John C. Grecula

Small Cell Lung Cancer

Neuroendocrine tumors account for approximately 20% of lung cancers; most (≈15%) are small cell lung cancer (SCLC). These NCCN Clinical Practice Guidelines in Oncology for SCLC focus on extensive-stage SCLC because it occurs more frequently than limited-stage disease. SCLC is highly sensitive to initial therapy; however, most patients eventually die of recurrent disease. In patients with extensive-stage disease, chemotherapy alone can palliate symptoms and prolong survival in most patients; however, long-term survival is rare. Most cases of SCLC are attributable to cigarette smoking; therefore, smoking cessation should be strongly promoted.

Phase IB Study of Gene-Mediated Cytotoxic Immunotherapy Adjuvant to Up-Front Surgery and Intensive Timing Radiation for Malignant Glioma

PURPOSE Despite aggressive therapies, median survival for malignant gliomas is less than 15 months. Patients with unmethylated O(6)-methylguanine-DNA methyltransferase (MGMT) fare worse, presumably because of temozolomide resistance. AdV-tk, an adenoviral vector containing the herpes simplex virus thymidine kinase gene, plus prodrug synergizes with surgery and chemoradiotherapy, kills tumor cells, has not shown MGMT dependency, and elicits an antitumor vaccine effect. PATIENTS AND METHODS Patients with newly diagnosed malignant glioma received AdV-tk at 3 × 10(10), 1 × 10(11), or 3 × 10(11) vector particles (vp) via tumor bed injection at time of surgery followed by 14 days of valacyclovir. Radiation was initiated within 9 days after AdV-tk injection to overlap with AdV-tk activity. Temozolomide was administered after completing valacyclovir treatment. RESULTS Accrual began December 2005 and was completed in 13 months. Thirteen patients were enrolled and 12 completed therapy, three at dose levels 1 and 2 and six at dose level 3. There were no dose-limiting or significant added toxicities. One patient withdrew before completing prodrug because of an unrelated surgical complication. Survival at 2 years was 33% and at 3 years was 25%. Patient-reported quality of life assessed with the Functional Assessment of Cancer Therapy-Brain (FACT-Br) was stable or improved after treatment. A significant CD3(+) T-cell infiltrate was found in four of four tumors analyzed after treatment. Three patients with MGMT unmethylated glioblastoma multiforme survived 6.5, 8.7, and 46.4 months. CONCLUSION AdV-tk plus valacyclovir can be safely delivered with surgery and accelerated radiation in newly diagnosed malignant gliomas. Temozolomide did not prevent immune responses. Although not powered for efficacy, the survival and MGMT independence trends are encouraging. A phase II trial is ongoing.

Predicting Control of Primary Tumor and Survival by DCE MRI During Early Therapy in Cervical Cancer

Purpose:To assess the early predictive power of MRI perfusion and volume parameters, during early treatment of cervical cancer, for primary tumor control and disease-free-survival. Materials and Methods:Three MRI examinations were obtained in 101 patients before and during therapy (at 2–2.5 and 4–5 weeks) for serial dynamic contrast enhanced (DCE) perfusion MRI and 3-dimensional tumor volume measurement. Plateau Signal Intensity (SI) of the DCE curves for each tumor pixel of all 3 MRI examinations was generated, and pixel-SI distribution histograms were established to characterize the heterogeneous tumor. The degree and quantity of the poorly-perfused tumor subregions, which were represented by low-DCE pixels, was analyzed by using various lower percentiles of SI (SI%) from the pixel histogram. SI% ranged from SI2.5% to SI20% with increments of 2.5%. SI%, mean SI, and 3-dimensional volume of the tumor were correlated with primary tumor control and disease-free-survival, using Student t test, Kaplan-Meier analysis, and log-rank test. The mean post-therapy follow-up time for outcome assessment was 6.8 years (range: 0.2–9.4 years). Results:Tumor volume, mean SI, and SI% showed significant prediction of the long-term clinical outcome, and this prediction was provided as early as 2 to 2.5 weeks into treatment. An SI5% of <2.05 and residual tumor volume of ≥30 cm3 in the MRI obtained at 2 to 2.5 weeks of therapy provided the best prediction of unfavorable 8-year primary tumor control (73% vs. 100%, P = 0.006) and disease-free-survival rate (47% vs. 79%, P = 0.001), respectively. Conclusions:Our results show that MRI parameters quantifying perfusion status and residual tumor volume provide very early prediction of primary tumor control and disease-free-survival. This functional imaging based outcome predictor can be obtained in the very early phase of cytotoxic therapy within 2 to 2.5 weeks of therapy start. The predictive capacity of these MRI parameters, indirectly reflecting the heterogeneous delivery pattern of cytotoxic agents, tumor oxygenation, and the bulk of residual presumably therapy-resistant tumor, requires future study.

