Hyperbaric oxygen as a radiotherapeutic adjuvant in advanced cancer of the uterine cervix: preliminary results of a randomized trial

Clinical study of a 125I particle-integrated esophageal covered stent and hyperbaric oxygen in the treatment of advanced esophageal cancer

OBJECTIVE

this study aimed to investigate the clinical efficacy and feasibility of the treatment of advanced esophageal cancer with a combination of a 125I particle-integrated esophageal covered stent and hyperbaric oxygen.

METHODS

forty-five patients with advanced esophageal cancer were enrolled and were randomly divided into two groups: a treatment group and a control group. Patients in the treatment group were treated with a 125I particle-integrated esophageal covered stent and hyperbaric oxygen, while patients in the control group were treated with a 125I particle-integrated esophageal covered stent. The clinical effects and long-term survival time of the two groups were observed.

RESULTS

in the treatment group, the complete remission (CR) rate and partial remission (PR) rate of local lesions were 19.2 % and 61.5 %, respectively, and the total effective rate was 80.7 %. In the control group, the CR rate and PR rate of local lesions were 10.5 % and 52.6 %, respectively, and the total effective rate was 63.1 %. The total effective rate was higher in the treatment group than in the control group, which was statistically significant (p < 0.05).

CONCLUSION

the combination of a 125I particle-integrated esophageal covered stent and hyperbaric oxygen shows a good short- and long-term efficacy in the treatment of advanced esophageal cancer.

Hyperbaric oxygenation for tumour sensitisation to radiotherapy

BACKGROUND

Cancer is a common disease and radiotherapy is one well-established treatment for some solid tumours. Hyperbaric oxygenation therapy (HBOT) may improve the ability of radiotherapy to kill hypoxic cancer cells, so the administration of radiotherapy while breathing hyperbaric oxygen may result in a reduction in mortality and recurrence.

OBJECTIVES

To assess the benefits and harms of administering radiotherapy for the treatment of malignant tumours while breathing HBO.

SEARCH METHODS

In September 2017 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library Issue 8, 2017, MEDLINE, Embase, and the Database of Randomised Trials in Hyperbaric Medicine using the same strategies used in 2011 and 2015, and examined the reference lists of included articles.

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing the outcome of malignant tumours following radiation therapy while breathing HBO versus air or an alternative sensitising agent.

DATA COLLECTION AND ANALYSIS

Three review authors independently evaluated the quality of and extracted data from the included trials.

MAIN RESULTS

We included 19 trials in this review (2286 participants: 1103 allocated to HBOT and 1153 to control).For head and neck cancer, there was an overall reduction in the risk of dying at both one year and five years after therapy (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.70 to 0.98, number needed to treat for an additional beneficial outcome (NNTB) = 11 and RR 0.82, 95% CI 0.69 to 0.98, high-quality evidence), and some evidence of improved local tumour control immediately following irradiation (RR with HBOT 0.58, 95% CI 0.39 to 0.85, moderate-quality evidence due to imprecision). There was a lower incidence of local recurrence of tumour when using HBOT at both one and five years (RR at one year 0.66, 95% CI 0.56 to 0.78, high-quality evidence; RR at five years 0.77, 95% CI 0.62 to 0.95, moderate-quality evidence due to inconsistency between trials). There was also some evidence with regard to the chance of metastasis at five years (RR with HBOT 0.45 95% CI 0.09 to 2.30, single trial moderate quality evidence imprecision). No trials reported a quality of life assessment. Any benefits come at the cost of an increased risk of severe local radiation reactions with HBOT (severe radiation reaction RR 2.64, 95% CI 1.65 to 4.23, high-quality evidence). However, the available evidence failed to clearly demonstrate an increased risk of seizures from acute oxygen toxicity (RR 4.3, 95% CI 0.47 to 39.6, moderate-quality evidence).For carcinoma of the uterine cervix, there was no clear benefit in terms of mortality at either one year or five years (RR with HBOT at one year 0.88, 95% CI 0.69 to 1.11, high-quality evidence; RR at five years 0.95, 95% CI 0.80 to 1.14, moderate-quality evidence due to inconsistency between trials). Similarly, there was no clear evidence of a benefit of HBOT in the reported rate of local recurrence (RR with HBOT at one year 0.82, 95% CI 0.63 to 1.06, high-quality evidence; RR at five years 0.85, 95% CI 0.65 to 1.13, moderate-quality evidence due to inconsistency between trials). We also found no clear evidence for any effect of HBOT on the rate of development of metastases at both two years and five years (two years RR with HBOT 1.05, 95% CI 0.84 to 1.31, high quality evidence; five years RR 0.79, 95% CI 0.50 to 1.26, moderate-quality evidence due to inconsistency). There were, however, increased adverse effects with HBOT. The risk of a severe radiation injury at the time of treatment with HBOT was 2.05, 95% CI 1.22 to 3.46, high-quality evidence. No trials reported any failure of local tumour control, quality of life assessments, or the risk of seizures during treatment.With regard to the treatment of urinary bladder cancer, there was no clear evidence of a benefit in terms of mortality from HBOT at one year (RR 0.97, 95% CI 0.74 to 1.27, high-quality evidence), nor any benefit in the risk of developing metastases at two years (RR 2.0, 95% CI 0.58 to 6.91, moderate-quality evidence due to imprecision). No trial reported on failure of local control, local recurrence, quality of life, or adverse effects.When all cancer types were combined, there was evidence for an increased risk of severe radiation tissue injury during the course of radiotherapy with HBOT (RR 2.35, 95% CI 1.66 to 3.33, high-quality evidence) and of oxygen toxic seizures during treatment (RR with HBOT 6.76, 96% CI 1.16 to 39.31, moderate-quality evidence due to imprecision).

