Complete remission of nonresectable pancreatic cancer after infusional colloidal phosphorus-32 brachytherapy, external beam radiation therapy, and 5-fluorouracil: a preliminary report

This is a preliminary report of five patients diagnosed with locally advanced nonresectable pancreatic cancer who achieved improved quality of life, delay of local progression, and reduction of biomarker CA 19-9 after infusion of colloidal phosphorus 32 (32P) and administration of combined chemoradiotherapy. A phase II trial using intratumoral colloidal 32P delivery for nonresectable pancreatic cancer without metastases is in progress. Patients initially were given infusions of decadron followed by macroaggregated albumin and 30 mCi colloidal 32P to the interstitial space of the tumor by two infusions 1 week apart. Through this method, doses ranging from 750,000 to 1,800,000 cGy were delivered. After administration of colloidal 32P, external radiation to a dose of 6000 cGy minimum tumor dose, including regional lymph nodes, was given concomitantly with four intravenous infusions of 500 mg bolus 5-fluorouracil on alternating days within the first 2 weeks after initiation of external radiation. All five of these patients demonstrated cessation of local tumor growth or regression of disease on serial computed tomography scans for a minimum of 10 months from completion of therapy. Three of these patients have survived without local disease progression over 24 months from initiation of therapy, with one patient approaching 36 months. CA 19-9 values for all patients declined within weeks after completion of therapy. This new method of isotope delivery has resulted in reduction of tumor volume, normalization of the biomarker CA 19-9, and improved performance status in those patients who have localized nonresectable disease without dissemination.

Metastatic nonresectable fibrolamellar hepatoma: prognostic features and natural history

Fibrolamellar hepatoma has a clinical course distinct from that of typical histologic hepatocellular carcinoma. The clinical behavior and prognostic features of nonresectable metastatic fibrolamellar hepatoma have not previously been fully addressed and are the focus of this report. Retrospective chart review of all patients (n = 17) with nonresectable metastatic fibrolamellar hepatoma referred to the Johns Hopkins Oncology Center from 1985 through 1990 was carried out. All patients had hepatic parenchymal involvement and regional node metastases at the time of referral. Metastases were limited to regional nodes in four patients. The remaining patients had lung metastases (n = 4), peritoneal metastases (n = 5), or both (n = 4). To assess the impact of the fibrolamellar variant, characteristic-matched control patients with typical histologic hepatocellular carcinoma were obtained from the Radiation Therapy Oncology Group database. Actuarial median survival from treatment was 14 months in the patients with fibrolamellar hepatoma and 7.7 months in the patients with hepatocellular carcinoma (p < 0.001). Karnofsky performance status and hepatic tumor volume at time of referral were important prognostic features. Multimodality treatment included radiation therapy and radiolabelled antibody, cisplatin-based chemotherapy, or both; results are discussed. Thirteen patients died, nine of liver failure, three of metastatic disease, and one of sepsis. Fibrolamellar histologic type, liver function tests, tumor volume, and patient performance status were significant predictors of survival. The cause of death in fibrolamellar hepatoma differs considerably from that observed in typical histologic hepatocellular carcinoma in the United States. The techniques of treatment of this uncommon disease were modeled after advances in the multimodality treatment of hepatocellular carcinoma and are discussed. Median survival was 14 months in patients with metastatic nonresectable fibrolamellar hepatoma.

Objective responses after fractionated infusional brachytherapy of unresectable pancreatic adenocarcinomas

BACKGROUND

The prognosis of unresectable pancreatic adenocarcinoma is poor. Therefore, the treatment potential of an intratumoral infusional brachytherapy using macroaggregated human albumin in combination with radioactive chromic phosphate [32P] was investigated in this group of patients.

METHODS

Seventeen patients with unresectable tumors received intratumoral infusional brachytherapy. Treatment and assessment of response was performed with the aid of ultrasonography.

RESULTS

Four patients had complete response with a duration ranging from 2-57 weeks and 5 patients had partial response with a duration ranging from 4-21 weeks, corresponding to an objective response of 53% (9 of 17 patients). Six of these patients were alive 33-57 weeks after treatment. Radiation necrosis was observed in 1 patient after a 19,000-gray cumulative radiation dose and a slight decrease in blood counts was observed in 2 patients.

CONCLUSIONS

Intratumoral infusional brachytherapy using radioactive colloidal chromic phosphate has the potential to reduce inoperable pancreatic tumors with few side effects.

Objective responses after fractionated infusional brachytherapy of unresectable pancreatic adenocarcinomas

BACKGROUND

The prognosis of unresectable pancreatic adenocarcinoma is poor. Therefore, the treatment potential of an intratumoral infusional brachytherapy using macroaggregated human albumin in combination with radioactive chromic phosphate [32P] was investigated in this group of patients.

METHODS

Seventeen patients with unresectable tumors received intratumoral infusional brachytherapy. Treatment and assessment of response was performed with the aid of ultrasonography.

RESULTS

Four patients had complete response with a duration ranging from 2-57 weeks and 5 patients had partial response with a duration ranging from 4-21 weeks, corresponding to an objective response of 53% (9 of 17 patients). Six of these patients were alive 33-57 weeks after treatment. Radiation necrosis was observed in 1 patient after a 19,000-gray cumulative radiation dose and a slight decrease in blood counts was observed in 2 patients.

CONCLUSIONS

Intratumoral infusional brachytherapy using radioactive colloidal chromic phosphate has the potential to reduce inoperable pancreatic tumors with few side effects.

Selective tumor irradiation by infusional brachytherapy in nonresectable pancreatic cancer: a phase I study

PURPOSE

Selective high-dose radiation of solid tumors has been a goal of radiation oncology. The physiological barriers of solid tumors (high interstitial tumor pressure, reduced tumor vascularity, and poor perfusion) have been major barriers in achieving significant tumor dose of systemically infused radioconjugates. Direct tumor infusional brachytherapy overcomes these barriers and leads to selective high tumor doses.

METHODS AND MATERIALS

The development of interstitial tumor infusion of macroaggregated albumin (MAA) followed by colloidal chromic phosphate 32P has overcome solid tumor obstacles in 47 patients with nonresectable pancreatic cancer in a Phase I dose escalation study. The colloidal 32P infusion was followed by external radiation and five fluorouracil.

RESULTS

Of the 28 patients with cancer limited to the pancreas, 15 of 16 patients retained 86-100% (mean 96%) of the infused colloidal 32P isotope. While the other 12 patients had partial shunting to the liver, shunting to the liver was due to high interstitial resistance with tumor dose deposition of 17-88% (mean 52 %). Of the 19 patients with metastatic pancreas cancer, colloidal 32P tumor deposition ranged from 22 to 100% of the infused dose (mean 79%). The less than optimal tumor deposition led to our increasing the MAA from 600,000 to 1.5-2.5 million particles. Interstitial dexamethasone 2 mg and later 4 mg was infused first and prevented liver shunting by somehow reducing tumor resistance. The median survival in 28 Phase I patients with nonresectable pancreas cancer without metastasis, was 12 months. No significant toxicity occurred when treatment was limited to two infusions with as much as 30 mCi each. The maximum tumor dose was 17,000 Gy (1.700,000 cGy). In 19 nonresectable pancreatic cancer patients with metastasis, a 6.9 months median survival was observed.

