as photosensitizers for PDT. Cellular uptake for photosensitizing doses of selected compounds was determined by fluorimetry. Dose escalation studies in rodents indicate that potentially photosensitizing doses promote no demonstrable systemic toxicity.

Anisotropy of radiance in tissue phantoms and Dunning R3327 rat tumors: radiance measurements with flat cleaved fiber probes.

BACKGROUND AND OBJECTIVE: The goal of this study is to determine if flat cleaved fiber probes are appropriate for interstitial measurements of radiance in tissue. Flat cleaved probes have the advantage of high responsivity, and they are easy to insert into tissue. Owing to the non-isotropic response of flat cleaved probes, a calibration function is required, taking the anisotropy in the radiance in tissue into account. STUDY DESIGN, MATERIALS AND METHODS: The method used to determine this function consists of radiance measurements in tissue, performed with a flat cleaved fiber probe mounted on a stereotactic stage for insertion into the tissue from different directions. Interstitial irradiation at 630 nm was delivered by a spherical source. RESULTS: We found that the degree of anisotropy in the radiance decreases with increasing distance from the interstitially implanted source in two different tissue phantoms and in the Dunning R3327-AT and R3327-H rat tumor models. CONCLUSION: A position-dependent calibration function is required for interstitially implanted flat cleaved fiber probes. An anisotropy function is presented, which modifies the measurements of radiance with a flat cleaved probe, to account for the change in anisotropy in the radiance. The anisotropy functions for the two tumor models differ substantially.

Photosensitization by anticancer agents 21: new perylene- and aminonaphthoquinones.

Hypocrellins are under intensive investigation as photosensitizing agents for photodynamic therapy (PDT). A recent advance in the synthesis of hypocrellin congeners resulted in the production of an amino-substituted hypocrellin-B, and its "half chromophore." Both compounds exhibit stronger red light absorption than previously reported hypocrellins, and, therefore, merit investigation as photosensitizers.

Stereotaxic needle core biopsy of breast lesions using a regular mammographic table with an adaptable stereotaxic device.

OBJECTIVE: Fine-needle aspiration and stereotaxic needle core biopsy (SNCB) are techniques used in the workup of breast lesions suggestive of cancer. Many surgeons are reluctant to rely on fine needle results, and until now, SNCB could be done only with a dedicated biopsy table. Our study was done to determine whether SNCB could be performed safely and effectively with a regular mammography unit and an added stereotaxic device. SUBJECTS AND METHODS: SNCB was performed on 254 patients by using a Siemens Mammomat 2 regular mammography table with an added stereotaxic device. Patients were referred from a breast screening center, a local tertiary care center, and from our own center. Patients who had unequivocal histopathologic evidence of a benign process (133 of 254 patients) did not undergo surgical biopsy and are being followed up mammographically. The remainder (121 patients) all had surgical biopsies. RESULTS: Sufficient material for histologic analysis was obtained in 249 (98%) of 254 cases. In 31 of 254 cases, sampling was problematic. This group comprised cases in which the patient moved within the compression device, the mammographic and histologic diagnoses were discordant, or calcifications were not present in the core sample when the indication for SNCB was the presence of microcalcifications. This group all had open biopsies. In 25 of 254 cases, the pathologic findings were suggestive of cancer. Cancer was detected in 11 of these cases on open biopsy. Of the 14 benign cases, 11 showed atypical features or ductal hyperplasia on open biopsy. Malignant tumor was diagnosed in 60 of 254 cases by SNCB. Corresponding malignant tumor was seen in 59 of 60 of the open biopsy specimens. CONCLUSION: The SNCB technique is not limited to use on a dedicated biopsy table but can be readily adapted to a regular mammography unit. It is a safe, reliable and cost-effective procedure that often spares the patient a surgical procedure.

Treatment of advanced ovarian carcinoma in the elderly.