AUTHORS' CONCLUSIONS

We found evidence that HBOT improves local tumour control, mortality, and local tumour recurrence for cancers of the head and neck. These benefits may only occur with unusual fractionation schemes. Hyperbaric oxygenation therapy is associated with severe tissue radiation injury. Given the methodological and reporting inadequacies of the included studies, our results demand a cautious interpretation. More research is needed for head and neck cancer, but is probably not justified for uterine cervical or bladder cancer. There is little evidence available concerning malignancies at other anatomical sites.

Microenvironment and radiation therapy

Dependency on tumor oxygenation is one of the major features of radiation therapy and this has led many radiation biologists and oncologists to focus on tumor hypoxia. The first approach to overcome tumor hypoxia was to improve tumor oxygenation by increasing oxygen delivery and a subsequent approach was the use of radiosensitizers in combination with radiation therapy. Clinical use of some of these approaches was promising, but they are not widely used due to several limitations. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that is activated by hypoxia and induces the expression of various genes related to the adaptation of cellular metabolism to hypoxia, invasion and metastasis of cancer cells and angiogenesis, and so forth. HIF-1 is a potent target to enhance the therapeutic effects of radiation therapy. Another approach is antiangiogenic therapy. The combination with radiation therapy is promising, but several factors including surrogate markers, timing and duration, and so forth have to be optimized before introducing it into clinics. In this review, we examined how the tumor microenvironment influences the effects of radiation and how we can enhance the antitumor effects of radiation therapy by modifying the tumor microenvironment.

Hyperbaric oxygenation for tumour sensitisation to radiotherapy

BACKGROUND

Cancer is a common disease and radiotherapy is one well-established treatment for some solid tumours. Hyperbaric oxygenation therapy (HBOT) may improve the ability of radiotherapy to kill hypoxic cancer cells, so the administration of radiotherapy while breathing hyperbaric oxygen may result in a reduction in mortality and recurrence.

OBJECTIVES

To assess the benefits and harms of radiotherapy while breathing HBO.

SEARCH METHODS

In March 2011 we searched The Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library, Issue 3), MEDLINE, EMBASE, DORCTHIM and reference lists of articles.

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing the outcome of malignant tumours following radiation therapy while breathing HBO versus air.

DATA COLLECTION AND ANALYSIS

Three review authors independently evaluated the quality of the relevant trials and extracted the data from the included trials.

MAIN RESULTS

Nineteen trials contributed to this review (2286 patients: 1103 allocated to HBOT and 1153 to control). With HBOT, there was a reduction in mortality for head and neck cancers at both one year and five years after therapy (risk ratio (RR) 0.83, P = 0.03, number needed to treat (NNT) = 11; and RR 0.82, P = 0.03, NNT = 5 respectively), as well as improved local tumour control at three months (RR with HBOT 0.58, P = 0.006, NNT = 7). The effect of HBOT varied with different fractionation schemes. Local tumour recurrence was less likely with HBOT at one year (head and neck: RR 0.66, P < 0.0001, NNT = 5), two years (uterine cervix: RR 0.60, P = 0.04, NNT = 5) and five years (head and neck: (RR 0.77, P = 0.01, NNT = 6). Any advantage is achieved at the cost of some adverse effects. There was a significant increase in the rate of both severe radiation tissue injury (RR 2.35, P < 0.0001, (number needed to harm (NNH) = 8) and the chance of seizures during therapy (RR 6.76, P = 0.03, NNH = 22) with HBOT.

AUTHORS' CONCLUSIONS

There is some evidence that HBOT improves local tumour control and mortality for cancers of the head and neck, and local tumour recurrence in cancers of the head and neck, and uterine cervix. These benefits may only occur with unusual fractionation schemes. HBOT is associated with significant adverse effects including oxygen toxic seizures and severe tissue radiation injury. The methodological and reporting inadequacies of the studies included demand a cautious interpretation. More research is needed for head and neck cancer, but is probably not justified for bladder cancer. There is little evidence available concerning malignancies at other anatomical sites on which to base a recommendation.

Hyperbaric oxygen therapy for late radiation tissue injury in gynecologic malignancies

BACKGROUND

Late radiation tissue injury is a serious complication of radiotherapy for patients with gynecologic malignancies. Strategies for managing pain and other clinical features have limited efficacy; however, hyperbaric oxygen therapy (HBO(2)) may be an effective option for some patients.

METHODS

In a systematic review of the literature, the Ovid medline, embase, Cochrane Library, National Guidelines Clearinghouse, and Canadian Medical Association Infobase databases were searched to June 2009 for clinical practice guidelines, systematic reviews, randomized controlled trials, or other relevant evidence. Studies that did not evaluate soft tissue necrosis, cystitis, proctitis, bone necrosis, and other complications were excluded.

RESULTS

Two randomized trials, eleven nonrandomized studies, and five supporting documents comprise the evidence base. In addition, information on the harms and safety of treatment with HBO(2) were reported in three additional sources. There is modest direct evidence and emerging indirect evidence that the use of HBO(2) is broadly effective for late radiation tissue injury of the pelvis in women treated for gynecologic malignancies.

CONCLUSIONS

Based on the evidence and expert consensus opinion, HBO(2) is likely effective for late radiation tissue injury of the pelvis, with demonstrated efficacy specifically for radiation damage to the anus and rectum;the main indication for HBO(2) therapy in gynecologic oncology is in the management of otherwise refractory chronic radiation injury;HBO(2) may provide symptomatic benefit in certain clinical settings (for example, cystitis, soft-tissue necrosis, and osteonecrosis); andHBO(2) may reduce the complications of gynecologic surgery in patients undergoing surgical removal of necrosis.

Hyperbaric oxygenation for tumour sensitisation to radiotherapy

BACKGROUND

Cancer is common and radiotherapy is one well-established treatment for some solid tumours. HBO may improve the ability of radiotherapy to kill hypoxic cancer cells, so the administration of radiotherapy while breathing HBO may result in a reduction in mortality and tumour recurrence.