CONCLUSIONS

Infusional brachytherapy is an outpatient procedure that delivers high-dose radiation selectively to pancreatic cancer. Results of the Phase I study in nonresectable pancreas cancer has led to a national multiinstitutional Phase II trial.

Preliminary experience of infusional brachytherapy using colloidal 32P

In the past, we have clinically evaluated radiolabelled antibodies in Hodgkin's disease and hepatocellular cancer. Increased tumour pressure, reduced vascularity and poor diffusion has limited significant radiolabelled antibody tumour dose deposition. Using intratumoural infusion of macroaggregated albumin to blockade exiting vasculature followed by colloidal chromic 32Phosphorous, we have been able to achieve 75% to 100% tumour dose deposition by interstitial tumour infusion under computerised tomographic guidance. Phase I studies in a variety of solid tumours indicate extremely high doses may be achieved without toxicity (i.e. non-resectable pancreas 900,000 cGy to 1.7 million cGy) with tumour control and remission. This is a review of those studies and how the technique was applied.

Quantitative bremsstrahlung single photon emission computed tomographic imaging: use for volume, activity, and absorbed dose calculations

PURPOSE

To perform bremsstrahlung single photon emission computed tomographic (SPECT) imaging using 32P chronic phosphate for volume and activity quantitation to calculate absorbed dose estimates.

METHODS AND MATERIALS

Seven cancer patients enrolled in clinical Phase I therapeutic protocols were injected with 2.5 million particles of macroaggregated albumin, followed by colloidal 32P chromic phosphate by direct interstitial injection into the tumor-bearing region under computed tomographic (CT) guidance. SPECT images were obtained in these patients. The patient body contour was defined through the use of two externally placed Compton backscatter 99mTc sources. A computer algorithm was written to facilitate region-of-interest volume and activity determination on the reconstructed SPECT slices based on a fixed threshold method. Three sequential SPECT studies were acquired in two of these patients, to determine the accuracy of activity quantitation for bremsstrahlung SPECT studies using Chang's postprocessing method of attenuation compensation with a computer-generated body contour based on the Compton backscatter sources, and an experimentally measured effective linear attenuation coefficient for 32P. The serial data in these two patients were used to calculate absorbed dose estimates.

RESULTS

The 99mTc backscatter sources enabled the patient body outline to be clearly visualized in all the transaxial reconstructed slices and did not contribute significant counts to the patient 32P counts. The calculated activities from the SPECT studies were within 7.8% of the administered 32P activity. The two calculated patient absorbed doses were 4.2 x 10(3) Gy and 5.9 x 10(3) Gy for injected activities of 736 MBq and 920 MBq, respectively.

CONCLUSION

We conclude that accurate quantitative bremsstrahlung SPECT imaging, for the case of high contrast well-localized activity distributions, with a commercially available postprocessing attenuation correction algorithm, can be performed in a clinical setting. Entirely SPECT-based measurements can be used to generate absorbed dose estimates.

A new method for delivering radioactive cytotoxic agents in solid cancers

PURPOSE

Therapeutic agents such as monoclonal antibodies, radiopharmaceuticals, and radioactive growth factors are limited in effectiveness due to the inability to deposit significant quantities of the agents and for limited periods of time in solid cancer. A new technique based on knowledge of the pathophysiology of solid tumors allows for significant concentration of these agents to accumulate and for a prolonged period of time, thus allowing interaction with the tumor for potentially increased effectiveness.

METHODS AND MATERIALS

Three agents have been studied: 131I antiferritin monoclonal antibody, colloidal 32P chromic phosphate, and 131I transferrin. The time required for maximal tumor uptake was determined in vitro in tissue culture and was 10 min, 25 min, and 40 min, respectively. The new method of in vivo tumor infusion consisted of a direct intratumoral injection of macroaggregated albumin (MAA) 10,000 particles, followed by the radioactive agents under study. Tumors were infused in vivo using the new technique and compared to intratumoral infused controls. In the instance of radiolabeled antiferritin antibody, intraperitoneal administration and intratumoral infusion were compared to the new technique. In the other two instances, intratumoral infusion was compared to the new method.

RESULTS

In all instances the direct vascular blockade caused by MAA led to greater deposition of the agent under study for at least 24 h. These results were clinically applied with MAA followed by 32P colloidal chromic phosphate and were consistent with the experimental findings.

CONCLUSION

A new technique is described that may be carried out in the experimental laboratory and clinic by direct tumor infusion of macroaggregated albumin (MAA), followed by other radioactive agents that will remain localized in solid cancers and will allow for high tumor dose deposition for potentially increased therapeutic efficacy.

Variable low dose rate irradiation (131I-anti-CEA) and integrated low dose chemotherapy in the treatment of nonresectable primary intrahepatic cholangiocarcinoma

Previous experience using 131I anti-CEA antibody, which irradiates at a variable low dose rate in combination with a multimodality treatment program, has demonstrated acceptable toxicity and response in primary intrahepatic cholangiocarcinoma. In attempting to improve therapy, Cis-platin was added to the prior regimen. Induction therapy was unchanged. One month later, chemotherapy was given (doxorubicin, 15 mg, 5-fluorouracil, 500 mg, plus Cis-platin, 20 mg/M2) followed the next day by outpatient administration of 20 mCi 131I anti-CEA by i.v. bolus. Five days later, 10 mCi was administered. The latter regimen (chemotherapy plus 20 + 10 mCi 131I anti-CEA) was repeated every 2 months using polyclonal antibodies derived from different species (rabbit, pig, baboon, and horse). Twenty-four patients (29% with prior chemotherapy and/or metastases) were prospectively treated according to this regimen. Toxicity was limited to hematologic toxicity and was manifested by thrombocytopenia and leukopenia (17% and 4% grade 4, respectively, according to RTOG toxicity criteria). Tumor remission was evaluated by CT volumetric analysis and demonstrated a 14% response rate for the induction portion of therapy, 24% for the radioimmunoglobulin portion of treatment, and 50% remission rate when all subsequent tumor volumes were compared to the pre-treatment volume (entire program). The median survival for the entire group of patients was 10.1 months. This result is superior to previously reported trials and, in comparison to our previous study (10.1 vs 6.5 months median survival), further advancement in protocol design appears to have been made. In view of the rarity of this disorder, a randomized trial is not possible and strict statistical analyses cannot be made. The mechanism of 131I-anti-CEA variable low dose irradiation and chemotherapy interaction is discussed as well as further potential modifications for treatment improvement.

Whole-abdominal irradiation for the management of gastrointestinal and abdominal manifestations of agnogenic myeloid metaplasia

A patient with a long-standing history of agnogenic myeloid metaplasia developed weight loss and ascites secondary to gastric/small bowel infiltration and peritoneal implants of myeloid tissue. Moderate doses of radiation were very effective in controlling her gastrointestinal symptoms. In contrast to previous reports, clinical improvement after irradiation was a slow, gradual process, requiring 5 months for complete resolution of the patient's ascites. Hematologic suppression may be profound and careful attention to the rate of change in leukocyte and platelet counts is necessary to avoid severe toxicity.

The Radiation Therapy Oncology Group: an update of clinical research activities

This paper provides an introduction into the clinical activities of the RTOG (Radiation Therapy Oncology Group), its goals, its organization, its format for protocol development, and presents major areas of achievement. It provides an organizational chart of the group, a disease site modality cross-reference for protocols, and appendices which provide the key published results of the Group's clinical activities. This paper presents an important overview of the RTOG clinical research activities, which are designed to improve the role of radiation therapy.