This study retrospectively analyzes the treatment of advanced ovarian cancer (Stages III and IV) in elderly patients (> or = 65) compared to that in younger patients (< 65). The purpose of this study was to identify possible treatment bias toward the elderly and to statistically analyze the nature of these differences. Seventy patients were evaluated of which 29 were identified as elderly and 41 as young. All patients were treated with platinum-based chemotherapy. Chi 2, log rank, Kaplan-Meier, and Cox model analyses were performed for multiple variables including age, grade of tumor, adequacy of surgery, and dose intensity. The elderly significantly differed from the young in the following analyses: median length of hospitalization, 20 days vs 11 days (P < 0.001); optimum surgery, 79.3% vs 97.5% (P = 0.02); initial chemotherapeutic dose reduction, 15.4% vs 0% (P = 0.02); median survival compared to age, 19.2 months vs 36.7 months (P < 0.03). When survival analysis was performed comparing 17 elderly patients and 40 younger patients who had optimum surgery and optimum initial chemotherapy, the median survival remained essentially unchanged, 22.0 months vs 36.7 months. There were differences in treatment intensity between young and old, however, the indications generally were valid and when analyzed by the Kaplan-Meier and Cox model, these differences became insignificant. It was concluded that when elderly patients can undergo aggressive surgical and chemotherapeutic management, survival remained significantly decreased for aged compared to younger patients. Physician bias was not a major factor accounting for the poorer survival observed in elderly patients. Age was the most significant variable related to survival and could not be accounted for by differences in adequacy of surgery or dose intensity.

Measurement of PDT-induced hypoxia in Dunning prostate tumors by iodine-123-iodoazomycin arabinoside.

Photodynamic therapy (PDT) is known to produce vascular damage in solid tumors resulting in secondary ischemia and tumor cell death from hypoxia. The oxygenation status of both non-treated and PDT-treated Dunning R3327-AT prostate tumors growing in Fischer X Copenhagen rats was investigated with the novel hypoxic marker, 123I-iodoazomycin arabinoside (IAZA). Both qualitative and quantitative data from planar scintigraphy of anesthetized tumor-bearing rats showed increased retention of 123I-IAZA in tumors treated with PDT. Tumor perfusion in the same tumors was measured with 99mTc-hexamethylpropyleneamine oxime (HM-PAO). Region of interest analyses revealed an inverse correlation between tumor hypoxia measured by 123I-IAZA and tumor perfusion as measured by 99mTc-HMPAO (coefficient of correlation, r = -0.72). Planar images of 2-mm frozen sections from a large tumor showed 123I-IAZA selectively retained in the region that had been treated with PDT. This and other iodinated azomycin nucleosides, labeled with 123I, show promise for monitoring tumor oxygenation status non-invasively and, in particular, for monitoring the effectiveness of interstitial PDT treatments where perfusion shutdown is a major mechanism of tumor response.

Optical properties of experimental prostate tumors in vivo.

The optical properties of tumor tissue provide important information for optimizing treatment plans in photodynamic therapy, especially when interstitial application by multiple fibers is planned. Near infrared light, required to activate novel photosensitizers, should facilitate improved light penetrance of tumor tissue compared with 630 nm light used for activating Photofrin II. We have measured light energy fluence rates for 630 and 789 nm light along radial tracks from a single laterally diffusing optical fiber centrally implanted into Dunning R3327-AT and R3327-H rat prostate tumors in anesthetized rats. A total of 20 R3327-AT and 10 R3327-H tumors were used in this study with volumes from 2.6 to 13.3 cm3. Light track data were analyzed by an empirical model that described light attenuation. At 630 nm, light attenuation coefficients (LAC) were approximately 1.9 x higher than those at 789 nm for both tumors with the well-differentiated, well-perfused tumor (R3327-H) attenuating to a greater extent than did the rapidly growing anaplastic tumor (R3327-AT). The intertumor variation of LAC was greater than the spatial variations observed within individual tumors. LAC were a function of tumor volume for only 630 nm light in the R3327-AT tumors.

A review of 1486 transurethral resections of the prostate in a teaching hospital.

The authors reviewed retrospectively 1486 consecutive transurethral resections of the prostate (TURP) gland performed in a teaching hospital between 1985 and 1987. The death rate was 0.8% in an institution where senior residents were the primary resectionists in approximately 75% of TURPs. The results of this review are compared with those of a 1974 study of 2223 patients. They indicated that TURP was a reasonably well-tolerated surgical procedure in the training environment and was associated with lower mortality and morbidity and a shorter hospital stay for the patient than in the 1974 study. The authors believe that with proper supervision and instruction, resident urologists can obtain satisfactory results while gaining competence and experience in performing TURPs.

Effect of transurethral resection of the prostate on detrusor instability and urge incontinence in elderly males.