OBJECTIVES

To assess the benefits and harms of radiotherapy while breathing HBO.

SEARCH STRATEGY

In November 2004 we searched The Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library Issue 3), MEDLINE, EMBASE , CINAHL, DORCTHIM and reference lists of articles. Relevant journals were handsearched.

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing the outcome of malignant tumours following radiation therapy while breathing HBO versus air (with or without sham therapy).

DATA COLLECTION AND ANALYSIS

Three reviewers independently evaluated the quality of the relevant trials using the method of Schulz (Schulz 1995) and extracted the data from the included trials.

MAIN RESULTS

Nineteen trials contributed to this review (2286 patients: 1103 allocated to HBO and 1153 control). With HBO, there was a reduction in mortality for head and neck cancers at both one year and five years after therapy (Relative risk (RR) 0.83, P = 0.03, number needed to treat (NNT) = 11 and RR 0.82, P = 0.03, NNT = 5 respectively), as well as improved local tumour control at three months (RR with HBOT 0.58, P = 0.006, NNT = 7). The effect of HBO varied with different fractionation schemes. Local tumour recurrence was less likely with HBO at one year (head and neck, RR 0.66, P < 0.0001, NNT = 5), two years (uterine cervix RR 0.60, P = 0.04, NNT = 5) and five years (head and neck (RR 0.77, P = 0.01). Any advantage is achieved at the cost of some adverse effects. There was a significant increase in the rate of both severe radiation tissue injury (RR 2.35, P < 0.0001, (number needed to harm (NNH) = 8) and the chance of seizures during therapy (RR 6.76, P = 0.03, NNH 22) with HBO.

AUTHORS' CONCLUSIONS

There is some evidence that HBO improves local tumour control and mortality for cancers of the head and neck, and local tumour recurrence in cancers of the head and neck, and uterine cervix. These benefits may only occur with unusual fractionation schemes. HBO is associated with significant adverse effects including oxygen toxic seizures and severe tissue radiation injury. The methodological and reporting inadequacies of the primary studies included in this review demand a cautious interpretation. More research is needed for head and neck cancer, but is probably not justified for bladder cancer. There is little evidence available concerning malignancies at other anatomical sites on which to base a recommendation.

In vivo assessment of tumor hypoxia in lung cancer with 60Cu-ATSM

Tumor hypoxia is recognized as an important determinant of response to therapy. In this study we investigated the feasibility of clinical imaging with copper-60 diacetyl-bis( N(4)-methylthiosemicarbazone) ((60)Cu-ATSM) in patients with non-small-cell lung cancer (NSCLC) and also assessed whether pretreatment tumor uptake of (60)Cu-ATSM predicts tumor responsiveness to therapy. Nineteen patients with biopsy-proved NSCLC were studied by positron emission tomography (PET) with (60)Cu-ATSM before initiation of therapy. (60)Cu-ATSM uptake was evaluated semiquantitatively by determining the tumor-to-muscle activity ratio (T/M). All patients also underwent PET with fluorine-18 fluorodeoxyglucose (FDG) prior to institution of therapy. The PET results were correlated with follow-up evaluation (2-46 months). It was demonstrated that PET imaging with (60)Cu-ATSM in patients with NCSLC is feasible. The tumor of one patient had no discernible (60)Cu-ATSM uptake, whereas the tumor uptake in the remaining patients was variable, as expected. Response was evaluated in 14 patients; the mean T/M for (60)Cu-ATSM was significantly lower in responders (1.5+/-0.4) than in nonresponders (3.4+/-0.8) (P=0.002). However, the mean SUV for (60)Cu-ATSM was not significantly different in responders (2.8+/-1.1) and nonresponders (3.5+/-1.0) ( P=0.2). An arbitrarily selected T/M threshold of 3.0 discriminated those likely to respond to therapy: all eight responders had a T/M <3.0 and all six nonresponders had a T/M > or =3.0. Tumor SUV for FDG was not significantly different in responders and nonresponders (P=0.7) and did not correlate with (60)Cu-ATSM uptake (r=0.04; P=0.9). (60)Cu-ATSM-PET can be readily performed in patients with NSCLC and the tumor uptake of (60)Cu-ATSM reveals clinically unique information about tumor oxygenation that is predictive of tumor response to therapy.

Carcinoma of the cervix and the use of hyperbaric oxygen with radiotherapy: a report of a randomised controlled trial

BACKGROUND AND PURPOSE

A randomised controlled trial of hyperbaric oxygen in the radiotherapy of Stage IIb and III carcinoma of cervix was performed between 1971 and 1980. Apart from an abstract giving an interim report in 1977, results have not been published.

MATERIAL AND METHODS

In a four arm study, 335 patients were randomised to treatment in 10 or 28 fractions, in hyperbaric oxygen or in air. Data is available concerning 327 cases and this has been analysed.

RESULTS

There was no advantage in tumour control shown with the use of hyperbaric oxygen. There was evidence for an increase in late radiation morbidity when treatment was given in hyperbaric oxygen rather than in air and when, using 10 fractions, a total dose of 45 rather than 40 Gy was achieved. For late intestinal morbidity, the fractionation sensitivity (alpha/beta ratio) was calculated to be 4.3 Gy and the steepness of the dose response curve (gamma50) to be 2.6.

CONCLUSIONS

Hyperbaric oxygen gave no benefit in the treatment of patients with stage IIb and III carcinoma of the cervix treated with radiotherapy using two fractionation regimes. Important data regarding late radiation morbidity has been revealed.