Phase I-II studies of yttrium-labeled antiferritin treatment for end-stage Hodgkin's disease, including Radiation Therapy Oncology Group 87-01

Radiolabeled antiferritin immunoglobulin (Ig) preparations were tested in patients with advanced, end-stage Hodgkin's disease. Four patients received indium-111 (111In)-labeled monoclonal antiferritin (QCI). Targeting was not observed in tumor-bearing areas. Instead, scans showed rapid accumulation of QCI in normal liver. Forty-five patients were injected with 111In-labeled polyclonal antiferritin (rabbit, pig, or baboon). Forty (89%) patients showed tumor uptake, with dosimetric estimates ranging from 300 to 3,000 cGy in 1 week for the subsequently administered yttrium-90 (90Y)-labeled antiferritin. Yttrium-labeled antibody caused hematologic toxicity. Treatment-induced toxicity was not observed in any other organ system. Intravenous autologous bone marrow cells, 18 days after the yttrium infusion, accelerated hematopoietic recovery in eight patients receiving 30 mCi or 40 mCi. Hematopoietic recovery after a 20 mCi 90Y-labeled antiferritin infusion was not influenced by an autologous bone marrow transplant. Two patients receiving 20 mCi and one patient receiving 50 mCi remained aplastic after transplantation for unknown reasons. In 29 assessable patients, a 62% response rate was observed; nine of the 18 responses were complete. Responses ranging from 2 to 26 months were more commonly noted in patients with small tumors and long disease histories. Dosimetric calculations did not predict for responses. Recurrences frequently occurred in new areas instead of areas exhibiting bulky disease at the start of the treatment. Complete responses after 90Y antiferritin were significantly (P less than .02) more frequent than in a previous study with iodine-131 (131I) antiferritin. Further improvements are needed to make this new treatment modality curative.

Delayed split whole abdominal irradiation in the combined modality treatment of ovarian cancer

Fifty-eight patients with ovarian malignancies have been treated using a delayed split whole abdominal irradiation technique (DSA) allowing the entire tumor volume to be irradiated with tumoricidal fractional doses without undue toxicity. The lower hemiabdomen was irradiated with 2 Gy per fraction to a total dose of 40 Gy. A 2-6 hour delay was used between the irradiation of each half of the abdomen to avoid excessive acute gastrointestinal toxicity. The upper hemiabdomen was irradiated with 1.5 Gy per fraction to a total dose of 30 Gy. The acute toxicity was acceptable, with 53 of 58 patients able to complete the prescribed course of treatment. Three patients (5%) experienced grade 3 or greater acute gastrointestinal toxicity. Fourteen of 60 patients (24%) required treatment breaks because of thrombocytopenia. Nadir platelet counts were lower in patients who had received previous chemotherapy than in previously untreated patients (80,000 vs 118,000; p = .02). However, only 4 out of 60 patients were unable to complete DSA because of prolonged thrombocytopenia. In addition to DSA, patients were also treated with intraperitoneal 32P (52 patients), intraperitoneal human ovarian antitumor serum (14 patients), and prior (14 patients) or subsequent (32 patients) chemotherapy. Granulocytopenia was more severe among patients who had received prior chemotherapy (mean nadir 900 vs 2200). Seven patients (11.5%) developed delayed bowel obstruction in the absence of recurrence. There was one death caused by hepatitis, presumably related to colloidal 32P and DSA. Twenty-five percent of Stage III optimally cytoreduced patients were disease-free at 5 years; these patients had a median survival of 45 months. DSA irradiation is an acceptable technique for delivering a high fractional dose of radiation to the entire peritoneal cavity. Shielding of the iliac crests spares bone marrow allowing DSA irradiation to be integrated into an aggressive combined modality treatment plan.

The role of chronic viral hepatitis in hepatocellular carcinoma in the United States

Although hepatocellular carcinoma is a relatively uncommon tumor in the United States, it is quite common in sub-Saharan Africa and the Far East, where most cases are associated with infection with the hepatitis B virus. We have studied 99 American patients with hepatocellular carcinoma for evidence of hepatitis B or hepatitis C viral infection and compared these findings to those in a group of matched controls with other cancers. The two groups differed in proportion, with hepatitis B surface antigen in serum being significantly higher in patients with hepatocellular carcinoma (7% vs. 0%, p = 0.009). Antibody to hepatitis C virus was also found more frequently in patients with hepatocellular carcinoma (13% vs. 2%, p = 0.002). The relative risk for hepatocellular carcinoma in hepatitis B surface antigen-positive patients was calculated to be 17.3 and for antibody to hepatitis C virus to be 7.3. The attributable fraction of cases related to the hepatitis B surface antigen carrier state was 6.7% and for patients infected with the hepatitis C virus was 11.4%. Approximately three quarters of cases of hepatocellular carcinoma did not have evidence of either hepatitis C or hepatitis B virus infection. These findings provide strong evidence that hepatitis C virus infection is associated with the development of hepatocellular carcinoma, and in the United States may even play a more important role than the hepatitis B virus.

Multimodality cisplatin treatment in nonresectable alpha-fetoprotein-positive hepatoma

Twenty-eight patients with alpha-fetoprotein-positive (AFP+) nonresectable hepatoma have been enrolled in a new multimodality Phase I, II program. Induction therapy consisted of 50 mg/m2 intravenous cisplatin followed by 2100 cGy irradiation to the tumor volume in seven fractions over 10 days. Hepatic arterial infusion of 50 mg/m2 cisplatin (IA-CDDP) was then administered at monthly intervals. Twenty-one patients have completed induction and at least two cycles of IA-CDDP. Twelve-month cumulative survival was 52% for all 28 patients and 69% for the 21 patients completing induction and IA-CDDP. Median survival has not yet been reached. Response rate (complete and partial) was 36% overall and 48% among the 21 patients who completed treatment. The improved survival of the present series of patients as well as the minimal hematologic toxicity suggests possible further integration of new modalities for therapy.

Prognostic factors in unresectable hepatocellular cancer: Radiation Therapy Oncology Group Study 83-01

The Radiation Therapy Oncology Group (RTOG) conducted a Phase I/II study in hepatocellular cancer that closed on September 9, 1987 and some results presented previously. Here, 17 patient characteristics are evaluated to identify any of prognostic significance. Two hundred sixteen patients were entered and 198 (74% with metastases and/or previous chemotherapy) were evaluable. Treatment began with an induction regimen of external beam radiotherapy to the liver (21.0 Gy, 3.0 Gy/Fx, 10 MV photons, 4 days per week) with low-dose chemotherapy (5-Fluorouracil (FU), 500 mg, i.v.; Doxorubicin, 15 mg, i.v.) on treatment Days 1, 3, 5 and 7. In the later stages of these studies, 56 patients received external beam radiotherapy as hyperfractionated treatment (1.2 Gy twice daily, 4 hours separation, 5 days per week, 24.0 Gy total) with similar chemotherapy. One month following induction therapy, cycles of radiolabeled antibody therapy were given every 2 months. Each cycle was derived from a different species of animal and consisted of 30 mCi I-131 antiferritin, Day 0, and 20 mCi, Day 5. On Day -1, 5-FU, 500 mg, and Adriamycin, 15 mg, were administered. The overall median survival for the entire group, including previously treated patients, was 4.9 months. The median survival for alpha-fetoprotein (AFP) - patients not previously treated was 10.5 months. Median survival for all AFP - patients was 8.5 months and for all AFP + patients was 4.6 months (p = 0.006). Of the 17 pretreatment characteristics investigated for prognostic value Karnofsky Performance Score (KPS) (80-100 vs. less than 80) (p = 0.0001), presence/absence of ascites (p = 0.0002), bilirubin level (less than 1.5 vs. greater than or equal to 1.5) (p = 0.018), SGOT (less than or equal to 35 vs. greater than 35) (p = 0.001); alkaline phosphatase (less than or equal to 95 vs. greater than 95) (p = 0.008) were found to be significant independently using a multivariant regression model. The relative risk of dying for the unfavorable component of each of these characteristics was 2.2, 2.0, 1.5, 1.9 and 1.7, respectively. Good and poor prognostic groups were then defined and compared to a similar patient population (RTOG study 83-19) with confirmation of the validity of the model. When stratification for these overpowering clinical factors was incorporated, AFP status was again significant with a relative death rate 1.80 times higher for AFP+ patients. Our recommendations for structuring future prospective randomized trials are discussed and include stratification by AFP status.