The role of local therapy in the management of lung and liver oligometastases

Despite recent advances in oncologic therapy, an important proportion of patients with primary cancer will develop distant metastasis. The standard therapy for metastatic cancer is systemic therapy, which typically does not yield excellent response rates for most solid tumors. Data in the literature support the existence of a state of limited metastasis or oligometastasis. Favorable outcomes have been observed in selected patients with oligometastases that are treated with local ablative therapies, which include surgical extirpation, stereotactic body radiation therapy, and radiofrequency ablation. Lung and liver are the two most common sites of oligometastases considered for local ablative therapy and this Review will focus on the role of local therapy in oligometastases that arise in these organs.

Longitudinal Changes in Tumor Perfusion Pattern during the Radiation Therapy Course and its Clinical Impact in Cervical Cancer

PURPOSE To study the temporal changes of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) perfusion patterns during the radiation therapy (RT) course and their influence on local control and survival in cervical cancer. METHODS AND MATERIALS DCE-MRI was performed in 98 patients with Stage IB(2)-IVA cervical cancer before RT (pre-RT) and during early RT (20-25 Gy) and mid-RT (45-50 Gy). Signal intensity (SI) from the DCE-MRI time-SI curve was derived for each tumor voxel. The poorly perfused low-DCE tumor subregions were quantified as lower 10th percentiles of SI (SI10). Local control, disease-specific survival, and overall survival were correlated with DCE parameters at pre-RT, early RT, and mid-RT. Median follow-up was 4.9 (range, 0.2-9.0) years. RESULTS Patients (16/98) with initial pre-RT high DCE (SI10 >or=2.1) had 100% 5-year local control, 81% disease-specific survival, and 81% overall survival, compared with only 79%, 61%, and 55%, respectively, in patients with pre-RT low DCE. Conversion from pre-RT low DCE to high DCE in early RT (28/82 patients) was associated with higher local control, disease-specific survival, and overall survival (93%, 74%, and 67%, respectively). In comparison with all other groups, outcome was worst in patients with persistently low DCE from pre-RT throughout the mid-RT phase (66%, 44%, and 43%; p = 0.003, 0.003, and 0.020; respectively). CONCLUSION Longitudinal tumor perfusion changes during RT correlate with treatment outcome. Persistently low perfusion in pre-RT, early RT, and mid-RT indicates a high risk of treatment failure, whereas outcome is favorable in patients with initially high perfusion or subsequent improvements of initially low perfusion. These findings likely reflect reoxygenation and may have potential for noninvasive monitoring of intra-treatment radio-responsiveness and for guiding adaptive therapy.

DISEASE CONTROL, SURVIVAL, AND FUNCTIONAL OUTCOME AFTER MULTIMODAL TREATMENT FOR ADVANCED-STAGE TONGUE BASE CANCER

Surgical resection and postoperative radiation for advanced‐stage malignancies of the oral cavity, oropharynx, and hypopharynx result in a dismal overall survival of 38%. Patients with carcinoma of the tongue base frequently have advanced disease at the time of presentation, and combined‐modality therapy is usually required to achieve cure. Because of the poor survival rates with advanced malignancies with standard therapy, new and innovative approaches continue to be developed in an attempt to have a greater impact on disease control, patient survival, and functional outcome after therapy. This study examines functional outcome, survival, and disease control in patients receiving an intensified treatment regimen with concomitant chemoradiotherapy, surgery, and intraoperative radiotherapy for previously untreated, resectable, stage III and IV squamous cell carcinoma (SCC) of the tongue base.

In vivo imaging of changes in tumor oxygenation during growth and after treatment.