Combination of radiation therapy and interferon alpha-2b in patients with advanced cervical carcinoma: a pilot study

Carcinoma of the uterine cervix is the most frequent malignancy in women in developing countries. Based on the possible synergistic effect of the combination of interferon and radiotherapy, a clinical trial was conducted in patients with advanced cervical cancer. The objective was to evaluate the efficacy and security of such a therapeutic approach. This prospective phase II trial was done at the Instituto Nacional de Cancerología in Mexico City. The study included 17 consecutive patients with previously untreated squamous cell cervical cancer, clinical stages III and IV, and tumor mean size of 9.7 cm. The patients received radiotherapy and interferon alpha-2b at a dose of 5 x 106 IU/m2 3 times a week for 6 weeks. Eleven (64%) complete responses were obtained among these patients. Long-term survival was observed in 4 patients (24%) who achieved complete response and are alive after 10 years of follow-up. Immediate toxicity was mild. Late toxicity included the development of proctitis in 13 patients, colostomy was performed in 3 (23%) of them. Our results indicate that the combination of radiotherapy and this cytokine is an active therapy for squamous cell carcinoma of the uterine cervix.

Modification of the Radiation Response of Patients With Carcinoma of the Uterine Cervix

BACKGROUND: The purpose of this review is to summarize clinical trials for patients with cervical cancer treated with irradiation and modifiers of the irradiation response. METHODS: The MEDLINE database was used to identify clinical studies that evaluated modifiers of the irradiation response for patients with carcinoma of the uterine cervix from 1970 through 1998. The studies included were prospective, randomized phase III clinical trials comparing irradiation alone to irradiation plus a chemical modifier for carcinoma of the uterine cervix. RESULTS: Various chemical agents have been combined with irradiation in the treatment of patients with carcinoma of the uterine cervix. These agents include hyperbaric oxygen, hydroxyurea, nitroimidazoles, neoadjuvant chemotherapy, and concurrent chemotherapy. CONCLUSIONS: Many prospective, randomized studies evaluating the use of chemical agents to modify the irradiation response in patients with carcinoma of the uterine cervix indicate no improvement over radiation therapy alone. However, the February 1999 NCI clinical announcement describes a survival advantage for cisplatin-based therapy and concurrent irradiation.

RSR13, an allosteric effector of haemoglobin, and carbogen radiosensitize FSAII and SCCVII tumours in C3H mice

Pre-clinical evaluation has demonstrated that 2-[4-(((3,5-dimethylanilino)carbonyl)methyl)phenoxy]-2-methylpropi onic acid (RSR13) acts as an allosteric effector of haemoglobin (Hb). RSR13 binding to Hb results in decreased haemoglobin-oxygen (Hb-O2) affinity, improved tumour oxygenation, and enhanced radiation-induced cell killing in several experimental tumour systems. In the present work, ex vivo clonogenic survival analyses are applied in two murine tumour systems to characterize the relationship between the magnitude of decrease in Hb-O2 affinity and radiosensitization, the influence of inspired pO2 upon this effect, and the efficacy of combining RSR13 and radiation during a course of repeated radiation exposures. For FSaII tumours in C3H mice breathing air, 100 mg kg(-1) RSR13 administered intraperitoneally produced an enhancement ratio (ER) of 1.3, but there was marked desensitization at a RSR13 dose of 300 mg kg(-1) (ER 0.6). The most likely reason for the increased radioresistance was insufficient oxygen loading of Hb in the pulmonary circulation due to reduced haemoglobin-oxygen affinity because carbogen breathing combined with 300 mg kg(-1) RSR13 reversed the effect and produced an ER of 1.8. In SCCVII tumours in C3H mice irradiated with eight fractions of 2.5 Gy over 4 days, the surviving fraction was reduced to 58-67% of control values when RSR13 was combined with radiation on days 1 and 2, days 3 and 4, or days 1-4. These results confirm that combining RSR13 and irradiation within a fractionated course of clinically relevant low-dose exposures provides significant radiosensitization. Additional preclinical experimentation is needed to define better the optimum dose-scheduling conditions for clinical applications.

Normobaric oxygen treatment during radiotherapy for carcinoma of the uterine cervix. Results from a prospective controlled randomized trial

BACKGROUND AND PURPOSE

Hypoxia, a frequent characteristic of cervical cancer, is associated with reduced sensitivity to irradiation and thus may be a source of radiotherapy failure. This study was planned to test the hypothesis, that inhalation of oxygen during radiotherapy may increase the radiation effect on the tumor and improve loco-regional control and overall survival.

MATERIAL AND METHODS

From 1963 to 1965, a consecutive series of 208 patients with cervical cancer stage II/III who were to be treated by external irradiation plus radium inserts, were included in this study. They were randomly assigned to either receive oxygen inhalations during the radiotherapy sessions or just breathing air. Due to technical reasons the oxygen group was divided. For the first 10 months, they did receive oxygen during the radium inserts only, the last 13 months during all radiotherapy sessions.

RESULTS

After median 33 years follow-up, there are no differences in overall survival, cancer-specific survival or loco-regional control. Subgroup analysis shows significantly improved loco-regional control in the stage IIB patients, with squamous cell carcinoma who received oxygen during all radiotherapy sessions. This improvement was especially pronounced among the patients who also received blood transfusions.

CONCLUSIONS

There was no influence of normobaric oxygen treatment on the overall outcome to radiotherapy in patients with stage II cervical cancer, but subgroup analyses support the hypothesis that there is tumor areas of hypoxia-based radioresistance that may be counteracted by oxygen administration.