Pretreatment evaluation of sexual function in patients with adenocarcinoma of the prostate

Forty-three patients with adenocarcinoma of the prostate and available partners were interviewed to assess qualitatively and quantitatively their levels of sexual functioning prior to radiotherapy. The mean age was 67.7 years (58-80 years). The Derogatis Interview for Sexual Functioning (DISF) was the evaluation used. The Derogatis Interview for Sexual Functioning measures five domains of sexual functioning: sexual fantasy, arousal, experience, orgasm, and drive. Twenty-seven of the 43 (62.7%) patients evaluated were considered impotent. Fifteen of the 27 patients scored low in all five domains of sexual functioning even though they could achieve erection but they were unable to maintain erection throughout the phases of the sexual response cycle. Twelve of the 27 patients had scored 0 on sexual arousal and orgasm, thus had no ability for erection. Sixteen of the 43 (37.2%) patients were considered potent. This group of patients had achieved erection throughout the phases of sexual cycle and scored adequately in all five domains of sexual functioning. Patients with DISF score less than 20 were impotent. Those with a Derogatis Interview for Sexual Functioning score of greater than 45 were potent. Only 6 of 19 patients with scores between 20 and 45 were potent. The Derogatis Interview for Sexual Functioning score was highly prognostic for impotence, (p = .002) was easy to use and could be used for follow-up of the effect of therapy on sexual function in patients with adenocarcinoma of the prostate. Patients who present for radiation therapy are older, 50% are on cardiac or antihypertensive medication, and the majority (62.7%) are already impotent prior to therapy.

Pre and posttreatment evaluation of sexual function in patients with adenocarcinoma of the prostate

Twenty-seven patients with adenocarcinoma of the prostate, and available partners, were interviewed to qualitatively and quantitatively assess their level of sexual function prior to and 12 months after radiotherapy. Assessments were made using the Derogatis Interview for Sexual Functioning (DISF). Five domains of sexual functioning are measured: sexual fantasy, arousal, experience, orgasm, and drive. Prior to therapy 17 of 27 patients (62.9%) were considered impotent. There were eight patients with a DISF score of less than 20 who were impotent. Six patients had a DISF score of greater than 47 and were considered potent. Of the patients with DISF scores between 20-47 four were potent, and nine were impotent. Post radiation therapy three of the patients considered potent (with a score greater than 47) maintained their potent status. Four patients considered impotent prior to therapy became potent after therapy. All patients with a score less than 20 prior to radiation therapy remained impotent after therapy. Results indicate that an objective evaluation of sexual function pre treatment is necessary to determine the effect of radiotherapy. Our method of qualitative assessment of sexual function was easy to implement, was reproducible and could be used to evaluate long-term effects of radiotherapy on sexual function. Of the patients presenting for radiotherapy, 62.9% were impotent. Twelve months after radiation therapy 19 of 27 (70.3%) were impotent.

Targeting and therapy of human glioma xenografts in vivo using radiolabeled antibodies

Radiolabeled antibodies provide a potential basis for selective radiotherapy of human gliomas. Monoclonal P96.5, a mouse IgG2a immunoglobulin, defines an epitope of a human melanoma cell surface protein and specifically binds the U-251 human glioma as measured by immunoperoxidase histochemistry. 111In-radiolabeled P96.5 specifically targets the U-251 human glioma xenograft and yields 87.0 microCuries (uCi) of tumor activity per gram per 100 uCi injected activity compared to 4.5 uCi following administration of radiolabeled irrelevant monoclonal antibody. Calculations of targeting ratios demonstrate deposited dose to be 11.6 times greater with radiolabeled P96.5 administration compared to irrelevant monoclonal antibody. Tumor dose found in normal organs is less than 20% of the tumor dose, further supporting specific targeting of the human glioma xenograft by this antibody. Monoclonal antibodies QCI054 and ZME018, which define a tumor-associated and a second melanoma-associated antigen, respectively, demonstrate positive immunoperoxidase staining of the tumor, but comparatively decreased targeting. To test the therapeutic potential of 90Y-radiolabeled P96.5, QCI054, and ZME018, tumors and normal sites were implanted with miniature thermoluminescent dosimeters (TLD). Average absorbed doses of 3770 +/- 445 (mean +/- SEM), 2043 +/- 134, and 645 +/- 48 cGy in tumor, 353 +/- 41, 243 +/- 22, and 222 +/- 13 cGy in a contralateral control intramuscular site, 980 +/- 127, 815 +/- 41, and 651 +/- 63 cGy in liver, and 275 +/- 14, 263 +/- 11, and 256 +/- 18 cGy in total body were observed 7 days following administration of 100 uCi 90Y-radiolabeled P96.5, QCI054, and ZME018, respectively. To test the therapeutic potential, tumor-bearing nude mice were given intracardiac injections of either buffer or 90Y-radiolabeled P96.5, QCI054, or ZME018. Striking tumor regression and prolonged survival were measured following administration of 90Y-labeled P96.5. Average maximal decreases in tumor volume were 42.7 +/- 11.9 and 94.2 +/- 3.3 percent 28 and 58 days following 100 and 200 uCi 90Y-radiolabeled P96.5 administration, respectively. The time required to achieve four times the initial tumor volume was 6.1 +/- 0.9 days for buffer; 43 +/- 12 and 63 +/- 10 days for 50 and 100 uCi 90Y-radiolabeled P96.5; 7 +/- 2, 20 +/- 1, and 53 +/- 4 for 50, 100, and 200 uCi 90Y-radiolabeled QCI054; and 9 +/- 1, 13 +/- 1, and 29 +/- 3 days for 50, 100, and 200 uCi 90Y-radiolabeled ZME018, respectively. Average tumor regrowth failed to occur 180 days following administration of 200 uCi 90Y-labeled P96.5.(ABSTRACT TRUNCATED AT 400 WORDS)