A novel procedure for in vivo imaging of the oxygen partial pressure (pO2) in implanted tumors is reported. The procedure uses electron paramagnetic resonance imaging (EPRI) of oxygen‐sensing nanoprobes embedded in the tumor cells. Unlike existing methods of pO2 quantification, wherein the probes are physically inserted at the time of measurement, the new approach uses cells that are preinternalized (labeled) with the oxygen‐sensing probes, which become permanently embedded in the developed tumor. Radiation‐induced fibrosarcoma (RIF‐1) cells, internalized with nanoprobes of lithium octa‐n‐butoxy‐naphthalocyanine (LiNc‐BuO), were allowed to grow as a solid tumor. In vivo imaging of the growing tumor showed a heterogeneous distribution of the spin probe, as well as oxygenation in the tumor volume. The pO2 images obtained after the tumors were exposed to a single dose of 30‐Gy X‐radiation showed marked redistribution as well as an overall increase in tissue oxygenation, with a maximum increase 6 hr after irradiation. However, larger tumors with a poorly perfused core showed no significant changes in oxygenation. In summary, the use of in vivo EPR technology with embedded oxygen‐sensitive nanoprobes enabled noninvasive visualization of dynamic changes in the intracellular pO2 of growing and irradiated tumors. Magn Reson Med 57:950–959, 2007.

Combination of boron neutron capture therapy and external beam radiotherapy for brain tumors.

PURPOSE Boron neutron capture therapy (BNCT) has been used clinically as a single modality treatment for high-grade gliomas and melanomas metastatic to the brain. The purpose of the present study was to determine whether its efficacy could be enhanced by an X-ray boost administered after BNCT. Two brain tumor models were used, the F98 glioma as a model for primary brain tumors and the MRA 27 human melanoma as a model for metastatic brain tumors. METHODS AND MATERIALS For biodistribution studies, either 10(5) F98 glioma cells were implanted stereotactically into the brains of syngeneic Fischer rats or 10(6) MRA 27 melanoma cells were implanted intracerebrally into National Institutes of Health (NIH)-rnu nude rats. Biodistribution studies were performed 11-13 days after implantation of the F98 glioma and 20-24 days after implantation of the MRA 27 melanoma. Animals bearing the F98 glioma received a combination of two boron-containing drugs, sodium borocaptate at a dose of 30 mg/kg and boron phenylalanine (BPA) at a dose of 250 mg/kg. MRA 27 melanoma-bearing rats received BPA (500 mg/kg) containing an equivalent amount of 10B (27 mg B/kg). The drugs were administered by either intracarotid or i.v. injection. RESULTS The tumor boron concentration after intracarotid injection was approximately 50% greater in the F98 glioma and MRA 27 melanoma after intracarotid injection (20.8 and 36.8 microg/g, respectively) compared with i.v. injection (11.2 and 19.5 microg/g, respectively). BNCT was carried out at the Brookhaven National Laboratory Medical Research Reactor approximately 14 days after tumor implantation of either the F98 glioma or the MRA 27 melanoma. Approximately 7-10 days after BNCT, subsets of animals were irradiated with 6-MV photons, produced by a linear accelerator at a total dose of 15 Gy, delivered in 5-Gy daily fractions. F98 glioma-bearing rats that received intracarotid or i.v. sodium borocaptate plus BPA, followed 2.5 h later by BNCT and 7-10 days later by X-rays, had similar mean survival times (61 days and 53 days, respectively, p = 0.25), and the non X-irradiated, BNCT-treated animals had a mean survival time of 52 and 40 days, respectively, for intracarotid vs. i.v. injection; the latter was equivalent to that of the irradiated animals. The corresponding survival time for MRA 27 melanoma-bearing rats that received intracarotid or i.v. BPA, followed by BNCT and then X-irradiation, was 75 and 82 days, respectively (p = 0.5), 54 days without X-irradiation (p = 0.0002), 37 days for X-irradiation alone, and 24 days for untreated controls. In contrast to the data obtained with the F98 glioma, MRA 27 melanoma-bearing rats that received i.v. BPA, followed by BNCT, had a highly significant difference in mean survival time compared with the irradiated controls (54 vs. 37 days, p = 0.008). CONCLUSION Our data are the first to suggest that a significant therapeutic gain may be obtained when BNCT is combined with an X-ray boost. Additional experimental studies are required to determine the optimal combination of X-radiation and neutron doses and whether it is more advantageous to administer the photon boost before or after BNCT.