A randomized trial of standard versus partially hyperfractionated radiation with or without concurrent 5-fluorouracil in locally advanced cervical cancer

The objective of this study was to determine whether the addition of concurrent 5-fluorouracil (5-FU) and/or a change in radiation fractionation improves pelvic control and survival or decreases complications in advanced cervical cancer, FIGO stages IB/IIA (>=5 cm) to IVA inclusive. After stratification by pelvic disease extent, 234 of a planned 292 patients were randomized to receive one of four possible treatments: (a) standard external beam pelvic irradiation (RT) 5000 cGy in 25 fractions versus (b) RT as in arm (a) with infusional IV 5-FU 1g/m2 daily in the first and last 4 days of RT, (c) partially hyperfractionated RT, 5280 cGy in 33 fractions, two fractions per day on the first and last 4 days of RT, or (d) arm (c) with the same FU. All were followed with a linear source of intracavitary RT to deliver 40 Gy. The median duration of follow-up for the 221 evaluable patients was 59 months. The 5-year Kaplan-Meier disease-free survival (DFS) in arm (a), (c), (d), and (b), respectively, were 45, 53, 58, and 61%. The differences in survival and pelvic control were not statistically significant. An exploratory subset analysis was performed within stratum 1 and stratum 2 to generate hypotheses for future studies. Only for the 99 patients in stratum 1 (IB/IIA or medial parametrial IIB disease) was the 5-year DFS significantly better (long rank P = 0.05) for standard RT and 5-FU. The DFS was 39% for arm (a), 76% for arm (b), 58% for arm (c), and 65% for arm (d). A multivariate analysis of patient, tumor, and treatment related prognostic factors identified only the use of 5-FU to account for the observed difference. The crude serious late bowel or bladder complication rate was 5.9%. Overall concurrent infusional 5-FU was not beneficial when added to standard RT in this study. The possible benefit for patients in stratum 1 requires exploration in a further randomized trial with appropriate accrual.

Concurrent 5-fluorouracil, mitomycin C and irradiation in locally advanced cervix cancer

We reviewed 177 patients treated with radical radiotherapy for locally advanced (FIGO stages IIB, IIIA, IIIB) cervix cancer between January 1979 and December 1989. The radiotherapy was given by external beam treatment to the pelvis and by an intracavitary caesium insertion. Ninety-three patients also received chemotherapy which consisted of infusional 5-fluorouracil during the first and last weeks of the external beam component of the radiotherapy, combined with bolus mitomycin C (group A, 64 patients) or without mitomycin C (group B, 29 patients). These groups were compared with patients treated by radiotherapy alone (group C, 84 patients). The median follow-up was 7.2 years. The median survival time for all patients was 47 months, but was significantly higher (87 months, p = 0.004) for group A. Rates of relapse-free survival and local control were also higher in group A. Toxicity was assessed in detail using the Franco-Italian glossary. There was a relatively high rate of complications, particularly in group A, with 36% of patients having grade 3 or 4 complications. This increase in toxicity persisted through all follow-up time intervals. Patients in group B also demonstrated a higher rate of toxicity than group C, but this increase was limited to the first 6 months of follow-up. The use of mitomycin C in addition to radiotherapy and 5-fluorouracil should be regarded with caution, as other studies have also shown that toxicity is increased, but without improvements in survival.

Evaluation of hyperbaric oxygen as a chemosensitizer in the treatment of epithelial ovarian cancer in xenografts in mice

BACKGROUND

Resistance to chemotherapy is common in bulky hypoxic tumors such as epithelial ovarian cancer. Hyperbaric oxygen (HBO) oxygenates hypoxic tissues and promotes neovascularization. These unique properties of HBO may help overcome chemotherapy resistance by increasing both tumor perfusion and cellular sensitivity. This study was undertaken to determine if HBO increases the response of epithelial ovarian cancer to cisplatin chemotherapy.

METHODS

In Phase I, 64 nu/nu mice were divided into four groups and subcutaneously inoculated with cells from the A2780 human epithelial ovarian cancer cell line. Group 1 served as controls. Group 2 received weekly intraperitoneal cisplatin (3.15 mg/kg). Group 3 was exposed to HBO (dives) at 2.4 atmospheres absolute pressure for 90 minutes, 7 days a week. Group 4 received both cisplatin and HBO. In Phase II, 72 mice were divided into two groups and similarly inoculated. Both groups received weekly intraperitoneal cisplatin (2.5 mg/kg). Group 1 was not exposed to HBO. Group 2 was exposed to HBO for 5 days a week.

RESULTS

Dramatic tumor neovascularization was found in tumors of mice exposed to HBO (P = 0.0001). There was significant (P = 0.014) tumor growth retardation in Phase I for mice receiving both cisplatin and HBO compared with those treated with cisplatin alone. This significance was noted after just two doses of cisplatin but subsequently lost due to reduced numbers of mice. In Phase II, neovascularization was detectable after 10 HBO treatments (2 weeks) and was maximal after 15 treatments (3 weeks).

CONCLUSIONS

Hyperbaric oxygen increases vascularity in bulky tumors such as epithelial ovarian cancer. There appears to be a relationship between increased vascularity and enhanced response to chemotherapy that merits further investigation.

The potential for proton beam therapy in locally advanced carcinoma of the cervix

Advanced cervix cancer has a local failure rate of 40-45% when treated with a combination of external beam irradiation and intracavitary implants, and approximately 60-65% when treated by external beam irradiation alone. Because of the absorption characteristics of protons, there is the potential for improved dose distributions and delivery of greater total doses to cervical neoplasms. Using computer-modelled examples, this theoretical advantage has been tested and the results have been extrapolated to show a therapeutic advantage in local control and morbidity. The first example shows the use of protons and intracavitary implants in advanced cervix tumors. Larger tumor doses are possible with protons than with photons, while the dose-volume to normal structures is decreased. In the second example, external proton beam treatment alone also reveals significantly higher tumor doses and lower normal tissue doses, compared to photon irradiation. With new proton therapy facilities being designed and built in the United States and overseas, protocols are being designed to evaluate the therapeutic potential of proton therapy in locally advanced cervix cancer.

What have we learnt from hyperbaric oxygen?

The 15 randomised controlled clinical trials of hyperbaric oxygen in radiotherapy yielded three with highly significant benefit and six with useful margins not reaching statistical significance. The increase in tumour control was partly negated by an increase in normal tissue effect. Now simple carbogen breathing in animal tumour models has shown high efficiency and there is the potential for its use in man as a simple means of hypoxic cell radiosensitization.