Targeting of human glioma xenografts in vivo utilizing radiolabeled antibodies

Radiolabeled antibodies provide a potential basis for selective radiotherapy of human gliomas. We have measured tumor targeting by radiolabeled monoclonal and polyclonal antibodies directed against neuroectodermal and tumor-associated antigens in nude mice bearing human glioma xenografts. Monoclonal P96.5, a mouse IgG2a immunoglobulin, defines an epitope of a human melanoma cell surface protein, and specifically binds the U-251 human glioma as measured by immunoperoxidase histochemistry. 111In-radiolabeled P96.5 specifically targets the U-251 human glioma xenograft and yields 87.0 microCuries (microCi) of tumor activity per gram per 100 microCi injected activity compared to 4.5 microCi following administration of radiolabeled irrelevant monoclonal antibody. Calculations of targeting ratios demonstrate deposited dose to be 11.6 times greater with radiolabeled P96.5 administration compared to irrelevant monoclonal antibody. The proportion of tumor dose found in normal organs is less than 10%, further supporting specific targeting of the human glioma xenograft by this antibody. Monoclonal antibody ZME018, which defines a second melanoma-associated antigen, and polyclonal rabbit antiferritin, which defines a tumor-associated antigen, demonstrate positive immunoperoxidase staining of the tumor, but comparatively decreased targeting. When compared to the 111In-radiolabeled antibody, 90Y-radiolabeled P96.5 demonstrates comparable tumor targeting and percentages of tumor dose found in normal organs. To test the therapeutic potential of 90Y-radiolabeled P96.5, tumors and normal sites were implanted with miniature thermoluminescent dosimeters (TLD). Seven days following administration of 100 microCi 90Y-radiolabeled P96.5, average absorbed doses of 3770, 980, 353, and 274 cGy were observed in tumor, liver, contralateral control site, and total body, respectively. Shared cell surface antigens among neuroectodermally derived neoplasms provide a basis for exploration of human glioma radioimmunotherapy.

Systemic radiotherapy--the new frontier

The present day use of systemically administered isotopes and conjugated isotopic combinations are reviewed. Administration of 131Iodine in thyroid cancer led to a 97% local control and 50% complete remission of pulmonary metastases. Specificity directed isotopic therapy (metabolic, hormonal, and antibody) is discussed and includes factors such as tumor physiology and isotopic linkage. The clinical results and new knowledge being gained in Hodgkin's disease, non-Hodgkin's, colorectal, hepatoma, intrahepatic biliary and gliomatous cancers are reviewed. The dose response relationship to tumor remission is demonstrated in Hodgkin's treated with 131I antiferritin (40% partial remission) and more recently 90Yttrium antiferritin (50% complete response). Varied routes of administration, the problem of anti-antibody and bone marrow transplantation are discussed. Finally, the challenge to radiobiologists, physicists, chemists, immunologists, nuclear radiologists, and radiation oncologists is emphasized by definition of the new laboratory and clinical approaches being developed in systemic radiation therapy.

Prevention of hypothyroidism related to mantle irradiation for Hodgkin's disease: preparative phantom study

To decrease the incidence of hypothyroidism related to mantle irradiation for Hodgkin's disease, we initiated a study designed to protect the thyroid gland using a phantom. A thyroid phantom was filled with technetium-99m. The thyroid phantom was placed inside of its corresponding anterior neck position in a whole body phantom. An anterior scintiscan of the head and neck region demonstrated the radioactivity in the simulated thyroid. A mantle port included a focused block that would shield the thyroid from the anterior port. The phantom was exposed (4 MeV) to 180 cGy (AP-PA) at midplane with lithium fluoride dosimeters in the position of the thyroid. The thyroid received an average of 12 cGy from the anterior field and 48 cGy from the posterior field for a total of 60 cGy per treatment or 30% of the prescribed dose. A complete mantle field course of radiation of 4000 cGy would lead to a thyroid dose of 1200 cGy at a daily fractional dose of 60 cGy. We elected not to block the thyroid from the posterior field to prevent shielding and potential underdosage of involved nodal sites. The present study suggests a method of safe and effective thyroid shielding which needs to be tested clinically to determine whether it would reduce the incidence of chemical and clinical hypothyroidism or simply extend the period until occurrence.

Accelerated fractionation radiation therapy for liver metastases: selection of an optimal patient population for the evaluation of late hepatic injury in RTOG studies

The palliation of hepatic metastases represents a major therapeutic problem in oncology. The generally unfavorable prognosis of patients with liver metastasis may complicate the evaluation of the efficacy and toxicity of various therapeutic modalities. The Radiation Therapy Oncology Group (RTOG) is evaluating new accelerated fractionation schemes for hepatic irradiation. In designing this study it became necessary to identify a favorable subpopulation of patients with an expected median survival of 6 months in whom the late effects of treatment could be evaluated. Data from two RTOG liver metastases studies (7605 and 8003) were analyzed using multi-variate techniques. Cases with a serum bilirubin level of greater than 1.5 mg%, performance score of less than 50, and gastric or pancreatic primary carcinomas were initially excluded because of the adverse influence of these factors on survival. One hundred and ninety cases met the criteria for inclusion in this analysis. A loglinear model was used to identify the patient characteristics associated with a favorable prognosis for survival. These included a performance score of 80-100, colorectal carcinoma primary, and no extrahepatic metastases. A logistic regression equation was derived and confirmed that the probability of surviving at least 6 months depended on the effects of performance score, primary site and the presence or absence of extra-hepatic metastases. Patients with all three favorable factors constituted 30% of the evaluable study population and had a predicted survival of 50% at 6 months. A patient population with these characteristics will be used to study the late effects of accelerated fractionated radiation therapy on the liver.

Staging, treatment, and results in testicular seminoma. A 12-year report

Sixty-one patients with histologically confirmed seminoma of the testis were treated by radiotherapy at The Johns Hopkins Hospital from 1975 to 1987. Fifty-seven patients remain disease-free, three patients died of intercurrent disease, and one patient (Stage IIB) died of widespread seminoma. Median follow-up for these patients is 5.5 years. Using a modified M.D. Anderson Hospital clinical staging system, 42 (69%) were Stage I, 16 (26%) were Stage IIA, and three (5%) were Stage IIB. Radiologic staging included both lymphangiogram (LAG) and abdominal computed tomography (CT) scan. Among Stage I disease, nine patients had false-positive CT scans, determined by negative LAG. Six patients had false-negative CT scans and were upstaged to Stage IIA by LAG. Treatment portals were altered in 15 of the 39 patients (38%) who had both LAG and CT scan. Overall actuarial survival (Kaplan-Meier method) was 97% at 5 years and 92% at 10 years. Five-year survival corrected for intercurrent disease was 100% for Stage I, 100% for Stage IIA, and two of three in Stage IIB patients. There were two distant treatment failures among the entire cohort. One patient who had Stage I disease was salvaged with local-field radiation and chemotherapy and is now without evidence of disease for 6 years. The second patient with Stage IIB seminoma receiving the same treatments disseminated and died. There were no significant acute toxicities or serious complications. In summary, proper staging with information gained from LAG and adequate radiation dose led to a 92% 10-year disease-free survival.

Radiolabeled antibodies: results and potential in cancer therapy

Radiolabeled antibodies are analyzed from the classical approach in radiation oncology being compared to geometric isotopic implants, external radiation, and tumor-dose response and energy of the isotope used for cytotoxicity. In addition, physiological factors that limit antibody uptake, varied routes of administration, toxicity of treatment, as well as present clinical progress are reviewed.

