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For other articles and previous issues click here. May 2, 2005 “Male
Lumpectomy” Targeted cyrotherapy may provide a so-called male lumpectomy treatment option for men with prostate cancer, according to the physician who presented preliminary results on the treatment at the Society of Interventional Radiology (SIR) in New Orleans last month. “Treating only the tumor instead of the whole prostate gland is a major and profound departure from the current thinking about prostate cancer,” said Gary Onik, MD, who pioneered prostate cancer cryoablation in the 1990s. “Focal cryoablation changes the whole picture in terms of complications, and the cancer control is as good as any other treatment.” In the trial, the nonsurgical treatment better preserved potency and continence in patients and may prove a more attractive alternative to radical prostatectomy—similar to how lumpectomy became a widely used alternative to mastectomy for many women with breast cancer. Prostate cancer is the most common cancer in men in the United States, with 230,000 cases diagnosed every year. Prostate cancer kills 30,000 men every year in this country. Onik, an interventional radiologist at Florida Hospital/Celebration Health in Celebration, Fla., presented results from 42 men in an ongoing study with one to eight years of follow-up. Forty of those patients (95%) had stable prostate-specific antigen tests suggesting no evidence of cancer. Seventy-eight percent of the men who were potent before the procedure remained so after the procedure, compared with 20% to 40% of men treated with unilateral nerve-sparing radical prostatectomy and 50% long-term for men who received radiation therapy (either external beam or brachytherapy). No study patients reported incontinence after the procedure. “Incontinence becomes a big issue with many patients,” Onik said. “For some, it’s a more important side effect than impotence.” One difference between targeted cryotherapy and breast lumpectomy is that the cryotherapy is a much less invasive procedure. While a surgeon removes the breast tumor through an external incision, cryoablation requires that only a small probe be inserted into the tumor under image guidance. When positioned, the physician circulates refrigerated gas through the probe—most of which is insulated to protect healthy tissue along the probe’s path of entry to the tumor. The extremely cold gas creates an ice ball around the probe tip and kills the tumor. After freezing, the tumor dies and the dead tissue is reabsorbed into the body. Onik said the procedure is done under general anesthesia and routinely done as an outpatient procedure. Patients without complications return to normal activities within a week or two, depending on the extent of the treatment. New Biopsy Method The study followed 42 patients who had previously undergone unilateral TRUS mapping biopsies and 17 who had previously had bilateral biopsies. The results showed that 56% of patients who previously had a negative TRUS on one side of the gland were found to have prostate cancer with transperineal mapping biopsy. Of the 17 patients who previously had a bilateral mapping biopsy, the transperineal biopsy findings resulted in a change of treatment in 15 of those 17 cases. “3-D transperineal mapping biopsies provide superior information on the extent and grade of prostate cancer, causing significant impact on therapeutic decision making,” Onik told the audience in his presentation on the subject at SIR. The transperineal biopsy complements the focal cryoablation approach because the earlier detection of smaller tumors increases the likelihood that a small tumor that can be treated using cryoablation, sparing most of the prostate and greatly reducing the chance of complications associated with radical prostatectomy. Other Cancer News From SIR Chemoembolization for Inoperable
Liver Cancer “The safety study shows that chemoembolization should be the standard first-line treatment for inoperable liver tumors,” said lead investigator Jeff Geschwind, MD. “Patients have minimal procedural toxicity and chemoembolization is already proven to substantially increase survival.” The safety study Geschwind discussed found that the chemoembolization caused no periprocedural mortality and minimal changes in liver enzymes and blood counts. Although surgical resection offers the best chance to cure liver cancer, most tumors are inoperable because of their size, number, or proximity to blood vessels or other critical structures. According to information from SIR, surgical removal is not viable for two-thirds of primary liver cancers and 90% of metastatic tumors. Chemoembolization is performed through a catheter inserted into the femoral artery and threaded through the blood vessels into the tumor using image guidance. The physician delivers the drugs (cisplatin, doxorubicin, and mitomycin C in this study) in a carrier oil medium followed by the embolic material that helps keep the drugs within the tumor. Geschwind, who is the director of interventional radiology and an associate professor at the Johns Hopkins University School of Medicine, also discussed results from 31 patients who underwent the procedure one or more times. Approximately one-half of the patients had poor initial liver reserve prior to chemoembolization, according to Geschwind. That group had a mean survival of five months. The group with better liver function had a mean survival of 12 months. Those survival times were longer than both patients with Hepatocellular Carcinoma and portal vein thrombosis and received no treatment (3.7 months) and those who received systemic chemotherapy (5.1 months). “Chemoembolization offers patients a nonsurgical option that preserves healthy tissue, is well-tolerated and has a short recovery time,” said Geschwind. “It can be repeated as needed to control tumor growth or progression, thereby extending life expectancy in the majority of cases.” RFA Kills Lung Tumors in 93%