Time-dose factors in radiotherapy: a review of the human data

The values for alpha/beta (fractionation sensitivity, or recovery capacity) for early and late reactions in human normal tissues are consistent with results from experimental animals. For breast treatments direct analysis indicates that for early reactions alpha/beta is in the range 7 to 11 Gy, while for late effects it is in the range 2 to 4 Gy. Data on recovery kinetics in human tissues is limited but these indicate that recovery may be slower in humans than in rodents. For early skin reactions the halftime of recovery is about 1 h, while for late telangiectasia it is more than 3 h. alpha/beta values for human tumors are more variable than in rodents: some are high (head and neck, lung, skin, cervix) and similar to those for early reacting normal tissues. Others are low, including melanomas, where alpha/beta was estimated at 0.6 (-1.1, 2.5) Gy, and liposarcomas, where direct analysis of cases surveyed from the literature suggested that alpha/beta = 0.4 (-1.4, 5.4) Gy. Repopulation kinetics is faster in the mucosa of the soft palate and faucial pillars (1.8 Gy/day) than in head and neck tumors (up to 1 Gy/day).

Treatment of 29 patients with bulky squamous cell carcinoma of the cervix with simultaneous cisplatin, 5-fluorouracil, and split-course hyperfractionated radiation therapy

Attempting to improve local disease control in bulky (greater than 8 cm) primary or recurrent pelvic tumors, 29 patients with squamous cell carcinoma of the cervix (stage II, 4; III, 10; IV, 6; recurrent, 9) were treated with concomitant chemotherapy and split-course hyperfractionated radiation therapy between April 1983 and August 1988. Cisplatin (CDDP) and 5-fluorouracil (5-FU) have been shown to be radiation enhancers; furthermore, CDDP, radiation therapy, and continuous-infusion 5-FU have elicited high local response rates in head and neck squamous cell carcinoma. A pilot study of cyclical week on/week off CDDP, continuous-infusion 5-FU, and hyperfractionated radiation therapy was developed. Radiation was administered at 116 cGy twice daily, Days 1-5, every other week for a median dose of 4600 cGy to a pelvic field, with paraaortic extension if indicated. Concomitant chemotherapy included CDDP 60 mg/m2 IV Day 1 and 5-FU 600 mg/m2 IV continuous infusion for 96 hr following CDDP infusion. Patients received a median of four cycles of combined treatment, and intracavitary or interstitial brachytherapy followed in 21 patients. Local pelvic response was achieved in 29 of 29 (100%): complete response (CR) in 19 of 29 (66%), partial response (PR) in 10 of 29 (34%). Among CR patients 10 of 19 (53%) were without evidence of disease at a mean follow-up of 29 (range 12-76) months. Five-year actuarial disease-free survival among complete responders was 65%. Of the 10 CR patients 2 failed in the pelvis, for a local control rate of 17/19 (89%). Chemotherapy-related and acute radiation morbidity was minimal but 2 patients required surgical correction of radiation injury. Aggressive combination of split-course hyperfractionated radiation therapy with radiation enhancers resulted in promising local control of bulky pelvic tumor, with an acceptable complication rate, in this otherwise very poor prognostic group of patients.

Concomitant continuous infusion chemotherapy and radiation

Attempts to duplicate the cytotoxic effect of oxygen on radioresistant tissues spurred a search by radiation oncologists for other radiosensitizing techniques. This led to large-scale investigations using neutrons and other heavy particle radiations, hyperthermia, altered fractionation schedules, and the systemic use of the halogenated pyrimidines and the electron-affinic compounds. Unfortunately, the promise that the nitroimidazole compounds would selectively sensitize the radioresistant tumor cells and prove to be an effective systemic agent has not been borne out in clinical trials thus far. Existing pharmokinetic and cytokinetic studies have suggested that continuous infusion chemotherapy given concomitantly (CCIC) with irradiation (RT) acts synergistically, resulting in a significant increase in tumor cell killing. These observations have been supported by clinical research studies treating certain epithelial cancers that have resulted in considerably higher locoregional control rates and improved survival. Although initially used in treatment of only advanced or inoperable epithelial carcinomas, CCIC and RT are now being employed in the treatment of lower staged cancers as an organ-sparing procedure. Carcinoma of the anus treated by anteroposterior (AP) resection alone have reported 5-year survival rates of 30% to 60%. CCIC and RT using 5-fluorouracil (5-FU) and mitomycin C have achieved a local control rate of 90% to 100% and a 5-year survival rate of 80% to 86% with sphincter preservation in 90% of these cases. The 5-year survival rate in advanced urinary bladder carcinoma is 25% to 30% for either radiation or surgery and 42% when combined in a preoperative radiation schedule. Using 5-FU CCIC and RT, the local control rate of transitional cell carcinoma of the bladder has been 71% to 86% with a 5-year survival of 62%. 5-FU CCIC and cisplatin and RT used in the treatment of Stages III and IV carcinoma of the cervix yields a locoregional control of 74% compared with the radiation alone local control of 63% for Stage III and 30% for Stage IV disease. Advanced head and neck and paranasal sinus carcinomas treated by cisplatin CCIC and RT show improved tumor clearance even in the presence of bone destruction. A complete response rate of 87% has been reported with the use of cisplatin CCIC and hyperfractionated radiation. Hyperfractionated radiation also appears to improve the local control of advanced head and neck cancers over patients treated with single fractions of radiation with 66% surviving at 22 months.(ABSTRACT TRUNCATED AT 400 WORDS)

The treatment of tumors by the induction of anemia and irradiation in hyperbaric oxygen

Because increased effects have been achieved when murine tumors are irradiated after a period of hypoxia and because of anecdotal clinical experiences of an improved result after irradiation of previously anemic patients in hyperbaric oxygen, the relationship between irradiation and increased survival was investigated in seventy-two patients with advanced head and neck or cervical cancer. Anemia was achieved by means of a two-stage isovolemic venesection maintained for seventy-two hours, hemoglobin was returned to a normal level, and treatment in hyperbaric oxygen was started. Marked tumor shrinkage after the induction of anemia and before radiotherapy was seen and was probably disease, site, and hemoglobin level related. As a result, a possible new approach to cancer therapy is suggested. After completion of therapy, the 1-year disease-free survival for patients with head and neck and cervical cancer was not improved, but the 21-month survival for cervical cancer was improved. Further studies are strongly urged.