Targeting and therapy of human glioma xenografts in vivo utilizing radiolabeled antibodies

Radiolabeled antibodies provide a potential basis for selective radiotherapy of human gliomas. We have measured tumor targeting by radiolabeled monoclonal antibodies directed against neuroectodermal and tumor-associated antigens in nude mice bearing human glioma xenografts. Monoclonal P96.5, a mouse IgG2a immunoglobulin, defines an epitope of a human melanoma cell surface protein and specifically binds the U-251 human glioma as measured by immunoperoxidase histochemistry. IIIIn-radiolabeled P96.5 specifically targets the U-251 human glioma xenograft and yields 87.0 microCi of tumor activity/g/100 microCi injected activity compared to 4.5 microCi following administration of 100 microCi radiolabeled irrelevant monoclonal antibody. Calculations of targeting ratios demonstrate the deposited dose to be 11.6 times greater with radiolabeled P96.5 administration compared to irrelevant monoclonal antibody. The dose found in normal organs is less than 20% of that in the tumor, further supporting specific targeting of the human glioma xenograft by this antibody. Monoclonal antibody ZME018, which defines a second melanoma-associated antigen, demonstrates positive immunoperoxidase staining of the tumor, but comparatively decreased targeting. To test the therapeutic potential of 90Y-radiolabeled P96.5 and ZME018, tumors and normal sites were implanted with miniature thermoluminescent dosimeters. Average absorbed doses of 3770 +/- 445 (SEM) and 645 +/- 48 cGy in tumor, 353 +/- 41 and 222 +/- 13 cGy in a contralateral control i.m. site, 980 +/- 127 and 651 +/- 63 cGy in liver, and 275 +/- 14 and 256 +/- 18 cGy in total body were observed 7 days following administration of 100 microCi 90Y-radiolabeled P96.5 and ZME018, respectively. Calculations of absorbed dose by the medical internal radiation dose method confirmed thermoluminescent dosimeter absorbed dose measurements. To test the therapeutic potential, tumor-bearing nude mice were given intracardiac injections of either buffer or 90Y-radiolabeled P96.5 or ZME018. Tumor regression was measured in 1 of 12, 9 of 10, and 12 of 12 compared to 0 of 10, 1 of 10, and 2 of 10 animals following administration of 50, 100, or 200 microCi 90Y-labeled P96.5 and ZME018, respectively. Average maximal decreases in tumor volume were 42.7 +/- 11.9 and 94.2 +/- 3.3% 28 and 58 days following 100 and 200 microCi 90Y-radiolabeled P96.5 administration, respectively. In contrast, no average decrease in tumor volume was noted following 50, 100, or 200 microCi 90Y-labeled ZME018.(ABSTRACT TRUNCATED AT 400 WORDS)

The theoretical implications and experimental and clinical results of radiolabeled antiferritin

Ferritin is produced in malignant and normal tissues. It acts both as an immunosuppressant and as an iron storage protein. As a tumor associated protein, it is related to virally induced tumors, and selective tumor targeting by radiolabeled antiferritin antibodies has led to its use in clinical trials. In patients with advanced Hodgkin's disease who have failed conventional therapy, 131I antiferritin produced partial remissions, while 90Y antiferritin led to complete remissions and a demonstrable dose-response relationship. Combining the variable low-dose radiation patterns produced by radiolabeled antibody therapy with chemotherapy in the treatment of hepatocellular cancer has led to enhanced tumor cytotoxicity and, in some cases, the conversion of non-resectable hepatoma to resectable. Further, the potential for clinical and laboratory investigation of radiolabeled antibody therapy is discussed in light of new findings.

194 hepatocellular cancers treated by radiation and chemotherapy combinations: toxicity and response: a Radiation Therapy Oncology Group Study

Hepatocellular carcinoma is known to have a doubling time of approximately 41 days. This rapid cell division suggested that hyperfractionated radiation and chemotherapy might add an advantage in gaining remission of this malignancy. One hundred and thirty-five patients (70% with metastasis and/or previous treatment) were prospectively treated with single daily fractions to the liver (3.0 Gy external beam radiation, total dose 21.0 Gy), and chemotherapy for hepatocellular carcinoma. The low dose chemotherapy used in conjunction with the radiation was 2 hr before treatment on days 1, 3, 5, and 7 and consisted of Adriamycin, 15 mg IV and 5-FU, 500 mg IV. These patients were compared to a second group of 59 patients (80% with metastases and/or previous treatment) treated using the same chemotherapy regimen but using hyperfractionated whole liver external beam irradiation (1.2 Gy twice daily, 4 hr between treatments, 5 days per week to 24.0 Gy, 10 MV photons). Response was determined by CT scan tumor volumetric analysis. The response rate for the single daily fraction patient group was 22% and for the new hyperfractionated group, 18% (p = 0.68). Toxicity was evaluated by RTOG criteria. The grade 4 hematologic toxicity noted in the daily fraction patient group was 6%. Among 59 patients treated with the hyperfractionated liver irradiation, 2% experienced grade 4 hematologic toxicity. Esophagitis occurred in 1% of patients in the standard fractionation group and 19% in the hyperfractionated group (p = 0.0001). Grade 1-4 thrombocytopenia occurred in 49% of patients in the conventional group and 68% in the hyperfractionated group (p = 0.03). Normal liver volume changes with treatment were measured with CT scan tumor volumetric analysis. The hyperfractionated group experienced a median of 11 cc increase in liver volume and the conventional group a 46 cc decrease, but the difference was not significant. Hyperfractionated radiation did not demonstrate a significant benefit over standard daily radiation, but acute toxicity appeared to be higher.

Yttrium-90 and iodine-131 radioimmunoglobulin therapy of an experimental human hepatoma

Therapeutic trials were performed on the HepG2 human hepatoblastoma implanted s.c. in the athymic nude mouse. Animals were treated with polyclonal and monoclonal antiferritin and control antibodies labeled with either iodine-131 (131I) or yttrium-90 (90Y). Administration of 400 muCi of 131I-labeled polyclonal antiferritin or 300 muCi of 90Y-labeled polyclonal antiferritin significantly increased survival (P less than 0.001). There were no tumor cures with radiolabeled polyclonal antibody therapy. Animals treated with 200 or 300 muCi of 131I-labeled monoclonal antiferritin (QCI054) did not show increased survival compared to controls. Although 400 muCi of 131I-labeled QCI significantly prolonged survival, treatment resulted in no long-term survivors. Monoclonal antiferritin labeled with 90Y significantly prolonged survival of animals (P less than 0.001) at doses of 100, 200, or 300 muCi compared with untreated controls. Fifty % of the animals treated with 200 muCi and 75% of the animals treated with 300 muCi showed no evidence of disease at 140 days following treatment. Four hundred muCi of 90Y-labeled QCI proved toxic to the animals. Increased survival was accompanied by a decrease in tumor mitotic rate and increase in cellular polymorphism as determined by pathological examination. The radiation dose absorbed in the tumor correlated directly with tumor response following treatment. The absorbed dose in tumors for complete decay of the isotope ranged from 165 and 330 cGy at the periphery and center of small tumors for an administered activity of 200 muCi of 131I-labeled polyclonal antiferritin, to 7,573 and 12,400 cGy for 300 muCi of 90Y-labeled monoclonal antiferritin QCI.