Detrusor instability is common in men with evidence of outflow obstruction due to benign prostatic hypertrophy and typically reverses in about two thirds of patients after transurethral resection of the prostate (TURP). It is also common among the elderly without outflow obstruction and may lead to urge incontinence. To determine whether TURP has an effect on detrusor instability and urge incontinence in elderly men, or whether these abnormalities are due to other age-associated changes, 12 males (mean age 80 years) with urge incontinence or frequency and urgency of micturition, and symptomatic benign prostatic hypertrophy, were studied by 24-hour monitoring of incontinence and videourodynamic examination, before and after TURP; 7/12 patients were significantly cognitively impaired. Preoperatively, all patients showed detrusor instability, which reversed postoperatively in only one patient, a significantly smaller proportion than that consistently reported in younger patients. Preoperatively, 11/12 patients were incontinent. After TURP, 8/11 patients had an improvement in the amount of incontinence, by up to 458 g in 24 hours. Those who improved had been urodynamically more severely obstructed preoperatively. Those with the most improvement were also cognitively impaired. We conclude that, in the geriatric population, detrusor instability and urge incontinence may be the result of age-associated changes and not secondary to obstruction. Detrusor instability is likely to persist following TURP. Preoperative urodynamic assessment of obstruction in the incontinent male with benign prostatic hypertrophy may be useful since the severity of incontinence responds well to TURP if there is marked obstruction. Cognitive impairment should not be a deterrent to operation.

Analysis of tissue optical coefficients using an approximate equation valid for comparable absorption and scattering.

New photosensitizers activated by longer wavelengths than 630 nm light used with Photofrin II are under evaluation by various groups for the treatment of malignancies. Any increase in tumour volume destroyed by these agents as compared to Photofrin II will be partly determined by tissue penetrance at the longer wavelengths. Attenuation coefficients were measured for various tissues at 630 nm and the more penetrative near infrared wavelength of 789 nm. A new model of light propagation in tissue is shown to be accurate for arbitrary ratios of absorption and scattering, by comparison with a rigorous solution to the transport equation. Absorption and transport scattering coefficients of tissues at 630 and 789 nm were obtained by fitting this model to optical attenuation measurements. In vitro tissues included bovine heart, kidney and tongue, pig liver and fat, and chicken muscle; in vivo tissues included Dunning R3327-AT and R3327-H tumours. The penetration depth was found to be 1.35-2.25 times greater at 789 than 630 nm, depending on tissue type. The greatest differences in penetration between the two wavelengths were in the highly pigmented tissues. These substantial increases in penetration in the infrared may be important in future applications of photodynamic therapy.

Dissociation of phosphaturia and 25(OH)D-1 alpha-hydroxylase trophism using a novel analogue of parathyroid hormone.

Certain parathyroid hormone (PTH) analogues have been shown to selectively impair some but not all physiological actions of PTH. In this study, transaminated rat (r) PTH [TA-rPTH-(1-34)], a PTH analogue that differs from the rPTH-(1-34) fragment in that the NH2-terminal alanine is converted to pyruvate, was infused into mice to determine its properties in vivo and specifically to determine whether stimulation of 25-hydroxyvitamin D-1 alpha-hydroxylase (1 alpha-hydroxylase) activity was more dependent on concomitant renal handling of phosphate or on generation of adenosine 3',5'-cyclic monophosphate (cAMP). High-performance liquid chromatography-purified TA-rPTH-(1-34) was infused into C57BL mice at 10 or 30 pmol/h for 24 h. At 30 pmol/h, TA-rPTH-(1-34) was comparable with rPTH-(1-34) in its hypophosphatemic and phosphaturic effects but was less potent than rPTH-(1-34) in raising serum calcium. TA-rPTH-(1-34) was markedly less effective in stimulating renal 1 alpha-hydroxylase than rPTH-(1-34). Stimulation of urinary cAMP excretion occurred after infusion with TA-rPTH-(1-34), but this effect was significantly less than that seen with rPTH-(1-34). These findings indicate that PTH-induced hypophosphatemia and phosphaturia can be uncoupled from PTH stimulation of 1 alpha-hydroxylase. Furthermore, cAMP-related signal transduction appears to be more significant in regulation of 1 alpha-hydroxylase than mechanisms that mediate PTH-sensitive phosphate transport, independent of cAMP.

Protection against light-activated photofrin II killing of tumor cells by nitroimidazoles.