Effect of anemia on tumor radiosensitivity under normo and hyperbaric conditions

The effect of chronic anemia on tumor radiosensitivity in a murine tumor has been investigated. Anemia was induced by bilateral kidney irradiation given several months before tumor implantation. Anemic, anemic transfused, and normal non-anemic age-matched tumor bearing animals were irradiated with X rays (2 F/24 hr) either in air, air plus misonidazole, or under hyperbaric oxygen. The most resistant response was that of tumors grown in normal mice treated in air. Anemia produced an increase in radiosensitivity which was further enhanced by red blood cell replacement. The most sensitive overall response was seen in the anemic-transfused group treated with HBO.

Radiotherapy with or without misonidazole for patients with stage IIIB or stage IVA squamous cell carcinoma of the uterine cervix: preliminary report of a Radiation Therapy Oncology Group randomized trial

Between August 1980 and November 1984, 119 patients with FIGO Stage IIIB or IVA squamous cell carcinoma of the uterine cervix were randomized to receive radiation therapy (4600 cGy pelvis plus 1000 cGy parametrial boost) followed by intracavitary or external boost to the primary with or without misonidazole (MISO) (400 mg/m2 daily 2 to 4 hours prior to radiation therapy). Patients in the two treatment groups were evenly distributed with respect to stratification variables including stage, Karnofsky Performance score, and positivity of para-aortic nodes. Eighty-nine percent of patients had Stage IIIB disease and 88% had a Karnofsky score of 80 or better. Seventy-five percent of patients treated with radiation therapy alone and 79% of patients treated with radiation therapy plus MISO received a boost via intracavitary application. Life threatening (Grade 4) complications occurred in 5 patients receiving radiation therapy alone and one patient receiving radiation therapy plus MISO. MISO toxicity (Grade 3) was limited to severe nausea and vomiting in two patients. With 119 evaluable patients and a median follow-up of 33 months, 64% of patients receiving radiation therapy alone are alive at 18 months compared with 54% for patients assigned to radiation therapy plus MISO. The median survival for patients treated with radiation therapy alone and radiation therapy plus MISO was 1.9 years and 1.6 respectively. At this point in the study the difference in survival is inconsistent with the hypothesis of an improvement associated with MISO. There have been 23 deaths among the 49 patients treated with radiation therapy plus MISO who have been followed for at least 18 months compared with 17 deaths in 48 patients treated with radiation therapy alone. The chance of observing this number of deaths with radiation therapy plus MISO if the addition of MISO improves survival by 10 to 20% is 0.003 and less than 0.001, respectively. The addition of MISO to radiation failed to improve survival for these patients. The results cannot be explained by an uncharacteristically high survival on the radiation therapy alone arm or by an imbalance in the distribution of prognostic factors. Local-regional control remains a problem in the management of patients with advanced cervical carcinoma. More effective and less toxic radiosensitizing agents are needed.

Radiation therapy in hyperbaric oxygen for head and neck cancer at Royal Adelaide Hospital--1964 to 1980

This report describes experience with radiation therapy in hyperbaric oxygen in 201 patients with squamous carcinoma arising in the mobile portion of tongue (anterior 2/3), oropharynx, hypopharynx, and supraglottic larynx, treated between the years 1964 and 1980. Although not statistically different, the overall 5-year determinate survival figures of 35% for all patients with tumors arising in the hypopharynx, 87.5% for Stage I and II, 55% for Stage III, and 27.1% for Stage IV supraglottic carcinoma were perceptibly better than those obtained in a contemporary but not randomly controlled series of patients treated in air at Royal Adelaide Hospital from 1970 to 1980. The results obtained for tumors arising in the oropharynx and mobile portion of tongue however were found to be very similar to those achieved in air. The results achieved in this series are discussed in the context of experience at other centers and the role of randomly controlled clinical studies in evaluating new treatment modalities is emphasized.

Perfluorochemicals and hyperbaric oxygen in radiation therapy

It has been postulated that tumors contain hypoxic cells of decreased radiation sensitivity, which limit curability with radiation therapy. Hyperbaric oxygen has been used in an attempt to improve tumor oxygenation. The nature of the oxygen concentration-radiation sensitivity relationship (oxygen increases the slope of the radiation cell survival curve) suggests that a small number of hypoxic cells, as few as one in one million, would limit tumor curability. Oxygen moves by diffusion from the capillary into the tumor. An increase in partial pressure in the capillary will increase the effective diffusion distance. To improve tissue oxygenation effectively the partial pressure of oxygen in blood must be significantly increased throughout the length of the capillary, in particular at the venous end. Theoretical considerations indicate that hyperbaric oxygen as presently used in radiation therapy, 3 ATA, would lead to only marginal improvement. PartO2 may be as much as 0.8 atm below that of the inspired gas; this plus the consumption of oxygen along the length of the capillary lead to predictions of values for PEnd CapO2 of less than twice normal. Such considerations explain the rather limited success of hyperbaric oxygen with radiation therapy. Thus it is unnecessary to postulate an absence of hypoxic cells to explain this clinical observation. In the presence of perfluorocarbon micelles the non-hemoglobin-bound oxygen carrying capacity of blood is significantly increased. Theoretical considerations predict that the difference between PartO2 and PO2 of the inspired gas should be decreased. Furthermore, the nonhemoglobin-bound oxygen carrying capacity should be adequate to satisfy tissue consumption requirements without unloading hemoglobin, thereby avoiding the "PO2 buffering effect of hemoglobin" and permitting a significant increase in PO2 throughout the capillary length. This effect has been demonstrated using a rodent tumor model.