Polyclonal 90Yttrium labeled antiferritin for refractory Hodgkin's disease

Six patients with chemotherapy resistant Hodgkin's disease were treated with intravenous polyclonal 90-Yttrium (90Y) labeled antiferritin. Eighteen days after isotope infusion, patients received an autologous bone marrow transplant that was cryopreserved prior to initiation of treatment. Ten (one patient), 20 (four patients), or 30 mCi (two patients) were used. One patient received three cycles, three patients received two cycles, and two patients received one cycle. The same antibody labeled with 111-Indium (111In) was helpful in documenting the absence of anti-antibodies in six out of six patients, the presence of tumor targeting in six out of seven patients, and allowed for dose estimates in two out of six patients. One patient with a complete response received approximately 20 Gy to the tumor, whereas a second patient with 20 Gy to the tumor showed progressive disease. A total of three patients obtained a complete response, one had a partial response, and two patients progressed on treatment. Acute toxicity was limited to bone marrow aplasia, without a clear-cut beneficial effect for transplantation after 20 mCi 90Y and the suggestion of a positive effect after 30 mCi. One patient died in complete remission 26 months after treatment with chronic lung insufficiency, probably unrelated to the isotope treatment. The early observations are that 90Y-labeled antiferritin has a pronounced antitumor effect as a single agent and less normal tissue toxicity than other treatment modalities for Hodgkin's disease, such as chemotherapy, external beam radiotherapy, or autologous bone marrow transplantation after high dose chemo/radiotherapy.

Treatment of supratentorial high grade gliomas with split course high fractional dose postoperative radiotherapy

Ninety-two patients with malignant supratentorial gliomas diagnosed from 1977 to 1983 received split course external beam radiotherapy. The initial course of radiation consisted of 3000 cGy whole brain in ten fractions 5 days a week. After a 2-week rest, treatment was continued to a portal restricted to the computerized tomography scan demonstrated abnormality plus a margin for an additional 2100 cGy (total 5100 cGy/17 fx/36 days). The optic chiasm and hypothalamus were excluded from the high dose region. Following review of all pathologic specimens, three patients with grade II glioma, three lacking histologic confirmation, two unbiopsied and eleven not receiving the prescribed treatment were excluded from the survival analysis. No patients were lost to follow-up. Surviving patients were followed 85 months (median); range 68-125 months. All remaining patients were followed until death. The median actuarial survival for 73 grade III and IV patients was 12.5 months. The 5-year actuarial survival was 10%. The median survival for 54 grade IV patients was 10 months. The 5-year survival was 4%. For 19 grade III patients the median survival was 22.5 months. The 5-year survival was 26%. There was one long-term grade IV survivor (68 mos.) and four long-term grade III survivors (76, 85, 108, 125 mos). No patient developed optic nerve or chiasm injury. One patient, an 85 months survivor, had biopsy documented radionecrosis and hemiparesis. The incidence of necrosis among 62 patients alive 6 months or more (and therefore at risk of brain necrosis) is 1/62 (2%). The incidence among survivors is 1/5. The nominal standard dose for this regimen is 1749 ret. The predictive value of the "nominal standard dose" and "equivalent dose" formulae for brain necrosis is explored. We conclude (a) that this regimen provides a survival probability equivalent to conventional treatment for grade III and IV supratentorial gliomas, (b) that neither the equivalent nor nominal standard doses predicted the incidence of brain necrosis, (c) that the time dose schedule is well tolerated and has an acceptable risk-benefit ratio, (d) that its advantage to the patient is decreased time requirement and cost.

Current status of radioimmunoglobulins in the treatment of human malignancy

Radioimmunoglobulin therapy is a new treatment modality that is easily administered, well tolerated, and can be given on an outpatient basis. It is not, however, as simplistic an approach to cancer therapy as commonly thought. It incorporates the sciences of immunology, physiology, radiobiology, chemistry, and physics, as well as oncology, all of which must be understood if radioimmunoglobulin therapy is to reach its potential. Partial and complete remissions have been achieved while the clinical teams involved in this research are still in the process of defining materials, methods, and future clinical approaches. The authors enumerate the varied problems in the development of radioimmunoglobulin therapy, and report on the current status of clinical trials.

Current status of radioimmunoglobulins in the treatment of human malignancy

Radioimmunoglobulin therapy is a new treatment modality that is easily administered, well tolerated, and can be given on an outpatient basis. It is not, however, as simplistic an approach to cancer therapy as commonly thought. It incorporates the sciences of immunology, physiology, radiobiology, chemistry, and physics, as well as oncology, all of which must be understood if radioimmunoglobulin therapy is to reach its potential. Partial and complete remissions have been achieved while the clinical teams involved in this research are still in the process of defining materials, methods, and future clinical approaches. The authors enumerate the varied problems in the development of radioimmunoglobulin therapy, and report on the current status of clinical trials.

Immunoradiotherapy for primary nonresectable hepatocellular carcinoma

The ability to convert a nonrectable lesion into a resectable one offers significant palliation and possible cure for patients with hepatoma. With increasing effectiveness of radiolabeled immunoglobulin and multimodality treatment, more patients are expected to become candidates for definitive resection after presenting with unresectable disease.

A phase I/II study of the hypoxic cell sensitizer misonidazole as an adjunct to high fractional dose radiotherapy in patients with unresectable squamous cell carcinoma of the head and neck: a RTOG randomized study (#79-04)

A randomized prospective trial was performed to study the toxicity and efficacy of the hypoxic cell sensitizer, misonidazole (MISO), used as an adjunct to high fractional dose radiotherapy in the management of unresectable Stage III and IV squamous cell carcinomas of the oral cavity, oropharynx and hypopharynx. From June 1979 to February 1983, 42 patients were randomized with 40 patients available for analysis. In the radiotherapy (RT) only group, 19 patients received a short course of high fractional dose radiotherapy with 400 rad per day, 5 days per week, to a total of 4400 to 5200 rad. In the radiotherapy plus misonidazole group (RT + MISO) 21 patients received the same radiotherapy plus 1.5 gm/m2 of misonidazole 3 times a week for a total of 7 doses. The observed side effects associated with misonidazole were: persistent numbness and paresthesia (1 patient), transient peripheral nerve paresis and persistent paresthesia (1 patient), and nausea and vomiting (2 patients). The treatment related morbidities were similar in both groups. Acute mucositis was seen in 4 of 19 patients in the RT group and 3 of 21 patients in the RT + MISO group. Acute airway obstruction requiring tracheotomy was seen in 2 patients with massive tumor in the base of tongue (1 in each group). Severe dysphagia requiring NG tube feeding was seen in 3 patients in the RT + MISO group and 3 patients in the RT group. The initial complete response rate in the RT group was 53%, versus 48% in the RT + MISO group. The estimated 2-year loco-regional control rates were 10% for RT alone and 17% for RT + MISO (no significancy). These results indicate that the addition of misonidazole does not improve the efficacy of high fractional dose radiotherapy for management of unresectable head and neck carcinomas. However, high fractional dose radiotherapy can be administered for the management of advanced head and neck carcinomas with acceptable morbidity and thus, is a useful regimen for future clinical trials of hyperbaric oxygen or new hypoxic cell sensitizers.