Nitroimidazoles are good quenchers of triplet state porphyrins in chemical systems, thereby inhibiting singlet oxygen formation and type II photodynamic reactions. Photobiological studies were performed with EMT-6 tumor cells in vitro utilizing Photofrin II (PII) in combination with etanidazole (ETAN), misonidazole (MISO), and trifluoromisonidazole (TF-MISO). After short-term (1 h) exposure of cells to PII, 5 mM ETAN and MISO had no effect on photoinactivation while 5 mM TF-MISO had a small but significant protective effect. When the intracellular oxygen level was equilibrated with 0.3% oxygen in the gas phase, all three nitroimidazoles produced significant photoprotection at concentrations as low as 0.3 microM. After long-term (24 h) exposure of cells to PII, all three nitroimidazoles demonstrated large photoprotective effects under both aerobic and 0.3% oxygen conditions. At equal concentrations of nitroimidazole, photoprotection was greatest for the most lipophilic compound (TF-MISO) and least effective for the most hydrophilic compound (ETAN). These studies suggest that nitroimidazoles can quench triplet state porphyrins (within cells) to reduce intracellular concentrations of singlet oxygen, the putative toxin in PII photoinactivation. In addition, after long-term exposures to PII when porphyrins have partitioned into cellular membranes and lipid environments, the lipophilicity of this class of photoprotector correlates with effectiveness in these mammalian cells.

Non-invasive monitoring of photodynamic therapy with 99technetium HMPAO scintigraphy.

The effect of photodynamic therapy (PDT) on tumour perfusion in both anaplastic (R3327-AT) and well differentiated (R3327-H) Dunning prostatic tumours was studied using the radiopharmaceutical 99Technetium hexamethylpropyleneamine oxime (99mTc-HMPAO). Tumours in the left flanks of rats (Copenhage x Fischer, F1 hybrids) were treated with interstitial PDT when their volumes reached 2-3 cm3. Qualitative and quantitative data from pre- and post-PDT scintigraphy revealed a light-dose-dependent shut-down of tumour perfusion which was also time-dependent. Maximal shut-down, following a 1,600 J light-dose, occurred about 8 h post-PDT. Light exposure 2 h after the intravenous administration of the photosensitiser (Photofrin II) produced a greater vascular shut-down than did light exposure 24 h after the administration of the drug. Regional differences in perfusion within treated and non-treated tumours were measured by tomographic procedures. Light-dose-dependent volumes of perfusion shut-down were demonstrated in addition to the naturally occurring regional differences in tumour perfusion. This radiopharmaceutical may have future utility for monitoring the clinical treatment of solid tumours with PDT.

Nuclear magnetic resonance spectroscopy and sensitizer-adduct measurements of photodynamic therapy-induced ischemia in solid tumors.

Dunning R3327-AT prostate carcinomas growing in Fischer X Copenhagen rats were treated with interstitial photodynamic therapy (PDT--15 mg/kg Photofrin II 4 hours before illumination with 630-nm light via four parallelly implanted optical fibers) at different light intensities. Forty to 60 minutes after treatment, 31P-nuclear magnetic resonance spectra of tumors in anesthetized animals were obtained at 2.35 Tesla using surface coil localization. Areas under resonance peaks were normalized to the area under the peak of a phosphorus standard positioned at a fixed distance on the opposite side of the surface coil. Tumor concentrations of phosphomonoesters and phosphodiesters showed no change after tumor light doses up to 3000 J. Phosphocreatine, alpha-adenosine triphosphate (ATP), beta-ATP, and gamma-ATP signals decreased and inorganic phosphate signals increased with increasing light doses. The intratumor pH did not change significantly at these short times after PDT. In other R3327-AT and R3327-H tumor-bearing animals, [3H]misonidazole was administered 30 minutes prior to PDT treatments of both tumors. Twenty-four hours later, the tumors were resected in toto, and levels of retained [3H]misonidazole were determined in lased tumor specimens by liquid scintillation procedures. The amount of [3H]misonidazole activity in tumor tissue (covalently bound after hypoxic reduction) increased with light doses up to 3000 J. Sensitizer-adduct formation was found to correlate with the ratio of the concentration of inorganic phosphate to that of beta-ATP, both of which are presumed measures of tumor oxygenation status. These measurements have high-lighted the heterogenous nature of the oxygenation status of these experimental tumors. The precision of each assay for estimating tumor oxygenation is discussed.