Eighth annual Juan del Regato lecture. Chemical modifiers of radiosensitivity--theory and reality: a review

In this review the poor clinical gains from hyperbaric oxygen (HBO) and misonidazole (MISO) are discussed critically. The biggest factor reducing clinical gains is almost certainly reoxygenation. Other possible reasons include vasoconstrictive self-limitation of HBO and neurotoxicity of MISO, so that the radiosensitization of any hypoxic cells in human tumors was not adequate. Nevertheless, there have been some positive clinical results, so that hypoxic cells can sometimes be a problem in some tumors, especially those of the head and neck, even after multiple fraction radiotherapy. While hypoxic cell radioresistance is obviously only one form of radioresistance it is a large factor of resistance when hypoxic cells are present. Current developments are briefly reviewed: the 'new' clinical sensitizers Ro-03-8799 and SR-2508 which should be 3 to 10 times more efficient than MISO if viable hypoxic cells are present; and methods of measuring which human tumors might have significant numbers of hypoxic viable cells.

Prognostic and treatment factors affecting pelvic control of Stage IB and IIA-B carcinoma of the intact uterine cervix treated with radiation therapy alone

This is a retrospective analysis of 264 patients with Stage IB and IIA-B carcinoma of the cervix treated with curative intent at the University of Florida from October 1964 through April 1980. There is a minimum 2-year follow-up. Patients dead of distant metastases (13), dead from intercurrent disease (14), or lost to follow-up (1) less than 24 months from treatment with pelvic disease controlled were excluded from analysis of pelvic control. All patients were included in analysis of complications and survival. Tumor size and hematocrit were noted to be significant prognostic factors with regard to control of disease in the pelvis in Stage IB and IIA cancers. Tumor size and hematocrit also influenced pelvic control in Stage IIB, but to a lesser extent than in Stages IB and IIA. Patient age was a weak prognostic factor for control of disease in the pelvis for Stages IB, IIA, and IIB, but more strongly influenced pelvic control when considered in conjunction with tumor size and hematocrit. Overall treatment time influenced pelvic control in all cases when the size of the lesion was greater than or equal to 6 cm. In lesions greater than or equal to 6 cm in diameter, the amount of tumor regression noted at the time of the radium application after 3500 to 4000 rad external beam irradiation was a predictor of pelvic control. Data on treatment complications and survival are included, and future treatment strategies discussed.

The Medical Research Council trial of misonidazole in carcinoma of the uterine cervix. A report from the MRC Working Party on misonidazole for cancer of the cervix

153 patients from 13 centres were entered into a randomised controlled trial of the hypoxic cell sensitiser , misonidazole, in the radiotherapy of Stage III carcinoma of the uterine cervix. In an interim analysis at a time when follow-up periods extended from 9 to 45 months, no benefit in survival or local tumour control has been demonstrated. When disease-free survival of all cases was considered it was found that the younger patients did less well than the older patients and that the greater the immediate response to radiotherapy the longer was the duration of survival free of disease.

Keynote address: the scientific basis of the present and future practice of clinical radiotherapy

At mid-century radiotherapy was more an art than a science, but is presently based on radiobiological parameters and cell kinetics. This close interaction between basic scientific principles and clinical practice has been made possible because one can correlate quantitatively doses of irradiation with observed responses. First, a short historical review will be made because it gives a perspective for the understanding both of progress made and prevailing misconceptions. The important radiobiological parameters and cell kinetics will then be discussed in some detail to demonstrate that they should be thoroughly understood in their relationship to radiotherapy. The overall treatment planning must be based on the clinical applications of the main radiobiological parameters. The combined treatment with surgery, either pre- or postoperatively, and multiple daily fractionations will be used as examples. The teaching of radiobiology should be considerably expanded, not only for its own scientific merit but also to show how it applies to clinical situations. This should be reflected in the expansion of the board examination.

Carcinoma of the cervix--anaemia, radiotherapy and hyperbaric oxygen

Further analyses of the material contained in trials of the hyperbaric oxygen chamber in the radiotherapy of carcinoma of the cervix have shown that patients who were severely anaemic prior to radiotherapy, and who required blood transfusion, showed very poor local tumour control when conventionally treated after transfusion, but very good local tumour control when treated in hyperbaric oxygen. The finding of a special sub-group where hypoxia would seem to be an important cause of radiation failure, and where hyperbaric oxygen was successful in overcoming it, may have importance in the evaluation of other methods for overcoming the hypoxia, including the use of chemical sensitising agents.

Carcinoma of the cervix: results of a hyperbaric oxygen trial associated with the use of the cathetron

Since 1971, 82 patients with advanced carcinoma of the cervix have been included in a randomised clinical trial in association with the Working Party on Radiotherapy and Hyperbaric Oxygen of the Medical Research Council. External irradiation was given in 10 fractions by an unconventional schedule, either in air or HBO, and combined with three large fractions of intracavitary irradiation using the Cathetron. The results are acceptable overall, with 69% local control, 15% with tumour developing outside the treated volume and 40% survival at five years, but no improvement has been shown with HBO. Symptoms suggestive of some degree of late damage to the small bowel were present in 13% of patients, with a higher but not statistically significant, incidence in the HBO group. It is postulated that the schedule of radiotherapy used has allowed reoxygenation during treatment and that no further gain due to the use of HBO may be achieved. After a review of the results from other centres and taking into account the difficulties of treatment in HBO it is concluded that for advanced carcinoma of the cervix the addition of HBO to radiotherapy is not clinically worthwhile.