Pilot study of intraoperative high dose rate brachytherapy for head and neck cancer.

PURPOSE To develop a new technique, intraoperative high dose rate brachytherapy (IOHDR), to deliver localized radiation therapy intraoperatively to head and neck tumors at sites inaccessible to intraoperative electron beam radiotherapy (IOEBRT) in the skull base region. METHODS After maximal surgical resection, afterloading catheters spaced 1 cm apart embedded in custom surface applicators made of foam or silicone were placed on resected tumor beds. IOHDR was delivered in a shielded operating room using preplanned dosimetry with a nominal 10 Ci iridium-192 source in an HDR micro-Selectron afterloader. Twenty-nine patients (20 males, 9 females) ranging in age from 9 to 80 years (median = 61) were irradiated intraoperatively for advanced head and neck tumors at sites inaccessible to IOEBRT. Six patients who had previously received external beam radiation (EBRT) ranging from 50 to 75 Gy, were given 15 Gy of IOHDR only. Twenty-three patients who had no prior radiation received 7.5 to 12.5 Gy IOHDR, and 45 to 50 Gy EBRT was planned post-operatively; however, six of these patients did not complete the planned EBRT. Doses to normal tissues were reduced whenever possible by shielding with lead or by displacement with gauze or retractors. Treatment time ranged from 3.8 to 23 min (median = 6.5 min). Five patients received concurrent cis-platinum based chemotherapy. RESULTS Twenty-nine patients treated to 30 sites had local tumor control of 67% and crade survival of 72%, with the follow-up ranging from 3 to 33 months (median = 21 months). In the group of 17 previously unirradiated patients who had completed full treatment (IOHDR and EBRT) to 18 sites, the local tumor control was 89%, and all of these patients survived. Tumor control in the six previously unirradiated patients who did not complete EBRT was 50% with a crude survival of 50%. In the group of six previously irradiated patients treated by IOHDR only, the local tumor control was 17% with a crude survival of 17%. No intraoperative complications were noted. The delayed morbidity included cerebrospinal fluid (CSF) leak with bone exposure (1), chronic subdural hematoma (1), septicemia (1), otitis media (1), and severe xerostomia (1). We cannot comment on long-term morbidity due to the relatively short follow-up period of 21 months. CONCLUSIONS It is feasible to deliver IOHDR, with acceptable toxicity, to skull base tumors at sites inaccessible to IOEBRT. The use of IOHDR as a pre-radiotherapy boost produced excellent local control and survival in the selected group of patients who had no previous radiation therapy. The use of exclusive IOHDR in the previously irradiated group resulted in poor outcome, possibly due to the limitations on re-irradiation doses and/or volumes determined by normal tissue tolerance or because these patients have inherently radioresistant tumors. Higher IOHDR doses, additional EBRT, and/or chemotherapy should be considered for this group. The use of IOHDR as a pre-EBRT boost to maximize local control has a promising future in the treatment of carefully selected patients with advanced skull base tumor.

Predicting outcomes in cervical cancer: a kinetic model of tumor regression during radiation therapy.

Applications of mathematical modeling can improve outcome predictions of cancer therapy. Here we present a kinetic model incorporating effects of radiosensitivity, tumor repopulation, and dead-cell resolving on the analysis of tumor volume regression data of 80 cervical cancer patients (stages 1B2-IVA) who underwent radiation therapy. Regression rates and derived model parameters correlated significantly with clinical outcome (P < 0.001; median follow-up: 6.2 years). The 6-year local tumor control rate was 87% versus 54% using radiosensitivity (2-Gy surviving fraction S(2) < 0.70 vs. S(2) > or = 0.70) as a predictor (P = 0.001) and 89% vs. 57% using dead-cell resolving time (T(1/2) < 22 days versus T(1/2) > or = 22 days, P < 0.001). The 6-year disease-specific survival was 73% versus 41% with S(2) < 0.70 versus S(2) > or = 0.70 (P = 0.025), and 87% vs. 52% with T(1/2) < 22 days versus T(1/2) > or = 22 days (P = 0.002). Our approach illustrates the promise of volume-based tumor response modeling to improve early outcome predictions that can be used to enable personalized adaptive therapy.