Low-dose-rate total lymphoid irradiation: a new method of rapid immunosuppression

Total Lymphoid Irradiation (TLI) has been successful in inducing immunosuppression in experimental and clinical applications. However, both the experimental and clinical utility of TLI are hampered by the prolonged treatment courses required (23 days in rats and 30-60 days in humans). Low-dose-rate TLI has the potential of reducing overall treatment time while achieving comparable immunosuppression. This study examines the immunosuppressive activity and treatment toxicity of conventional-dose-rate (23 days) vs low-dose-rate (2-7 days) TLI. Seven groups of Lewis rats were given TLI with 60Co. One group was treated at conventional-dose-rates (80-110 cGy/min) and received 3400 cGy in 17 fractions over 23 days. Six groups were treated at low-dose-rate (7 cGy/min) and received total doses of 800, 1200, 1800, 2400, 3000, and 3400 cGy over 2-7 days. Rats treated at conventional-dose-rates over 23 days and at low-dose-rate over 2-7 days tolerated radiation with minimal toxicity. The level of immunosuppression was tested using allogeneic (Brown-Norway) skin graft survival. Control animals retained allogeneic skin grafts for a mean of 14 days (range 8-21 days). Conventional-dose-rate treated animals (3400 cGy in 23 days) kept their grafts 60 days (range 50-66 days) (p less than .001). Low-dose-rate treated rats (800 to 3400 cGy total dose over 2-7 days) also had prolongation of allogeneic graft survival times following TLI with a dose-response curve established. The graft survival time for the 3400 cGy low-dose-rate group (66 days, range 52-78 days) was not significantly different from the 3400 cGy conventional-dose-rate group (p less than 0.10). When the total dose given was equivalent, low-dose-rate TLI demonstrated an advantage of reduced overall treatment time compared to conventional-dose-rate TLI (7 days vs. 23 days) with no increase in toxicity. This was accomplished without compromise of the immunosuppressant activity of TLI as demonstrated by comparable allogeneic skin graft survival times between the two 3400 cGy treatment groups. This clinical advantage would prove to be beneficial where immediate suppression of the immune system is desirable.

Dosimetry and treatment planning for 90Y-labeled antiferritin in hepatoma

Radiation absorbed-dose estimates and treatment planning are reported for 11 patients with hepatoma who were administered 90Y-labeled polyclonal antiferritin IgG for therapy in a Phase 1-2 trial. Dosimetric studies included quantitation of the localization and clearance of 111In-labeled antiferritin IgG in tumor and normal tissues and computer-assisted tumor and normal liver volumetrics from X ray CT scans. For the group of patients studied, hepatoma volumes at the time of treatment ranged from 135 to 3442 cm3. Quantitative 111In antiferritin imaging prior to and following 600 or 900 cGy of external-beam irradiation of the primary tumor demonstrated that tumor uptake increased 1.1 to 5.8-fold (mean 2.8) following external beam. In contrast, changes in uptake of radiolabeled antiferritin in normal liver ranged from 0.35 to 2.1-fold (mean 0.93) after external irradiation. Administered activities of 90Y antiferritin ranged from 8 to 37 mCi and were dependent on tumor volume and tumor localization of radiolabeled antiferritin. Following external-beam irradiation, tumor dose rates achieved with 90Y antiferritin ranged from 10 to 20 cGy/hr and normal liver dose rates from 1.1 to 5.7 cGy/h. The corresponding absorbed dose in hepatomas ranged from 900 to 2150 cGy and in normal liver from 80 to 650 cGy. After external-beam irradiation, tumor and normal liver uptake of 90Y antiferritin was consistent with that of 131I antiferritin.

Radiation enhancement of radiolabelled antibody deposition in tumors

Recent clinical observations led to the use of external radiation to increase tumor targeting by radiolabelled 131-I antiferritin. Examination of increased uptake of 131-I labelled antiferritin following external radiation was carried out in syngeneic implanted hepatomas (H4IIE, 3924A, 7800, and 7777). Exposure to 10 Gy increased the tumor: liver uptake ratio from 1.55 to 1.86 for H4IIE; from 1.56 to 2.0 for 7800; from 1.34 to 1.97 for 7777; and from 1.05 to 1.19 for 3924A. The pattern of uptake varied among the different tumor types, reflecting their inherent differences in vascularity, tumor permeability, antigen density and growth rate, all of which influence antibody targeting of the tumors. When tumor and liver were irradiated, the tumor showed increased differential uptake of labelled antibody compared to normal liver. 51-Cr labelled erythrocytes were used to study the relative vascularity and blood pooling in H4IIE hepatoma and normal tissue. External radiation to the tumor did not increase the uptake of 51-Cr labelled erythrocytes in any site. These studies provide an insight into the role of external radiation as a modality that increases radiolabelled antibody targeting in hepatoma.

Conversion by new treatment modalities of nonresectable to resectable hepatocellular cancer

Eleven patients with hepatocellular cancer had nonresectable lesions, ten as determined by laparotomy and one by computed tomographic (CT) evidence of inferior vena caval invasion. These patients were treated with a variety of new modalities, particularly radiolabeled antiferritin antibodies. Following treatment, seven of the 11 patients were considered to have converted their lesions to possible resectability. Six patients had complete resections, and one patient was partially resected. All patients had the common features of either nodular massive or nodular multifocal hepatocellular cancer. Relative to the patient's initial status, the quality of life remains high, and a new approach in the treatment of the nodular form of nonresectable hepatoma has been demonstrated. The present rate of such conversion to resectability is unknown. However, with further advances in radiolabeled antibody therapy, these results offer a new opportunity in the management of hepatocellular cancer.

A comparison of misonidazole sensitized radiation therapy to radiation therapy alone for the palliation of hepatic metastases: results of a Radiation Therapy Oncology Group randomized prospective trial

Between May 1980 and July 1983, the RTOG conducted a randomized prospective study comparing external radiation therapy and misonidazole to radiation therapy alone for patients with hepatic metastases. Two hundred fourteen patients were accessioned to this study of whom 187 were evaluable. Radiation therapy was delivered to the whole liver to a dose of 21.0 Gy in 7 fractions. Misonidazole was administered orally, 1.5 gm/m2 daily 4-6 hr before each treatment. Patients in the two treatment groups were evenly distributed with respect to stratification variables including primary site, extent of metastatic disease, and Karnofsky Performance Score (KPS). End points examined included amelioration of hepatic pain, improvement of KPS and alkaline phosphatase, decrease in liver and tumor size, and survival. The addition of misonidazole did not significantly improve the therapeutic response to radiation therapy in any of the parameters studied. Hepatic irradiation was effective in relieving abdominal pain with 80% of the symptomatic patients achieving improvement following therapy. Pain was completely relieved in 54% of these patients. Patients with liver metastases from colon carcinoma improved more frequently than those with metastases from other primary tumor sites (p = 0.02). Relief of pain occurred more frequently in patients treated with radiation therapy and misonidazole (87%) compared with radiation therapy alone (74%) (p = 0.08). Palliation of pain was prompt, occurring within a median of 1.7 weeks from the initiation of treatment, and 94% of patients who improved did so within 6 weeks of treatment. The median duration of response was 13.0 weeks in the symptomatic patients; 52% of those surviving 3 months remained improved. KPS improved in 28% of patients. Serial CT scans revealed a partial response in 7% and a marginal response in 13% of patients. One patient had a complete response to treatment. The median survival of patients treated in this series was 4.2 months with no difference between the two treatment groups. Patients with metastases from colon carcinoma and an initial KPS of 80 or more (48% of the patient population) had a median survival of 5.8 months with radiation therapy alone compared with 6.6 months with radiation therapy and misonidazole (p = 0.36). There was no significant treatment related morbidity. Radiation therapy remains an excellent palliative tool for the management of patients with symptomatic hepatic metastases. Further research must continue to identify new methods of selectivity enhancing the tumor response to radiation therapy.