of Cases “This research shows that CT-guided radiofrequency ablation effectively destroys cancer cells inside the lung without surgery,” said Riccardo Lencioni, MD, an interventional radiologist at the University of Pisa. “For patients with primary lung cancer or lung metastases from colorectal cancer who are not surgical candidates, this research also shows that the interventional radiofrequency ablation treatment can improve patients’ survival without worsening their quality of life.” RFA is performed by inserting a needle probe through the skin and into the tumor in the lung under image guidance. Then the radiofrequency energy is applied through the probe to heat and cook the tumor tissue. The tumor tissue slowly shrinks and forms scar tissue. By the time lung cancer becomes symptomatic, 85% of patients cannot be cured, according to information provided by SIR. Most patients diagnosed with non-small cell lung cancer are not surgical candidates. RFA offers patients the chance to improve survival, reduce pain, and increase quality of life. Lencioni reported on a prospective trial of RFA treatment of 186 malignant tumors 3.5 centimeters or smaller in 106 patients. CT evaluations found that the tumors were completely ablated in 173 of 186 tumors (93%). The survival rate for cancer-only deaths in the primary cancer group was 91%. Part of the tragedy of lung cancer is that patients frequently die from poor respiratory function or other serious coexisting conditions not directly caused by the cancer. In Lencioni’s trial, primary lung cancer patients had an overall survival rate of 69% at one year after surgery and 49% at two years. Colorectal cancer patients with lung metastases had a much lower survival rate in the study. In that group, the cancer-only related deaths were 88% at one year and 72% at two years. There were no procedure-related deaths in the study. Major complications included 27 pneumothorax cases, four pleural effusions requiring treatment, two pneumonia cases, and one case of atelectasis. Pain Relief for Bone Metastases “Pain affects greater than 60% of patients with advanced cancer and for many the pain is due to bone metastases, often destroying the quality of their remaining life,” said Matthew Callstrom, MD, PhD, of the Mayo Clinic in Rochester, Minn. “This research shows that these new interventional techniques are effective to help these patients without surgery, and offer a short recovery time. The treatments work within weeks, are well-tolerated and can be repeated if needed.” In the first prospective trial evaluating percutaneous cryoablation to provide pain relief for metastatic bone lesions, eight of the 10 initial patients report that the procedure was safe and the patients reported on an average 74% reduction of their worst pain, according to data presented at SIR. The study is ongoing and expanding the number of patients followed. Cryoablation techniques have been around for years, but it’s the shrinking size of probes and the ability to better insulate them that makes freezing bone metastases feasible. In the image-guided (CT and ultrasound) procedure, the physician inserts up to eight probes into the tumor under anesthesia to freeze and kill the cells. RFA can also provide pain relief from metastatic bone tumors. Delivered in a similar manner as cryoablation, it uses heat to kill cells and provide palliation. In the results presented at SIR, all 11 patients reported pain relief of at least two points on the 10-point visual analogue pain scale. The mean reduction was 6.4 to 0.7 with no locally recurrent pain during the mean five-month follow-up. In a different approach, interventional radiologists reported preliminary results from a trial where the patients received injections of medical-grade bone cement into their tumors. The hardening cement gives off heat, which kills cancer cells. When set, the cement provides strength for the weakened bones. Eight patients were treated in the initial series; all reported prompt and lasting pain relief with no significant complication. “As a physician, it’s particularly rewarding to treat these patients because we make such a difference in their lives,” Callstrom said of palliative treatment for bone tumors. “Many of these patients were disabled from their pain, unable to perform everyday activities without pain. These new interventional treatments offer cancer patients a chance to feel more normal as well, without the constant reminder of their illness.” — Compiled from Radiology Today staff reports. |
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